Notes onMine Management, Legislation and General Safety

S.C.BatraDeputy Director General of Mines Safety (Retired)

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INDEX

Chapter Contents Page1 Safety, health and welfare legislation 32 Safety Standards 93 Disaster Management 154 Risk Assessment and Risk Management 345 Underground Mining 396 Opencast Mining 467 Blasting 528 Noise in Mines 569 Dust in Mines 5910 Recent Developments in Mine Safety 6212 Answers to questions of the year 2005 66

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Chapter 1

Legislative framework regarding safety, health and welfare of persons in mines

Safety, health and Welfare of persons working in mines is a central subject and is governed by

the Mines Act. The Mines Act is an Act of the Parliament. The basic objective of the Act is to provide for safety, health and welfare of persons employed in mines. It is “An Act to

amend and consolidate the law relating to the regulation of labour and safety in mines”.

In countries with parliamentary system of government, there is a clear distinction

between an Act and Regulations, Rules, etc. An Act is the Principal statute on the subject and

is passed by the legislature.

Rules and Regulations are piece of legislation subordinate to the Act and are made by the

executives.

How Act is amended? Whenever it is felt by the Government that the provisions of the Act

need amendment due do changed circumstances, a draft proposal is made (usually by DGMS

duly vetted by legal experts in the ministry). The draft is given wide circulation amongst those

likely to be affected, viz.

All the State Governments,

The Committee constituted under Section 12 of the Act’

All recognised organisations of mine employers and employees, and

All other parties connected with the working of the mines.

The comments/ opinion of the above parties is sought within a specified period. The proposal

along with comments are considered by a standing committee of members of parliament, which submits its recommendations to the Government. These recommendations are

considered by the Government and a Bill is placed before the Lok Sabha where it is

considered clause by clause. After the Bill is passed by Lok Sabha, it is placed before Rajya Sabha. On its approval, the Bill goes to the President for his assent. After assent by the

President, it becomes law.

How Rules and Regulations are framed: The Mines Act, under Sections 57 and 58

empowers the Central Government to make Regulations and Rules. First step in the process of

making these Regulations and Rules is to frame a draft. Normally this draft is prepared by

DGMS. The draft regulations and rules are referred to the Committee constituted under Section

12 before publication. After the same are considered by the Committee, the draft regulations or

rules are published in the official gazette. Three months time is given for receipt of any

objections. After lapse of 3 months period, all objections are considered and the draft is

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modified if considered necessary. The regulations and rules are then published in the Gazette.

On such publication, the regulations or rules have the effect as if enacted under the Act.

Exception: For prevention of apprehended danger, or for speedy remedy of the conditions

likely to cause danger, the above procedure may be dispensed with in case of regulations. The

Regulations so framed shall be sent to Committee for information and shall not remain in force

for more than one year from the date of their announcement.

Existing Regulations and Rule framed under the Mines Act 1. The Coal Mines Regulations, 1957

2. The Metalliferous Mines Regulations, 1961

3. The Oil Mines Regulations, 1984.

4. The Mines Rules, 1955

5. The Coal Mines Pithead Bath Rules, 1959

6. The Mine Crèche Rules, 1966

7. The Mines Vocational Training Rules, 1966

8. The Mines Rescue Rules, 1985.

What are Byelaws? Byelaws are sort of Regulations which are framed by the management of

a particular mine for the use of any particular machinery or for adoption of a particular method

of work in a mine e.g. several mines in the past had their own Byelaws in respect of use of

locomotives.

Procedure for framing Byelaws – This is given in Section 61 of the Mines Act.

The owner, Agent or manager of a mine shall if called upon by the Chief Inspector or an

Inspector, frame and submit a draft Byelaws within 2 months.

- If management fail to submit bye-laws in 2 months or the draft bye-laws are not considered

sufficient, DGMS may propose a draft bye-laws or propose such amendments as are

considered necessary.

- The above draft/ amended draft will be sent to management for consideration.

- If the draft is agreed upon by the management, it will be forwarded to the Central

Government.

- If there is disagreement, the draft will be sent to Committee constituted under Section 12

for settlement.

- The settled draft will be sent to Central Government.

- The Central Government may make such modifications as it thinks fit.

- The Central Government shall give notice to the affected persons informing them of the

proposal. A period of at least 30 days shall be given for sending objections.

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- Any objections received will be considered by the Government and the Byelaws in final

form will be approved.

- The mine management shall have copies of such approved Byelaws in English and in

prescribed languages posted at conspicuous places where the same can easily be seen by

mine employees.

- The Central Government may be an order in writing, annual a Byelaw as a whole or part.

Role of Parliament in case of Rules, Regulations or Bye-lawsAccording to Section 61 of the Mines Act, the Rules, Regulations and Bye-laws framed as

above are required to be placed before both houses of Parliament for at least 30 days when the

Parliaments are in session. If both houses agree in making any modifications or they agree that

the rules, regulations or byelaws shall not be made the rules, regulations or byelaws shall have

effect in modified form or be of no effect as the case may be.

Requirements of ideal legislation The Health and Safety Commission, UK, have suggested the following features for the

Regulations:

The Regulations should be free of potential obsolescence

The Regulations should be just

The regulations should have a strategic aim

The Regulations should have clear safety aims

The regulations should be instructive

The Regulations should be enforceable

The above is applicable in any country and not UK alone.

Inadequacies in legislationThe Mines Act, 1952

1. Duties and responsibilities of Owner:

(a) CEO of a mining company should also be treated as owner.

(b) The owner shall formulate well-defined policy for safety and health. Owner and

agent shall ensure that every mine is properly planned, designed,

commissioned, maintained and decommissioned with safety.

2. Manager shall be given financial powers.

3. Duties and responsibilities of the manufacturers of equipment, appliance,

machinery and material etc. shall be laid down.

4. Duties and responsibilities of Mining Consultants should be laid down in the Mines

Act.

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5. Provisions should be made in the Act for safety audit of the mines by accredited auditors.

6. There should be provisions in the Act empowering the Government to formulate

regulations on “noise” and “vibrations”.

7. There should be provisions in the Act regarding “occupational health services” in the

mines.

(Seventh Safety

Conference)

8. Kumarmangalam Committee on “Role and Function of DGMS” (19822) recommended

establishment of special mining tribunals for speedy trial of Mines Act cases. The

Committee also recommended that a suitable system for levying fines by DGMS on

individuals and management for violations of statutory provisions should be introduced

early.

Inadequacies in the Coal Mines Regulations, 19571. There should be separate regulations for opencast workings since the present

regulations are inadequate for opencast. (Third Safety Conference 1973)2. Terms “abandoned workings”, “disused/ unused workings” and “discontinued

workings” shall be defined.3. Standard conditions for permissions of routine nature like those relating to conveyors-

Regulation 92, Locomotive- Regulation 95, Solid blasting etc. may be incorporated in the Regulations. No permission from DGMS may be required for these operations.

4. There should be provision for advance planning. Regulation 60 may be amended requiring management to submit a programme plan regarding workings during next two years.

5. Regulation 58: Standards of accuracy of mine plans may be laid down in the Regulations.

6. In addition too the plans required under Regulation 59, “subsidence plan”, “water danger plan”, and “joint survey plan” may be required to be maintained.

7. Higher supervision levela) Strata Control officer may be required in deep mines.b) Engineers too should hold certificates of competency.c) Face supervision by overman.d) Basic qualification of surveyor should be at least B.Sc.e) Upper age limit of persons employed in mines may be fixed as 60 years.

8. Man-riding facilities should be provided when long and arduous travel is involved (Fifth Safety Conference 1980)

9. Factor of safety for winding ropes may be specified in Regulation 80 (2) (d):Depth in metres F.SUp to 300 10300.500 09500.700 08700.1000 07 1000 06

9. Following may be added to Regulation 126 – danger of inundation from surface water:

a) Mine openings shall be at least 3 m above HFL instead of 1.5 m.b) Danger level shall be fixed 1.2 m below HFL.c) Depth of hard cover above workings shall not be less than 15 m.

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d) Quick communication arrangements shall be provided at the mine from riverside to the mine; from surface to workings below ground etc.

e) Arrangements for communication with dam or barrage authorities shall be provided.

10. Regulation 145: Continuous environmental monitoring device shall be installed in gassy mines of degree three. (Fifth Safety Conference 1980)

11. Following may be added to Regulation 131(2):a) Electric supply to mechanical ventilator shall be through separate circuit than the

main distribution point.b) In degree II/ III gassy mines, there should be two separate sources of drive for

the main mechanical ventilator (Jeetpur Court of Inquiry)12. Following changes may be made to other Regulations:

a) Regulation 159 (2): Liquid Oxygen Explosive shall not be used in mines.b) Regulation 161: Omit – explosive shall be used in cartridge form.c) Regulation 168(5): Omit “explosive used in a hole shall be of the same type”d) After Regulation 181, following Regulation may be added:Regulation 181A: Owner, agent or manager while acquiring any approved type of machine, equipment, appliance or material shall ensure that they conform to the approved specification and shall be responsible for maintenance of approved specification.

13. Regulations regarding noise levels and ground vibrations shall be included.

Inadequacies in Mines Rules 19551. Occupational health servicesSeventh Safety Conference (19-20 December 1988) recommended that each mining company working mechanized mines should create department of Occupational Health Services. This needs to be incorporated in the Rules after making provisions in the Mines Act.2. Workers’ participation in Safety Management

A. Eighth Safety Conference (14-15 May 1993) recommended:a) Members of Safety Committee shall be given one week training.b) There shall be yearly review of the work of Safety Committee.c) Once in a year the meeting of Safety Committee shall be attended by

senior officials of the Area and Trade Unions. B. Ninth Safety Conference recommended:

a) Tenure of Safety Committee should be two years.b) Workmen’s Inspectors should be elected by trade unions.c) Workmen’s Inspectors should have the right to ask for and examine any

plans or records maintained under the Mines Act.d) Workmen’s Inspectors should supplement the efforts of mine management

on safety matters.e) Workmen’s Inspectors should also be appointed in all mechanized mines.

These recommendations should be incorporated in the Mines Rules.3. First-aid

I. Seventh Safety Conference recommended that ambulance vans should be fully equipped with life saving drugs, medicines and appliances needed in emergency e.g. Oxygen cylinder etc.

II.The Manager should ensure that suitable means of transport are provided for carrying injured/ sick persons to the surface.

These recommendations may be incorporated in the Mines Rules.4. Additional duties and responsibilities of welfare officer

a) Weekly review of the performance of welfare activities in the mine.

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b) Control of absenteeism and ex-gratia payment should be looked after by the welfare officer.

c) Welfare officer should give charge report at the time of transfer or discharge.

Inadequacies in Mines Rescue Rules1. There is no upper age limit for rescue work. Rescue and recovery calls for very

high standard of fitness. An upper age limit of 50 years is desirable.2. It is of utmost importance that analysis results of air and dust samples collected

from the mine after fire or explosion are available quickly. There should be a mobile laboratory in every rescue station.

3. Training in rescue and recovery should include handling of causalities as it has been seen that if not properly handled, injuries of persons can get aggravated.

4. There should be under- water training of rescue personnel.5. A hot and humid chamber should be provided in the rescue stations and

training should be given in these chambers, as is the practice in some of the developed countries.

6. Rescue stations should have mobile winders, large diameter mobile drills and capsules for emergency drilling of large diameter holes for rescue of trapped persons in capsules as was done in Mahabir Colliery (November, 1989). Safety Conferences have also made recommendations to this effect.

7. In case of fiery seams, whenever employment exceeds 350 persons, provision of rescue room irrespective of the location of rescue station shall be made at the mine as recommended by ninth Safety Conference.

Inadequacies in MVT Rules

Mines vocational training Rules, 1966 were framed long back to impart vocational training to mine workers, which include:

Initial/basic training to new entrants followed by further training at the place of work under close supervision of experienced workmen.

Refresher training for persons already employed and also for persons who return to work after absence of 1 year.

Additional initial training for U/G workers. Special training of support gang, shot-firer etc.

Subsequently, MVTR 1966 were revised with a view to make these need-based and job-oriented for improvement of knowledge, skill and correct job procedures.

However, there have been considerable changes in mining technology in U/G, Surface and O/C in the form of fast and rapid mechanization and outsourcing activities. The existing statutory provisions contained in MVTR 1966 are not adequate to fulfill the present day need.In the present day context of heavy mechanization in U/G, Surface and O/C and increase in outsourcing activities particularly in open cast, the following are the flaws/inadequacies in the existing MVTR:

1. Duration of training: The present duration of trainings of 12 days for surface/opencast/UG works are not adequate workers.

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2. Course content: The course content designed for the purpose is very old and inadequate and also does cover all aspects of mining technology.

3. Type of training: In the present rule, there is provision only for theory and practical training. Training modules are too general in nature and oriented towards departmental employees.

4. Applicability: MVTR is applicable only for limited categories workers debarring officials, supervisors and officers, office staffs and rescue persons.

5. Training for contractor’s workers: No provision exists in this regard.6. Appointment of training officer: Provision in respect of qualification, experience,

and nos. of training officers at training centre is not adequate.7. Staffing: Provisions in respect of qualified training staff, instructors and their

qualifications are not prescribed adequately in the statute.8. Training of trainers: There are no provisions for training of trainers.9. Training aids & course material – Existing provisions lack modern amenities like

films, documentary, video, literature, models etc. at VTC.10. No provision of training on occupational health safety.11. No provision for special orientation training for female workers.12. No provision for training to workmen and supervisors in respect of environmental

protection. 13. Training allowance – Allowances paid to trainers and trainees are not adequate.

Suggestions/steps to be taken forFor improvement in MVTR:

Suggestions for improvements

MVTR 1966 has become out of date and irrelevant and needs to be repeated and replaced by a new set of rules incorporating the revised modules for basic training, modules for refreshing training, provision for different types of VT centers, building accommodations, furniture, training aids etc.

In view of many changes sweeping the mining industry in the form of new technologies, changed mining conditions etc., an acute need has been felt to recast the existing statutory provisions contained in MVTR 1966.

Following are the suggestions/steps to be taken for improvements in MVTR 1966 in order to make it effective in the present day context of heavy mechanization and outsourcing in Indian mines:

1) Duration of training: Keeping in mind the increasing mechanization and outsourcing activities in Indian mines the duration of training should be increased. The duration should be fixed based on type of organization, type of mine and category of workmen. The suggested duration should be as follows:

SrNo

Categories of workers Duration of training (days)

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Initial training Refresher training1 Surface workers 17 062 Open cast workers 18 063 Underground workers 48 124

5.

Additional training for specificCategories open cast workers/supervisorsa. Drillers, blasting crewb. Operators dumper, shovel, dozerc. Dragline operators, fittersmechanicsd. Electricianse. Auto electriciansf. Electrical supervisorsAdditional training for specificCategories U/G workers / supervisorsa. Tramm. WE drivers, banks menon setter, fan attendantsb. Track layers, ventilation gang,shot firing gangc. Support gangd. Machine drivers/long wall crewe. fitters, electricians, mechanicsf. Electrical supervisors

365472

967218

18

2430485418

121212

12129

09

1212121209

Refresher training period has been kept 50% of the initial training period but not exceeding 12 days. In the initial and refresher training, the last 1-2 days have been kept for feedback/test.

2) Course Content: For effective training, the syllabus needs to be organization specific, mine specific and cadre specific. A standard write-up should be prepared covering theoretical aspect of syllabus circulated in the form of text book in local language to all instructors and trainees.

3) Applicability: It should be applicable for workers, supervisors and officers, officer staff and rescue persons.

4) Training of contractor’s workers: Separate modules should be drawn for contractor’s workers as the present modules are too oriented towards departmental employees.

5) Appointment, duties and responsibilities of training officers: The rule should provide for appointment of a training officer in each mine employing more than 500 persons besides instructors. The qualifications of the training officer, and the no. and qualification of instructor’s should be prescribed.

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All training centers shall be adequately staffed as per following details:

1st class Manager – Overall in-charge. Adequate nos. of training officer and for Assistant Training officers having degree

in Mining/Mechanical/Electrical Engineering. Adequate nos. of trained instructors at least diploma in

Mining/Electrical/Mechanical Engineering. Adequate nos. of experienced and safety minded trainers for each specialized or

skilled jobs. Adequate sub-ordinate staff.

6) Training of trainers, instructors & training officers should be given statutory backing.

7) Training aids: All training centers should be provided with computers with required software, overhead projectors, slide projectors and TV + VCP/VCD Player etc.

8) Special orientation training for female workings should be included in the training programme.

9) Considerable damage is occurring to environment due to various mining activities. Training on environmental protection to workmen and supervisors should be made mandatory.

10) Provision of training in respect of occupational health and hygiene should be made in the statute.

11) In view of the new Information Technology (IT) waves sweeping the globe, mining industry has to keep pace with it and accordingly the very nature/kind of vocations done by our workmen change. Such IT application to industry should be anticipated and accordingly such training should be included in Mines Vocational Training Rules.

Till the existing MVT Rules are thoroughly revised and amended incorporating the above mentioned suggestions, the following additional steps should be taken –

a) Each mining company should draw up model training schedules for different categories of work persons. Such schedule should be got vetted by the tripartite review committee.

b) All front line supervisory officials like sirdars, over men, surveyors, foremen, electrical/mechanical supervisors as well as persons supervising other surface operation should be imparted structured training in safety management for at least 2 weeks once in a very 5 years covering about 20% strength every year.

c) Specialized training: Courses should be arranged for the development of skilled operators required for HEMM. L/W faces equipment etc. including contractor’s workers.

d) All persons engaged at any work within the mine premises through the contractors should be imparted relevant training and other job oriented briefings and the drivers of vehicles belonging to contractors entering the mine premises

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should be explained the salient provisions of traffic rules framed by manager of mine. Each mining company should draw up appropriate training schedules and modalities in this regard and implement the same.

ExerciseQ.1: Discuss the system of “Occupational Health Surveillance” in coal mines of your company. State shortcomings and suggest improvements (First Class, 1999)Q.2: Discuss how Safety Committee constituted under the Mines Rules can play an effective role in improving safety standards in mines. (Second class, 1999)Q.3: Discuss present role and functions of Workmen’s Inspector. How can he be made pore effective? (Second class, 2001)Q.4: Suggest measures for improving effectiveness of safety committee and Workmen’s Inspectors. (Second Class, 2002)Q.5: Write duties of Manager in Emergency. (First Class, 1998, 2000 and 2002; Second Class, April, 1999 and June, 2001)Q.6: Under the present scenario comment on adequacy of safety statute along with suggested improvements on:

a. Duties and responsibilities of owner.b. Statutory record and registers.c. Duties and responsibilities of manager.d. Workmen’s Inspectors.

(First Class, 2003)Q.7: What are the improvements required in respect of the provisions of CMR regarding Opencast mines. (First Class 2001)

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Chapter 2Safety Standards

It is often stated that safety status of a particular mine is not up to the mark. What exactly it means? Till recently we have been comparing safety status of mines using accident rates per thousand persons employed or accident rates per million tonnes of output. It is also called frequency rate. The safety standard of a mine can also be evaluated using severity rates. The severity of accidents is evaluated by time lost due to resulting injury. To calculate the severity rate, it is necessary to calculate actual man-days lost in case of reportable and minor injuries and add the specific time charges taken from the standard tables in respect of fatal and serious bodily injuries given in Workmen’s Compensation Act. This requires compilation of all reportable and minor injuries and time loss due such injuries. Unfortunately these figures are not readily available and hence DGMS has given an empirical formula for calculating severity index of a mine. This is as follows:S.I = (50F + S) x 105/ Man-shifts workedWhere S.I = Severity index

F = No. of fatal accidents in a yearS = No. of serious injuries in a year

The above criterion is used for identifying accident-prone mines.Accident statistics for Indian coal mines are given at Appendices. It will be observed that - about 100 to 150 persons are killed in mine accidents every year;- about 600 persons are seriously injured every year;- Death rate per thousand persons employed is nearly 0.3;- Serious injury rate is nearly 1.5 per thousand persons employed;- Roof and side falls and track-less transport machines are the major contributors to fatal accidents.

Prevention of accidents due to ground movement The problem of ground movement has engaged the attention of practicing mining

engineers, researchers and the regulatory authority. The Mines Regulations have elaborate statutory provisions for inspection, dressing and support of roof and sides. As a result of these efforts, the accident rates due to ground movement have come down to some extent but much more is still required to be done. The difficulties being faced are due to the following reasons:

The predominant method of work being Bord and Pillar, there are numerous working places and long stretches of roadways requiring inspection and support. The supports at these places often become loose and require to be examined, tightened or replaced from time to time. Supporting every inch of roof is not practicable and economical.

The strata overlying the coal seams is massive and strong in several locales and does not cave in easily after extraction of coal thereby throwing weight on the pillars and supports resulting often in pillar collapse, bumps or failure of supports; it also keeps hanging in goaf over a considerable area and results in air blast when it falls.

Following are some of the steps to reduce such accidents:

The sixth Conference on Safety in Mines recommended inter alia formulation of support plan for each mine taking into consideration the local geological conditions, physico-mechanical properties of the strata, method of work, mechanization, past experience etc. The Director General of Mines Safety constituted an expert group in the year 1988 to help enable the mining industry in drawing up the support plan properly and scientifically. The Expert group submitted its report recommending extensive use of roof bolting as system of supports. The group also suggested the norms for calculating the support density on the basis of rock mass rating (RMR) of overlying strata. The mining industry was advised by the Director general of Mines

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Safety to implement the recommendations. It was a beginning of scientific approach towards supporting the roof, particularly in development workings. The system needs to be followed in all the mines sincerely. Having gained some experience in roof bolting, it is advisable that another expert group may be constituted to review the work and recommend norms of support for depillaring workings and longwall faces.

Till now, roof bolting is being done using cement capsules for grouting the roof bolts in the boreholes. Experience reveals that the cement takes fairly long time to set and thus the roof bolt cannot take load immediately. Resin capsules, on the other hand set almost immediately. It is suggested that time has come to switch over to resin capsules.

Attempts were made in some of the mines to facilitate caving by blasting in the goaf behind last line of supports. At Balrampur 10 & 12 Inclines of M/S SECL, blasting was done by drilling holes from the surface over longwall panels worked by powered supports, charging them in deck pattern and doing delay firing. In one panel, charge per hole was 50 Kg whereas charge weight per delay was 150 Kg. Total charge per round of blast was 650 Kg. In another panel 1200 Kg of explosive was used in a blast. Yet another blast comprised 2192 Kg of explosives. It was reported that as a result of induced caving by deep hole blasting from surface, load on the powered supports had reduced by about 170 to 200 tonnes and loading density by 43 tonnes/m2.

Despite elaborate precautions like supporting the roof and doing induced blasting, possibility of occurrences like major falls or air-blasts cannot be ruled out completely. Experience shows that there are normally indications and warnings before any major fall. Many disasters have been averted by withdrawal of persons from the mine on appearance of such indications or warning signals. Experienced supervisors like overmen and sirdars have been of great help. There is a need for intensive training and education not only for the supervisors but also of the workers in underground mines to examine, dress and support the roof and also examination of vulnerable areas like goaf, areas under extraction. These efforts should be supplemented by use of strata pressure monitoring devices and devices to check weaknesses in the roof and sides.

Manager of every underground mine is required to prepare an emergency plan. It is of utmost importance that this emergency plan is well rehearsed so that every one knows and carries out his duties in emergency.

Concluding remarksAccidents and disasters due to ground movement pose a challenge to the mining industry, research organizations and regulatory authority. The problems relating to ground control are likely to get aggravated as mining activities are extended to deeper horizons and more difficult geo-mining locales in future. Therefore concerted efforts are needed to evolve a practical solution to the problem. A beginning has already been made with geo-mechanical classification of strata and use of roof bolts and cable bolts and induced blasting of overlying strata. Further efforts are needed to getter a better insight into the mechanism of strata failure. These efforts must be supplemented with sincere implementations of the laws to prevent such accidents. Training of supervisors, workers and support crew should receive more attention because they are not only the persons who are exposed most to the hazardous environment but they are the key personnel in an accident prevention drive.

MEASURES TO IMPROVE SAFETY STANDARDS IN MINES

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For every accident there are many contributory factors. These factors combine in random fashion causing accidents. Further, it must be clearly understood that the accidents are not the problems but are only the symptoms of certain problems existing at the mine/ mines. To eradicate accidents these problems need to be identified and then corrective action should be taken.In general terms we may say that to improve safety standards, two fold action as follows should be taken:

Legislative measures

Statutory provisions are the minimum to be achieved. The mine management should aim at higher standards than those required by the statute. In order to comply with statutory provisions, it must be ensured that-- Adequate and competent supervision is provided by qualified and experienced officials and persons. This requires appointment of sufficient number of statutory persons including those to take care of absence and leave etc.

- Adequate number of competent persons is appointed for the operation of machinery, equipment and appliances.

- Adequate and proper machinery, equipment, appliances and material are provided and maintained for carrying out various operations. Proper records of maintenance need to be maintained. Enough spares should be provided.

- The manager should carefully examine the records, reports, registers and plans to ensure compliance with various statutory provisions.

- Mines/mine should be audited for safety at regular intervals. The safety audit reports should be examined by the management and discussed in the meetings of safety committees.

PROMOTIONAL MEASURES Incentive should be given to the mines/individuals for higher safety performance. Message of safety should be propagated through safety campaigns like safety weeks,

safety fortnights etc. Thorough training should be given whenever any new method of work, technique or

machinery is introduced in mines/mine. Management should practice self-regulation. Workers’ participation in safety management should be made more effective.

OTHER MEASURES New concepts and practices like risk assessment and risk management, accident

analysis and problem identification etc should be introduced. Guidelines given in DGMS circular 13 of 2002 and circular 2 of 2011 may be referred to.

Use of latest management tools like use of computers, information technology may be made.

Safety Conferences at National level should be convened at shorter and regular intervals.

Rope haulages should be phased out. Quality roof bolts including resin grouted bolts should be used as supports wherever

applicable. Recommendations of various safety conferences should be implemented.

ExerciseQ.1: The rate of fatalities per thousand persons employed in coal mines has remained almost steady during last decade. How can it be brought down further? (First Class 2001)Q.2: Discuss the purpose, scope and impact of Mines Vocational Training. Are you satisfied with the new modules? (Second Class 2001)Q.3: How can you harness human resources to make mining safe and efficient?

(First Class 2002)Q.4: Write short note on accident-prone mines. (First Class 2002)

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Q.5: Suggest measures for improving effectiveness of Safety Committee.(Second Class 2002)

Q.6: Roof fall continues to be single largest cause of fatal accidents in our coalmines. How would you reduce such accidents? (First Class 2003)Q.7: Write short notes on: (a) Risk management (b) Effectiveness of Safety Committee

(First Class 2003)Q.8: What are the objectives of convening the National Safety Conferences? Briefly state major recommendations made by it till date and their impact on safety in mining industry.

(First Class 2005)

APPENDICES Table 1 Trend in fatality rates in coal mines

Year Rates per ,000 persons employed, ten yearly averageAvg. no. accidents

Acc. rate Avg. no.Fatalities

Fatality rate

1901-10 74 0.76 92 0.931911-20 139 0.94 176 1.291921-30 174 0.99 219 1.241931-40 172 0.98 228 1.331941-50 226 0.87 273 1.011951-60 223 0.61 295 0.821961-70 202 0.49 259 0.621971-80 187 0.40 264 0.5551981-90 162 0.30 185 0.341991-00 140 0.27 170 0.332000-05* 92 0.22 115 0.27

* Provisional

Table2 Trend in incidence of accidents in coal minesYear Number of accidents

Fatal Serious Total1996 131 677 8081997 143 677 8201998 128 523 6511999 127 595 7222000 117 661 7782001 105 667 7722002 81 629 71020003 83 563 6462004 89 962 10512005 103 907 1010

Note: Figures for the years 2004and 2005 are provisional

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Table 3 Trend in serious accidents and death rates and serious injury rates in coal minesYear Number of accidents Accident

Frequency rate/lac

manshifts worked

Number of persons Rate per 1000 persons employed

Death rate per million tones output

Fatal Serious Total Killed Seriously injured

Death rate

Serious injury rate

1996 131 677 808 0.51 146 723 0.29 1.43 0.481997 143 677 820 0.52 165 725 0.33 1.44 0.521998 128 523 651 0.43 146 560 0.30 1.14 0.461999 127 595 722 0.48 138 650 0.29 1.37 0.442000 117 661 778 0.54 144 707 0.31 1.54 0.432001 105 667 772 0.57 141 720 0.32 1.64 0.412002 81 629 710 0.54 97 665 0.23 1.57 0.27

2003 83 563 646 0.50 113 590 0.27 1.42 0.302004 89 962 1051 0.81 98 991 0.24 2.38 0.262005 103 907 1010 0.78 124 931 0.30 2.23 0.33Note: Figures for the years 2004 and 2005 are provisional

Table 4 Trend in fatal and serious accidents and rates in coal mines – Place-wiseYear Number of fatal

accidentsNumber of serious accidents

Death rate per 1000 persons

Serious injury rate per 1000 persons

B/G O.C A.G Overall

B.G O.C A.G Overall

B.G O.C A.G Overall

B.G O.C A.G Overall

1996 75 27 29 131 478 71 128 677 0.31 0.42 0.19 0.29 1.83 1.10 0.86 1.431997 94 27 22 143 440 79 158 677 0.41 0.42 0.14 0.33 1.71 1.24 1.05 1.441998 80 24 24 128 346 172 105 523 0.36 0.35 0.16 9.30 1.41 1.06 0.70 1.141999 74 30 23 127 408 77 110 595 0.33 0.43 0.16 0.29 1.73 1.19 0.81 1.372000 62 38 17 117 444 108 109 661 0.30 0.74 0.13 0.31 1.92 1.67 0.82 1.542001 67 26 12 105 464 73 130 667 0.43 0.38 0.10 0.32 2.100 1.12 1.07 1.642002 48 22 11 81 434 92 103 629 0.27 0.32 0.11 0.23 2.07 1.43 0.80 1.572003 46 23 14 83 380 82 101 563 0.33 0.35 0.13 0.27 1.85 1.30 0.77 1.422004 49 33 07 89 757 82 123 962 0.26 0.49 0.05 0.24 3.61 1.26 0.95 2.382005 54 28 21 103 682 93 132 907 0.35 0.41 0.16 0.30 3.24 1.39 1.03 2.23

Note: Data for the years 2004 and 2005 are provisional

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TABLE 5 Cause-wise fatal accidents in coal minesCause Yr BCCL CCL ECL MCL NCL NECL SECL WCL CIL SCCL Other TotalFallOfroof

03 1 1 3 0 0 0 5 1 11 6 0 1704 3 2 5 2 0 0 3 4 19 6 1 2605 8 1 2 3 0 0 4 1 19 1 0 20

FallOfsides

03 1 1 2 0 0 0 0 0 4 0 1 504 2 0 2 0 0 1 0 1 6 1 0 705 0 0 3 0 0 0 0 2 5 1 1 7

Ropehaul-age

03 1 0 2 0 0 0 1 2 6 3 1 1004 1 1 1 0 0 0 0 1 4 0 1 505 1 1 3 0 0 0 1 2 8 3 0 11

Dum-per

03 5 3 3 1 1 0 1 3 17 1 0 1804 1 0 2 1 1 1 1 2 9 1 1 1305 0 1 5 3 0 0 4 3 16 1 1 18

Trucktankeretc

03 0 0 0 2 0 0 0 0 2 0 1 304 1 1 1 0 1 0 2 1 7 0 1 805 0 0 0 0 0 0 0 0 0 0 0 0

Othermach-inery

03 0 1 1 3 0 0 2 2 9 5 0 1404 1 2 0 0 0 0 1 3 7 0 2 905 3 1 4 5 1 0 3 1 18 3 1 22

Expl-osives

03 0 0 0 0 0 0 2 0 2 1 0 304 0 0 1 1 0 0 0 0 2 3 0 505 0 0 0 0 0 0 2 0 2 0 0 2

Fallof persons

03 2 0 2 0 1 0 0 1 6 0 0 604 0 1 3 0 0 0 0 1 5 0 0 505 1 1 2 0 1 1 0 0 6 1 1 8

Fall of ob-jects

03 0 0 0 0 0 0 0 0 0 0 1 104 0 1 0 0 0 0 0 0 1 0 0 105 2 0 0 0 0 0 0 0 2 0 2 4

Othercause

03 2 0 0 1 0 0 0 0 3 3 0 604 2 2 2 0 1 0 1 0 8 0 2 1005 3 2 1 0 0 0 0 0 6 3 2 11

Total 03 12 6 13 7 2 0 11 9 60 19 4 8304 11 10 17 4 3 2 8 13 68 11 10 8905 18 7 20 11 2 1 14 9 82 13 8 103Note: Figures for 2004 and 2005 are provisional. Data for 2005 are as on 31.12.05

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CHAPTER 3Disaster Management in Mines

The Encyclopedia of Occupational Health and Safety describes `disaster’ as a catastrophic

situation in which the day to day patterns of life are in many instances suddenly disrupted and

people are plunged into helplessness and suffering and, as a result, need protection, clothing,

shelter, medical and social care and other necessities of life. In common mining parlance, we

are used to call accidents with high fatalities (10 or more) as disasters. However, defining

disasters in terms of fatalities may be merely a post mortem. There may be accidents resulting

in trapping of workers which will require all the inputs of a disaster management. A classic

example is the accident at Mahabir colliery on 13th. November 1989 when 6 persons lost their

lives but 65 persons were trapped when an inundation occurred from underground waterlogged

workings. These persons were subsequently rescued on 16th, November. There is recent

outlook to define ‘disaster’ in terms of ‘major accident’ which means an unexpected, sudden

occurrence, including, in particular, a major emission, fire or explosion, resulting from abnormal

developments in course of an industrial activity, leading to a serious danger to workers, public

or the environment whether immediate or delayed, inside or outside the installation involving

one or more hazardous substances.

POTENTIAL OF DISASTERS IN MININGThe history of mining has been marred by many disasters killing and maiming a large number

of workers, the worst being at Couriers Colliery in France in the year 1906 when an explosion

killed 1100 persons. In India, inundation at Chasnalla Colliery in Jharia Coalfield in the year

1975 killed 375 persons. In Indian coal mines 2197 persons have been killed in 55 disasters

from 1899 to 2005 (Appendix 1). The main causes of disasters in mines are explosions,

inundation, fire, and ground movement including fall of roof, fall of sides, premature collapse

etc.

DISASTER MANAGEMENTDisaster management is an obvious necessity to guard against and mitigate the consequences

of major accidents. For effective management of disasters, it is essential that a comprehensive

action plan evolved through scientific principles and approach is in position. The issue is not

simple, as there can be no fully prepared model, which will be ideal for all types of disasters.

The principle, however, remains the same namely,

Prevention Preparedness Mitigating the effects through rescue, recovery, relief and rehabilitationPrevention of disasters1. Identification of disaster potentialThis requires risk assessment.

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2. Control measures – technical and organizational(a) Selection of appropriate equipment, material and technique

(b) Introduction of safety devices and safety systems

(c) Maintenance and monitoring schedules

(d) Location and delineation of waterlogged workings

(e) Education and training

PreparednessTo mitigate the hardship caused by disasters, preparedness calls for action with a view to

organize and facilitate timely rescue, relief and rehabilitation operations. The measures are:

(a) Setting up of training and rescue services.

(b) Provision of alarm system.

(c) Preparation of emergency plan setting out an information dissemination system, the

personnel and procedure for tackling the emergency, the provision of an emergency control

with alarm and communication routes, escape route and evacuation procedure.

(d) Liaison with local and other authorities and emergency services so as to coordinate action

particularly with relation to off-site emergency plan.

There is a need for consultation, close coordination and cooperation between bodies such as rescue services, fire brigade, police, hospitals and public utilities.

Emergency responseIn the development of emergency plans for mining disasters, systematic work started in the

early sixties and in some mines emergency plans were framed based on the model standing

orders circulated by DGMS. Later Sudamdih court of Inquiry (1976) also recommended that

there should be definite emergency plan for every mine and rehearsals should be undertaken

periodically for evacuation and rescue etc. The Coal Mines Regulations and the Metalliferous

Regulations were amended in the year 1985 to provide for emergency plan for general action

for use in emergency to be prepared by the mine management for every belowground mine.

The regulation in respect of coal mines reads as follows:

Regulation 199A. Emergency Plan1) The manager of every mine having workings belowground shall prepare a general plan of

action for use in time of emergency. The plan shall outline the duties and responsibilities of

each mine official and key-men including the telephone operators, so that each person

shall know what is expected of him in case fire, explosion or other emergency occurs. All

officials and key-men shall be thoroughly instructed in their duties so as to avoid

contradictory orders and confusion at the time when prompt and efficient action is required.

The emergency plan shall also provide for mock rehearsals at regular intervals.

2) The manager shall submit a copy of the aforesaid emergency plan prepared by him to the

Regional Inspector, within 60 days of coming into force of the Coal Mines (Amendment)

Regulations, 1985, or in the case of a mine which is opened or reopened thereafter, within

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thirty days of such opening or reopening. The Regional Inspector may, by an order in

writing, approve of such action plan, either in the form submitted too him or with such

additions or alterations as he may think fit and action plan so approved shall be enforced in

the mine.

3) On receiving information of any emergency, the manager and in his absence the principal official present on the surface, shall immediately put the emergency plan in operation.

The basic functions of emergency plan are:

(1) Sending information to different parts of the mine.(2) Safe and orderly withdrawal of persons from unaffected part of the mine.(3) Rescue of trapped persons. Speed of rescue operations is important. This requires: Early location of trapped persons;

Precise location of trapped persons;

Training of rescue workers in use of rescue capsules;

Special clothing for rescue persons near fire.

(4) Recovery of dead bodies and their identification.(5) Prevention of further danger in mine.(6) Keeping press and public informed about the correct situation to avoid rumours.The emergency plan to deal with disaster should come into action almost instantaneously at the

very onset of a disaster.

A model emergency plan is given in the appendix 2.

Besides the normal elements, an emergency plan may also contain the following:

Seismic sensing system for locating trapped persons.

Provision of underground shelters.

Remote sensing of in-mine conditions.

High penetration drill rigs.

Radio facilities.

Mobile van with borehole probing facilities.

Mobile winders.

Inundation in minesSources of inundation From surface water

From underground sources

From Surface watera) Accumulation of water over low-lying area; Example – Burradhemo disaster (1956) 28

persons killed.

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b) Rivers/ nullahs in spate; Breach of embankment; Example – Gaslitan disaster (1996) 64

persons killed.

c) Water inrush through subsidence cracks;

d) Water flowing back due to flood on the main river or due to discharge of water from dam;

Example – disaster in Central Saunda (1976); 10 persons killed.

e) Through bore holes.

f) Collapse of river/ nullah bed.

From Underground sourcea) Accidental connection with old waterlogged workings; Example: Chasnalla (1975); 375

persons killed.

b) Inrush of water along a fault plane; Example: Damua (1960); 16 persons killed.

c) Waterlogged workings of other seam coming in line or close to the active workings;

Example: Newton Chikli (1954); 63 persons killed.

d) Connection with water bearing strata.

e) Failure of water dams.

The most common cause is accidental connection with old waterlogged workings generally due

to incorrect plans or incorrect survey.

Prevention Surface source: In addition to the provisions of Regulation 126, the following points should be borne in mind:a) Entry point to be at least 3 m above H.F.L instead of 1.5 m;b) Goaves, subsidence, boreholes should be treated as entry points;c) Danger on account of H.F.L of watercourse rising as a result of back flow of water from the

main river in flood should be taken into account.d) Where there are dams on river, sudden discharge of water from such dams may cause

sudden rise of water. Therefore, management of mines on downstream side should maintain liaison with the dam authorities.

e) Liaison with meteorological department for getting advance warning of heavy rain fallf) Barriers between mines in different seams should be vertically coincident so that danger

from one mine is not transferred to other mine.(See appendix 3 for precautions recommended by ninth safety conference)

Danger from Underground sourceRegulation 127 deals with precautions to prevent danger from underground sources. Since most of these accidents have taken place because of incorrect plans, the first precaution is to carefully examine old plans of waterlogged workings including AMPs. Information may also be collected from old employees particularly surveyors. Open-ended galleries should be treated with suspicion. If possible old workings shall be dewatered by putting boreholes.Surveys of workings near old waterlogged workings should be accurate and may be counter-checked by another survey team from the area. Flow of water seepage should be checked by installing V-notch.

Standing orders for withdrawal of persons in case of apprehended danger should be framed and enforced.

Important DGMS Circulars:(a) 3 of 2000- recommendations of 9th Safety Conference (Appendix 3)

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(b) 1 &2 of 2001- Recommendations of Gaslitan Court of Inquiry (Appendix 5)(c) 4 of 2005- Recommendations of GDK 7 (LEP) (Appendix 6)(4) 5 of 2003 – Recommendations of Bagdigi Court of Inquiry.

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Appendix 1

Disasters in coal mines 1899 to 2005 in India

Serial No. Causes Disasters

Numbers % of

total

Killed

Numbers % of total

1 Ignition and explosion 22 40 1171 53.3

2 Inundation 17 30.9 749 34

3 Fall of roof/ Premature collapse 8 14.5 106 4.8

4 Fire 3 5.5 100 4.6

5 Explosives 1 1.8 13 0.6

6 In shafts 1 1.8 14 0.7

7 Miscellaneous on surface 2 3.7 20 0.9

8 Miscellaneous belowground 1 1.8 24 1.1

9 Total 55 100 2197 100

Appendix 2Model Standing Orders for Immediate Action on Occurrence of Disaster Underground

1. Duty of any person:Any person realizing that anything serious has happened anywhere belowground shall

immediately inform the nearest mining official, Mining Sirdar, Overman or assistant manager. If

near the pit bottom, he shall inform the onsetter.

2. Duty of underground official:Mining Sirdar/ Overman or other mine official and onsetter on being informed about the disaster

shall send information by telephone/ special messenger to-

(a) Other parts of the mine so that persons may be withdrawn therefrom.

(b) To the surface, in particular to the manager.

(c) To any senior official who may be present belowground at that time.

The Mining Sirdar/ Oveman/ Mine Official shall verify the veracity of the information and try to

withdraw all persons safely through previously fixed “escape route” with the help of self-

rescuers, if necessary.

If unsuccessful, he shall withdraw all persons to the ‘safe base’, seal off all openings, if

arrangement is provided, and await help.

3. Duty of OnsetterOnsetter on getting information of disaster shall inform the banksman on surface by telephone/

signalling by giving 10 raps and confirm the same by special messenger.

4. Duty of Banksman

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The banksman on getting information about disaster from underground shall arrange to give

warning to the following persons in the order given below without leaving his place of duty:

(a) Manager or in his absence principal official present at the surface.

(b) Attendance clerk.

(c) Safety officer.

(d) Engineer.

5. Duty of Attendance clerk:On receiving information of a disaster underground, he shall immediately-

(a) Send information by messenger to all members of the consultative committee available at

the mine and all key personnel at the mine;

(b) Prepare a statement showing number and names of persons in different parts of the mine

and send a list to the operations control room. He shall keep the list updated and keep the

operations control room informed;

(c) Not allow anybody to proceed belowground without authorisation of ‘control room’ and

await further instructions.

6. Duty of lamp room in charge:On hearing of emergency, he shall-

(a) stop issue of lamps without authorization from operations control room;

(b) Prepare a statement showing names of persons who were issued lamps, with cap lamp

number and send a copy to the operations control room. He shall keep the list updated and

keep the control room informed;

(c) Keep all lamps brought out from belowground separately till further orders.

7. Duty of Store keeper:On hearing of emergency, he shall immediately-

(a) Proceed to stores;

(b) Check the materials according to emergency list;

(c) Send a list to the operations control room;

(d) Arrange for procuring additional material from central stores/ other mines in consultation

with the control room; and

(e) Arrange for transport of material underground in consultation with the control room.

8. Duty of members of consultative committee:On hearing of the disaster, all members shall immediately rush to the operations control room,

authorize a line of action and authorize different officials for –

(a) Surface control;

(b) underground control;

(c) Officer in charge for control room and send information to the managers of adjoining mines,

likely to be endangered.

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9. Duty of officer in-charge of Surface control:He shall -

(a) Ensure that all key personnel are on duty according to pre-arranged plan on surface ;

(b) Organize an authorization system in consultation with control room;

(c) Check materials available in store and arrange for their transport belowground;

(d) Organize a system of relief;

(e) Arrange for rescue teams in consultation with rescue station superintendent.

10. Duty of Engineer:The Engineer shall

(a) Report to control room;

(b) Contact the store keeper;

(c) Send messengers to call all such workmen and mechanics as are required;

(d) Check the winding and ventilation plants; if message from underground states that up-cast

shaft is not to be used, take necessary steps to prevent access to the shaft or fan drift;

(e) Establish transport system from store and stock-yards to the downcast shaft;

(f) Get loaded quickly available emergency stores, like sand bags, brattice cloth, timber,

girders, auxiliary fans, air ducts, water pipes, pumps, etc. as may be required;

(g) Issue authorization cards to surface emergency workmen.

11. Duty of SurveyorHe shall

(a) Arrange for extra rescue plans;

(b) Arrange for staff to go underground as soon as possible and put numbering labels on

bodies before removal;

(c) Record the date on plans regarding position of bodies and other evidence.

12. Duty of DoctorHe shall

(a) Report to control room;

(b) Proceed to the mine forthwith, taking such instruments and drugs (particularly morphine) as

are likely to be useful;

(c) If required proceed underground guided by a responsible person.

13. Duty of welfare officer He will report to the control room and assist in preparation of the following accommodation:

i. Stretcher casualty station

ii. Walking casualty station

iii.Mortuary accommodation

In addition, he shall

(a) Supervise the preparation of the following accommodation;

26

Room for rescue teams to assemble in and receive instructions;

Sleeping accommodation, if rescue operations are going to be prolonged.

(b)Get a copy of the list of men in the pit from the attendance clerk and check from time

to time with bankman’s list and make a note of the men who have come out of the pit;

(c) Cooperate with police for identification of the bodies;

(d) Deal with inquiries from the relatives;

(e) coordinate with the canteen in-charge regarding food supplies;

(f) Prepare list of volunteer workers.

14. Duty of Canteen in-chargeHe shall report to the control room and take necessary steps to obtain additional supplies of

food if necessary.

15. Duty of security staff(a) They shall keep the roads clear for ambulance and other vehicles.

(b) They shall arrange for identification of bodies.

(c) They shall supervise mortuary arrangements.

Appendix 3

RECOMMENDATIONS OF THE NINTH CONFERENCE ON SAFETY IN MINES HELD ON 2 ND

AND 3 RD FEBRUARY 2000, AT New Delhi. 1.0 Review of Status of Implementation of Recommendation of the 8th Conference on Safety in Mines:

1.1 Necessary facilities for monitoring the environmental parameters in respect of Methane & Carbon Monoxide should be provided at mines. Facilities of continuous type monitoring should be installed within two years in all degree III gassy coal mines and in such other mines having active underground fire. Indigenous manufacturers should be encouraged to manufacture necessary equipment.

1.2 In mines where long or arduous travel is involved, arrangement for transport of men should be made. 1.3 In respect of small-mechanized mines, which are operating in non-coal sector, it may not be feasible for a small organization to create a special department on Occupational Health Services. For such small mines, it is suggested that an Association of small mines operators creates common facilities and infrastructure for occupational health services. Creation of such facility is specially needed for asbestos, manganese and mica mines. Simultaneously with creation of facilities for occupational health services, it is also necessary to improve quality of life of employees working in mining industry by provision of well planned housing colonies provided with all modern facilities such as good drinking water, good sanitation, drainage and recreational facility.

1.4.1 Suitable types of steel/metal supports should be introduced in all the development districts in coal mines within two years. 1.4.2 Wherever practicable, roof bolting as a method of support in coal mines should be used. Its performance should be monitored regularly. A few conventional timber props may be used as indicator props. 1.4.3 Coal mining companies should take initiative to select/promote development of suitable type of drills & other accessories for use in various types of roof strata. A task force may be created for the purpose which may oversee the introduction of steel supports.

27

1.4.4 Development of a portable instrument for detecting the hidden slips in the roof of coal mines should be taken up on priority by R&D organizations.

1.5 All front-line supervisory officials like Sirdars/Mates, Overmen/Foremen, Surveyors, Electrical/Mechanical supervisors/Chargemen/Foremen as well as persons supervising other surface operations should be imparted structured training in safety management, for at least two weeks, once in every five years, covering about 20% strength every year. 1.6 The recommendations of DGMS (Tech) Circular No.18 of 1975 shall be implemented forthwith. 1.7 Audiometry should be introduced, as a part of mandatory medical examination, for persons seeking employment in mines and for persons engaged in operations/areas where noise level exceeds 90 dB (A). 1.8.1 The portion of surface haul road in mine premises where there is heavy traffic of men and machines should have a separate lane properly fenced off from the haul road for pedestrians and two wheelers. 1.8.2 Trucks and other heavy vehicles, not belonging to management should not be allowed in the mine premises without a valid pass issued by the competent authority of the mine. Before the pass is issued the mine engineer should check the road-worthiness of such vehicles. In order to check entry of unauthorized vehicles in mine premises, each mine should establish properly manned check gate(s) at the entrance(s) where record of entry and exit of each such vehicle should be maintained. At the check gate the license of the drivers should also be checked for eliminating the possibility of unlicensed persons driving the vehicles. 1.9 Persons engaged in surface operations and, in particular, the contractors' workers, who incidentally are often inexperienced and least informed about job-safety matters, need closer and more competent supervision. To minimise accidents due to surface operations it would be ensured that: All persons engaged at any work within the mine premises through the contractors have received relevant training and other job-related briefings and that the drivers of vehicles belonging to contractors entering the mine premises have additionally been explained the salient provisions of "traffic rules". Each mining company should draw up appropriate training schedules and modalities in this regard and implement the same. In case of smaller mines, such arrangement may be made by association of mine operators. 2.0 Preventing Mine Disasters from Inundation2.1 Each mine shall be critically examined for its proneness to inundation and assessment regarding danger of inundation and precaution to be taken should be reviewed and updated yearly preferably before the onset of the monsoon. The recommendations may be deliberated in the (Pit) Safety Committee of the mine and information disseminated as widely as possible. 2.2 Suitable infrastructure at area level may be provided for drilling advance bore holes to detect presence of waterlogged workings in advance. 2.3 Embankments provided against river and jore to guard against inundation should be designed properly keeping in view the engineering parameters. The details of such construction should be properly shown in the underground plan and water danger plan. 2.4 Surface excavation or disturbance in or near major sources of water, which are connected or are likely to be connected to below ground workings should be filled up completely. 2.5 Detailed precautions against inundation may be laid down while working beneath or in the vicinity of river and major water bodies. This may include framing and implementing standing order for safe withdrawal of persons, including system of information both manual and automatic, effective communication system and system of safe and timely withdrawal of persons to safety.

28

2.6 Mechanism may be developed for warning mines about impending heavy rains similar to warning of impending cyclone issued in coastal areas for taking necessary action. Also coordination with concerned agencies/departments about opening of dams in the rivers on the upstream side should be examined. 2.7 Winding system serving as sole means of ingress and egress may be made constantly available even in adverse weather conditions, failure of steam or electricity or any other reasons. 2.8 Effective communication may be established within the mine and between mines for safe withdrawal of persons. Necessary standing orders in this regard need to be framed and enforced. 2.9 Recommendations of 6th Conference on Safety in Mines to evolve suitable cadre structure for mine surveyors and up gradation of their skill by availing facilities at various institutions, appointment of qualified surveyors and providing infrastructure including computerized facility at area level to oversee survey work of the mine etc. may be implemented. 2.10 R&D efforts should be continued to develop a system for construction of water-tight chamber as last refuge below ground in case of inundation. 3.0 Preventing Mine Disasters from Fire, and Effective Emergency Response3.1 Considering the risk of fire, all coal mine companies shall rank its coalmines on a uniform scale according to its risk from fire on scientific basis. Guidelines may be framed by DGMS and circulated to all mining companies. 3.2 Recognizing the urgent need for making the emergency plan responsive, speedy and effective, each mine shall review the existing emergency plan, at a higher level keeping in view the risk from fire. 3.3 A tripartite committee may be formed to study the feasibility of establishing rescue rooms in coal mines having high risk of fire and employing more than 350 persons ordinarily employed in a shift below ground may be considered. 3.4 A tripartite committee may be formed to study the feasibility of storing oxygen type self rescuer at strategic places below ground in coal mines with risk of fire in such scale so as to cater to the needs of persons who can be affected in an emergency may be explored. 3.5 Each mining company shall formulate and implement structured training programme for development of awareness and increasing effectiveness of emergency response in case of fire amongst work persons, officials and management. 3.6 Through sustained and meaningful R&D activities, mining companies and research institution shall help in creating a better understanding of the complex geo-mining situations leading to the occurrence of fire, which in turn will help in formulating guidelines to combat the problem of fire in effective manner. Early detection of heating effect of reversal of fan and control of fire, other associated aspects may be studied.

4.0 Risk Management as a Tool for Development of Appropriate Health and Safety Management Systems.4.1 Every mining company should identify one or more mines and should undertake a formal risk assessment process aimed at reducing the likelihood and impact of mishaps of all kinds in mines. Subsequently risk assessment process should be extended to other mines. 4.2 Risk assessment process should aim at effective management of risks, by identifying,

(i) which risks are most in need of reduction, and the options for achieving that risk reduction, (ii) which risks need careful on-going management, and the nature of the on-going attention

4.3 The risk assessment exercise should follow an appropriate process. 4.4 Risk management plans shall be prepared on the basis of risk assessment and implemented in the identified mines.

5.0 Quality Control for Improving Safety

29

5.1 Each mining company and the manufacturer/supplier shall satisfy themselves that the product has valid approval where applicable and conform to relevant standards where available at the time of supply. 5.2 Each large mining company may setup quality control cell or strengthen where the same exist, identify critical items which require testing for quality assurance at the time of procurement and during use and arrange testing of the same. Testing facilities may be setup wherever feasible; 5.3 Any defect or failure of approved items or those having BIS certification may be promptly brought to the notice of the appropriate authority for further action.

6.0 Communication System between DGMS Offices and Mine Management at Site. 6.1 Recognizing existence of a large variety of communication systems in mines, a comprehensive review of the existing communication systems at all mines in all mining companies should be undertaken and a consolidated status report prepared for working out a realistic and effective system of communication. 6.2 In organized mining sector, an effective internal and external system of communication besides P&T means shall be established both ways between the mines and, Rescue Rooms/stations, hospitals and DGMS offices. 6.3 Each mining company in the organized sector shall formulate and implement a comprehensive communication protocol clearly assigning duties and responsibilities of persons at various levels. 6.4 In un-organized mining sector, effective communication system shall be established in the following manner,(i) In large mines effective wireless communication within the mine including attendance rooms and managers’ office and residence; and, (ii) P&T telephone at managers’ office and residence.6.5 Steps shall be taken to strengthen communication system within DGMS offices and amongst DGMS offices and mine sites besides other concerned agencies.

Appendix 4

Recommendations of New Kenda Court of Inquiry1. Penalty for contravention of Regulation 87(4) (b) for non-provision of telephone is

inadequate.

2. Provision should be made for third separation door between D.C and U.C.

3. It should be made mandatory that every workman inside the mine must be acquainted with

the escape route. There must also be signs/markings to indicate existence of such route.

4. Rescue Rules should be amended to make it obligatory to keep rescue apparatus in a mine

which employs 350 or more persons underground in one shift.

5. DGMS may only nominally be attached to a suitable ministry of the Government of India,

but it should be autonomous in its functioning.

6. For effective fighting of fires, the role of controlling authority, emergency response

mechanism and method of fighting fire, need to be clearly defined. A comprehensive

regulation in this regard to be made after consideration of all these relevant factors. In this

regard, the provision for ventilation should also be further considered.

7. A large area was developed in the mine unsystematically. Even for development, the

Government should create an authority and frame rules regulating grant of such

permissions for development.

30

8. Efficient officers and cadres should be appointed in Rescue Organization. Age limit should

also be determined looking at the job they are required to do. Other facilities including

training should also be adequately provided for.

9. Many aspects of the mechanism of underground coal mine fires are not yet thoroughly

probed and known to the mine operators. It is suggested that special R&D activities be

initiated in this field encompassing all aspects of underground fire of Indian coal mines.

10. There is an immediate need for development of awareness among workers, supervisors

and management officials for identifying hazards due to fire in underground coal mines.

The Central Government may take appropriate action to meet this objective through

intensified programme of education and training.

11. The provisions of the Act regarding penalty for commission or omission of the provisions of

Coal Mines Regulations is inadequate in the sense that no distinct classification between

graver and lighter violations has been made. The legislation should be made either by way

of amending the regulations or a separate enactment declaring some commission or

omission in working mine as grave offence and providing for stricter punishment.

Appendix 5Disaster at Gaslitan and recommendations of Court of Inquiry

Disaster at Gaslitan CollieryDate of Accident: 26-09-1995Number of persons killed: 64Cause of accident: InundationGaslitan mine is situated on the bank of river Katri. On 26th. September, 1995 the entire district of Dhanbad experienced very heavy rainfall. The rain was also very heavy in and around Katras town where the mine is situated. The heavy rain compounded by breach of several tanks and ponds on the upstream side caused the water in the river Katri to rise rapidly, which soon crossed the danger level and then touched the withdrawal level before the midnight of the fateful day. The lurking danger however, went unnoticed as the guards for the purpose were not posted and the mine officials did not come out to monitor the water level in the river. The danger came to the notice only after midnight when the third shift river guard saw the river in fury and found that water had crossed the danger level.Rainfall from 00 hrs to 23 hrs (26.09.95) 285.49 mm. Do ,, 08 ,, to 07 ,, (27.09.95) 360.66 mm ,, 19 ,, to 23 ,, (26.09.95) 87.12 mmStanding orders :In consonance with DGMS Circular No. 2of 1978, the management had framed standing orders in respect of action to be taken in case of abnormal rise of water level in Katri river. The standing orders included amongst others, provision of river guards in all three shifts who shall keep a check on the water level in the river and inform the attendance clerk or the manager or any other official, should the water touch the danger mark. The guard was also required to inform the manager in case of any breach in the embankment.

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Interconnections: Gaslitan colliery consisted of two units namely Union Angarpathra and Gaslitan. Solid barriers 15 to 45 metres existed between these units but stability of these barriers could not be assessed as workings on the outbye side were packed and hence unapproachable.Inter-mine connections: Following inter-mine barrier exist between Gaslitan and adjoining mines:Angarpathra Colliery:The workings of all seams starting from XIV seam to VIII B seam, except X top and X bottom seams in Union Angarpathra unit were connected to Angarpathra Colliery through caved goaves and in VIII B seam through galleries. It was however not connected with other units because of faults. Katras Choitudih Colliery: Vertical barriers with Katri River as boundary existed from XV seam to XII seam. Vertical barrier was not provided in XI seam and below. The stowed workings of 8.2 m thick X seam were separated from overlying XI seam with a horizontal barrier of 20 m around 78 m R.L. It was also suspected that a connection existed between two mines in XIV seam corresponding to 78 m RL.

Mudidih Colliery:In XII seam a gallery had encroached into the common barrier between the two mines and it formed a thin barrier but it was strengthened by a dam. In XV top and bottom seams also galleries had encroached in the common barrier resulting in thin barriers. These galleries were later isolated by dams (8 nos.)Sequence of events:On 26.09.1995 one depillaring district was being worked in X special seam in all three shifts. In second shift 92 persons had marked their attendance. By 10.30 p.m. 28 persons came out of the mine. At about oo hrs. Sri Domar Mahto Sirdar who had been deputed to keep watch on water level in the river came to the pit top and informed that water level had touched the warning level. He informed banksman Sri Bilas Mahto not to allow any persons to go down the mine and to take out all the workers from underground workings.He then accompanied by Sri Zibrail Mian went to the river bank and saw the water level fluctuating around the danger mark. He then rushed to the bungalows of the manager and safety officer to inform them, as the telephones were not working.

The manager and safety officer rushed to the mine. Safety officer went to no. 7pit and tried to withdraw persons from 7 pit. He found that steam pressure in the boiler was not adequate. By using bricks/girders as counterweight, persons from 7 pit were raised.The manager went to No. 6pit and found that winding engine operator was experiencing difficulty in operating the winding engine. Signals were continuously being received from underground. At about 1.00 hr. an unsuccessful attempt was made to operate the winder. Soon there was a loud sound in No.6 pit which shook all structures including the guide ropes. At this time while attempts were being made to operate winding engine an overwind took place. Subsequent dewatering and inspection of 6 pit showed that cage at the pit bottom together with its suspension gear and rope had been swept away in a gallery by the force of rushing water to a distance of about 40 m. At this stage manager arranged to send a signal to 6 pit bottom for persons to proceed to 4 pit bottom which is second outlet of the mine.From the statement of Sri Domar Mahto who was watching the water level in the river it appears that some time after 00.45 hrs. the water overflowed the embankment and the embankment breached. The causes of accident can be briefly summarised as follows: Unprecedented heavy rainfall within a short span of time which surpassed all previous

records caused abrupt rise in water of Katri. The abnormal rise of water went unnoticed as no river guard was posted and the mine

officials did not exercise any vigilance to monitor the rise in water level in the river.

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The embankment built against river breached and the flood water soon filled up adjoining quarry and then breached a thick retaining wall built further away and the flood waters entered the quarry having connections with underground workings resulting into accident.

Extraction of barrier between the quarry having no connection with belowground workings and the quarry having connections resulting in direct passage of water from river to the mine.

Steam at sufficient pressure was not available due to premature stoppage of boilers. Failure to ensure that steam was constantly available to the winders. Not running the winder to raise persons at the end of second shift when steam was

available, even on receiving the signals from belowground. Not making any efforts to ensure that persons were not left belowground at the end of the

shift. Failure to place the afternoon shift under supervision of assistant manager, or even an

experienced overman resulting in indiscipline and chaotic conditions to prevail at the surface thereby failing to withdraw persons from belowground to surface at the end of the shift.

OBSERVATIONS AND RECOMMENDATIONS1. DGMS to be suitably strengthened.2. Prosecution cases of violations of the Mines Act may be expedited. Necessary

amendments in Cr.P.C. and Mines Act may be made so that such cases are heard by specified magistrates and disposed off within a time frame.

3. Before onset of monsoon mines situated on river banks should be inspected by DGMS along with mine management.

4. The feasibility of reclamation of opencast mines including disused ones, near rivers and major sources of water, particularly those having connections with belowground workings either directly or through subsidence cracks and fissures may be examined to prevent inundation in such mines.

5. Detailed precautionary measures against danger of inundation should be laid down while working beneath or in the vicinity of rivers and major surface bodies, particularly during rainy season. This may include framing and implementing of standing orders for safe withdrawal of persons etc.

6. The need for forewarning of mines about possible impending heavy rains, similar to the warning of impending cyclone issued in coastal areas, may go a long way in ensuring safety of mine workers from inundation. The feasibility of linking coalfields to meteorological laboratories for timely dissemination of information may be examined.

7. Mines having vertical shafts as the only means of exit may require captive generators. In case of steam boilers basic precautionary measures like keeping the boilers under shed, providing sufficient insulation around the boilers and pipe lines as well as attending the boilers constantly particularly in adverse weather need to be religiously followed.

8. The need for an effective communication system over and above the signalling system between the surface and belowground which shall remain in operation even with failure of electricity and also rugged enough to remain operative in adverse condition has been felt strongly. Suitable system may be developed.

9. Intermine barrier is an effective means to prevent transference of danger from one mine to another. In mines where barriers have become ineffective due to interconnections or otherwise, the same may be restored early, even artificially by building dams, explosion proof stoppings and other methods.

10. All disused pits, potholes and surface subsidence existing in the vicinity of river or surface source of water and where there is danger of inundation present, shall be sealed by reinforced concrete seals or other suitable means.

Recommendations of technical assessor1. Sanctity of mine boundary: Vertical barriers in different seams to be maintained with

adjacent mines. Where such barriers do not exist protective measures to be adopted.2. Embankment: Guidelines regarding foundation design, material of construction, nature of

slope, and procedure of construction to be laid down. There is need to do so.

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3. River channel: Due to mining of several seams the ground level adjacent to river courses has been lowered. This needs to be considered.

4. H.F.L: The river cross-section changes with mining activities. Therefore, HFL also changes. This aspect should be paid due attention.

5. Abandoned pits: All abandoned pits or pits proposed to be abandoned should be properly secured at collar level.

Appendix 6DGMS (Tech) Circular No. 04 of 2005 Dhanbad dated the 18th May, 2005Subject: Recommendations of Godavarikhani No. 7 (LEP) Court of Inquiry,To,Owners, Agents & Managers of all belowground Coal MinesThe Court of Inquiry appointed under Section 24 of the Mines Act 1952 to inquire into the cause and circumstances attending the accident that occurred in Godavarikhani No. 7(LEP) colliery of M/s Singareni Collieries Co. Ltd. on 16th June,2003 causing loss of 17 lives due to inundation, had made, inter-alia, the following recommendations:-1. As it is not possible to check the efficacy of stowing once the mouth of a gallery or mouth of a district is filled with sand, it is essential to device a system to ensure proper effective stowing and fix the accountability. It is recommended that the Asst.Manager and Overman, apart from the Surveyor, should record the actual amount of void filled up together with the efficacy of the stowing. When stowing in a district is completed, the Asst. Manager and Manager should certify in writing the actual status of stowing in the district. The volume of sand stowed in should invariably be recorded at the time of closing the District.2. Before starting a new district, clearance from the Internal Safety Organization must be taken in writing by the local mine management.3. Detailed planning for production in different districts must be done at corporate level and projections given should not be altered at the mine level.4. Owners must monitor important Safety functions, including stowing in districts at regular intervals.5. Safety in mines is a very complex phenomenon and support from the highest quarter is needed for implementation of safety measures in the mines. If the person with the maximum power does not have the highest responsibility for safety, there is always a possibility of miscued stress on the production, sometimes at the cost of safety. So it is recommended that the Chief Executive or the company should be nominated as the owner under Section 76 of the Mines Act, 1952.6. Key personnel in the mines like agents, managers and Surveyors, who have a strong bearing on the safety in mine, should not be transferred frequently. Before positing such key personnel due diligence should be undertaken to ascertain the suitability of the persons for the post, so that they do not have to be transferred after a short time except on rare occasions.7. During our deliberations we were of the view that information technology could be used for efficiency, increasing production and also mine safety. But we are of the view that this is altogether a different subject, although we are convinced that information technology can be used for mine safety, but it needs a details study and experts need to be grafted into a study team, which could study the subject. Singareni Collieries are being operated by adopting the old age methods of mining almost 100 years and there are not significant changes either in management or in mining. Information technology is being used successfully in every filed. Therefore we have no doubt in our mind than it proper information technology is used mine would be much safer. Proper implementation of this recommendation can bring about definite improvement in the safety standards in the mines, especially against the danger of inundation.You are requested to take suitable steps to implement the above-mentioned recommendations of the Godavarikhani No. 7(LEF) Court of Inquiry in all mines under your control.

APPENDIX 7Method of Examination following a Colliery Explosion

By

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F.V.Tideswell(Abstract of paper read before the Midland Counties Institution Of Engineers at Nottingham,

April 23, 1952)It is important that during early operations of rescue and recovery, no vital evidence should be destroyed, or opportunity to make valuable observations lost. One of the rescue team members should be deputed to record immediate observations and mark objects necessarily disturbed.The special investigation team should follow as closely as possible, without interfering with the recovery. Finally, early collection of evidence from witnesses may assist the actual underground investigations and vice versa.

General observations on mine explosionsAlmost every recent explosion has begun by ignition of firedamp; within the last 20 years only two have been ascribed to direct ignition of coal dust, though coal dust has seriously extended the spread of explosions on many occasions. The explosive combustion may be initiated by a wide variety of causes and once initiated continues as long as medium remains inflammable. The effect is development of heat energy concentrated in the flame. The flame provides a continuing igniting source, enabling the explosion to eat its way through that part of the medium yet unburnt. The expansion due to heat develops pressure which pushes equally against the gas already burnt and that remaining unburnt. The actual movement of gas depends on how free it is to move.If we take a simple and common case, that of a firedamp-air mixture ignited at the face of a heading; the expansion can only push the flame front and the unburnt gas forward, and the flame advances at a speed compounded of its speed through the inflammable medium and that of the medium itself. Thus a flame tends to accelerate when passing from a closed to an open end. Conversely, a flame moving from an open towards a closed end moves more slowly and steadily and the movement of gas is greater behind the flame than in front. Thus release of pressure in front of the flame accelerates the flame; behind the flame retards it.Even with an explosion which has started near a closed end and is spreading outbye, there may be considerable movement of burnt gas back from the flame towards the source of ignition. This is particularly marked if the explosion increases rapidly in intensity and pressure. Finally, as the burnt gases cool behind the flame, there is a general contraction which tends to pull the flame back; this is usually less violent than the forward and backward pushes we have already considered. These movements are of importance in considering the significance of displacement of material in an explosion, and of deposition of coke.The same considerations apply when coal dust takes part.Generally a coal dust explosion is started by one of firedamp. If the layout is such as to cause a violent blast of air in front of the flame (and it often is) and this blast raises a cloud of dust significantly rich in coal dust to be inflammable, then the firedamp explosion will ignite the cloud of dust and a coal dust explosion will follow, and will continue to propagate until the composition or the density of the dust becomes unfavourable. The change in conditions of cloud tending to extinguish the flame is unlikely to be sudden and the extinction of a coal dust explosion by a deposit of stone dust must be regarded as usually a gradual process.The dimension of the dust cloud formed ahead of the flame depends on the effective expansion (in that direction) of the exploding medium upto that point. The spread of flame of a firedamp air mixture on burning may be upto seven the original spread of the mixture. In the road layout of a pit, such long projections of flame are unlikely to be realized, and three to four fold projections or less are more likely. For dust explosions, where the coal dust is diluted with stone dust, a much lower projection ratio is to be expected.The main effects of explosion are:

Blast – causing disturbances and damage extending often

Burning – the spread of flame is customarily taken as defining the extent of explosion.

Afterdamp – the products of combustion mainly CO2, and CO, steam and nitrogen, with smoke and dust, which first fill the area traversed by the flame, are sucked back on cooling to occupy a volume of the order of that of the original explosive medium, and then diffuse or are blown through the workings forming as great a dander as the original explosion.

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Differentiation of firedamp and coal dust explosionThis differentiation to some extent is artificial, for there is every gradation from purely firedamp explosion to one of a coal dust explosion alone. A dust cloud not inflammable in itself may be made inflammable by the presence of firedamp in less than the concentration needed for its own inflammation (5%). It is convenient to regard firedamp explosions those where the gas-air mixture can propagate the flame without the assistance of any coal dust; as coal dust explosions, those where gas is not so sufficient, but the dust cloud by itself is capable of carrying on the explosion; and as joint gas-dust explosions, those where neither is adequate by itself. In a mine explosion, any or all of these may occur at different stages of explosion.It is not possible to say merely by examination of the residues left whether an explosion is one of coal dust or whether it has been carried on mainly, or in part, by firedamp. What can be done is: To establish the path and spread of the explosion;

Observe closely for evidence of presence of inflammable dust in sufficient quantity in the air during explosion, indicating that in the absence of firedamp, coal dust could have propagated the explosion;

Estimate the possibilities of presence of firedamp. It is then usually possible to estimate, with some certainty and moderate precision, the parts played by firedamp and coal dust respectively in propaga6ting explosion.

In making such an estimate, the quantitative as well as qualitative aspects must be considered and due regard must be paid to different mobilities and geographical accumulations in the mine of coal dust and firedamp. The salient features of coal dust are:

It is likely to be distributed more or less uniformly along the potential path of the explosion;

it may be dispersed progressively by the advance blast of explosion, giving a dust cloud filling a much longer length of roadway than was covered by the original deposit, so that a succession of isolated accumulations of coal-rich dust may be as dangerous as a more uniform deposit;

the wide range of concentration over which a cloud dust is inflammable, ranging from low value of one twentieth ounce per cubic foot (if pure coal) to one hundred or more times that value. Consequently, if a sufficiently coal rich dust is present, the chance of the flame of explosion finding a continuously inflammable cloud in its path is great.

On the other hand, as regards firedamp:

its occurrence in high concentration is usually local;

Being a gas, it is swept along with the air ahead of the explosion and intimate mixing of gas and air originally in consecutive long lengths of road cannot be expected;

the explosibility of mixtures of methane in air changes rapidly over a narrow range of concentration rising from nil to maximum and falling again to nil as the proportion of methane rises from 5 to 15%. Thus it is unlikely that any long length of roadway will offer a continuously inflammable firedamp-air mixture to an advancing explosion, unless it was nearly uniformly fouled initially. These considerations provide one reason why explosions of firedamp do not usually spread so far as of coal dust.

Detailed Examination undergroundThe tracing of the course of a mine explosion to its source and determination of its nature are difficult. There are two complementary methods of approach. One, the intuitive approach, is based on experience and knowledge of the pit and of the mining operations in progress; the other, the analytical approach which it is the peculiar duty of the scientist to follow, is based on a dispassionate survey of all evidence recoverable. Both approaches are needed and must be related.Main types of observations made concern:

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Violence – This may be bursting of doors or air-crossings by pressure, or the bending of weak, locally fixed objects by dynamic pressure of the blast, but it is mainly due to movement of objects by blast and their subsequent sudden arrest.

Heavy falls of roof are not signs of great violence. The nether roof may be lifted by the explosion pressure, or its weight eased enough to loosen the supports and allow these to be blown out. Generally arches, props and girders are pushed in the direction of the forward blast of explosion but the contrary is often seen, interspersed with the former. A series of bendable structures, e.g. signal supports or conveyor supports, bent consistently in one direction is a useful indication of the direction of forward blast of explosion but can be misleading, because if the explosion passes from a mild to an intense stage, a stronger blast may run back from the flame.The best guide to the general direction of spread of explosion is movement of heavy objects, machinery, loaded tubs and heavy girders. These, if free to move, are progressively accelerated by the forward blast of explosion and because of their inertia they are not too seriously affected by the return forces, unless these are unusually strong. Light objects are untrustworthy guides since they are at the mercy of small subsidiary forces.It is desirable that any evidence of motion or bending should be separately and factually recorded on the plan rather than that a general indication should be given expression of the direction of force. It is often taken as a general guide that the evidence of violence is least marked about the origin of the explosion. This is not invariably true, for the area may be traversed subsequently by severe blast from the explosion as it intensifies. Movement damage is greatest in the long roads and particularly when approaching release of pressure, but high pressure may also build up there.

Evidence of burning – Generally evidence of flame is quite hard to find; the flame passes so rapidly that heavy material is not noticeably affected. The materials most sensitive to flame are the fibrous edges of torn paper, string and cloth, the raised pile of textiles, the finest fibres of torn wood and hair on human skin. Eye is a poor judge of signs of burning. A good magnifying glass is a help but it is usually necessary to examine the object under microscope. A positive sign of scorching, however small, is a reasonable assurance that flame has passed. Absence of scorching does not prove the contrary. Loose scorched paper should be noted.

Generally serious burning is found towards the points of extinction of the explosion where heated material has access to air sucked in again as hot products of explosion retreat. Coked dust – When a flame passes through a cloud of coal dust there is left a residue of

partially or heavily coked dust, which is ultimately deposited in the roadway. If the cloud is dense, the coal dust pure and from a coking coal, and the explosion slow, very heavy deposit of coke may be found in the roadways. But if the cloud is fairly thin and the coal dust well diluted with stone dust, and not of good coking coal, then massive deposits of coke will not be found. Particularly in a straight and comparatively smooth roadway and with a medium to fast moving flame, it may be difficult to find any evidence of deposition of coke though the explosion is known to be one of coal dust. Thus the absence of obvious deposition of coked dust is not a proof or even an indication that coal dust has played no part. Coked deposits have three origins:

i. Coal dust accumulated during normal working of the pit and coked insitu. This gives useful evidence of availability of coal dust and the passage of flame over it; such deposits usually show a thin crust of coke resting on almost unheated dust;

ii. Coal dust disturbed by explosion blast, in advance of flame, impacted on surfaces and coked there; generally found quite near the source of dust – a loading point, a filled tub; again there is a thin crust of coke;

iii.A coal dust cloud through which flame has passed and from which hot plastic particles have been subsequently deposited as a nearly homogeneous deposit, which may be loosely spattered, or a coherent crust, thick or thin. As a rule, when the flame is moving

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steadily, or accelerating, this coked dust is thrown back by the flame and deposited consistently on surfaces facing in the direction the flame has gone.

Samples of all deposits should be collected and examined under microscope.

Explosion dust –The deposited coked dust is a special case of what we call ’explosion dust’. The blast of the explosion raises ahead, in and behind the flame, a cloud of dust, only a part of which is traversed by flame. This dust settles after the explosion has died down. This dust is interesting because it gives the composition of the dust dispersed during the explosion. It is often clearly recognisable as a bulky deposit on what would normally be clean surfaces. Like paper, it is found nearer the origin of the explosion than where it was when burnt.

Explosion dust may divided into four classes, in order of deposition:

Thermal deposit, an immediate deposit of fine dust from a hot medium on to a cold surface;

Gravity-settled, or impacted, coarse dust, merging into;

Gravity-settled fine dust;

Slowly deposited ultra-fine dust, e.g. soot-like streamers;Thermal deposit is the dark, smoky deposit often seen on stone sides and roof and often taken to be evidence of passage of flame.The sooty streamers which at first sight appear to indicate the presence of heavy, tarry smoke and hence flame, are essentially composed of extremely fine and often unburnt dust whose aggregation is doubtless assisted by steamy warm conditions, and they are found in stagnant places where they can slowly aggregate and settle. The light-brown dust which sometimes forms a crackled surface on the floor is doubtless similar. Neither should be regarded as a sure sign of passage of flame.Composition of road dust –It is customary to take strip samples from the roof and sides, and floor over every 50 yards of the affected area and beyond, with a view to assessing the composition of the road dust available to the explosion. Excluding the regions of heavy falls, or of upsetting of coal in transport, such samples do give a rough guide to the general composition of the road dust before the explosion. In some explosions, however wide differences have been observed between the composition of the road dust as disclosed by statutory sampling and the composition of dust cloud raised by the explosion, the latter being much richer in combustible content due to preferential raising of coal dust.Collection of specimens and samples – The observing and collection of samples is best dealt with by staff specialising in such matters. Dust samples may be taken in envelopes but preferably in tins or tubes. Specimen of any kind suspected of showing coked or scorching should be guarded against crushing.

Broader ExaminationEvidence of the presence of firedamp – It is seldom that there is factual evidence of the presence of firedamp immediately before the explosion. On the other hand, the nature and previous history of the place (e.g. a waste or a heading left unventilated) may be such as to lead unreasonably to assumption that an explosive gas mixture was present. But the where history or circumstance does not suggest the occurrence of gas in dangerous proportions, a search may be made by drilling or by examining adjacent areas for possible feeders of gas. The occurrence of firedamp in the afterdamp left by the explosion is not necessarily proof that gas was there before, neither is a continued make of gas after explosion, for the disturbance of the strata by the explosion may release gas previously not accessible. They are, of course, evidence that gas was near at hand and may have been present.Search for possible sources of ignition – It is not often that there is immediate and clear-cut evidence of means of ignition. The general investigation may have led towards and narrowed down the likely place of ignition, where search for a cause may be concentrated, but it is usual and preferable additionally to survey carefully the whole of the affected area for possible source of ignition. All lamps and electrical equipment are withdrawn for examination (unless heavy and found satisfactory by examination on the spot), other

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possible causes of ignition looked for include explosives, compressed air equipment, cutting and other mining operations, mechanical faults, fires, contraband.Position of equipment and victims – The positions of victims and equipment in relation to what might have been expected in normal work may yield valuable information not only as to the operations being carried on but also unusual happening about that time. The posture, injuries, burns and carbon dioxide poisoning of victims may give evidence regarding the course and nature of explosion.General – By the time the results of preliminary examination have been collated, it is usually possible to reach a reasonably based interim hypothesis as to the cause and nature of explosion. Before a final conclusion can be reached it is necessary to consider the results of detailed examination of all specimens and observations and to test impartially the favoured and other hypotheses in the light of this full evidence. Only thus can the explosion be reconstructed with any assurance.

ExerciseQ.1: State statutory provisions in respect of Emergency plan and sketch of accident site.

(First Class, 2000, 2002)Q.2: Draw a scheme of emergency plan for a large belowground mine having dangers of inundation and fire.

(First Class 2001)Q.3: Inundation happens to a major hazard in belowground workings. As a manager, what action would you take to identify and eliminate this hazard from your mine? Draw an action plan for the same.

(First Class 2005)Q.4: In an underground mine, the overman has reported probable explosion in a mechanised development district and 16 persons are missing. Draw a list of action in order of priority that you would take to deal with emergency and rescue/ recovery of missing persons.

(First Class 2004)Q.5: What are the statutory provisions relating to “Emergency Plan”? Briefly explain the essential elements of a good emergency plan and their rationale. How will you incorporate modern technology advancements into emergency plan for a large colliery with belowground workings.

(First Class 2005)

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CHAPTER 4

RISK ASSESSMENT AND RISK MANAGEMENT

Objective of risk management: It aims to reduce the likelihood and impact of mishaps of all kinds, reduce the inherent potential for major accidents which could kill or injure persons or cause production and profit losses. Ninth Conference on safety in mines recommended that risk management should be used as a tool for development of appropriate health and safety management system.

Some important terms

Risk is the chance of some thing happening that will have an impact on objectives. The objectives may be to produce mineral at a reasonable cost and with good productivity and safety etc. Therefore, any happening that affects adversely the production, productivity or safety will be termed as “risk”. In the context of mine safety management, the term ‘risk’ will have a limited meaning as anything happening that will have adverse effect on safety of the persons and of the mine.

Risk is measured in terms of consequences and likelihood.

Risk= Cosequence x Probability x Exposure.

Where

Consequence is the degree of harm by the hazard;

Probability indicates the chance of harm;

Exposure means how often and how long are the persons exposed to hazard when talking of safety.

Hazard means a source of potential harm or a situation with a potential to cause harm, for example, inaccurate surveying is a hazard causing the risk of inundation.

Tolerable risk: A risk that we are prepared to live with so as to secure certain net benefits in the confidence that is being properly controlled, kept under review and further reduced as and when possible.

Risk analysis: The use of available information to estimate the risk to individuals or property or the environment from hazards.

Risk assessment: The process whereby risk management priorities are evaluated.

Risk Management: The systematic application of management policies, procedures and practices to the tasks of identifying, analyzing, assessing, treating and monitoring risks

Steps involved in preparation of RISK MANAGEMENT PLAN

Risk Assessment

Risk assessment is to be performed on a regular basis. The goal for each risk assessment session is to identify hazards, determine risk ratings and controls, and to review the implementation of risk controls from previous risk assessment sessions.

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The following workflow diagram illustrates the areas involved in performing a risk assessment session.

Risk Identification:

This is the process of identifying hazards and their causes and determining what, how and why things may go wrong. All major activities being carried on like mine design, surveying, excavation, blasting, support, stowing, loading, transport, coal dispatch, generation, transmission and use of electricity, traveling etc. are considered to find out hazards. A list of all possible risks is generated using brainstorming sessions, check lists, fault tree analysis etc. Past accidents and incidents like fires, inundations, major roof falls, overwinds, occurrence of gas etc. may also be considered to have an idea of the hazards/risks.

Normally the best process is to proceed step by step through a task. A number of other processes can also be utilized like –

Previous experience of accidents or occurrences in the mine. Work process evaluation. Consultation with the employees who may have experience in the job. Advice from consultants. Fault tree analysis to determine underlying issues and hazards that might not be evident at first glance. Safety statistics of the mine and of the adjoining mines. Incidents and near miss accident reports. Inspections of the mine.

Notwithstanding whichever method is used for identification of hazards, they should all be noted down so that a record of their existence is kept.

Some examples of the hazard identification are given below:

1. Activity: Support design and execution

Hazard: Inadequate support design and inadequate support.

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2. Activity: Travelling

Hazard: Improper maintenance of traveling roadway

3. Activity: Transportation of coal by conveyor

Hazard: Improper laying of conveyor.

Assessment of Risk and Ranking

The process of risk ranking is carried out by considering both the likelihood of the occurrence of each hazard and potential consequence should the hazard occur.

The values used for likelihood, consequence and exposure or probability need to be agreed by risk assessment team. It is, therefore, very important that members of the team are knowledgeable and experienced persons

As has been mentioned in the very beginning

Risk score = Consequence X Probability X Exposure.

Following values may be used:

Scale of Consequence

Several dead 5 One dead 1

Significant chance of fatality 0.3 One permanent disability/ 0.1

less chance of fatality

Scale for exposure

Continuous 10 Frequent (daily) 5 Seldom (Weekly) 3 Unusual (Monthly) 2.5 Occasional (Yearly) 2 Once in 5 years 1.5 Once in 10 years 0.5 Once in 100 years 0.02

Scale for probability

May well be expected 10

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Quite possible

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Unusual but possible 3 Only remotely possible 2 Conceivable but unlikely 1 Practically impossible 0.5 Virtually impossible 0.1

An

Example of Risk assessment and action

S.No. Hazard Risk Consequence Probability Exposure Total risk1 River Inundation 5 10 10 5002 Roof

supervisionRoof fall 1 7 5 35

3 Sulphur in coal

Spont. heating

5 3 10 150

4 Haulage Runaway 1 7 10 705 Blasting Fly rock 5 5 7 175

Treatment, Control and Action Plans

Examine high priority risk Consider various steps

Elimination e.g no blasting Substitution Separation Administration: reduce exposure Training Personal protective equipment

The team should develop an action plan recommending:

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Actions Responsibility Time frame

Training Monitor Review/audit

Conclusion

Management of safety issues based on assessment of risks not only integrates safety with productivity but also can be used as a very good tool for reduction of costs. The systems stand on the premise that all risks need not be eliminated and different control measures can be adopted for different levels of risks. The key here is to aim for ALARA (as low as reasonably achievable), which eventually depends on cost considerations. The system allows prioritisation of allocation of scarce resources thereby cutting costs and reducing wastages. This assumes great importance in the current Indian scenario.

The other merits of the system are that it is created by the mine operators themselves through considerable brainstorming. This approach let the mine operators/users feel ownership of the system, something that is not cast upon hem by experts, Govt. agencies or outsiders, and hence chances of successful implementation is much more. In this system, grey areas are minimized; responsibilities for action are pinpointed and scopes for auditing and improvements are always present.

Exercise

Q.1: Write short notes on “Risk Management”

(First Class 2002. 2003)

Q.2: Discuss Safety management plan vis-à-vis safety in mines.

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Chapter 5Underground MiningA. Longwall Mining

Longwall is the future of underground mining in India. Attempts have been made from time to time to extract seams by this method without much success. The failure has been either due to collapse of faces, strata control problems or poor productivity due to various factors. The causes of failure can be summarized as follows:

Poor planning.

Absence of total system approach.

Mismatch of equipment to the geotechnical environment.

Presence of hard strata posing problems of caving.

Inadequate coal clearance facilities.

Non-availability of spares.

Non-availability of workshop facilities.

Improper machine maintenance.

Non-availability of new panel due to poor development drivage.

Inadequate machine maintenance of machines and supports.

Lack of trained manpower.

Lack of experience.

Action/ strategies for success of Longwall mining in India Selection of suitable supports If we look at the history of Longwall mining in India, we would find many pitfalls. And the reason is that before starting these faces, adequate study was not carried out to estimate the load that would be coming on the workings at different stages (e.g. before and during first weighting and then during periodic weighting), inadequate support resistance, inadequate or no monitoring of important parameters like convergence, load etc. In order to estimate load at different stages, it is essential to study physico-mechanical properties of coal measure strata. In this direction we should know the mechanism of loading of face. When a longwall face is worked by caving, immediate roof should cave in the void. The

success of longwall mining depends on cavability to a large extent. What is cavability?

A roof may be considered to be ideally cavable when the following conditions are satisfied:

The overlying rock fills in the goaf as soon as the supports are withdrawn. The fallen rock debris fill in the goaf behind the last row of supports completely.

For complete filling of goaf by debris, a sufficient thickness ‘t’ of overlying roof should be involved in the caving process. The value of ‘t’ may be worked out from the following relationship:

t = h/(k-1)Where h = height of extraction;k = bulk factor of roof strata.With k = 1.2, t = 5 h; with k = 1.5, t = 2 h For hard and massive rocks, k = 1.2 and hence immediate roof upto 5 times the height

of extraction should be considered. However it would be safer to study the rocks up to 10 h.

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Another very convenient method is to assess the cavability on the basis of data collected from B&P depillaring panel. The area extracted in depillaring panel may be taken as measure of cavability. The value of cavability index ‘I’ and the exposure necessary in B&P depillaring before the occurrence of first weight.

Influence of depth on cavabilityThe depth has got a role to play in inducing caving. The immediate roof rocks in advance of the face are subjected to front abutment pressure which is proportional to depth. In case the depth is high, the rocks are subjected to higher abutment pressure which produces minute cracks in advance of the face. Such cracks have generally not been noticed in any of the Indian faces with depth less than 200m but have been observed at depth of around 300m and above. It has also been observed that rocks with comparable cavability index exhibit better caving behaviour at greater depths. However, it has not been possible to quantify the influence of depth on caving indices developed by CMRI.

Assessing support requirementsStudy of collapsed faces in Indian mines showed that after start of the face, the immediate roof of shale was caving in the goaf after an advance of 8 to 12 m. The caved shale, however, in most of the cases did not fill up the goaf due to inadequate thickness. The overlying bed of sand stone hanged in the goaf over a considerable span till the stresses in the rock beam due to its own weight exceeded the strength of sandstone bed and rock beam started fracturing throwing heavy weight on supports and solid coal ahead of the face. The support system of any longwall face should be such that it may be able to offer reasonable working conditions during period of weighting. Taking convergence as the objective criterion of roof condition, the support resistance should be so arranged that that the convergence is kept within acceptable limits. Analysis conducted by CMRI at various faces indicates that with roofs of complete shale and sand stone normally met in our mines, good maintenance of roof is achieved when the convergence does not exceed 60 mm/m per m advance. When convergence exceeds 80-mm/m face advance (corresponding to a change in roof slope of approximately 70) continuity of roof gets lost and dislocation starts occurring. With convergence exceeding 160 mm per m of advance (corresponding to a roof slope change of approximately 90) roof falls may occur leading to collapse of the face. These limits would not apply to less compact and friable roofs.1. CMRI Methods

(i) Caving index I’ = t0.6(m)n

Where t = thickness of strong bed (m) = Uniaxial compressive strength (Kg/cm2) m = (RQD+10)/100 n = A factor the value of which depends on the value of RQD of strong bed. The value of n=1.1 to 1.3.

(ii) Cavability index-I = Lnt0.5 5

Where = Compressive strength (Kg/cm2) L = Average length of core (cm) t = Thickness of strong bed (m) n = 1.2 for uniformly massive rocks with weighted average RQD of 80 % and above; in other cases n = 1This method gives better results than the first method.The support resistance needed at longwall face would mainly depend on

Height of extraction. Cavability of overlying roof and nature of immediate roof. Position of strongest bed with respect to coal seam.CMRI has given monograms indicating support resistance required for different values of cavability index for various heights of extraction.Capacity of Powered Support = R x S x S2 x K1 x K2

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------------------------ nWhere R =Effective support resistance S = Span at Longwall face S2 = Spacing between members of support system K1 = Factor to take care of span variation (1.2) K2 = Factor to compensate for leakage and low setting load (1.1) n = Efficiency (0.8 to 0.9)Example:If R == 80 (from Nomogram) h = 2 S = 4 S2 = 1.2Then Capacity = 80x4x1.2 ------------- 1.2x1.2 == 600 tonnes 0.8

Ground movement monitoring in longwall mining

It is necessary to monitor ground movement. For this, convergence in the gate roads, location and magnitude of front abutment, stress in barrier pillars which indicate side abutment, closure and pressure changes in the support legs need to be monitored. Instruments required are:

Magnitude and location of front abutment: For this purpose, Stress gauges (e.g. vibrating wire stress gauges or VWS gauges) can be installed in boreholes of suitable length ahead of face from the gate roadways. The holes should be parallel to the face and about 12 m long.

Side abutment: The side abutments can be measured by VWS gauges installed in bore holes made in the barrier pillars similar to those for front abutment monitoring.

Gate road deformation: Spring Anchor wire extensometer (SAWE) can be used along with Convergence recorders to monitor gate road deformation.

Closure and pressure changes in supports A few Powered supports preferably one in the center of the face and other on either side can be selected. The closure of individual leg of the support can be measured using leg closure indicator. The pressure of the hydraulic fluid in the legs can be measured using the pressure gauges provided on the powered supports.

Hard Roof Management in longwall mining

Many longwall faces have failed because the roof did not cave in regularly and easily. The cavability of overlying roof rock depends on:

Massiveness of bed vis-à-vis band density. Strength of beds. Uninterrupted thickness of bed involved in caving vis-à-vis presence of shale or

coal bands. Porosity, permeability clay content, grain size and shape of overlying rock

mass. Depth of workings. Length of face.Of the above six parameters, the most important parameter affecting cavability in Indian mines is the un-interrupted thickness of bed involving caving.

Recently trials have been made to induce caving successfully by blasting from the surface in the target strata or by hydro-fracturing.

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B. Extraction of pillars by caving method using continuous miner and shuttle car combination

A permission letter for extraction of pillars by caving method using continuous miner and shuttle car combination contains standard conditions like those required under (a) Regulations 100(5) read with DGMS technical circular 2 1988 regarding precautions against air-blast, Regulation 112 (1) (c) regarding fencing, (b) Regulation 118 A (1) regarding formation of panels, (c) Regulation 118(3)(c) regarding inspection of isolation stoppings and (d) DGMS circular No. 4 of 1988 regarding subsidence survey. Conditions regarding manner of extraction comprise the most important part of the permission. The conditions may include the following:

i. Geological mapping of the panel shall be done to delineate presence of geological disturbances in advance. Such disturbances shall be provided with additional supports.

ii. Remote umbilical cord control shall be provided on the continuous miner so that persons shall be employed under supported roof only in the slice under extraction.

iii. Each pillar shall be divided into two equal halves by driving a split not exceeding 6.6 m in width and 4.5 m in height. Each half pillar so formed shall be extracted by driving slices at an angle of 600 with respect to centre of the split gallery. Such slice shall not exceed 6.6 m in width and 4.5 m in height. A rib of about 2 m thickness shall be left between slices. This may be extracted judiciously while retreating.

iv. The first slice in the half pillar shall commence at least 5 m away from the corner of the pillar, so however that in case of an overhanging goaf the distance may be increased to 7 m.

v. The maximum cut-off distance in split and slice shall not exceed 14 m and 10 m respectively.

vi. Extraction shall be restricted to minimum pillars at a time such that only one pillar shall be under splitting and only one under actual extraction at a time.

vii. Line of extraction shall be straight.viii. Extraction of pillars shall commence from the dip and proceed systematically to the

rise.ix. Once extraction of a slice commences, the continuous miner shall work non-stop till

the extraction of slice and rib is completed. In case the continuous miner stops for more than 2 hours due to breakdown or other reason, extraction shall not commence unless the stability of the slice has been evaluated and found satisfactory.

x. DUST CONTROL: Cutting of coal shall not commence unless water-spraying arrangements at the cutting picks is provided, maintained and is working. Suitable mechanism to interlock the operation of water spraying and cutting shall be provided and maintained at all times.

xi. OPERATION AND SUPERVISION: Each shift shall be under the supervision of an assistant manager. The maintenance shift shall be under the charge of an experienced engineer. The Continuous miner and shuttle cars shall be operated by specially trained competent operators.

xii. STRATA CONTROL and ground movement monitoring shall be kept under the supervision of an assistant manager.

xiii. MONITORING: Scientific body having expertise and infrastructure shall be engaged for monitoring strata behavior including caving characteristics, load on supports and stresses developed over the pillars and suggest corrective measures.

xiv. STRATA MANGEMENT PLAN including detailed scheme monitoring shall be drawn out in consultation with a scientific body. Rotary tell-tales at every junction and convergence indicator shall be installed at every alternate pillar along the central heading and other critical places. Stress capsules shall be placed to assess

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the development of load in pillars. Caving behaviour may be studied with the help of multipoint bore hole extensometers.

xv. Standard operating procedures for installation, operation and maintenance of face machinery and equipment shall be framed based on the concept of risk assessment and shall be adhered to.

xvi. A contingency plan for withdrawal of continuous miner safely in case of aBreakdown or stoppage due to fall of roof or other reason shall be famed and put into operation when required.

C. Working under adverse geo-mining conditions

Great depth, geological disturbances, highly gassy seams, susceptibility to spontaneous heating, thick seams, hard roof that is difficult to cave and waterlogged workings or water- charged strata above are some of the conditions which make mining complex and pose safety problems.

(a) High Depth: Higher strata load and stresses may pose problems of ground control. Proper planning requiring design of workings and adequate supports including immediate support of roof and strata monitoring should be paid attention to. Higher depths are associated with high strata temperature. Geothermal gradient in our coalfields is 10 C for every 36 m. Temperature at a depth of 18 m is 27.20 C. At higher depths higher ventilation standards should be aimed at. If temperature is very high, spot coolers or air conditioning may have to be done.

(b) Geological disturbances:While preparing support plan, additional supports should be provided for working in the vicinity of geological disturbances. Higher gas emission may be expected near faults and sills or dyke. Advance boreholes should be drilled. Water from higher horizons may be expected along geological disturbances. Possibility of waterlogged workings coming in line of the present workings may be carefully examined.

(c) Gassy seams:During development, level and dip headings should be driven. Extraction by stowing should be done in degree 3 gassy seams. Blind headings should not be allowed to exist. If there are any blind headings, air should be kept coursed.

(d) Seams liable to spontaneous heating:Development should be done strictly on panel system. As far as possible, extraction may be done with stowing otherwise goaf may be kept flooded with nitrogen. Environmental monitoring for CO, CO2 should be done with continuous monitoring system. Firefighting and sealing arrangements should be provided. Emergency plan should be prepared and rehearsed. Oxygen type self-rescuers should be kept at strategic places. Telephonic communication should be provided. Escape routes should be provided and clearly marked belowground.

(d) Extraction of thick seams :Extraction of thick seams poses strata control problems. A large amount of coal is lost in partings between different sections and also in goaf. This poses serious problem of spontaneous heating. Any method of extraction of thick seams should address these problemsRecent methods like sub-level caving, integrated sublevel caving, hydraulic mining or blasting gallery method should be adopted. Where there is chance of spontaneous heating goaves may be kept flooded with Nitrogen. There should be continuous monitoring of

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environment. Monitoring of parameters like strata load / pressure and convergence should be carried out.

(f) Hard roof, difficult to cave:If extraction is done with caving, then measures such as induced blasting, hydro-fracturing may be carried out to bring down massive roof during extraction. Precautions as per DGMS Circular No. 2 of 1988 may be taken. Convergence recorders should be used. An imminent fall is indicated if C1/C2 is more than 2.Where C1 is daily convergence on day n;C2 is average daily convergence upto day n-1. Induced blasting and hydro-fracturing are of great help in dealing with such conditions.

(g) Working under water:While working below water-charged beds additional pumping capacity should be provided. Development should be done by driving levels and rise galleries. For extraction below waterlogged goaves/ workings it is ideal to making such goaves and workings dry. Otherwise extraction should be done by noneffective (NEW) method. Width: Depth ratio of the panel should not exceed 0.3 to 0.5 (Generally 0.4). The width of panel barrier shall not be less 10 times the height of extraction or 0.15 times the depth, whichever is more.If full extraction is done by caving then, the value of tensile strain in the bed of waterlogged workings/ goaf shall not exceed 3 mm/m. Value of tensile strain may be estimated by following formula:

e = 0.35 X t / DWhere e = Tensile strain in mm/m t = Thickness of extraction in mm D = Parting between the waterlogged workings and the seam under extraction. In case extraction is done with stowing, the value of strain may be taken as 15 % of the value obtained by above formula. Please note that this is a rough formula for estimation of the tensile strain.

(h) Working over goaved out seams: Following difficulties are likely to be encountered:

Upper seam gets damaged and hence there may be difficulty in proper planning of haulage layout.

Problems of strata control in view of broken/ disturbed roof. Rise side workings may contain water and CO2 that may enter the upper

seam workings through cracks. Roof may be disturbed near panel barriers in lower seam.

If upper seam is virgin and parting is more than 12T (where T is the thickness of extraction in lower seam), there may be no difficulty in working upper seam. If upper seam is standing on pillars then safe parting may be taken as 100T.If extraction is done with hydraulic stowing, the formula may be modified taking shrinkage of 15 %.

(i) Working under fire area:The most common problems associated with extraction below fire areas include those due to noxious gases. Following precautions / steps should be taken for safe work:

Permission should be taken from DGMS if the parting is less than 10 m of hard cover [Regulation 122 (1) (c)]

Ventilation of lower seam should be independent of top seam fire area. Forcing system of ventilation should be adopted. The area should be free from fault planes so that fire does not travel along the fault

plane.

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As far as possible extraction below fire area should be done with sand stowing. Caving may be done if the parting is more than 15T and the parting is free from carbonaceous matter.

Continuous monitoring for noxious gases should be done.

ExerciseQ.1: A moderately thick seam at shallow cover is proposed to be extracted for the first time in a mine by longwall powered support. How would you make a statutory application for the extraction and what informations are required? (First Class 2002)Q.2: Draw up conditions for use of:(a) LHD(b) Belt conveyors belowground (First Class 2002)Q.3: What are the statutory requirements before abandonment of belowground workings? What are dangers from such workings and how can it be reduced? (First Class 2002)Q.4: A seam, 4 m thick and dipping at 1 in 12 is proposed to be worked by longwall caving. Describe the preparatory work needed and prepare an application seeking permission under Regulation 100 A of Coal Mines Regulations, 1957. (First Class 2000)

Q.5: An 8 m thick seam (third degree gassy) dipping at 1 in 7 is being extracted in 3 lifts by Bord and Pillar method with sand stowing. While developing second/ third lifts over sand, some of the faces give out large volumes of inflammable gas for several weeks. What are the possible reasons for gas emission? State the dangers involved and precautions to be taken during development.

(First Class August 1999)Q.6: Draw a scheme of safe operating practice with continuous miner. How would you implement it?

(First Class 2002)Q.7: What are the safety problems associated with working thick seams by underground methods? How can such problems be solved?

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CHAPTER 6OPENCAST MINING

General Safety Problems associated with opencast minesProblems associated with mechanized opencast mines are as follows:Technical problems

i. Slope stabilityii. Blasting related problemsiii. Transport related problemsiv. Those arising from machine operations.v. Miscellaneous problems like fire, inundation or even coal dust explosion in

opencast mines quarrying out formed pillars.Administrative problemsThese include those arising from deployment of contractors’ workers.

In this chapter it is proposed to deal with the problems of slope stability.

Slope stability

In opencast mines, the sides are kept sloped or benched for ensuring safety against slides. Slope designs have impact on safety as well as economy. Steeper slopes favour economy but adversely affect safety. A balance has to be struck between safety and economy.Types of slope failures:

i. Plane failure: A major discontinuity like a fault plane causes the slope to slide along the weak plane.

ii. Circular failure: This type of failure normally takes place in weak material and dumps. The failed surface assumes a concave shape.

iii. Wedge failure: When there are two discontinuities striking obliquely, the wedge shaped pieces collapse.

iv. Toppling failure: There is no sliding but in weatherd ground, the entire slope may topple.

v. Non-circular failure: Weak material with strong layer at base which prevents complete circular failure.

vi. Falling: Any overhangs created by undercutting or otherwise may cause the overhanging material to collapse.

Indications of damage in slopes/ potential failures: i. Small recent failuresii. Fresh erosioniii. Recent movementsiv. Tension cracksv. Recent seepagevi. Floor heavingvii. Reduction in R.Lviii. Change in drainage slopes

Factors affecting slope stability: Natural factors

.i Physico-mechanical properties of rock.ii Geological structures

.iii Hydrological properties.i Litho logy

. Seismic activity .i Climatic conditions

Artificial factors:

i. Slope geometry including height, angle and curvature

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ii. Mining method including rate of production, type of drilling and blasting and the height of benches.

iii. Presence of old workings – this may require height of benches to be reduced. Prevention of slope failures:

1. Form well designed slope. Factor of safety should be more than one and preferably about 1.2.

2. Reduce driving force and increase resisting force by: Removal of top benches Flattening of slope Forming terraces in steep slopes Removal of unstable material Forming well designed surface drainage Drainage of sub-surface water by horizontal drains, vertical

boreholes with submersible pumps Soil nailing / rock bolting Providing retaining walls Stone columns Vegetation on dumps Soil hardening by grouting / lime injection of dumps. Removal of overhangs / undercuts.

Monitoring pit slopes is very important.

MONITORIONG OF PIT SLOPES:This can be done by:

1. Visual observations / inspection2. Instrumentation

EDM- Theodolite – level based monitoring Tension cracks monitoring Terrestrial photogrametric methods GPS Laser profile based monitoring Using piezometers in boreholes to monitor hydraulic pressure

Movement-wise monitoring techniqueRange of movement Suggested

monitoring method10 – 100 mm B.H.Extensometer100 – 500 mm E.D.M survey

BALANCING DIAGRAMIt indicates the position of a dragline with respect to O.B it can remove from that position and the position where O.B will be dumped. The diagram indicates re-handling of O.B if required. The balancing diagram shows sequence of operation for O.B. removal by the dragline. Many such diagrams are drawn by trial and error method before most optimum scheme of operations is selected for the available dragline. This can also be done with the help of computer programme.

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8ExerciseQ.1: Write short note on haul road gradient in opencast mines.

(First Class 2005)Q.2: A large opencast mine is being planned in a virgin area. Briefly state and discuss the statutory notices that are to be sent and permissions/ relaxations to be obtained. What steps should be taken to select, recruit and train the workmen, staff and officers?

(First Class 2004)Q.3: The management of a large opencast mine has entrusted the work of removal of overburden to a contractor. Deployment of contractor’s trucks and workers for removal of overburden has led to increase of accidents. Discuss the reasons for increase in accidents and suggest preventive measures.

(First Class 2001)Q.4: What are the improvements necessary for better and safer use of Opencast machinery?

(First Class 2002)Q.5: What are the common causes of slope failures in opencast mines? How can such failures be prevented?

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Chapter 7Blasting

Accidents and safety problems due to blastingLarge amount of explosive is used in opencast as well as belowground mines. In spite of elaborate precautions given in the Coal Mines regulations, it has not been possible to eradicate accidents due to use of explosives. As would be seen from Table 5, Chapter 2, there were 3, 5, and 2 fatal accidents during the years 2003, 2004 and 2005 respectively during blasting operations.These accidents are mostly caused by fly rock. Elaborate precautions are given in Regulation 170 of the CMR, 1957. These accidents can be prevented by strict adherence to the provisions of this regulation. In large opencast mines, the manager should prepare a code of practice for safe use of explosives with due regard to these provisions.General causes of fly rock are local geological disturbances, poor blast design, insufficient or very high front row burden, inadequate stemming, excessive or low amount of explosive, improper delay time and initiation sequence and explosive very close to the mouth of blast-hole, etc. In case the fly rock is to be controlled within short distances, the blast round needs to be muffled to inhibit the travel distance.Apart from fly rock, blasting may some time cause ignition/ explosion of inflammable gas, accidents due to inhalation of poisonous post detonation fumes, coal dust explosion while extracting formed pillars and premature detonation while blasting in fire area. Precautions against such miscellaneous dangers have been given in several circulars by DGMS, the important ones being:

DGMS circular 2 0f 1985: Blasting in hot holes. DGMS circular 4 of 1983: Precautions against coal dust explosion. DGMS circular 4 of 1984: Precautions against blasting fumes. DGMS circular 3 of 1980: Precautions against blown through shots while quarrying

pillars. DGMS circular 7 of 1981: Precautions against inhalation of nitrous fumes.

Ground vibrationsThe second most important problem relating to blasting is ground vibrations. When an explosive charge is blasted in a hole, it is instantly converted into gases under high pressure that exert intense pressure on the blast-hole walls. The rock around the blast-hole up to twice the radius of the hole gets completely crushed. Expanding gases continue to work on the rock, extending the cracks and moving the broken rock outward and upwards. These activities consume a part of explosive energy. The remaining part of energy which is quite substantial causes elastic ground vibrations. A seismic wave travels along the ground generating particle motion on the surface. The velocity of oscillating rock particles is called particle velocity and its maximum value is called peak particle velocity or PPV. Generally peak particle velocity is recorded in three orthogonal directions (longitudinal/radial, transverse and vertical). PPV is measured with the help of seismograph. These vibrations can cause damage to the surface structures as these structures also tend too vibrate. The damage that results will depend on inherent strength of the structure, its height and strength and rigidity of the foundation. A kutcha hut will be more prone to damage than a pucca building.The US Bureau of Mines has developed a mathematical model which relates PPV to charge weight and distance from the blast hole. The formula for site predictor equation is-

V = K (D/\ / Q)- b

Where V = PPV in mm/sec D = radial distance from hole to monitoring station in m Q = Maximum charge per delay (kg)K and b are site constants.D/\ / Q is called scaled distance.

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For a new area in which the seismic characteristics are not known, the constants ‘k’ and ‘b’ are determined by monitoring the ground vibrations at different distances for known quantity of explosive per delay. The value of PPV recommended by DGMS for various types of structures are given in Technical circular 7 of 1997. The values for structures not belonging to the owners are given below:

Type of structure PPV in mm per secFrequency <8 Hz Frequency 8 – 25 Hz Frequency >25 Hz

Kutcha/ brick houses 5 10 15Industrial building 10 20 25

Historical monuments 2 5 10

Following are the parameters affecting ground vibrations:Parameters influencing ground vibrations

Variable factors InfluenceControllable Significant Moderate Insignificant1. Charge delay yes2. Delay interval yes3. Delay accuracy Yes4. Burden spacing Yes5. Stemming length Yes6. Stemming material yes7. Charge length yes8. Hole Diameter test9. Hole angle yes10. Charge depth yes11. Bare/ covered D.F yes12 Charge wt. per blast yesNon-controllable1. Surface terrain yes2. Type of O.B yes3. Wind and weather conditions

yes

Reducing ground vibrations1. Reduce charge weight per delay.2. Avoid too much burden and or sub-drilling.3. Primer should not be in sub-drilling.4. If delays in rows are arranged in sequence, the lowest should be nearest to the structure i.e. shots should propagate away from the structure.5. Air decking.6. Good blast design.

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Vibrations induced by blasting on roof and pillars of underground coal mines

A study by CMRI showed that:1. Roof vibrates with higher magnitude of PPV than the sides of the galleries by 4 to 6.5 times.2. Roof of developed pillars was found to vibrate with lower magnitude in comparison to the virgin area where limited galleries were driven as in case of B.G method.3. Safe vibration level for roof of below ground workings is 100 mm per second.

Controlled BlastingControlled blasting techniques are used to minimize over-break (or fracturing) beyond the designed boundary. This is used both in opencast and below ground workings. This is done by:

Line drilling: Single line of unloaded, closely spaced holes are left between place of blasting and the boundary.

Preshearing: A single row of holes, 5 to 10 cms in diameter are drilled, charged with 2.5 cms dia cartridges and fired before main blasting. The annular space in the holes is filled with crushed stone.

Cushion Blasting: A single row of holes is drilled along the neat excavation line, loaded with light, well distributed charges and fired after main excavation is removed.

Air overpressuresAir overpressure is the energy transmitted from the blast through the atmosphere in the form of pressure waves consisting of wide range of frequencies, some of which are audible and some are inaudible which result in annoyance problem. Air overpressure is measured in decible (dB). Low frequency air vibrations (less than 20 Hz) cause air-blast while high frequency air vibrations (20 Hz to 20 KHz) produce noise. Air overpressure may also result in cracks in the plaster or breakage of window panes.Minimising noise and airblast

Cover detonating cord with earth. Use Nonel. Avoid secondary blasting with plaster shooting. Blasting should be done under favourable weather conditions like clear sky and

light wind. Blasting may be done during period of high ambient noise.

Sleeping of holesThe Coal Mines Regulations, 1957 require that only those holes shall be charged which are to be fired in a round. In large opencast mines, it causes practical operational difficulties. Several rows of holes may be required to be charged at a time, out which only few will be fired. The other charged holes are called “sleeping holes”. In large Opencast mines using drag lines, sleeping may extend to even 15 days or so.Following precautions shall be taken in case of sleeping holes:

1) Smoking or open flame including welding shall not be allowed within 30 m of loaded holes.

2) At least two rows of unloaded holes shall be left between loaded holes and holes under drilling.

3) The area of loaded holes shall be conspicuously marked by visible bright red flags during day and by red fluorescent paint during night hours.

4) Entry to the area shall be cordoned off.5) Blast-holes shall be stemmed immediately after loading and a short length of

D.F shall be kept exposed.6) The bore hole and collar area shall be covered by soft stemming material so

that the detonating fuse is completely covered and does not come in contact with discharge of static electricity and lightening.

7) Connections for blasting shall be done only day of blasting during day light.

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8) Only detonating fuse shall be used in the blast hole. Detonator shall be connected just before blasting.

9) No hole shall remain loaded beyond the period permitted by DGMS (Up to 15 days in case of dragline and up to 7 days in shovel benches).

10) Records of all sleeping holes shall be maintained and signed by the blasting officer/ incharge.

ExerciseQ.1: What are the causes of damage to buildings and structures due to blasting in opencast mines? What precautions should be taken to prevent such damage?

(First Class 2005)Q.2: Write short notes on “Fly rocks in opencast mines, their causes and prevention”.

(First Class 2004)Q.3: Write short notes on “firing of shots near surface structures”.

(First Class 2003)Q.4: Draw up a set of conditions for;

(a) Use of SMS.(b) Firing of shots in the shaft from mains.

(First Class 2001)

Q.5: Write short notes on: (a) Controlled blasting(b) Dealing with misfire in deep-hole blast.

(First Class 1998) Q.6: A mechanized opencast mine has approached a village. What safety and health problems are likely to arise? Suggest steps to get over these problems.

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Chapter 8Noise in Mines

Many sounds are unpleasant or unwanted. These are called noise.Sound is “vibrating energy”. When an object vibrates, it pushes air in one direction; then pushes air in other direction. This back and forth movement causes a rise and drop in pressure. The changes in pressure due to sound waves are quite small compared to atmospheric pressure. The change in pressure is what really sound level measuring instruments measure.As a general rule, sound waves move with equal intensity in all directions from the source of noise. As the sound waves move outward from their source they cover a large area and their strength diminishes. Generally speaking, the sound intensity is at full strength for a distance that is three times the size of noise source itself. For example, if the noise source is one metre in diameter, then the sound is at full strength for approximately 3 metres from the source. With each doubling of distance from the sound source, the sound strength is reduced by one half. Therefore, in this example the sound would be at 100% strength from 0-1 metre, at 50% at 6 metres, and 25 % strength at 12 metres.

Sound is described by three quantities namely frequency, wave length and amplitude. The number of pressure variations per second is called frequency and is measured in hertz (Hz). The normal hearing range of a healthy person extends from 20 Hz to 2000 Hz.Wave length () Speed of sound FrequencyThe next main quantity used to describe a sound is the size or amplitude of pressure fluctuations. The weakest sound a human ear can detect has an amplitude of 20 micro Pascals (Pa) - some 5109 times less than normal atmospheric pressure. If we measured sound in Pascals we would end up in some large unmanageable numbers. To avoid this, another scale called decibel scale is adopted and is logarithmic scale and uses hearing threshold of 20 Pa as the reference level. This is defined as 0 dB. When we multiply the sound pressure measured in Pa by 10, we add 20 dB to decibel level. So 200 Pa corresponds to 20 dB, 2000Pa to 40 dB and so on.dB scale20Pa =0 dB200 Pa = 20dB2000Pa = 40dB20000Pa = 60dBHow the above scale is derived?Hearing obeys, as all human senses, the law of differential sensitivity which states that the increase in intensity necessary to produce the minimum perceptible increase in loudness is directly proportional to the original intensity and the increase in loudness. Thus

dI dL X I Or dL=KdI/IIntegrating both sides

L=Klog10I+CSubjective change between two loudness perceptible to human ear =L-L 0

=K (Log10 I- Log10 I0)=K Log10 I/I0

K=20, taking 20 Pa = 0Thus the ear reacts to logarithmic change in level which corresponds to the decibel scale where one decibel is the same relative change everywhere in the scale (e.g. doubling ‘I’ does not make ‘L’ double but difference in loudness remains constant in successive doubling of intensity)Decibel is the sound pressure in logarithmic scale reference to a pressure P0 (20Pa) which corresponds to the hearing threshold of average young person at on KHz frequency.In terms of sound pressure level, audible sounds range from the threshold of hearing at 0 db to the threshold of pain which can be over 130 dB.

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Basic Sound Level MeterA sound level meter is an instrument designed to respond to sound in approximately the same way as the human ear and to give objective responsible measurements of sound pressure level (SPL). The basic sound level meter consists of a microphone, a processing section and a readout unit.Several different types of processing may be performed on the signals. It is relatively simple to build electronic circuit whose sensitivity varies with frequency in the same way as human ear, thus simulating equal loudness contours. This has resulted in three different internationally standardised characteristic terms the A, B, and C weightings.The ‘A’ weighting network weights a signal in a manner which approximates to an inverted equal loudness contour at low SPLs, the ‘B’ network corresponds to contour at medium and ‘C’ network to an equal loudness contour at high SPL. Now-a-days the ‘A’ weighting network is the most widely used since ‘B’ and ‘C’ weightings do not correlate well with subjective tests.After the signal has been weighted and/or divided into frequency bands the resultant signal is modified, and the root mean square value determined in a RMS detector. The RMS value is directly related to the amount of energy in the sound being measured.ENERGY PARAMETERSAs sound is a form of energy, the potential of hearing damage of a given sound environment depends not only on its level but also on its duration. So, to assess the hearing damage potential of a sound environment, both the sound level and the duration of exposure must be measured and combined to provide a determination of energy received. For constant sound level, this is easy but if the sound varies, the level must be sampled repeatedly over a well-defined sampling period. Based on these samples, it is then possible to calculate a single value known as the ‘equivalent continuous sound level’ or ‘Leq’ which has the same energy content and consequently the same hearing damage potential as the varying sound levels.If the sound level varies in steps, ‘Leq’ can be calculated using measurements from sound level meters and stop watch. However, if the sound level varies randomly, it is not easy to use manual calculations to evaluate ‘Leq’. In such cases integrating sound level meters are used. Such meters automatically calculate the ‘Leq’ of the sound being measured.An alternative energy parameter to the Leq is ‘sound exposure level’ or ‘SEL’ which is defined as the constant level acting for one second which has the same amount of acoustic energy as the original sound. An SEL measurement is often used for describing the noise energy of a single event, such as a vehicle passing by. As all SEL measurements are normalised to a one second time interval, the energy content of different types of noise events can be easily compared by using SEL measurements.Types of noises

Continuous noise as in case of surface fan. Impact noise (single impulse of short duration) as in blasting. Repetitive noise as produced by a type writer.

Noise in minesNoise is produced in mines generally due to operation of machines like mechanical ventilator, booster fan, auxiliary fans, coal cutting, drilling and loading machines, transport machinery at surface, opencast or belowground, crushing and loading operations and blasting operations etc.Hazards associated with noise are as follows:

It interferes with communication. This may lead to safety problems besides operational difficulties thereby affecting production and productivity.

It may affect hearing. Exposure to noise over a long period of time may lead to temporary or permanent hearing loss.

Exposure to noise may also result in irritability, high blood pressure, headache, neurological disorders, anxiety, fatigue and loss of working efficiency.

NOISE DOSENoise exposure of individuals who move between different noisy environments during the working day can be obtained using ‘Noise Dose Meters.’ They can be carried in person’s pocket. The International Standards Organisation (ISO) defines one method, which uses only the energy criteria and makes no allowance for recovery of hearing. Thus an increase in sound

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level from 90 dB (A) to 93 dB (A) must be accompanied by halving the permissible exposure duration from 8 hours to 4 hours. In USA the Occupational Safety and Health Administration (OSHA) defines another relationship which permits a 5 dB (A) increase in sound level for each halving of allowable exposure period.There are no statutory provisions in the Mines Act. However, DGMS has recommended through Circular No. 17 of 1975 the following norms:

Warning level for 8 hours daily exposure - 85dB(A) Danger limit for 8 hours daily exposure - 90dB(A) Compulsory use of ear protection - 115dB(A) No work - 140dB(A)

Noise abatementNoise can be controlled by:

i. Reducing noise at the sourceii. Interrupting the path of the noiseiii. Providing protection to the workers (Ear muffs, ear plus, helmets).

Some of the techniques for noise abatement are:a. Lubrication, maintenance and speed rating of the machines;b. Proper design of equipment; use of silencers; damping sound by use of sound

absorbants;c. Restricting time exposure of persons to noisy environment;d. Controlled blasting, covering D.F with soil; blasting under favourable weather

conditions.

ExerciseQuestion 1: How noise is produced in mines? What are the harmful effects of noise? Suggest ways and means to prevent such effects.

Question 2: Discuss “noise in mines”.Question 3: Write short notes on “noise”.

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Chapter 9Dust in Mines

Mining is a dusty occupation. Almost all operations like cutting, drilling, blasting, loading, transport, screening or sizing produce dust. Whereas coal dust can be a source of explosion, all types of dusts including coal dust pose serious health hazard causing respiratory diseases. Dust is also an environmental pollutant.There are detailed provisions in The Coal Mines Regulations, 1957 regarding precautions against dust (Regulation 123). The regulation requires “Owner, agent and manager to take such steps as are necessary for minimizing of emission of dust and for suppression of dust which enters the air at any workplace belowground or on surface and for ensuring that the exposure of workers to respirable dust is limited to an extent that is reasonably practicable, but in any case not exceeding the limits that are harmful to health of persons.”Respirable dust is the fraction of dust which poses greatest hazard to health. It has not been defined in the regulations. In the Mines Regulations of U.S.A, the term Respirable dust has been defined as “the dust collected with an approved safety device.” What are the limits of such dust as are not harmful to health?This has been clarified at sub-regulation (2). According to this sub-regulation, “a place shall not be deemed to be in harmless state for persons to work or be therein if the 8 hours time-weighted average concentration of airborne respirable dust in milligrams per cubic metre of air sampled by a gravimetric dust sampler of a type approved by and determined in accordance with the procedure as specified by the Chief Inspector by a general or special order exceeds 3 where working is being made wholly in a coal seam or where free silica present is less than 5 % and the value arrived at by dividing 15 with the percentage of free respirable silica present in other cases.” Thus sampling is to be done with an approved type of gravimetric dust sampler. One of the approved types of sampler is MRE 113 A.What are the prescribed intervals for sampling? This is given at sub-regulation (3) (a). According to this regulation, sampling shall be done at an interval of 6 months. If the concentration exceeds 50 % of the permissible limit then, sampling shall be done at 3 months interval;If it exceeds 75 % of the permissible limit, then at monthly interval;What action should be taken if the sampling shows that the concentration of respirable dust is exceeding the permissible limit?This is given in sub-regulation (4). This requires that in such a case immediate steps shall be taken to minimize emission of dust and to notify the R.I.M. If the average concentration of respirable dust in a series of 5 samples taken in 7 successive normal working shifts during subsequent month exceeds one and a half times the permissible limits, the relevant operations causing excessive dust shall cease.However, purely as a contingency measure or as secondary means of work situation wherein it is technically not feasible to reduce the respirable dust concentration below permissible limit or during the time period necessary to install and commission any device or to institute any new work practice for dust prevention or suppression, compliance with the permissible limit of dust may be achieved by remote operation or by job rotation and failing which, by use of suitable dust respirator.Steps to prevent liberation and accumulation of dust in general and propagation of airborne dust in particular are given in sub-regulation (6)The Regulations also require manager to prepare a scheme for taking suitable action regarding respirable dust.DGMS has given detailed guide lines for conducting respirable dust surveys in Circular no. 1 of 2004.

Effect of dust on human health

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The adult human lung, with surface area 40 to 120 square metres, comes in contact with about 10,000 to 20,000 litres of air daily and is exposed to the particles present in the air. Silica dust causes Silicosis and coal dust causes coal workers’ pneumoconiosis (CWP)The respiratory system is composed of two lungs. The air passages begin at the nose and mouth, and include the windpipe (trachea) and its two branches known as bronchi. The bronchi divide into five main branches and then subdivide finally reaching the terminal bronchi (or respiratory bronchioles) deep within lungs. At the end of bronchioles is the countless tiny air sacs known as alveoli.Particulate matter inhaled is deposited in various regions of the respiratory system depending on the particle size. The human respiratory system is illustrated in the figure on the next page. The upper respiratory system consists of nasal cavity and trachea, while the lower respiratory system consists of bronchial tubes and the lungs. Each bronchus divides into smaller and smaller branches, terminating with a large number of tiny air sacs called alveoli. Large particles that enter the respiratory system are trapped by the hair and lining of the nose and are driven out by cough or sneeze. Particles larger than about 10 μ are quite effectively removed by upper respiratory system. Smaller particles are captured by mucus and sent back to throat by tiny hair like celia and removed by swallowing or spitting. Fine particles in the range 0.5 μ to 5 μ deposit in bronchioles, which are lined with hair like structures called cilia and brought back to throat with mucus but a few reach the alveoli. The health risk is due to the deposition of these particles. The dust particles below 0.2 μ are most injurious and cause Pneumoconiosis. Lesser the size, greater is the effect. ILO has adopted the following definition of Pneumoconiosis:“Any condition of the lungs resulting from inhalation of dust that may or may not be of any clinical significance.”Symptoms of Pneumoconiosis include shortness of breath, chronic cough, fatigue and in advanced stage even fever. The symptoms depend upon the stage of the disease. In early stage, there may not be any symptoms. The diagnosis at the early stages may be possible through radiological techniques.The precautions against the disease include the following:

I. Precautions to prevent/control formation and dispersion of respirable dust.II.Strict adherence with the statutory norms of respirable dust laid down in Regulation 123

of CMR.III. Monitoring of respirable dust at intervals provided under Regulation 123 of

CMR and to take measures including stoppage of work if the dust concentration exceeds one and half time the limiting value.

IV. Job rotation if the dust concentration is excessive.V. Provision of dust respirators as purely contingency measures.VI. Medical examination of work persons as prescribed under Rule 29 B of Mines

Rules, 1955 for detection of the disease. If any person is found to be suffering from the disease, further investigations may be done and remedial measures may be taken.

Safety problems associated with coal dustCoal dust when raised in the air as a cloud can form an explosive mixture which can explode if a source of ignition is present. Normally, a gas explosion can raise roadways coal dust as a cloud and the moving front of gas explosion can cause this cloud to explode. The safety precautions include keeping the place free of coal dust and making the dust if present safe by treating it with adequate amount of stone dust or water. Stone dust barriers are required to be provided in gassy seams of degree two and three or in the development workings of degree one gassy seams. The precautions are given in Regulations 123, 123 A, 123 B and 123 C.

ExerciseQuestion: What are the causes of Pneumoconiosis? What are the precautions to be taken to prevent it?State statutory provisions relating to periodical medical examination and discuss relevance of ILO classification of radiographs for detection of Pneumoconiosis. (First Class 2005)

Human respiratory system

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Chapter 10Recent developments in Mine Safety

Like any other field, there have been developments in mine safety in the recent past. The same are briefly described below:

.. Identification of hazards, problem areas and analysis of accidents The first step in improving safety standards is to identify the hazards. Earlier and even now, some times the starting point is analysis of accidents in conventional way. However, this may not give a complete picture of the problems, which are causing accidents and incidents at the mine. Recent tools for proper assessment include risk assessment, accident analysis and problem identification method. Risk assessment became a part of Safety Legislation in U.K in 1992. Health and Safety risk assessment became a legal requirement in South Africa in January 1997. In India, Ninth Safety Conference emphasized on risk assessment. Accident analysis and problem identification (AAPI) is a technique used in USA. The technique is based on the fact that accidents are the result of absence of physical barriers or presence of human barriers. Example of physical barriers are: roof supports, fencing, cut-off switches etc. Human barriers are information, knowledge, tools and equipment, and bad incentives.

Safety audit is another technique for identification of hazards... Computer based Systems for analysis, detection and prevention of hazards

Management Information System (MIS ): It is a computer based information system which provides information support for decision making in an organization. In any organization a major portion of time goes in data collection, processing and communicating it to the people concerned. This is applicable to data relating to safety also. MIS has been of great help in collecting, processing, analyzing, storing, retrieving and communicating the information in processed form to all concerned.MINOS (Mines Operating System) - This is a computer based remote monitoring and control for coal clearance, environmental monitoring, pumping and face monitoring.The other information systems in use are MIDAS (Machine information display and Automation System), IMPACT (Inbuilt Machine Performance and Condition Testing), and OPTIC (Operating Performance and Technical Information Console).

3. Control of accidents due to ground movement :Following are some of the recent developments for prevention of accidents due to ground movement:

SSR based on geo-mechanical classification of strata (RMR). This includes, classification of roof strata, calculating support resistance and devising support pattern. In case of Longwall faces worked with powered supports, similar approach is used but the empirical formulae used are different.

Use of roof bolts/ cable bolts for support of roof and sides. Use of yielding supports including powered supports in Longwall faces. Induced blasting/ hydro-fracturing of massive bed above caving panels. Attempts

were made in some of the mines to facilitate caving by blasting in the goaf behind last line of supports. At Balrampur 10 & 12 Inclines of M/S SECL, blasting was done by drilling holes from the surface over longwall panels worked by powered supports, charging them in deck pattern and doing delay firing. In one panel, charge per hole was 50 Kg whereas charge weight per delay was 150 Kg. Total charge per round of blast was 650 Kg. In another panel 1200 Kg of explosive was used in a blast. Yet another blast comprised 2192 Kg of explosives. It was reported that as a result of induced caving by deep hole blasting from surface, load on the powered supports had reduced by about 170 to 200 tonnes and loading density by 43 tonnes/m2.

4. Prevention of methane ignitions/explosions Classifications of seams according to gassiness. Continuous environmental monitoring. Methane drainage.

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Use of ultra-safe explosives.

5. Prevention of coal dust explosions and their spread Water barriers/ triggered barriers

Triggered barriers: their function does not depend upon explosion pressure. The explosion is detected and triggered by optical, infrared or thermocouple sensors. The triggered barrier comprises an electrical installation and extinguishing facility. The distance of the barrier from the face may be as much as 500 metres. The mobile triggered barriers are installed in those places where working point moves continuously.The triggered barriers disperse water over a radius of approximately 2 metres as compared to one metre for passive water barrier. In case of failure of electrical triggering, the triggered water trough barriers can still serve as passive barrier to some extent.In Germany triggered barrier with dry powder as extinguishing medium are used. The triggering mechanism is actuated by an ultraviolet light sensor. The powder type triggered barriers are designed to be fitted to face machines and they suppress methane ignition before development of dust explosion.6. Prevention of fires/spontaneous heating

Continuous environmental monitoring Use of crossing point temperature and other indices like fire

risk index for determination of relative proneness of a seam to spontaneous heating.

Use of fire resistant material like brattice, belts etc Treatment of coal pillars with sealants to prevent/ reduce air

leakages. Use of nitrogen for inertisation of goaf.

7. Rescue and recovery Use of liquid nitrogen for quenching fire. Development of Oxygen type self-rescuers. Underground shelters/refuge bays. Large diameter drills and capsules for rescue of

trapped persons. Improved communication devices.

8. Safer mining methods Harmonious mining for prevention of

damage to the surface features due to subsidence during extraction of coal.

Hydraulic mining Insitu gasification Non-effective width extraction below surface

features (NEW) or below workings in upper seams.

PSLW faces9. Blasting in hot strata: Blasting in hot strata as in case of fire area is fraught with

danger of premature blasting. DGMS recommended precautions for blasting under such situations in Circular 2 of 1985.

10. Application of scientific approach while designing and monitoring slopes in opencast mines. (Refer to chapter 6)

11. Equipment and software to study blast induced ground vibrations and air over -pressures: Instantel make Minimate (D- 077) with Blast mate software can give printout of blasting results with printer provided along with the machine or through a PC. The output is in graphic form with four wave pattern showing separately transverse, longitudinal, vertical waves recorded by geophone and air-overpressure reading recorded by microphone. To find safe charge per delay for various distances, a number of blasts are monitored by keeping geophone and microphone at various

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distances. The data is stored in the machine. After the field study, data is down loaded in a PC and regression analysis is done.

12. Use of Software for Mine Planning : CMPDI is using MINEX software for mine planning. This is supplied by Surpec Minex group. Basic requirement for planning by this software is bore hole data. Based on the data various models are made e.g. Gridded model, Triangulations, Geometry data and Geological models etc. This programme is very user friendly. Using the data, various layers can be made and quantities of coal, O.B at various cut-off depths can be calculated. 3 - D sections of the mine can be prepared.

13. Application of controlled blasting techniques . (Refer to Chapter 7)14. Safety in opencast machines

ROPS/ FOPS: In USA, the Mines Safety and Health Administration (MSHA) require provisions of seat belts and Roll Over Protected Structures on every equipment where there is a danger of overturning.

FOPS or falling objects protective structures are overhead structures that provide operators with protection from falling objects.

15. Application of computers in mine surveying: Data entry: The system provides interface to the advanced survey instruments to

directly capture the survey data, thus eliminating the need for manual entry. Traverse module: The system captures both traverse and offset data. After data

entry, the traverse is computed and plotted and offset p [points are stored for further processing by ‘edit’ facility. For closed traverse, closing error can be calculated and distributed Plotter and printer output can be taken through report generation module.

Leveling module: It takes up raw data as recorded in the field book, calculates reduced levels and updates data base. Coordinates can be accessed wherever required.

What the system can provide: Contours Volume Haul road design Stowing range layout Pumping layout Updation of mine status

System requirement: PC Digitilizer Plotter Software

Benefits: 1. Fast calculation and plan generation2. higher degree of accuracy3. clearer plans4. No problem of shrinkage.

Limitations: A plan once plotted cannot be revised. Fresh plan

is to be prepared. The peripherals need special attention. The surveyor has to be specially trained.

Various softwares are available for the purpose. LISCAD Plus Surveying and Engineering Environment (SEE) is one such surveying application developed for Microsoft Windows operating system. 16. Global Positioning System (GPS): Twenty four man made satellites are orbiting earth

in different orbits at an altitude of about 23,000 km. These satellites constantly transmit signals. Receivers at earth can determine distance from each satellite and can

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calculate its latitude, longitude and altitude as at a particular time, position of each of the satellites is precisely known. In mining, the system can be used for: Mapping Transportation fleet management Tracking machinery and persons.

ExerciseQ.1: How can you make effective use of Electronics and information technology in mine safety?

(First Class 2003)Q. 2: Discuss recent developments in mine safety.

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Chapter 11Answers to Questions of the year 2005

Managers’ First Class CertificateDecember 2005

Q1: What are the objectives of convening the National Safety Conferences? Briefly state major recommendations made by it till date and their impact on legislation and safety in mining industry.Answer: OBJECTIVES OF SAFETY CONFERENCES:Conferences on Safety in Mines are organized with a view to provide a common forum at national level for all those who are concerned with health, safety and welfare of mine workers to review in a spirit of mutual cooperation the status of safety in mines, adequacy of safety, health and welfare measures and to make recommendations for improvements of the same. Being tripartite in nature, the Conferences are attended by representatives of mine owners, workers, managers, supervisors, government organizations, educational research institutes and professional bodies.RECOMMENDATIONS:Till date nine such conferences have been held and numerous recommendations have been made. Following are the important recommendations:Danger of Inundation:

1. Water danger plan should be prepared. (1st Conference)2. Standards of accuracy of mine plans may be prescribed. (1st Conference)3. The work of correlation of mine plans and linking them with national grid shall be done.

(5th Conference)4. Precautions against inundation prescribed arising out of the recommendations of

Gaslitan Court of Inquiry. (9th Safety Conference)Workers’ participation in Safety Management:

1. Appointment of Workmen Inspectors and constitution of Safety Committees (1st Conference)

2. The Mines Act should be amended to give statutory backing to Pit Safety Committees and Workmen’s Inspectors. (5th Conference)

3. Members of Safety Committees to be trained. Once in year meeting of Safety Committee to be attended by senior mine officials and trade union officials. (8 th Conference)

4. All mechanized mines where 100 or more persons are employed should appoint Workmen’s inspectors. In large mines sectional, departmental safety committees should be constituted. The tenure of safety committee should be 2 years. Trainers of the safety Committee should be trained. (9th Conference)

Internal safety organization1. Mine management should develop ISO (4th Conference)2. ISO should be independent of production line. Detailed guide lines should be laid for

efficient functioning of ISO. (5th Conference)Prevention of roof and side fall accidents

1. With effect from 1.7.1982, no worker to be employed below unsupported roof. Strata control units should be developed in mining companies and DGMS within one year. (5th

Conference)2. Manager of every u.g mine to formulate “support plan” (6th Conference)3. Roof strata should be classified using RMR method. Supports by roof bolts as per Paul

Committee should be introduced. (8th Conference)

Safety in Opencast mines1. Suitable codes of practice for regulating traffic, prevention of injuries to persons

engaged in tipping, dumping, at loading points etc. Other detailed precautions in o.c operations recommended. (7th Conference)

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2. Precautions to control accidents due to dumpers and trucks prescribed. (6th Conference)

Occupational Health Services1. Occupational Health Services at Company level should be established as soon as

possible. (3rd Conference)2. The provisions regarding initial and periodical medical examination should be

implemented. (5th Conference)3. Each mining company working mechanized mine to create a department of

Occupational Health services. (7th Conference)4. Details regarding medical surveillance, precautions against dust, noise prescribed. (8th

Conference)Health

1. In mines where long and arduous travel is involved, arrangements should be made for transport of men.

Accuracy of mine Plans1. Accuracy of mine plans should be given importance. (5th Conference)2. A team of qualified surveyors should be appointed at are level to connect the mines to

national grid.Prevention of disasters from fire Detailed precautions against disasters from mine fires were prescribed. (9th Conference)Risk ManagementGeneral Safety Risk assessment and risk management should be done at least in two mines in each company. (9th Conference)IMPACT : Many of the recommendations have been now included in the legislation, e.g., workers’ participation in safety in mines, systematic support rules, precautions against danger of inundation etc. The recommendations have certainly played important role in improving safety and health standards in mines.

Question 2: Inundation happens to be a major hazard in belowground workings. As a manager, what action would you take to identify and eliminate this hazard from your mine? Draw an action plan for the same.

Answer : Several disasters due to inundation have taken place in our coal mines from time to time. These disasters have taken place both from surface and underground sources.As a manager of a mine, I will take following action to identify and eliminate this hazard from my mine:

1. Inundation from surface source I will get an up-to-date and correct water danger plan made showing the latest HFL of any water courses, lakes, ponds and tanks etc. The plan will also show:

Surface contours Any subsidence Any bore holes Opencast workings, both new and old Mine openings with R.L of the lowest level of the opening Bore hole section showing clearly the hard and unconsolidated strata Mine workings showing also the reduced levels

The plan will be carefully studied to show if there is any possibility of water entering the mine from:

Mine openings Quarry Bore holes Subsidence

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Low lying areas having low depth of hard coverWhile studying the danger, provisions of Regulation 126 of CMR will be kept in view. R.L of mine openings will be raised at least 1.5 m and preferably 3 m above HFL of water course if any. Bore holes will be closed. Subsided ground will be filled in if there is any danger of water entering through it. If possible, quarries near river or jore side will be filled in if the same are connected to workings belowground. The embankments against river or nullah side will always be kept in good repair with river side pitched with stone.

The permissions granted for working beneath and within 15 m of the surface water sources will be carefully studied to ensure that the conditions laid down in the permission letter are adhered to. Such workings will be clearly demarcated belowground and inspected at regular intervals.In addition to the above I will take following action:

Before onset of monsoon, review the situation; inspect the protective measures like embankment.

Check danger level, warning level and withdrawal levels. Check telephonic communication Ensure that winding arrangements are properly maintained sop that they do not fail at

the time of emergency. Liaison will be maintained with dam authorities (if there is any dam on the upstream

side) to ensure that information is received well in time before water is discharged from the dam.

Danger from Underground sourcesI will carefully study the underground plans of the mine and also the plans of adjacent mines including abandoned/ discontinued mines. If there are any workings the extent of which is not precisely known, all information will be gathered from the old workers, DGMS etc. If possible, the workings will be dewatered. Otherwise, no work within 60 metres of such workings will be done without permission under Regulation 127 from DGMS. While working in the area, apart from the conditions laid down in the permission letter, following precautions will be taken:

A joint survey plan will be prepared. A line indicating 120 metres barrier will be drawn. Precautions stipulated in Reg 127

will be observed while extending workings in this area. Check surveys will be carried out by a survey team from the area level. V notch will be installed to measure seepage of water. If any unusual seepage is

observed, work will be suspended.In addition to the above, Risk assessment exercise will be carried out.An emergency plan indicating action to be taken in the event of an emergency will be drawn and implemented.Action planFollowing is an action plan to prevent danger of inundation:

1. Preparatory arrangements The embankment against river/ nullah will be maintained in good repair. A pole indicating H.F.L, danger level and withdrawal levels will be fixed on river/

nullah side. During rainy season (i.e. 15th June to 31 st October every year, guards will be

posted round the clock to keep watch on water level and condition of the embankment.

Telephonic communication shall be provided fro river side to attendance room. Escape routes shall be clearly demarcated in the workings of the mine. Escape routes shall be shown on mine plans and posted at prominent places in

the mine.2. Action

If the water level in the river touches warning level, the guard shall inform the attendance clerk.

When the water level touches withdrawal level or if any breach is noticed in the embankment or if any other dangerous condition is noticed the guard shall inform the attendance clerk telephonically.

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The attendance clerk shall inform the manager and the banks man. The banks man shall inform the on setter, The on setter shall inform the nearest official present. The official shall withdraw all persons from the mine in an orderly manner

through escape routes. Whenever any abnormal seepage of water is noticed, action for withdrawal of

persons as given above will be taken. Dealing with emergency

A control room shall be set up at the surface. In the event of emergency, action suggested by the consultative

committee shall be taken. The decisions made and action taken shall be recorded in a register.

3. Resumption of work Where work was stopped and persons were withdrawn, the place shall be thoroughly examined by the manager or assistant manager before resumption of work. The results of such inspection shall be recorded in a register kept for the purpose.

Q.3: DefinitionsPlease see Mines Act, CMR, and IER etc.

Q.4 (a) What are the statutory provisions relating to SSR? Explain the factors that you will take into account while formulating SSR for your mine?This is a direct question. Read Regulation 108 and reply (b) What do you understand by the Term “RMR”? What is its application in strata control?Answer: “R.M.R” or rock mass rating is a system of classification of the roof strata on the basis of geo-technical parameters. The purpose of this is to design support system. There are different systems for such classification namely Bieniawski’s RMR system and CMRI/ISM system. In India, we use the later system as recommended by Paul Committee.Five parameters namely layer thickness, structural features, rock weatherability, strength of roof strata and ground seepage are considered to determine the RMR of the roof. The roof is then classified as very poor, poor, fair, good and very good depending on this value.An empirical relation obtained between RMR and rock load is:Likely rock load in tonnes/m2 = span in m x mean rock density x (1.7 – 0.037 RMR + 0.0002 RMR2)Knowing the load bearing capacity of a support, we can determine the number of supports like roof bolt required in a row and the distance between the rows.

Q.5: What are the statutory provisions relating to “Emergency Plan”? Briefly explain the essential elements of a good Emergency Plan and their rationale. How will you incorporate modern technology advancements into emergency plan for a large colliery with belowground workings?

AnswerThe statutory provisions regarding emergency plan are contained in Regulation 199A of CMR, 1957. The provisions are as follows:Regulation 199A. Emergency Plan

1.The manager of every mine having workings belowground shall prepare a general plan of action for use in time of emergency. The plan shall outline the duties and responsibilities of each mine official and key men including the telephone operators, so that each person shall know what is expected of him in case fire, explosion or other emergency occurs. All officials and key men shall be thoroughly instructed in their duties so as to avoid contradictory

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orders and confusion at the time when prompt and efficient action is required. The emergency plan shall also provide for mock rehearsals at regular intervals.2.The manager shall submit a copy of the aforesaid emergency plan prepared by him to the Regional Inspector, within 60 days of coming into force of the Coal Mines (Amendment) Regulations, 1985, or in the case of a mine which is opened or reopened thereafter, within thirty days of such opening or reopening. The Regional Inspector may, by an order in writing, approve of such action plan, either in the form submitted too him or with such additions or alterations as he may think fit and action plan so approved shall be enforced in the mine.3. On receiving information of any emergency, the manager and in his absence the principal official present on the surface, shall immediately put the emergency plan in operation.

The essential elements of emergency plan are: 1. Sending information to different parts of the mine so that persons from unaffected parts of the mine can be safely and quickly withdrawn. 2. Safe and orderly withdrawal of persons from unaffected part of the mine. 3. Rescue of trapped persons. Speed of rescue operations is important. This requires: Early location of trapped persons; Precise location of trapped persons; Training of rescue workers in use of rescue capsules; Special clothing for rescue persons near fire. 4. Recovery of dead bodies and their identification.

5. Prevention of further danger in mine.6. Keeping press and public informed about the correct situation to avoid rumours.

The emergency plan to deal with disaster should come into action almost instantaneously at the very onset of a disaster.Following modern technology advancements may be incorporated in the emergency plan:Besides the normal elements, an emergency plan may also contain the following: Seismic sensing system for locating trapped persons. Provision of underground shelters. Remote sensing of in-mine conditions. High penetration drill rigs. Radio facilities. Mobile van with borehole probing facilities. Mobile winders.

Q.6: (a) What are the causes Pneumoconiosis? What are its symptoms? What are the precautions to be taken to prevent it? (b) State statutory provisions relating to periodical medical examinations and discuss its relevance to ILO classification of radiographs for detection of Pneumoconiosis.Answer:(a) ILO has adopted the following definition of Pneumoconiosis:“Any condition of the lungs resulting from inhalation of dust that may or may not be of any clinical significance.”In other words, Pneumoconiosis is caused by inhalation of dust particles. Except asbestos, these particles have to be of very fine size, generally below 5 micron and mostly below 2 micron. Symptoms of Pneumoconiosis include shortness of breath, chronic cough, fatigue and in advanced stage even fever. The symptoms depend upon the stage of the disease. In early stage, there may not be any symptoms. The diagnosis at the early stages may be possible through radiological techniques.The precautions against the disease include the following:

1. Precautions to prevent/control formation and dispersion of respirable dust.2. Strict adherence with the statutory norms of respirable dust laid down in Regulation 123 of CMR.

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3. Monitoring of respirable dust at intervals provided under Regulation 123 of CMR and to take measures including stoppage of work if the dust concentration exceeds one and half time the limiting value.

4. Job rotation if the dust concentration is excessive. 5. Provision of dust respirators as purely contingency measures. 6. Medical examination of work persons as prescribed under Rule 29 B of Mines Rules, 1955 for detection of the disease. If any person is found to be suffering from the disease, further investigations may be done and remedial measures may be taken.

(b) The statutory provisions regarding periodical medical examination are stipulated in Rule 29 B of the Mines Rules. This states that the periodical medical examination of every person employed in mines shall be carried out at intervals of not more than 5 years. (For asbestos mines, it is at shorter interval). The standards of medical examination are laid down in Form ‘P’.Provided that the periodical medical examination or X-Ray examination or both shall be conducted at more frequent intervals if examining authority deems it necessary to confirm a suspect case of a dust related disease.ILO has classified the stages of Pneumoconiosis on the basis of chest radiographs. The classification is made on the basis of size and shape of opacities detected in the chest radiographs. The standards of medical examinations laid down in the Mines Rules require a full size chest radiograph large enough to include thoratic inlet and both costphrenic angles obtained by an x-ray machine of at least 300mA (milli- Ampere) strength.The periodical examination is very relevant for detection of the disease but it is suggested that standards of the medical examination may clearly state that ILO classification may be used for diagnosis of the disease.

Q.7: A large opencast mine is approaching a village hutments that can not be vacated. What actions would you take to fulfill production targets with due regard to safety? Draw a detailed plan of action for the same.

Answer:Following are the likely dangers/hazards to the village and the persons living in the village due to extension of O.C workings in the vicinity:

1. Dangers due to blasting operations including those due to fly rock, ground vibrations, air-blast.

2. Dangers due to plying of vehicles.3. Danger of persons falling in the quarry or drowning in water-logged quarries /

illegal mining.Keeping the above hazards in view, following is the action plan for fulfilling production targets with due regard to safety:

Hazards due to blasting1. A careful technical study will be carried out to determine scale distance for

keeping the standards of ground vibrations as specified in DGMS circular 7 of 1997. Controlled blasting to ensure that besides controlling ground vibrations, the fly rock is also minimum will be planned. Help of technical Institutions like CMRI or ISM will be taken for the purpose.

2. Muffle blasting will be done to prevent danger of fly rock.3. Blasting personnel will be specially trained in controlled blasting techniques.4. A code of practice for blasting indicating the duties of various personnel will be

prepared and given to the persons concerned.5. Blasting will be done at fixed hours and the village inhabitants will be informed

about it.6. Warning about blasting operations will be given with the help of sirens having

distinct tone.

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7. As far as possible blasting operations will be suspended if the weather is cloudy with low clouds to prevent air-blast.

8. Blasting will be done when ambient noise level is high.9. All blasts will be monitored and records thereof will be maintained.10. Any complaint from the village will investigated by an assistant manager and

records thereof will be maintained.Hazards due to vehicular traffic

1. Separate road for heavy vehicles will be provided. If possible, the road will be kept fenced.

2. Traffic rules will be prepared and followed.3. Traffic signals will be installed at strategic locations.4. Only licensed vehicle operators will be employed.5. No pedestrian will be allowed on the road used for heavy vehicles.

Danger due to persons falling in the quarry/drowning/ illegal mining1. The quarries will be kept fenced off. The abandoned quarries if not filled in will be kept effectively fenced off to prevent entry of persons.2. Warning signals indicating that entry of unauthorized persons is prohibited will be posted.3. If there is any chance of illegal mining, guards will be posted to guard the abandoned/ discontinued quarries. 4. Any incident of illegal mining will be reported to the state authorities. Q.8 (a) In an underground coal mine three persons of shotfiring crew including shotfirer, several hours after returning home, complain of chest pain and breathing difficulty and have to be hospitalized. One of them dies next day. What may be the possible causes of this episode? How would you enquire into it? Discuss possible causes and statutory contraventions. (b) At the end of a working shift, the assistant manager is informed that one underground worker is missing. What actions should be taken?

Answer:Since all the persons of the shotfiring crew have the same symptoms, it is indicative of a common problem relating to their work. Breathing difficulty is a classic symptom of Nitrous fumes poisoning. Nitrous fumes are a constituent of products of blasting. Hence all the three persons have been exposed to high concentration of nitrous fumes exceeding 5 p.p.m concentration.Possible causes of exposure to such high concentration and statutory contraventions may be as follows:

a. Bad quality of explosive or very old explosive which did not detonate properly producing high concentration of noxious gases. This is a violation of Regulation 159 of CMR.

b. Use of very large quantity of explosive at a time producing excessive amount of fumes. In contravention of Regulation 168(6), not adhering to proper pattern of shot holes.

c. Poor ventilation in the working places resulting in fumes not getting cleared there from in contravention of Regulation 130 of CMR.

d. Entering the working places after blasting without waiting for fumes to clear in violation of Regulation 176 of the CMR.

The matter will be investigated as follows: Post-mortem report will be checked for the cause of death. Similarly the medical

examination report of other affected persons will be examined. If it is established that the death was due to nitrous fumes then further investigations as follows will be carried on.

Medical history of the persons affected will be checked to rule out any health problem already existing.

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Explosive from the batch of explosive used will be examined to find out date of manufacture. It will be physically examined to check its condition. The magazine will be inspected to see the storage conditions.

A sample of explosive will be sent for thorough analysis. The analysis results will be compared with those given by the explosive manufacturer.

A sample of explosive will be sent to CMRI for checking the post detonation fumes generated per Kg of explosive. It will be compared with the figures given at the time of approval of the explosive.

The working places will be checked for ventilation. The possibility of the shotfiring crew not following the waiting time norms will be

thoroughly examined by making calculations of the time required for each blast and actual time taken. This will be cross checked with statements of the coworkers.

All the above results will then be thoroughly examined, analysed and correlated to determine the exact cause.

(b) First of all we will make sure that the missing person has actually not come out of the mine. For this purpose, we will search for him at his residence and enquire from his neighbourers whether they have seen him. If it is established beyond doubt that he has not come out of the mine, then we will search for him in the workings belowground. There can be several possibilities as follows:

He might have lost way if he is not conversant with the mine workings. He might have fallen ill. He might have entered in an ill ventilated heading to answer call of the nature and

got affected due to deficiency of Oxygen. He might have fallen asleep. He might have strayed into disused part of mine.

First of all the entire district where he was employed will be searched to find out if he is sleeping. Failing this, depending upon the extent of workings, a few search parties will be made. They will be assigned different parts of the mine to search for. During these operations, the search parties will carry with them hand plans, safety lamps, birds, and if possible stretchers. They will thoroughly search for him in the part of mine assigned to them. If he is not found, the matter will be reported to the police and DGMS.

First Class Managers’ Certificate of CompetencyDecember 2006

Q.1: There has been considerable increase in mechanization of underground and opencast mines. Discuss the adequacy of the provisions of Coal Mines Regulations,

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1957 in respect of qualifications and appointment of Safety Officers, First Class and Second Class Managers and Engineers in mines. Assume your own conditions.Answer:In the CMR, the managers certificates required for below ground mines and opencast mines are the same. However, the conditions in the two types of mines are different. Hence there is a need to have two types of managers certificates namely, unrestricted for belowground mines and restricted type for opencast mines.

(a) Safety Officer: Qualifications of safety officer are stipulated in Regulation 31.A. According to this regulation, the minimum qualifications of S.O are as follows:

Average monthly output Qualifications1. More than 15,000 tonnes First Class managers’ certificate2. > 10,000 tonnes – 15,000 t First or Second Class3. > 5,000 tonnes - 10,000 t First or second class or degree in miningThe above qualifications do not take into account mechanization.If we look at the duties of safety officer given at Regulation 41. A, it will be observed that he has to investigate all types of accidents to analyse the same with a view to pin pointing the nature and common causes of the accidents. Apart from the above, he has to discharge very important duties of inspections, providing assistance in formulation of training programmes and holding safety classes. In other words, he is to discharge functions of a safety manager. Mechanized mines have multitude of safety problems and complexities. Therefore, a fresh graduate or holder of second class managers’ certificate may not be well equipped to discharge these functions. Hence a safety officer should be holder of a First Class Managers’ Certificate holder.In respect of large mines, there are provisions in the Regulation, empowering C.I to require additional persons. This is adequate. (b) First Class and Second Class Managers: Provisions regarding qualifications and appointment of manager are given at Regulation 31 and those regarding under managers or assistant managers are given at Regulation 32. As far as the qualifications of manager are concerned, there is a need to change the same. Irrespective of the output, he should be a holder of Managers’ First Class Certificate. Output may not be the true indicator of complexities and problems in mines. Depending upon the class of mine, he should be holder of unrestricted or restricted certificate. In case, a mine has both opencast and belowground workings, he should be holder of unrestricted type of certificate.Similar criteria should be applied the qualifications of assistant managers. However, the number of assistant mangers for the underground mines may be appointed on the scale given in the Regulations but for opencast mines, the total material removed may be considered instead of output. In such mines, the assistant managers may be appointed at the following scale:

Material removed/ month No. of asst. managers/shift

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1.5 lac cu.m to 7.5 lac cu.m One for every 50,000 cu.m There should be one First Class asst. manager in each shift

> 7.5 lac cu.m One for every 100,000 cu.m. First Class asst manager in each shift.

(c) EngineerRegulation 33 of CMR specifies qualifications of engineer. The qualifications based on aggregate horse power of the machinery. This is not a correct criterion. The regulations should take into consideration not only the size of machinery but also voltage used and the total wattage of electrical machines. The regulation may be changed as follows:

(1) At every mine where machinery is used, an engineer holding a degree or diploma in mechanical engineering, electrical engineering, mining machinery or mining engineering or equivalent qualification shall be appointed to hold general charge of such machinery, and to be responsible for its installation, maintenance and safe working.Provided that where electrical energy at medium voltage and above is used and the installedCapacity of all electrical equipment is 5 mega watts and above, an engineer holding a degree orDiploma in electrical engineering or equivalent qualification shall be appointed to hold charge ofAll the electrical equipment installed at the mine in addition to that specified above.Provided further that nothing in this sub-regulation shall be deemed to prohibit the employment ofTwo or more engineers at one mine so long as the jurisdiction and sphere of responsibility ofEvery such engineer is defined by the manager in writing.Q.2: (I) What is meant by remote operation of coal face apparatus with pilot core protection? Discuss associated voltage and current. (ii) Describe a transwitch unit used belowground. What are (a) its special features and (b) the protected devices incorporated in it.ANSWER:The coal face atmosphere may contain inflammable gases. When electrical machines like coal cutter or drill operate at such faces, there may be a chance of gas explosion due to electric sparking at the time of switching on or off. Therefore, the main switches are kept away and a low voltage circuit is incorporated in such a way that when it is switched on at or near the face, the main switch operates through magnetic relays at a distance sufficiently away from the face where the environment is free from inflammable gases. Further, there is less chance of electric shock to the operator because of low voltage.A sketch diagram of pilot circuit is given below;

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According to Rule 118 of IER, the maximum voltage of circuit for remote control or interlocking of apparatus shall be 30 volts.

(i) A.Transwitch unit is a composite Electrical Transforming Equipment comprising (a) HV (3.3 KV) Primary control (b) FLP air cooled transformer (315 KVA, 3.3 KV/5500V) (c) FLP L.V (550v) secondary control.

B. It is used in underground mines basically as a district transformer which feeds power to face equipment like drill machines, face pumps, SDL/LDL, chain conveyor/ pony belt at desired voltage of 550 V. C. The transwitch unit has a unique electrical protection system as the H.V side C.B is vacuum break type with protective devices like over current relays, under voltage relay and in case of a fault, tripping is through 110 V D.C.The unit is mounted on flanges of transformer and is equipped with 3 poles off load isolator. The L.V side C.B is mounted on L.V side of transformer flanges and consists of sensitive earth leakage relay and a thermal over current relay, earth resistor mounting relay with fault indication facility.The neutral of transformer is earthed through resistor to limit earth fault current to 750 mA.Q.3 (a) What are bye-laws? How are they framed? (b) Frame a set of bye-laws for the use of continuous miner in degree one seam.ANSWER:(a) Byelaws are sort of Regulations which are framed by the management of a particular mine

for the use of any particular machinery or for adoption of a particular method of work in a mine

e.g. several mines in the past had their own Byelaws in respect of use of locomotives.

Procedure for framing Byelaws – This is given in Section 61 of the Mines Act.

The owner, Agent or manager of a mine shall if called upon by the Chief Inspector or an

Inspector, frame and submit a draft Byelaws within 2 months.

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- If management fail to submit bye-laws in 2 months or the draft bye-laws are not considered

sufficient, DGMS may propose a draft bye-laws or propose such amendments as are

considered necessary.

- The above draft/ amended draft will be sent to management for consideration.

- If the draft is agreed upon by the management, it will be forwarded to the Central

Government.

- If there is disagreement, the draft will be sent to Committee constituted under Section 12

for settlement.

- The settled draft will be sent to Central Government.

- The Central Government may make such modifications as it thinks fit.

- The Central Government shall give notice to the affected persons informing them of the

proposal. A period of at least 30 days shall be given for sending objections.

- Any objections received will be considered by the Government and the Byelaws in final

form will be approved.

- The mine management shall have copies of such approved Byelaws in English and in

prescribed languages posted at conspicuous places where the same can easily be seen by

mine employees.

- The Central Government may be an order in writing, annual a Byelaw as a whole or part.

(b) Byelaws for use of continuous miner in degree I gassy seam

CONSTRUCTION:a) Motors and switches – FLP enclosureb) FLP and I.S features to be strictly maintainedc) Cables to be connected through glands and bushesd) Safety devices – horns, lights, LMD, remote control, AVA etc.

OPERATION:a) Operation by authorized personb) Operator to check lights, horn, AVA & other safety devicesc) Cable man to wear glovesd) Before starting, operator to see that all persons in vicinity been warned

EXAMINATION: a) Manager to frame standing ordersb) In every shift by competent foreman, every week by Engineer

SCHEME OF MAINTENANCE: As recommended by Manufacturer.

VENTILATION: a) Velocity: Not less than 30 m per sec; b) Quantity: 284 Cu. M per minc) Inflammable gas: Not more than 0.5 %

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DUST CONTROL:a) Complete set of picksb) Speed : As specified by Manufacturerc) Avoid cutting in stoned) Interlocking cutting and water sprayinge) Strict dust Monitoring

SUPPORT:a) Development galleries & splits: with resin bolt as per SSRb) Goaf edges: 3 rows of roof bolts at 0.8 m between bolts and between rows;

length 1.8 mc) In development and split headings, C.M will not be taken 3.2 m beyond last row

of roof bolts; in slice not 10 m beyond last rowd) Strata monitoring as per strata management plan drawn

IMPLEMENTATION:a) Duties of person will be drawn and implementedb) Adequate number of supervisorsc) Trainingd) Proper recordse) Discussion in Safety committee meeting

GENERAL:a) Cut off power at shift endb) Park at safe place at shift endc) Joints in trailing cable to be vulcanized

Q.4: An explosion has occurred in Degree III mine in a depillaring district with stowing. How will you determine the cause of explosion and its point of origin? How will you ascertain whether explosion has occurred due to inflammable gas or coal dust or both. Assume your own conditions.Answer:The investigation into explosion must start as soon as possible. The rescue teams going down the mine should be directed to collect air samples from different places, carefully record the position and postures of victims on the plan, and note down vital information like falls of roof and displacement of objects. These records should be supplemented by detailed observations of the team conducting detailed investigation.Origin of explosion

(a) Attempts will be made to trace the course of mine explosion to its source by analysis of all evidences recoverable with regard to neighbourhood of source, direction of progress of explosion and experience of the pit.

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(b) Near the place of origin of the explosion, there is minimum violence. The violence increases as the explosion wave progresses.

(c) Arches, girders and other heavy objects are thrown / bent in the forward direction of the explosion wave.

(d) In coking coal mines, coked dust may be found in the headings and roadways in which explosion wave traveled.

(e) In those places through which explosion wave has traveled, the hair of victims may be singed. Similarly, the fibres of wooden supports and edges of torn paper will show signs of singing.

(f) Postures of victims give indication of course of explosion; he would normally try to run away from the danger.

(g) Position of lighter objects may not be relied upon as such objects may first be displaced in the direction of the explosion wave but may subsequently be pulled back due to back lash generated by cooling of gases.

Source of ignitionTracing back the path of flame, we may be able to locate the area where the explosion originated. The area will then be very carefully and minutely examined for:

(a) Contrabands(b) Signs of any fire or spontaneous heating(c) open machinery which might have caused electric spark(d) signs of blown out or blown through shots if blasting has been done at any face(e) signs of rubbing of parts of moving machine giving rise to frictional spark(f) any burst or cut electric cables causing electric spark(g) signs of any welding(h) use of any Non-FLP enclosures of machines, use of defective FLP enclosures

or lights or signaling circuits or telephones which are not intrinsically safe. For this purpose, the machines, light fixtures, telephone circuits etc shall have to be tested thoroughly.

(i) Samples of explosives shall be tested to check whether the same were safe and of permitted type.

Type of explosionThe nature of explosion can be inferred from the following:(a) Projection ratio of flame: In case of firedamp explosion, the spread of flame

may be up to 3 to 4 times the original spread of inflammable mixture. For coal dust explosion, flame does not project much beyond the coal dust cloud. If stone dust barrier has prevented further spread, it may be safe to assume that it was a coal dust explosion though possibility of it being initiated by a gas explosion cannot be ruled out.

(b) Composition of afterdamp: In case of methane explosion, the ratio (CO2 + ¾ CO – ¼ H2)/ O2 absorbed ≤ 0.5 In case of coal dust explosion, this ratio is ≥ 0.85(c) Degree of violence: Coal dust explosions are more violent than gas explosions.(d) Presence of explosive dust and gases: Presence of coked dust is evidence of coal

dust explosion. Non-coking coal dust may not produce coke. Bulky deposits of uncoked explosion dust on surfaces which otherwise would have remained

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clean is often recognizable as deposited explosion dust. Strip samples of dust collected from the galleries will give useful information.

Q.5: Write short notes on:I. Initial and periodical medical examinationII. Workmen’s Inspectors and their dutiesIII. Medical attention in case of injuryIV. Disability allowance and compensation for occupational diseases

Answer:(I) Initial and periodical medical examination

Mining involves safety and health hazards. To ensure safety and health of the persons employed in the mines, it is necessary that apart from precautions to control and prevent such hazards, the health of the workforce is monitored to detect any adverse impact of the polluted mine environment on their health. At the same time it is essential to ensure that the persons to be employed in the mine are physically fit to undertake arduous job and they do not have any health condition which will get aggravated due to the effect of mine environment. Accordingly provisions have been made in the Mines Rules 1955 for initial medical examination of the persons to be employed and periodical medical examination of specified category of persons once in 5 years in case of coal mines and at shorter intervals in asbestos mines (Rule 29B). The medical examination is carried out by a medical officer appointed for the mine or a medical officer in the employment of the owner of the mine, if any, or by any medical officer employed in the Coal Mines Welfare Fund or any other mines welfare organization, failing which by any Central Government medical officer not below the rank of an assistant civil surgeon.The standards of medical examination are given in the Mines Rues. Emphasis is on detection of respiratory diseases, hearing impairment, vision defects and general health.In case a person fails in the medical examination, he can appeal and will be examined by an appellate medical board. If he is declared medically unfit, he will not be allowed to work in the mine.

II. Workmen’s Inspectors and their duties It has long been felt that Workers’ participation in Safety management can go a

long way in improving safety standards in mines. Accordingly provisions have been made in the Mines Rules for appointment of workers’ representatives called Workmen’s Inspectors.

According to Rule 29Q, for every mine where 500 or more persons are ordinarily employed, the owner, agent or manager shall designate three W.I. One of them has to be an Overman’s Certificate holder, and an Electrical Supervisor’s Certificate holder and one a mine foreman. They are to be designated in consultation with the trade unions.

The duties of such Inspectors are given at Rule 29R. They are required to work as W.I for two days in a week for making inspections, to suggest remedial measures, to accompany DGMS officers during complete inspections etc. They submit their report in Form U.

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Training of W.I: Every W.I has to undergo an orientation course of 30 lectures and demonstration of two hours duration each.

Tenure of W.I: Tenure of a W.I is 3years. He can be re-nominated.Suggestions for improvement:Ninth Conference on Safety in Mines recommended that in mechanized mines where employment is 100 or more, W.I should be appointed.It is felt that W.I should be allowed to function as such on full time basis instead of two days in a week.III. Medical attention in case of injuryMining is a hazardous occupation. Apart from natural causes, there can be chance of injuries due to operation of machines or failure of any machine parts. Every year about 500 to 600 persons get seriously injured and several thousands receive reportable and minor injury. If due care is not taken to treat these injuries immediately, the conditions can aggravate and minor injuries can turn into reportable. Some serious injuries can even result in death. This not only causes misery to the injured person but also results in avoidable time and financial loss. Therefore, in the safety statute much emphasis has been laid on medical attention in case of injury by way of First aid.As per Rule 45 A, (I) every person receiving an injury in the course of his duty shall as soon as possible, report the same to an official. Where he is not in a position to report, it shall be the duty of the person who comes to know to report it to an official. The official shall make arrangements for rendering first-aid to the injured. If in the opinion of the official the injury is such as too require immediate attention of the medical practitioner, he shall arrange for the medical practitioner to come. (ii) Under Rule 45, Overman, Sirdar, Shotfirer etc are required to carry First-aid kits. If such an official receives information of injury, he shall himself attend to injured person.(iii) First-aid stations are required to be provided near work places. Attendant of such First-aid station shall render such first-aid to the injured as may be required.Q.8: A thick seam that was developed in two sections was being extracted by opencast mining. There was active fire on a coal face and a shovel was under operation at a distance of 50 metres on lower coal bench of the same seam. Suddenly, water gas explosion occurred and the shovel was covered by hot ash/dust etc. causing instantaneous death of the shovel operator. Write an enquiry report of the accident suggesting out contraventions, responsibilities and suggestions to prevent similar accidents in future. Assume your own conditions. Answer

Enquiry ReportMine: X YOwners: WCLAgent: R.S.A Manager: K.B.SDate of accident: 12-05-2007 Time of accident: 11.30 hoursPlace of accident: Second coal bench in Quarry no. 2Name of deceased: Raghu Designation: Shovel operator Age; 37 yearsWhile a shovel was loading coal at the face of second coal bench in quarry No. 2, a water gas explosion occurred in the underground workings in upper bench having

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active fire. The shovel was covered by hot ash / dust ejected as a result of the explosion, killing the shovel operator almost instantly.Description of the mine:In this mine Mayo seam, 15 metres thick was developed in the past in two sections maintaining superimposition of workings. The seam was on fire. The pillars in the two sctions along with parting were being quarried by mechanized opencast method. Fire in the sea was kept under control by drowning the dip side workings and by keeping the exposed openings covered with OB. Blasting was done in O.B as well as coal benches. There were three benches in O.B and three in coal.Occurrence of accident:On 11-05-2007, the first shift started at 8 hrs. In the lower most coal bench two shovels were deployed to load blasted coal. At about 11.30 hrs. there was a sudden loud blast in the second coal bench followed by ejection of hot material which spread over a radius of about 60 metres. One of the shovels working within a distance of about 50 metres of the site of blast was engulfed in the hot material. The shovel operator named Raghu did not get time to come out of the shovel and was killed almost instantly as a result of severe burn injuries.Rescue and recoveryThe occurrence was sudden. The Overman RamNaresh and Sirdar Shiv Shanker who were on the OB bench rushed towards the site of blast. When the environment cleared, they could see the shovel covered with ash and dust. The immediately went there and with the help of workers from O.B bench, took out Raghu. He was found dead.Inspection, inquiry and conclusionI inspected the quarry at 16 hours the same day. I recorded the statements of workers and supervisors on 12-05-07.During my inspection, it was observed that in the second coal bench there was active fire and the galleries which had got exposed were not kept blanketed as required by permission granted under Regulation 122 of CMR, 1957. A water pipe had been laid right up to the coal face on this bench and water was constantly being pumped to quench the fire. The fire was very active and flames were coming out from it. Water going in the galleries formed steam and when it came in contact with red hot coal, formed water gas resulting in an explosion. As a result of the explosion, hot ashes and hot material was ejected which engulfed the shovel on the lower bench.Regulation 119 (2) (b) require that adequate precautions shall be taken to prevent danger to persons from any explosion of water gas. The circumstances under which water gas formed in the instant case could easily be visualized by a mining engineer. It was revealed that the manager had given instructions to deal with the fire in the manner mentioned above. I, therefore hold him responsible for this accident.A sketch plan illustrating the site of accident is enclosed.

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Answers toFirst Class Coal Mines Managers’ Examination, Dec 2008

Legislation

Q.1: In the present day context of large demand of coal, what are the recommendations of 10th Conference for safety in mines with respect to:

(a) Mechanisation with a view to phase-out manual loading & to improve standards.

(b) Reduction of risk from roof and side falls in coal mines.------------------------------------------------------------------------------------------------------------Answer:(a)The recommendations of 10th Safety Conference for safety in mines with respect to mechanization to phase out manual loading and improve safety standards are as follows:1 Keeping in view the objective of phasing out manual loading, all coal companies shall identify appropriate technology suitable for the prevailing geo-mining conditions and introduce the same in such a manner so as to phase out manual loading operations completely within a period of five years in coal seams with gradient of 1 in 5 or less, and within a period of seven years in coal seams with gradient steeper than 1 in 5.2 While formulating the strategies for face mechanization in underground workings, it shall be ensured that back up facilities like coal evacuation, support system,Ventilation arrangements etc. are compatible with face mechanization.3 The scheme of face mechanization shall be based on proper scientific investigation.The scheme shall also include arrangements for monitoring strata behavior andEnvironmental conditions.4. Possibility of deployment of multi-skilled miners in the face shall be explored toreduce the exposure at hazardous areas without affecting employment.5. Suitable training for efficient & safe operation of machinery shall be imparted to all concerned.6 While planning for face mechanization, due considerations shall be given for longterm sustainability of the technology.7 A policy document shall be framed by each coal mining company within a period ofsix months for addressing the implementation issues. It shall also be ensured that all safety features are inbuilt into the system.

(b) Recommendations of 10th safety conference with respect to reduction of risk from roof and side falls in coal mines are as follows:

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1 In every coal mining company, STRATA CONTROL CELL shall be established atcorporate and area levels within a period of one year, to assist mine managers, forformulation of Systematic Support Rules, monitoring strata control measures in ascientific way to ensure efficacy of support system and for procurement/supply ofquality supporting materials. Such cell shall be manned by adequate number oftechnical personnel headed by a senior official not below the rank of General Manager at Corporate level and Dy. General Manager at Area level.2 Roof bolting shall be used as a primary means of support for freshly exposed roof in development as well as depillaring districts. For the roof category “Poor”, havingvalue of RMR of 40 or less, or where there is excessive seepage of water from theroof strata, roof bolts exclusively with resin capsules shall be used to ensure adequate & immediate reinforcement of the strata.3 Due emphasis shall be given to support the sides of galleries while framingSystematic Support Rules.4 Suitable steps shall be taken by the mining companies to inculcate a culture of “nowork at face” other than supporting work, till the roof is supported by roof bolts up to at least 0.6 meter from the face.5 To ensure proper drilling for roof bolting in all types of roof strata, suitable fit-for-use roof bolting machines shall be introduced in all mines within a period of one year.Such machines shall be capable of being operated from a distance or be providedwith suitable canopy to protect the supporting personnel during drilling or boltingoperations.6 Risk assessment exercise shall be carried out in the mines for assessing the risk from the hazards of roof & side falls and identifying the control mechanism with specific responsibility for implementation. This exercise shall be reviewed at regular intervals not exceeding a year.7 Each company shall take steps to impart structured training to officers, supervisorsand support personnel on roof bolting. ---------------------------Q.2: What are the various problems of safety when a part of work in opencast mine is outsourced? How will you ensure enforcement of Mines Act, Rules and regulations by workers of hired contractor?

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Answer: Following are the salient problems of safety when part of opencast mine is outsourced:

a) Big contractors award part of jobs to petty contractors not having adequate capacity or concern for safety.

b) Employees are purely temporary or migratory and not well conversant with mining activities or laws.

c) More risk taking attitude as earning depend on output.d) Contractors have little commitment for ensuring safety.e) Sometimes safety is considered as a cost component only, ignoring the cost of

lives or working conditions.f) Contractors’ workers are not given adequate training.g) Supervision of various operations and places is not adequate.The matter regarding the above problem was considered by 10th Safety conference. Following recommendations emerged:

Contractor work vis-à-vis Safety1 Employer’s responsibilities(a) Suitable clauses (in consistence with risk of the work allotted) shall be included intender document (including NITs) stating how the risk arising to men & material from the mining operation / operations to be done by the contractors shall be managed.(b) Ensure that contractors are familiar with the relevant parts of the statute, health and safety management system and are provided with copies of such documents prior to commencing work.(c) Ensure that contractor’s arrangements for health and safety management areconsistent with those for the mine owner. All the rules, regulations and bye-laws asapplicable to the mine owner are also applicable to the contractor. Details of thecontractors’ workmen should be maintained in the owner’s Form-B Register. Whereas, C, D & E Registers for contractor men may be maintained independently by the owner. All the above Registers shall be kept in the mine office of the manager.(d) Ensure that contracts should preferably be of longer period (three years), so thatthere is adequate scope of management of safety by the contractor.(e) Ensure that contractor’s provide the machinery, operator and other staff with written safe work procedures for the work to be carried out, stating clearly the risk involved and how it is to be managed.(f) Monitor all activities of the contractors to ensure that contractors are complying with all the requirements of statute and the system related to safety. If found noncompliant of safety laws directing the contractor to take action to comply with the requirements, and for further non-compliance, the contractor may be suitablypenalized. Clause to this affect may be a part of the agreement between the

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employer and the contractor.(g) Where a risk to health or safety of a person arises because of a non-compliancedirecting the contractor to cease work until the non-compliance is corrected.2. Contractor’s responsibilities(a) Prepare written Safe Operating Procedure (SOP) for the work to be carried out,including an assessment of risk, wherever possible and safe methods to deal withit/them.(b) Provide a copy of the SOP to the person designated by the mine owner who shall be supervising the contractor's work.(c) Keep an up to date SOP and provide a copy of changes to a person designated by the mine owner.(d) Ensure that all work is carried out in accordance with the Statute and SOP and for the purpose he may deploy adequate qualified and competent personnel for the purpose of carrying out the job in a safe manner.(e) For work of a specified scope/nature, develop and provide to the mine owner a site specific code of practice.(f) Ensure that all sub-contractors hired by him comply with the same requirement as the contractor himself and shall be liable for ensuring compliance all safety laws by the sub or sub-sub contractors.(g) All persons deployed by the contractor for working in a mine must undergo vocational training, initial medical examination, PME. They should be issued cards stating the name of the contractor and the work and its validity period, indicating status of VT & IME.(h) Every person deployed by the contractor in a mine must wear safety gadgets to be provided by the contractor. If contractor is unable to provide, owner/agent/manger of the mine shall provide the same.(i) The contractor shall submit to DGMS returns indicating – Name of his firm,Registration number, Name and address of person heading the firm, Nature of work,type of deployment of work persons, Number of work persons deployed, how manywork-persons hold VT Certificate, how many work persons undergone IME and typeof medical coverage given to the work persons. The return shall be submittedquarterly (by 10th of April, July, October & January) for contracts of more than oneyear. However, for contracts of less than one year, returns shall be submittedmonthly.3. Employee’s responsibilities

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(a) An employee must, while at work, take reasonable care for the health and safety of people who are at the employee’s place of work and who may be affected by theemployee’s act or omissions at work.(b) An employee must, while at work, cooperate with his or her employer or otherpersons so far as is necessary to enable compliance with any requirement under theact or the regulations that is imposed in the interest of health, safety and welfare ofthe employee or any other person.Compliance with the above recommendations will go a long way in enforcement of the statutory safety, health and welfare provisions in contractual work. ------------------------------------------------------------------------------------------------------Q.3: what is workers participation in safety management? How can this help attain high safety standards? Suggest some deterrents for habitual unsafe workers.

Answer: A worker invests his labour in and ties his fate to his place of work. Therefore, he has a legitimate right to have a share in influencing the various aspects of organisation’s policies. Since mine workers are exposed to the hostile environment of their workplace, they have a right to have a say in management’s policies and actions in safety matters. Further, because of their intimate knowledge of the safety hazards at workplace, their association in safety matters is likely to improve safety standards. This is the concept of workers’ participation in safety management.In our mines workers participation in safety management is achieved through statutory and non-statutory forums. The same are given below:Statutory:

1. Workmen’s Inspectors appointed under Rule 29Q of the Mines Rules,19552. Safety Committees constituted under Rule 29T of the Mines Rules.

Non-statutory:1. National Conferences on Safety in Mines.2. Ttripartite safety committees of mining companies including CIL Safety Board.

Usefulness of Workers participation in safety management1. Workers have intimate knowledge of their workplace and hence the hazards

present there. Hence, they can spot such hazards during inspections and help improve safety standards.

2. Workmen can advise the management about the hazards better because of their intimate knowledge of work place.

3. The participation keeps communication channel between workers and senior management personnel open. Because of easy communication, there is least delay in taking corrective steps.

4. The workers feel a sense of belonging with the mine and take pride in improving conditions including safety issues.

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5. Once workers are associated with safety management, they try to correct their coworkers indulging in involuntary or voluntary unsafe acts.

Deterrents for habitual unsafe workers It has been observed that in majority of the cases unsafe acts were involved in causation of mines accidents. Therefore, focusing on behaviour of unsafe workers is essential to achieve improved safety standards. This can be done as follows:

1. Counselling the unsafe workers by specialists like psychologists. A psychologist can find out the psychology of the unsafe workers and give them correct advice.

2. An aptitude test may be conducted and if a worker is unsuitable for a job, he may be assigned another job.

3. Such workers may not be rebuked or blamed in public. This is counterproductive.

4. If it is found that the unsafe acts committed are due to lack of knowledge or incorrect training, the worker should be retrained in correct way. Such retraining may also be imparted whenever he meets an accident or near miss accident.

5. Help of workers representatives may be taken in confidence to know the root cause of unsafe behaviour.

6. If the unsafe behaviour is the result of bad habits like use of alcohol, action should be taken to remove the bad habits by taking help of workers representatives.

7. Last but not the least if all above actions fail to yield results, punitive action provided under the law may be taken to set an example.

-----------------------------------------------------------------------------------------------------------Q.4: Enumerate various types of instruments (along with objective, principle and functioning of each) which are used for monitoring ground movement in deep underground mines.Answer:----------------------------------------------------------------------------------------------------------(Note for students: Please note that in the following answer various aspects of ground movement monitoring have been given in detail for your benefit. You should shorten it so that you may answer the question in about 25 to 30 minutes.)

Host rock geometry in coal mining is represented by stratified rock masses ofrelative weaker strength. Such stratifications are compound and unite in theirvirgin state before any kind of mining. Mining underneath (Bothdevelopment and depillaring ) tend to develop strain along weaker beddingplanes generating bed separation, called as Dilation.By the action of gravity, the dilated mass / stratums are supposed to sagalong its span within the mining voids / openings, subsequently reducing thegap between the floor and roof of workings, called as Convergence.Sagging of stratums from the roof under the influence of Dilation andsubsequent convergence tend to exert certain Load on the support systemand remaining pillar sides either static or dynamic.

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Dilation / Bed separation causes change in stress from its in-situ state,which in turn is propagated in the rocks around. Such induced effect of stresscan be revealed in the workings with the help of instrumentation, aidingapprehension of strata movement and subsequent assessments.Following are the instruments to measure these parameters in deep underground mines:1. DilationThis is the width of gap generated due to bed separation, between twoconsecutive stratums. This can be monitored by installation and function of,(i) Tell Tale(ii) Multi Point Bore Hole Extensometer(iii) Magnasonic Extensometer(i) Tell TalePrinciple of operation and functioning –Due to point anchorage at two predetermined bedding planes, it givesvisual indication of dilation inside roof mass up to two horizons, one within the mass of bolted height and another above / beyond the bolted height.Dilation in any of the horizons can be visually seen from the relativemovement of multi coloured pipes at mouth of the hole and can be measuredin mm by reading the relative movement of graduations beyond ‘0’ set.(ii) Multi Point Bore Hole ExtensometerPrinciple –It is a basic instrument designed to measure strata dilation i.e., bedseparation at strategic horizons, being placed inside a bore hole. It is aremote sensing instrument can be used at both accessible and inaccessiblelocations. It is very helpful to inculcate dead load in the roof mass andsubsequent design of support requirement of the workings.It consists of anchors, rods, protective casing and transducers withdisplacement sensors. The anchors are made pre set to strategic horizonswithin a bore hole through anchor rods. Any dilation in these horizons causemovement of anchors and there causes a resultant displacement of anchorrods within transducer. Transducer, by the help of displacement sensorscause change in frequency, which is inculcated by the Read Out Unit andfurther converted to mille meters(mm).Installation –Usually a vertical bore hole of 5 – 10m depth is drilled and the multiplesensors (4-6) are locked at predefined horizons. These anchors areindependently connected to the transducer at the mouth of the hole, throughanchor rods. Change in reading due to dilation at any of such horizons maybe measured through Read Out Unit connected to transducer by wire.Magnasonic extensometerIt consists of anchors, rods, protective casing and transducers withdisplacement sensors. The anchors are made pre set to strategic horizonswithin a bore hole through anchor rods. Any dilation in these horizons causemovement of anchors and there causes a resultant displacement of anchorrods within transducer. Transducer, by the help of displacement sensorscause change in frequency, which is inculcated by the Read Out Unit and

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further converted to mille meters(mm).Installation –Usually a vertical bore hole of 5 – 10m depth is drilled and the multiplesensors (4-6) are locked at predefined horizons. These anchors areindependently connected to the transducer at the mouth of the hole, throughanchor rods. Change in reading due to dilation at any of such horizons maybe measured through Read Out Unit connected to transducer by wire. (iii) Magnasonic extensometerPrinciple of operation – It is a basic instrument designed to measure strata dilation or bed separation at strategic horizons, being placed inside a bore hole. It is a remote sensing instrument can be used at both accessible and inaccessible locations. It is very helpful to inculcate dead load in the roof mass and subsequent design of support requirement of the workings. It is designed to measure the distance between pairs of magnets up to 8m depth to accuracy of 0.02mm.Installation –Usually a vertical bore hole of about 8m depth is drilled and the multiplesensors are locked at predefined horizons. These anchors are magneticallyconnected to the transducer at the mouth of the hole. Change in reading dueto dilation at any of such horizons may be measured through Read out Unitconnected to transducer by wire.2. ConvergenceThis is the closure of vertical gap between roof & floor, created either due todownward movement of roof or upward bulging of floor or both. This is aphenomena, generally occurs during Dynamic Loading. This is an indicativeparameter deciding extent of advance support during extraction.This can be inculcated by installation and analysis of out comes of(i) Telescopic Convergence Indicators(ii) Remote Convergence Indicators(i) Telescopic Convergence IndicatorPrinciple of operation –It is a simple instrument comprising two nos. of telescopic pipes to coverthe height of gallery on extension. The inner pipe has graduations over it.Telescope end of the outer pipe acts as the reference point. Any relativemovement of graduations due to movement of pipes gives reading ofconvergence directly.Installation –This instrument is designed to be used within workings only, where access ofmen is possible. For installation, the base end of the outer pipe is fixed to thefloor of the gallery by some means at a strategic place and the top end ofthe inner ( telescopic pipe) pipe is fixed to any point in the roof ( preferablyprojected end of installed roof bolts), keeping the instrument perfectlyvertical.Any convergence between roof and floor, causes relative movement of pipes,

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giving direct reading from the graduations of inner pipe.( ii ) Remote Convergence IndicatorPrinciple of Operation –This is a very useful and reliable instrument for measuringconvergence at accessible / inaccessible locations. This instrument can even work efficiently in side the goaf till destruction by roof fall. So it is a very useful instrument for prediction of roof fall. It may be vibrating wiretype or rheostat type. In case of vibrating wiretype, displacement ofstretched spring loaded, vibrating wire due to convergence causes change infrequency which can be further converted to mm by the help of read out unit.In case of Rheostat type instrument, displacement of stretched spring loadedrheostat can cause change in resistance due to convergence (Closure ofspring), which can be further converted to mm by the help of read out unit.3. Stress and strainStresses are the ground pressure associated with every location in thestratum. Principally these originate from the mechanism of dual equilibriumof forces due to spinning actions of the Earth around the Sun and around itsown axis. Knowledge of magnitude and direction is important for safe stratamanagement. These are derived from several sources.Stress MeterPrinciple –It is a vibrating wire type instrument, designed and developed for thepurpose of monitoring stress changes both in situ and induced due to miningoperations at accessible and inaccessible locations. It is a predictiveequipment for inculcating stability of workings. The basic principle of thisequipment is that the change in natural frequency of a stretched wire isproportional to the change of tension in the wire. In the vibrating wire typestress meter, the gauge wire is stretched diametrically across the walls of ahollow steel cylinder, which are inculcated as changes in natural frequency ofvibration of the steel wire.Installation –It may be used both in horizontal or vertical bore holes at strategic depth butusually 3.5m depth to the sides / roof. It is tightly fixed into the bore hole bymeans of sliding wedge and platen assembly with the help of setting tools.The change in frequency so measured is converted in to stress changes,using Read Out Unit and calibration factor of the stress meter.(i) Load Cell ( Mechanical Type )(ii) Load Cell ( Electronic Type )Electronic Load Cells

Principle-It is potentiometer / resistance sensor based and is designed to measureload on support system at accessible and inaccessible locations. Thisinstrument can even work efficiently in side the goaf till destruction by roof

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fall. So it is a very useful instrument for prediction of roof fall.This can be used with both positive and non positive support system. Load onsupport system in turn on the Load Cell causes change in frequency /resistance, which can be inculcated from a safe distance through wires andRead out Units and subsequent conversion to the required units.Installation –The instrument is made fixed either between roof and top of the positivesupport or to the projected bottom end of the roof bolts and is connected tothe Read Out Unit through wires up to a safe distance. Accumulation of loadcan be well read through the Read Out Unit with conversions.Strain Gauge Rock Bolt -Where roof bolting is a system of support, Strain Gauge Rock Bolt are veryhelpful to measure distribution of axial loads and bending movement, alongthe length of the bolt. This is very useful for the purpose designing boltlength and grout strength.Principle –Strain / Bolt Load / Axial Load is measured using pairs of strain gaugeattached to the opposite sides of the roof bolt at specific intervals, along itslength. The arrangement is made in the common roof bolts with formation ofgrooves along the length for implanting strain gauges.Installation –It is same as that of normal rock bolts, but the lead wire at the mouth of thehole is kept open for connection to the Read Out Unit.4. Movement along Joints, Slips & CracksGeological disturbances like joints, slips and cracks are the vulnerable places,where rock interfaces may cause relative movement, which in turn maycause any collapse or failure of mass. So identification and inculcation ofeven slightest relative movement along slips and joints is important forprevention of strata failure at such places.Instruments available for identification and inculcation of relative movementalong slips / joints are;(i) Crack Meter(ii) Joint Meter(i) Crack MeterIt is designed for measuring movements across surface cracks or jointspreferably in the roof. It can be used at both accessible / inaccessiblelocations.Principle –It consists of an electrical transducer coil and two anchors. These anchors arepre fixed in the roof. Any change in the distance across the two anchors,changes the tension corresponding to change in electrical signal, which canbe inculcated through Read Out Unit in the form of required physical units.Installation –The reference points in the roof are precisely located across the separation to

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be monitored, using an installation jig. Anchors are installed and thereference points are fixed in the place. Once the span length is read, the usercan calculate the variation between the two points by comparing the newreading against the initial reading. Remote reading is possible through aRead Out Unit.(j) Joint MeterIt is designed for measuring movements across joints or slips ( Relativemovement of mass along slip planes ) preferably in the roof. It can be usedat both accessible and inaccessible locations.Principle & Installation –It is composed of a transducer, a sensor socket and sensor targets. Thetargets and sensor sockets are grouted in the in small holes about the joint.A thin wall section of the sensor socket is designed to break when the jointopens. Also slightest movement about the joint changes the frequency signalwhich can remotely read by the ROU--------------------------------------------------------------------------------------Q.5: Enumerate the provisions of Mines Rescue Rules, 1985 regarding any two of the following:

a. Establishment and location of rescue stations.b. Appointment of rescue trained persons in mines, their

disposition and accommodation.c. Apparatus and equipment to be provided in belowground

mine where no rescue room is located.Answer: This is a direct question of Rescue Rules. One is supposed to write the provisions of Rules 3, 19 and 11(3) read with Schedule III. Q.6: Write short notes on any four of the following:

a) Angle of draw and its relevance in longwall mining.b) Risk assessment as a tool to improve safety.c) Vocational training as an effective tool in improving safety

and productivity.d) Role of ISO in reducing accidents.e) Direct and indirect costs of accidents.f) Use of diesel locomotives.

Answer:

. Angle of draw

When coal is extracted in a belowground mine, surface subsidence takes place after extraction is done in sufficiently large area. Assuming a rectangular worked out area, the strata affected by subsidence takes form of a frustum of pyramid. The subsided area is larger than the extracted area. The angle between the side of pyramid and vertical is called “angle of draw”.

The angle of draw varies from coalfield to coalfield. Factors governing angle of draw are:

I. Nature of superincumbent strata

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II. Existence of faults

III. Method of working and packing

IV. Dip of seam and direction of work

V. Surface contours

VI. Cleavage or natural jointing of rock

Some authorities have quoted the values of angle of draw in our coalfields varying from as low as 12 degrees to as high as 30 degrees.

Angle of draw is relevant while determining the total surface area that will be affected and precautionary measures to be taken if there are any surface features above area under extraction.

In case of longwall mining, the subsidence is regular as no pillars are left in the extracted area and hence if there are any surface features like roads, railways, buildings or water bodies, angle of draw should be duly taken into account and precautionary measures like diverting or removal of these features may be considered.

b. Risk assessment as a tool to improve safety

Fatality rates per thousand persons in our mines are stagnating for a long time. It has now been thought that apart from reactive approach, there is a need to adopt proactive approach to prevent or reduce accidents. Risk assessment aims at this approach. Risks associated with different hazards due to geological and working conditions, machinery and methods are assessed in advance and such risks are given rating. Higher rated risks are given due attention.

It aims to reduce the likelihood and impact of mishaps of all kinds, reduce the inherent potential for major accidents which could kill or injure persons or cause production and profit losses. Ninth Conference on safety in mines recommended that risk management should be used as a tool for development of appropriate health and safety management system

Risk assessment is to be performed on a regular basis. The goal for each risk assessment session is to identify hazards, determine risk ratings and controls, and to review the implementation of risk controls from previous risk assessment sessions.

The following workflow diagram illustrates the areas involved in performing a risk assessment session.

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The risk assessment is done by a multidisciplinary team.Ninth Safety Conference had recommended that every mining company should conduct risk assessment in at least two mines. 10th Safety Conference recommended that every mine should employ a sound risk analysis process and conduct risk assessment.Experience in developed countries showed that risk assessment has been useful in formulating safety improvement programmes. It is expected that our mines too will benefit by adopting the system.

C. Vocational training as an effective tool in improving safety and productivity

Mining is a hazardous occupation as it is a war against nature. Every year, about 150 to 200 persons get killed and about 500 are injured seriously in accidents in our coal mines. An analysis shows that about 80% of the fatal accidents are caused by fault of workpersons. Lack of adequate knowledge is one of the reasons for the unsafe acts. Mines Vocational Training Rules have been framed to impart class room knowledge and on the job training.The importance of training has been realized by all concerned. This is reflected in the fact that the matter has been discussed in several Safety conferences at national level. Quality training prepares workers to carry out their job in a safe and efficient manner. Thus they can save themselves, their coworkers and prevent damage to the mine property.Apart from avoiding miseries caused by fatal and serious accidents, to the workers and their family members, prevention of accidents results in better production, productivity and consequently reduction in cost of production. Every accident or incident results in disruption of work. A study had earlier showed that in a particular mining company, the loss in production as a result of every fatal accident was to the tune of 5000 t. In other

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words, by preventing a fatal accident the company produced additional 5000 t with the same facilities and manpower. It would be seen from the above that VT plays a significant role in improving safety and productivity.

D. Role of ISO in reducing accidents Internal safety organization is a management institution for self regulation. It has been realized that legislative measures are the minimum to be achieved by any management. Self-regulation aims at higher standards than the prescribed legislation. Self-regulation being a voluntary effort, meets with less resistance and therefore is readily adopted by all concerned. That is the idea for its success in improving safety standards and hence reducing accidents.Jeetpur court of inquiry had stressed this point and recommended that every mine management should organize the pattern of internal safety audit. A separate cadre of safety and ventilation officers should be created. Realising the importance of the issue, 5th Safety conference in 1980 deliberated and recommended that ISO should be independent of production line-up at all levels and that Chief of ISO should be senior officer next to the Chief Executive. Since then this has been adopted by all mining companies and ISO is effectively functioning. ISO being a multidisciplinary institution is capable of taking care of different situations, machinery and methods of work. ISO has indeed matured and been a success story in improving safety standards.E. Direct and indirect costs of accidents.It is a well known fact that apart from disruption in production, accidents in mines result in increased cost of production or in other words there is cost involved in every accident. There are two components of this cost, namely one which is quite apparent like the compensation to be paid and expenditure on medical treatment and the second which is not apparent like loss of production, loss of productivity due to disruption of work and loss of morale etc. The apparent part is called direct cost and the other part is indirect cost. OSHA, U.S.A has estimated that in case of industrial accidents, the ratio of direct:indirect cost varies from 1:1 to 1:20.Direct cost: As has been mentioned, it the cost on account of compensation and medical expenditure. The minimum compensation to be paid is given in Workmen’s compensation Act. However, the mining companies pay much more than that.Indirect cost: It includes:

Higher insurance premium to the insurance companies. Cost of rescue and recovery. Cost on account of appointment of another person in case of fatal

accident and training him. Cost on account of absenteeism and overtime wages resulting after

accident. Cost on account of loss of production and productivity due to

accident. Cost on account of accident investigation. Cost on account of court case, if any instituted by regulatory

authorities or police. Cost for replacing the damaged machinery or making the place safe.

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It will be observed from the foregoing that if total cost of accidents is like an iceberg with only a small portion of direct cost which is visible above water level while majority of it (indirect cost) remains submerged and invisible.F. Use of diesel locomotivesDiesel locomotives provide a very flexible mode of traction. However, there are certain inherent limitations associated with it. These are:

a. Locomotive can be deployed on gentle gradients only.b. It produces noxious gasesc. It is associated with risk of ignition in gassy environments.

Use of Locomotives is regulated by the provisions of Regulation 95 of CMR, 1957. The salient provisions are:

1. Permission from DGMS for use belowground.2. Locomotive not to be used on gradient exceeding 1 in 15.3. None except the driver to ride on locomotive.4. Locomotive to lead the train of tubs except during shunting operations.

So far as the use of diesel locomotives in particular is required, It should be used only in main intake airway. It should be provided with flame trap. The engine should be properly maintained so that it does not

emit excessive amount of CO, NOX, SO2 and aldyhydes. Air samples should be collected in the airways where diesel

locomotive works to check for noxious and inflammable gases.

It should be provided with LMD to monitor presence of inflammable gases.

Q.7: What are the the provisions of Electricity Rules with respect to:a. Portable and transportable apparatusb. Switch gearsc. Appointment and duties of electrical supervisor.

Answer: This is a direct question of Indian Electricity Rules and provisions of relevant rules may be quoted.

Q.8: Spontaneous heating in advanced stage has been detected in a caving district.i. How would you deal with the situation, andii. What are the statutory obligations that should be fulfilled?

Answer:(i) Following action will be taken to deal with heating:

All persons other than those not required for dealing with the heating will be withdrawn -Regulation 119(1).

Emergency plan will be set into action. Regulation199A Location of heating: First the seat of heating will be located by checking

for indications like smoke, heat any flame if any. As the heating is in advanced stage, the option of digging it out does not

appear to be feasible. Hence, one of the following options will be considered:

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a. Stowing: If sand stowing is done in the mine, b. Drowning if the site is located on dip side and it can be done

without affecting other parts of the mine.c. Sealing off. This is the most common and preferred option. The

affected district can be sealed off quickly by closing the openings in preparatory stoppings. The operations will be carried out under rescue cover in the presence of competent persons taking due precautions to prevent danger to persons from noxious, asphyxiating or inflammable gases, flame, steam and ejected or rolling down hot material, explosion of water gas- Regulation 119(2) (b).

d. After sealing off, all persons will be withdrawn from the mine. It is preferable to wait for 24 hours before re-entering the mine. In a gassy degree 2 or 3 mine this precaution is a must.

e. An inspection will be made by the under manager after sealing off and if the workings are safe, only then normal employment will be resumed.

(ii) Statutory obligations1. Regulation 9: RIM will be immediately informed and a notice of occurrence

will be sent in form IV-A to DM, CIM and RIM.2. Rule 24 of Mines Rescue Rules: Action to inform rescue station/rescue

room, summon rescue trained persons, and send information to neghbouring mines if any resue trained persons of the mines are required.

3. Precautions prescribed in Regulation 119 will be taken. These are briefly given below:

a. All persons except those for dealing with fire will be withdrawnb. During dealing with fire precautions mentioned above will be taken.c. Adequate number of self-rescuers and at least two smoke helmets, a

cage containing birds or other means of detecting CO, a flame safety lamp or other means of detecting carbon dioxide will be kept.

4. Regulation 199.A. (3): Emergency plan will be put into action.

1.

Afternoon SessionTHE MINES ACT, 1952

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Examination for Mine Manager’s Certificate of Competency under the Coal Mines Regulations, 1957

FIRST CLASSMINE MANAGEMENT, LEGISLATION & GENERAL SAFETY

Sunday, the 12th December, 2010Full Marks: 100

Time: 3 Hours

Answer Any SIX Questions

(Question 1 carry 20 marks and all other questions carry 16 marks)--------------------------------------------------------------------------------

1. (a). Elaborate the terms “fixed cost”, “variable cost” and “marginal cost” in respect of a coal mine for its financial viabilities. Assume your own conditions.

For any industry cost is the amount of resources given up generally in terms of money or if not in terms of money, they are always expressed in monetary units. Fixed cost, variable cost and marginal cost in respect of a coal mine for its financial viability is a classification based on changes in activity or volume.

i) Fixed cost: It is a cost which does not change in total for a given time of period despite wide fluctuations in output or volume of activity. This includes expenses which must be incurred irrespective of the changes in use of direct materials and do not vary directly with volume or rate of output.

Examples of fixed cost are rent, property taxes, supervising salary, depreciation, advertising, insurance, welfare expenses, administrative cost, etc. fixed cost are expressed in terms of time such as per day, per month or per year and not in terms of unit. It is improper to say that fixed costs never change in amount. Rents, insurance rates, taxes, salaries and other similar items may go up or down depending on the circumstances. The basic concept is that the term “fixed” refers to fixity (non-variability) related to specific volume (or relevant range); the term does not imply that there will be no changes in fixed cost.Fixed costs can be classified in the following categories for the purpose of analysis:1. Committed costs: P & M depreciation, taxes, insurance premium rate, rent

charges, etc.2. Managed costs: Management & staff salaries etc.3. Discretionary costs: R & D costs, marketing programmes costs, new system

development costs etc.4. Step costs: Supervision costs etc.

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Total fixed costs remain unchanged when activity changes within a relevant range. Fixed costs per unit decline as activity increases.

ii)Variable cost: Variable costs are those cost that vary directly and proportionately with the output.

Examples of variable costs are materials (explosives, power, spares, support materials, POL, etc.), labour cost (salary and wages, OT, retirement benefits, etc.).

Total variable costs change when activity changes. Variable costs per unit do not change as activity increases.

iii) Marginal cost: Marginal costs are the increase or decrease in total costs that result from producing as additional unit of product. These are also known as incremental costs per unit. If fixed costs remain unchanged by increasing output by one more unit, the marginal cost of the product will consists of variable cost only.

Marginal costing is used to ascertain costs for increased production and to separate fixed and variable elements to show volume-profit relationship. It is essential in determining the profitability and to decide whether to increase the production or not.

Assumptions:The mine is a coal mine. Cost of production – Rs. 1000/- per tonne.Production of the mine is 1000 tonnes per day.Fixed cost per tonne – Rs. 300/-Variable cost per tonne – Rs. 700/-Marginal cost per tonne – Rs. 700 provided fixed cost remains unchanged.This shows that for increasing 10 tonne production in addition to 10000 TPD per tonne total cost of production will be Rs. 1000 x 1000 + 7000 = 1007000.Overall cost per tonne will be 1007000/1010 = 997. This shows that as the volume increases, variable cost will decrease.

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(b) What is the economic impact of mining? Define in your own terms and enumerate “corporate social responsibilities”.

Economic impact of mining: Mining is a major economic activity. Minerals are of great economic significance for the well-being of man as well as for his survival. Mining activity generates employment opportunities and substantially boosts the domestic economy. They are important sources of tax revenue and contribute to national income. Royalty from mines is an important source of revenue for the state.

In addition to this following are other economic impacts

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i) Minerals are at the foundation of industrial development in any country.ii) The Project Affected People (PAPs) are given jobs and are also trained for self

employment as per provisions of Rehabilitation and Resettlement (R&R) schemes.

iii) The mining and associated activities in mining areas bring about infrastructural development, i.e., roads, schools, hospitals, etc.

iv) Due to mining and associated activities, ethnic people are exposed to various developments and this increases their aspirations.

v) It develops environmental awareness amongst the employees and the villagers.

Adverse economic impacts of mining:1. Mining affects the environment adversely. Ecological factor should be a

criterion in deciding the exploration & extraction of minerals in an area. 2. Since, the land is taken for mining and associated activities, these people lose

their livelihood.3. Development of activities in such areas generate more money, increases buying

power of the people and the cost of living, which adversely affects the people who are not directly associated with these activities.

4. Health of the people living in and around the mining complexes gets affected due to the environmental degradation.

Corporate Social Responsibility:Corporate Social Responsibility is the continuing commitment by business organisations to behave ethically and contribute to the economic development. It also cares for improving the quality of life of the workforce and their families as well as of the local community and society at large.CSR emphasizes that the companies have not only economic and legal obligations, but also certain responsibilities to the society.

Objectives of CSR:Taking responsibility by mining companies for impact of mining on society and taking measures to minimise them or improve the conditions better than what they initially were.

Measure areas covered under CSR:i) Health careii) Educational facilitiesiii) Civic amenities

Advantages of effective implementation of CSR:i) It improves the trust between the employees, villagers and the management.ii) It also improves the brand image of the company.iii) Improves overall performance of the company.

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Q. 2. Answer any two:(a) Composition of Safety Committee and function of Safety Committee.

Safety Committee is a bipartite statutory forum for Workers participation in Safety Management at mine level.

The Safety Committee shall consist of:-(a) The manager who shall be the Chairman;(b) Five officials or competent persons of the mine nominated by the Chairman;(c) Five workmen nominated by the workmen of the mine in accordance with the procedure prescribed inClause (a) of sub-rule (1) of rule 29Q for nomination of Workmen’s Inspector;(d) Workmen’s Inspector where so designated; and(e) The Safety Officer, or where there is no Safety Officer, the senior most mine official next to the manager, who shall act as Secretary to the Committee;Provided that any other official, competent person or work person may be co-opted by the Chairman as a member of the Committee on any day or days of the meeting, if considered necessary.

The functions of the Committee shall be-(1) To discuss remedial measures against the unsafe conditions and practices in the mine as pointed out in the reports of Workmen’s Inspector or otherwise brought to the notice of the Committee and make appropriate recommendations;(2) To consider, before commencement of operations in any new district of mine or commissioning of new electrical or mechanical installation or introduction of new mining technique, the proposed Safety and health measures including related codes of practice and to make appropriate recommendations;(3) To discuss the report of inquiry into accident and make appropriate recommendations;(4) To formulate and implement appropriate Safety campaign based on analysis of accidents;(5) To meet at least once in 30 days to consider the matter placed before it and any other matter that may be raised by the members and make such recommendations as it may deem fit; and(6) To serve as a forum for communication on Safety and occupational health matters.

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(b) Withdrawal of supports and standing orders.Withdrawal of supports is a hazardous operation and several accidents take place during this operation. Therefore, provisions have been made in Reg. 110, CMR, 1957 for this important operation.

According to Regulation 110, whenever supports are to be withdrawn, the withdrawal shall be done in accordance with the method which shall be specified in Manager’s Standing Orders. The standing orders shall cover-

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(a) The supply and use of appropriate tools and safety contrivances; (b) the setting of extra supports to control the collapse of roof from which supports

are being withdrawn;(c) the sequence of withdrawal of supports; withdrawal of a cog to precede

withdrawal of its corner props;(d) safe positioning of persons engaged in operation and all persons present nearby;(e) training of competent persons who are entrusted with the operation; and(f) Supervision during withdrawal of supports.

A model standing order for withdrawal of supports is given below –This standing order shall apply to all the workings of ‘X’ mine for withdrawal of supports. The withdrawal shall be carried out as per the following procedure –

i) The supports should be withdrawn by experienced workers only under the general supervision of a mining sirdar.

ii) A safety prop withdrawer or other suitable tool/ contrivance supplied by the management shall be used.

iii) Work should be done by installing the prop withdrawer at a safe place. Adequate length of chain shall be used for this purpose.

iv) Blasting and other activities in the district shall be kept suspended during the withdrawal operation.

v) Withdrawal of supports shall be carried out strictly following the sequence of withdrawal, starting from the goaf edge and withdrawal of a cog is to precede withdrawal of its corner props.

vi) One prop shall be withdrawn at a time and before withdrawing second prop, the movement of the roof shall be observed carefully.

vii)Withdrawn props shall be kept sufficiently away from the area to provide free passage for workers to run away in an emergency.

viii) No attempt shall be made to dislodge any support by hammering which has got jammed/ fixed too tight against the roof. That may be left to collapse under roof pressure.

ix) In stowing district, in the areas where persons have to work, pass or remain for a length of time, adequate supports for their safety must be left or re-erected till the voids are fully stowed.

x) Any danger noted during the withdrawal of support shall be immediately brought to the notice of safety officer/ manager.

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(c) Cost of accident, frequencies and severity rate.It is a well known fact that apart from disruption in production, accidents in mines result in increased cost of production or in other words there is cost involved in every accident. There are two components of this cost, namely one which is quite apparent like the compensation to be paid and expenditure on medical treatment and the second which is

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not apparent like loss of production, loss of productivity due to disruption of work and loss of morale etc. The apparent part is called direct cost and the other part is indirect cost. OSHA, U.S.A has estimated that in case of industrial accidents, the ratio of direct: indirect cost varies from 1:1 to 1:20.Direct cost: As has been mentioned, it is the cost on account of compensation and medical expenditure. The minimum compensation to be paid is given in Workmen’s compensation Act. However, the mining companies pay much more than that.Indirect cost: It includes:

Higher insurance premium to the insurance companies. Cost of rescue and recovery. Cost on account of appointment of another person in case of fatal accident and

training him. Cost on account of absenteeism and overtime wages resulting after accident. Cost on account of loss of production and productivity due to accident. Cost on account of accident investigation. Cost on account of court case, if any instituted by regulatory authorities or

police. Cost for replacing the damaged machinery or making the place safe.

It will be observed from the foregoing that if total cost of accidents is like an iceberg with only a small portion of direct cost which is visible above water level while majority of it (indirect cost) remains submerged and invisible.

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3. An intensively Bord & Pillar developed mine is planning to increase production from 2000 to 5000 tonnes per day by introducing highly productive machinery. List out the preparatory work to be undertaken till the targeted production is achieved. Describe the safe operating procedure for one of the machinery used for production.

Answer:Such a high production from Bord and Pillar workings can be achieved by using Continuous miner with shuttle cars and conveyor.Assuming that the above mentioned machines are to be introduced, the important preparatory work to be done will include:

(a) Transport facilities for transport of machinery belowground;(b) Good workshop facilities for maintenance;(c) Recruitment of competent operators;(d) Training of operators and workers;(e) Training of supervisors;(f) Procurement of genuine spare parts;(g) Providing adequate facilities for clearing of coal;(h) Providing man-riding facilities to save time prevent fatigue;

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(i) Providing adequate ventilation to meet the statutory requirements, including changing the main mechanical ventilator of higher capacity;

(j) Providing adequate lighting;(k) Procuring and providing adequate power at high voltage;(l) Appointing and training adequate number of officials as per CMR;(m)Getting statutory permissions, exemptions and relaxations from DGMS for

mechanized extraction of pillars (Reg 100) , widening of roadways (Reg99), use of high voltage machines belowground (IER), etc;

(n) Strengthening of supports. (o) Establishing R&D facilities for monitoring of strata control etc.(p) Preparing safe operating procedures.

Safe operating procedure for Continuous minerCONSTRUCTION:

e) Motors and switches – FLP enclosuref) FLP and I.S features to be strictly maintainedg) Cables to be connected through glands and bushesh) Safety devices – horns, lights, LMD, remote control, AVA etc.

OPERATION:e) Operation by authorized personf) Operator to check lights, horn, AVA & other safety devicesg) Cable man to wear glovesh) Before starting, operator to see that all persons in vicinity been warned

EXAMINATION: c) Manager to frame standing ordersd) In every shift by competent foreman, every week by Engineer

SCHEME OF MAINTENANCE: As recommended by Manufacturer.

VENTILATION: d) Velocity: Not less than 30 m per sec; e) Quantity: 284 Cu. M per minf) Inflammable gas: Not more than 0.5 %

DUST CONTROL:f) Complete set of picksg) Speed : As specified by Manufacturerh) Avoid cutting in stonei) Interlocking cutting and water sprayingj) Strict dust Monitoring

SUPPORT:

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e) Development galleries & splits: with resin bolt as per SSRf) Goaf edges: 3 rows of roof bolts at 0.8 m between bolts and between rows;

length 1.8 mg) In development and split headings, C.M will not be taken 3.2 m beyond last row

of roof bolts; in slice not 10 m beyond last rowh) Strata monitoring as per strata management plan drawn

IMPLEMENTATION:f) Duties of person will be drawn and implementedg) Adequate number of supervisorsh) Trainingi) Proper recordsj) Discussion in Safety committee meeting

GENERAL:d) Cut off power at shift ende) Park at safe place at shift endf) Joints in trailing cable to be vulcanized

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4. Write short notes on any two:

(a) Special training to front line supervisors with reference to 10th Safety Conference.

Front line supervisors like Overmen & Sirdars’ role is very important for improving safety standards in mines as they are the officials who are required to take on the spot decisions. For example, it is the overman in a depillaring district who will decide whether it is safe to continue with withdrawal of supports in case the goaf is ‘talking’. Hence it is necessary that these officials have adequate practical experience. Since the mining techniques and safety management systems are changing rapidly, their past experience of working under old conditions may not prove adequate. Hence it is essential to keep them updated. This is possible through periodical training.

In this regards following recommendation of 10th Safety Conference is relevant:“All front-line supervisory officials like Sirdars / Mates, Overmen /Foremen, Surveyors, Electrical/ Mechanical supervisors/Chargemen / Foremen as well as persons supervising other surface operations should be imparted structured training in safety management, for at least two weeks, once in every five years, covering about 20% strength every year.”

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(b) Risk management.

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Fatality rates per thousand persons in our mines are stagnating for a long time. It has now been thought that apart from reactive approach, there is a need to adopt proactive approach to prevent or reduce accidents. Risk management aims at this approach. Risks associated with different hazards due to geological and working conditions, machinery and methods are assessed in advance and such risks are given rating. Higher rated risks are given due attention.

Objective of risk management: It aims to reduce the likelihood and impact of mishaps of all kinds, reduce the inherent potential for major accidents which could kill or injure persons or cause production and profit losses. Ninth Conference on safety in mines recommended that risk management should be used as a tool for development of appropriate health and safety management system.

Tenth Safety Conference made the following recommendations:

1. Every mine should employ a sound risk analysis process, should conduct a risk assessment and should develop a safety management plan to address the significant hazards identified by the analysis assessment.

2. The managements of every mining company should adopt the process of safety management system and commit itself for proper formulation and implementation of the same in totality.

3. Necessary training of all employees of mining companies should be organized with the help of experts for optimal adoption of the safety management system

Risk Management is the process of identifying, analyzing, assessing, rectifying and monitoring of hazardous activities and formulates the management policies, procedures and practices to reduce the chances of uneventful happening.The risk management plan involves:

Risk assessment, risk identification, assessment of risk and ranking and treatment, control and action plans

Risk assessment is the most important part of risk management. This is to be carried out by a multidisciplinary team in order to assess all types of risks arising out of method of work, natural conditions and due to machinery etc.

Risk assessment is to be performed on a regular basis. The goal for each risk assessment session is to identify hazards, determine risk ratings and controls, and to review the implementation of risk controls from previous risk assessment sessions.

The following workflow diagram illustrates the areas involved in performing a risk assessment session.

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After risk assessment, the risks with high rates are tabulated and control measures are determined. A control programme is then formulated indicating also the time frame and responsibility. A beginning has been made and it is expected that soon it will yield results and the accident rates which are stagnating for the last several years will start declining.

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(c) Goaf edge support in mechanised depillaring.Purpose of goaf edge support:In caving methods, goaf edge is heavily supported to ensure that strata movement in goaf area does not affect the working area. In stowing methods, requirement of goaf edge support is not heavy as the roof is supported by stowed material and only load of a small span of roof is to be taken by supports. Statutory provisions –Reg. 108 of CMR 1957 stipulated that, every area in depillaring district including goaf edge shall be supported as per SSR framed by manager of mine and approved by DGMS.

Goaf edge support by roof bolts –Goaf edge in mechanised depillaring by caving with continuous miner and shuttle cars shall be supported in the following manner:

i) All the goaf edges shall be supported by rows of non-retractable roof bolts with resin at 0.8m interval in between the two bolts and the side of the pillar as well as between the rows of bolts. The length and diameter of such bolts shall not be less than 1.8m and 22m respectively. Such goaf edge support shall be supported in the split/ original gallery, as the case may be, at the start of the slice cut by the continuous miner.

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ii) Each such goaf edge shall have three parallel rows of roof bolts, 0.5m inside the roadway except those in between slices where only two rows of roof bolts shall be provided.

iii) One wooden prop shall be installed 2.0m inside of every primary breaker line near the goaf edge on the rib side/ centre of the gallery as an indicator prop.

iv) Anchorage testing of 10% of the roof bolts shall be done and record shall be maintained.

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5. A number of incidences/ accidents are occurring due to hard landing of cages. List out the main causes and the statutory provision in man-winding in shafts.

Answer:If the descending cage in which persons are traveling lands at a high speed, it is likely to cause accident to persons traveling therein. Accident to persons in descending cage may also occur in the event of over-winding.It may occur due to following reasons:

a. Negligence of winding engine manb. Failure of brakesc. Breakage of roped. Accidental declutching of drum due to failure of the clutch locke. Maladjustment/ mal-calibration of automatic contrivance.f. Making the automatic contrivance defunct.g. Wrong calibration of speed indicator.h. Overloading of cage/ cages.

Statutory provisionsBriefly, following are the provisions of CMR to prevent hard landing of cages:Regulation 76:

a. Where drum clutches are provided, the following provisions shall have effect:I. The operating gear of the drum shall be provided with locking gear to

prevent inadvertent withdrawal of the clutch.II. Every engine used for lowering or raising persons shall have suitable

interlocking device so fitted that it is not possible –(a) to unclutch any drum unless brakes of such drum are applied; or(b) To release the brake until the drum clutch is fully engaged and securely

locked.b. Unless the cage attached to the drum is resting at bottom of shaft, the drum shall

not be unclutched unless the winding engineman has assured himself immediately beforehand that the brake is fully applied.

c. In every shaft the engine shall be fitted with an automatically recording speed indicator.

d. In a shaft exceeding 100 meters in depth, there shall be provided an effective automatic contrivance to prevent over speeding and over winding. It shall prevent descending cage from being landed at pit bottom at a speed exceeding

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1.5 m per sec and control movement of ascending cage in such a manner as prevent danger to persons in it. The RIM may specify maximum speed by an order in writing. The contrivance and brakes shall be tested by engineer or other competent person, once in every 7 days by raising each cage in turn to pass the last control point above the top most landing, and once in every thirty days by attempting to land the descending cage at excessive speed. Results shall be recorded in a register kept for the purpose.

e. Except where automatic contrivance is provided, a point shall be fixed and marked on the indicator of the engine in such a way as to show when the cage is at a distance of not less than twice the circumference of the drum from completion of the wind. If persons are traveling in cage, W.E man shall not raise the remaining distance at a speed exceeding 1.2 metres per second.

f. Not more the specified number of persons shall travel in cage.g. No person shall carry any bulky material in the cages.

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6. Define arduous travel with respect to underground mechanised mine. What are the statutory requirements before commissioning of such a system in your mine? Enumerate how to ensure safety of the persons travelling belowground in one such system.

An arduous travel with respect to underground mechanised mine may be defined as the journey in which workers needs much effort or energy to reach their authorised working place due to long travel distance and steep gradient. An arduous travel may be considered where

1) The seam gradient is more than 1 in 4 and travelling distance to the work place is more than 1.5 km.

2) The seam gradient is less than 1 in 4 but the travelling distance is more than 3 km.

Statutory requirements before commissioning man riding system:i)Reg. 88(5) for haulage, Reg. 92(4) for belt conveyor, Reg. 95 for

locomotive of CMR 1957 stipulates that no haulage, belt conveyor or locomotive shall be used for the general conveyance of persons/ man riding except with the permission in writing of CIM and subject to such conditions as may be specified.

ii) No man riding system shall be used U/G unless it is of a type approved by the Chief Inspector of Mines. All equipment used for man riding system shall be –(a) Of sound construction(b) Inspected at regular intervals and (c) Maintained in good and safe condition.

Statutory requirements of man riding system:

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In our mine for ensuring safety of persons travelling belowground in endless haulage (man riding system), the following provisions shall be strictly complied with –

i) Gradient: The man riding car shall not run in a steeper gradient more than 1 in 12.

ii) Speed: The normal speed of the system shall not be exceed 7 km/hr.iii) FOS & life of haulage rope: Factory of Safety shall not be less than 10 and Life

of the rope shall not be more than 1 ½ years.iv) The man riding car shall be provided with brake system which actuates when

speed of car exceeds 2.7 m/s.v) Number of persons allowed to travel shall be notified by manager. Provision of

station shall be made for riding & embarking.vi) Rope and attachment used with man riding car shall be of approved type.vii)Track shall be not less than 35 lb/yard.

Ensuring safety of the persons:The following safety devices should be incorporated in the man riding haulage system.

(a) Safety devices –1. Over speed tripping device2. Position indicator and rope speed indicator3. Run over indicator4. Service brakes – having restraining torque capable of holding 1.5 to 2.0

times the torque resulting from the rope pull.5. Emergency brakes6. Track limit switch – to be provided at in-bye and out-bye end of journey.7. Over travel limit switch.8. Pull cord system for stopping the train in case of emergency.

(b) Clearance: - Below the roof – 0.3mOn the side of track on which manholes are provided - 0.6m. On that side of track opposite to the man holes when there are not more than two tracks – 0.3m.In any other case – 0.6m

(c) Effective signalling system: Suitable code of signalling to be specified by manager for strict enforcement.

(d) Notices –1. Rope speed limit notice in the engine room2. Notice at each stations prohibiting travel beyond specified point.

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7. Write short notes on any two:(a) Occupational health survey and its importance.

Now-a-days Occupational health is an important part of mining in view the health hazards created due to respirable dust, noise, fumes, vibrations etc in mechanized

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mines. Though the workers undergo periodical medical examination as per the statutory requirements at five yearly intervals, it is equally important to keep a watch on occupational health status apart from watch on occupational health hazards. There are no provisions in the statute for such surveys.The matter has been considered by various safety conferences who made valuable recommendations . The most important aspect is to have Occupational Health Surveillance cell for which recommendation was made by sixth Safety Conference. The Occupational Health Surveillance cell is required to have necessary appliances like X-ray machines, equipment for audiometric tests, appliances for doing lung function tests etc. In addition it has to be manned by competent and qualified manpower trained in the latest techniques of occupational health surveys.Indeed it is very important to make occupational health surveys at intervals to know the occupational health problems so that corrective steps can be taken in time. If the occupational diseases like Pneumoconiosis and hearing loss are allowed to go beyond certain limits, it may be too late and the damage may be permanent.

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(b) Objective of Tripartite & Bi-partite meetings. How far it is useful in increasing the status of safety of a mine.

Mine management and workers are the stake holders in management as far as safety in mines is concerned. Therefore, it is necessary the stake holders should meet from time to time to discuss and sort out the safety and occupational health issues. That is exactly the objective of bi-partite meetings between management and mine workers. These meetings provide forum for safety and health promotional measures.Apart from the above two stake holders, the Central Government too has very valid part to play in promotion of safety as the Safety, health and Welfare of mine workers is a central subject and is regulated through the Mines Act, 1952. It is therefore, necessary that there should be regular interaction between the mine management, DGMS on behalf of Central Government and the mine workers to discuss and resolve the issues pertaining to mine safety and occupational health in mines. That is the objective of tri-partite meetings. This too is a safety promotional forum.Indeed very important part has been played by these meetings in promoting safety in mines. Important amendments of statute have emerged through the recommendations of various safety conferences. The mining companies have been sort out in the past many safety problems through bi-partite meetings. These meetings will continue to play important role in future too.

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(c) Emergency response procedure for entrapped underground workers.

Speed is vital for rescue of workers trapped in mines due to accidents and incidents like explosions, fires or even roof falls. Hence there has to be a set of standing

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orders or emergency response plan drawn and rehearsed well in advance so that the rescue operations can be carried out with utmost speed and urgency. Regulation 199 A of CMR requires such a plan in underground mines. The provisions are as follows:

4) The manager of every mine having workings belowground shall prepare a general plan of action for use in time of emergency. The plan shall outline the duties and responsibilities of each mine official and key men including the telephone operators, so that each person shall know what is expected of him in case fire, explosion or other emergency occurs. All officials and key men shall be thoroughly instructed in their duties so as to avoid contradictory orders and confusion at the time when prompt and efficient action is required. The emergency plan shall also provide for mock rehearsals at regular intervals.

5) The manager shall submit a copy of the aforesaid emergency plan prepared by him to the Regional Inspector, within 60 days of coming into force of the Coal Mines (Amendment) Regulations, 1985, or in the case of a mine which is opened or reopened thereafter, within thirty days of such opening or reopening. The Regional Inspector may, by an order in writing, approve of such action plan, either in the form submitted too him or with such additions or alterations as he may think fit and action plan so approved shall be enforced in the mine.

6) On receiving information of any emergency, the manager and in his absence the principal official present on the surface, shall immediately put the emergency plan in operation.

The essential elements of emergency plan are:(7) Sending information to different parts of the mine.(8) Safe and orderly withdrawal of persons from unaffected part of the mine.(9) Rescue of trapped persons. Speed of rescue operations is important. This requires:

Early location of trapped persons; Precise location of trapped persons; Training of rescue workers in use of rescue capsules; Special clothing for rescue persons near fire.

(10) Recovery of dead bodies and their identification.(11) Prevention of further danger in mine.(12) Keeping press and public informed about the correct situation to avoid rumours.

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8. In present day context of heavy mechanisation and outsourcing in mines how as a manager of a mine you prevent employment of persons below eighteen years of age. What is laid down under the provisions of the Mines Act, 1952, Regulations, Rules and Orders made thereunder including penalties.

To meet the energy demand of the country, coal production is to be increased manifold. This can be possible by mechanising the industry. Due to the non-availability of trained experienced manpower, many mining activities are being outsourced. Outsourcing has become attractive due to the following reasons –

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1) It is difficult to manage the manpower directly on roll of the company.2) Specialised agencies can do the job faster, maintaining quality and at cheaper

cost with higher productivity.3) Outsource of production activities in mines reduces the requirement of capital to

be invested on equipments.

Inspite of above advantages there are many disadvantages and risks to the safety of persons. The outsourcing agency may be tempted to engage under aged persons (below 18 years).

As a manager I would take following steps to prevent employment of persons below 18 years of age.

1. I shall form a committee consisting of personnel & mining executive to judge the age of the person by physical appearance of the employee.

2. Age of the person shall be checked from the board certificates of education. These certificates may be verified from the issuing authority.

3. In case of the workers possessing driving license, high school certificate, the age may be verified.

4. In case of any doubt, medical examination of the worker by certifying surgeon shall be arranged for ascertaining the age.

5. Condition of heavy penalties shall be included in the work order of the contractor in case he is found to be engaging workers below 18 years of age.

Statutory provisions (section 40 of the Mines Act, 1952) regarding employment of persons below 18 years of age.

(1) No person below eighteen years of age shall be allowed to work in any mine or part thereof.

(2) Apprentices and other trainees, not below sixteen years of age, may be allowed to work, under proper supervision, in a mine or part thereof by the manager:

Provided that, in the case of trainees, other than apprentices prior approval of theChief Inspector or an Inspector shall be obtained before they are allowed to work.

If an inspector has reason to believe that any mine worker is not an adult or an apprentice/ trainee is either below 16 years of age or is not to fit to work in a mine, he may require medical examination of such a person by a certifying surgeon.

(3) No person below 18 years of age shall be allowed to be present in any part of mine above ground where any operation connected with or incidental to any mining operation is carried on, if notified by Central Govt. except apprentices and trainees.

Penalties for contravention of above mentioned provisions:

Section Offence Punishment Punishment awarded to

67 Contravention of provisions Imprisonment - 3 Person

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regarding employment of labour

months or fine - Rs. 1000/- or both

contravening provisions

68 Employment of persons below 18 years of age

Fine - Rs. 500/- Owner, agent or manager

74 Repeated conviction for the same offence committed again within 2 years of previous conviction

Double the punishment of first contraventions

Owner, agent or manager

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