BHARAT HEAVY ELECTRICALS

LIMITED, JHANSI (U.P.)

ROTATION REPORT

&

SUMMER TRAINING PROJECT REPORT ON

LOCOMOTIVE MANUFACTURING

FOR A PERIOD OF FOUR WEEKS

UNDER GUIDANCE OF: Submitted by:

MR. Yogyesh Tripathi Gaurav Singh

Production Engg. (loco) B.Tech. (Mechanical)

Bhel Jhansi JNIT, Jaipur

ACKNOWLEDGEMENT

I am extremely thankful & indebted to the numerous BHEL Engineers and technical staffs who provided vital information about the functioning of their respective departments thus helping me to gain an overall idea about the working of organization. We are highly thankful for the support & guidance of each of them.

I am extremely thankful to Mr. Dhruv Bhargava (Manager-HRD) for providing me the opportunity to undergo this training and to work on my project. We also express my thanks all the members of HRD for their help & cooperation.

I am highly indebted and thankful to my project guide, Y R TRIPATHI for giving me their valuable time and helping me to grasp the various concepts of locomotive manufacturing and their various parts and assembly processes and testing. We would also like to thank all other members of LME Dept. for providing enough support and cooperation.

Last but not the least, We would like to thank my parents & all my fellow trainees who have been a constant source of encouragement & inspiration during my studies & have always provided me support in every walk of life.

BHEL – AN OVERVIEW

BHEL is the largest engineering and manufacturing enterprise in India in the energy

related infrastructure sector today. BHEL was established more than 40 years ago when

its first plant was setup in Bhopal ushering in the indigenous Heavy Electrical

Equipment Industry in India a dream which has been more than realized with a well-

recognized track record of performance it has been earning profits continuously since

1971-72.

BHEL caters to core sectors of the Indian Economy viz., Power Generation's &

Transmission, Industry, Transportation, Telecommunication, Renewable Energy,

Defense, etc. The wide network of BHEL's 14 manufacturing division, four power Sector

regional centers, over 150 project sites, eight service centers and 18 regional offices,

enables the Company to promptly serve its customers and provide them with suitable

products, systems and services – efficiently and at competitive prices. BHEL has

already attained ISO 9000 certification for quality management, and ISO 14001

certification for environment management.

POWER GENERATION

Power generation sector comprises thermal, gas, hydro and nuclear power

plant business as of 31.03.2001, BHEL supplied sets account for nearly 64737 MW or

65% of the total installed capacity of 99,146 MW in the country, as against nil till 1969-

70.

BHEL has proven turnkey capabilities for executing power projects from

concept to commissioning; it possesses the technology and capability to produce

thermal sets with super critical parameters up to 1000 MW unit rating and gas turbine

generator sets of up to 240 MW units rating. Co-generation and combined-cycle plants

have been introduced to achieve higher plant efficiencies to make efficient use of the

high-ash-content coal available in India, BHEL supplies circulating fluidized bed

combustion boilers to both thermal and combined cycle power plants.

The company manufactures 235 MW nuclear turbine generator sets and has

commenced production of 500 MW nuclear turbine generator sets.

Custom made hydro sets of Francis; Pelton and Kaplan types for different head

discharge combination are also engineering and manufactured by BHEL.

In all, orders for more than 700 utility sets of thermal, hydro, gas and nuclear have been

placed on the Company as on date. The power plant equipment manufactured by BHEL

is based on contemporary technology comparable to the best in the world and is also

internationally competitive.

The Company has proven expertise in Plant Performance Improvement through

renovation modernization and updating of a variety of power plant equipment besides

specialised know how of residual life assessment, health diagnostics and life extension

of plants.

TRANSPORTATION

BHEL is involved in the development design, engineering, marketing, production,

installation, and maintenance and after-sales service of Rolling Stock and traction

propulsion systems. In the area of rolling stock, BHEL manufactures electric

locomotives up to 5000 HP, diesel-electric locomotives from 350 HP to 3100 HP, both

for mainline and shunting duly applications. BHEL is also producing rolling stock for

special applications viz., overhead equipment cars, Special well wagons, Rail-cum-road

vehicle etc., Besides traction propulsion systems for in-house use, BHEL manufactures

traction propulsion systems for other rolling stock producers of electric locomotives,

diesel-electric locomotives, electrical multiple units and metro cars. The electric and

diesel traction equipment on India Railways are largely powered by electrical propulsion

systems produced by BHEL. The company also undertakes retooling and overhauling of

rolling stock in the area of urban transportation systems. BHEL is geared up to turnkey

execution of electric trolley bus systems, light rail systems etc. BHEL is also diversifying

in the area of port handing equipment and pipelines transportation system.

INTERNATIONAL OPERATIONS

BHEL has, over the years, established its references in around 60 countries of the

world, ranging for the United States in the West to New Zealand in the Far East. These

references encompass almost the entire product range of BHEL, covering turnkey

power projects of thermal, hydro and gas-based types, substation projects, rehabilitation

projects, besides a wide variety of products, like transformers, insulators, switchgears,

heat exchangers, castings and forgings, valves, well-head equipment, centrifugal

compressors, photo-voltaic equipment etc. Apart from over 1110MW of boiler capacity

contributed in Malaysia, and execution of four prestigious power projects in Oman,

Some of the other major successes achieved by the Company have been in Australia,

Saudi Arabia, Libya, Greece, Cyprus, Malta, Egypt, Bangladesh, Azerbaijan, Sri Lanka,

Iraq etc.

VISION, MISSION AND VALUES OF BHEL

VISION

A WORLD-CLASS ENGINEERING ENTERPRISE COMMITTED TO ENHANCING

STAKEHOLDER VALUE.

MISSION

TO BE AN INDIAN MULTINATIONAL ENGINEERING ENTERPRISE

PROVIDING TOTAL BUSINESS SOLUTIONS THROUGH QUALITY PRODUCTS,

SYSTEMS AND SERVICES IN THE FIELDS OF ENERGY, INDUSTRY,

TRANSPORTATION, INFRASTRUCTURE AND OTHER POTENTIAL AREAS.

VALUES

ZEAL TO EXCEL AND ZEST FOR CHANGE.

INTEGRITY AND FAIRNESS IN ALL MATTERS.

RESPECT FOR DIGNITY AND POTENTIAL OF INDIVIDUALS.

STRICT ADHERENCE TO COMMITMENTS.

ENSURE SPEED OF RESPONSE.

FOSTER LEARNING, CREATIVITY AND TEAMWORK.

LOYALTY AND PRIDE IN THE COMPANY

VARIOUS UNITS OF BHEL ACROSS THE COUNTRY

FIRST GENERATION UNITS

Bhopal : Heavy Electrical Plant.

Haridwar : Heavy Electrical Equipment Plant.

Hyderabad: Heavy Electrical Power Equipment Plant.

SECOND GENERATION UNITS

Tiruchy : High Pressure Boiler Plant.

Jhansi : Transformer and Locomotive Plant.

Haridwar : Central Foundry and Forge Plant.

Tiruchy : Seamless Steel Tube Plant.

UNITS THROUGH ACQUISTION & MERGER

Bangalore : Electronics Division

Electro Porcelain Division.

NEW MANUFACTURING UNITS

Ranipet : Boiler Auxiliaries Plant.

Jagdish : Insulator Plant.

Govindwal : Industrial Valve Plant.

Rudrapur : Component and Fabrication Plant.

Bangalore : Energy Systems Division

BHEL is growing concern to meet the changing needs of the nation has taken it

beyond power into the total gamut of energy, industry and transportation BHEL is able

to offer a service in each of this fields. Its manufacturing capability is supported by a

corporate R&D division at Hyderabad works closely with the research and development

cells at various units and Welding Research Institute at Tiruchinapalli.

ACTIVITY PROFILE OF BHEL

POWER SECTOR PROJECTS

Thermal sets and Auxiliaries.

Steam generators and Auxiliaries.

Industrial fans.

Electrostatic precipitators.

Air pre heaters.

Nuclear power equipments.

Hydro sets and Auxiliaries.

Motors.

Transformers.

Rectifiers.

Pumps.

Heat Exchangers.

Capacitors.

Porcelain/Ceramics insulators.

Seamless steel tubes.

Casting and forging.

SYSTEMS/SERVICES

Turnkey power station.

Data acquisition Systems.

Power systems.

HVDC Commissioning systems.

Modernization and Rehabilitation.

TRASPORTATION SECTOR

Diesel Electric generators.

AC/DC locomotives.

DC locomotives and loco shunters.

Traction system for railways.

Electric trolley buses.

INDUSTRY SECTOR

Boilers.

Valves.

T.G. sets.

Power devices.

Solar Cells.

Photo Voltaic cells.

Gas Turbines.

Compressors.

Drive Turbines.

Oil rigs.

Blow out preventers.

Wind mills.

Control systems for electric devices.

MODERN MACHINARY IN BHEL JHANSI:-

CNC CROPPING LINE MACHINE

VAPOR PHASE DRYING SYSTEM

COMPUTER ICM 6040 AND 6080 AND IRISII 40/20 WITH GRAPHIC

FACILITIES

BOGIE FRAME MACHINE CENTER

CNC AXLE TURNING LATHE

FACING AND CENTERING MACHINE

WHEEL FORCING PRESS

CNC PIPE BENDING MACHINE

PRODUCT PROFILE OF BHEL JHANSI UNIT

1. Power transformer up to 400 KV class 250 MVA.

2. Special transformer up to 180 KV.

3. ESP transformer 95 KVp, 1400 mA.

4. Freight Loco transformer 3900 to 5400 KVA & 7475 . KVA for 3 phase.

5. ACEMU transformer up to 1000 KVA (1-phase).

1385 KVA (3 phase). .

6. Dry type transformer up to 6300 KVA 33 KV class

7. Instrument transformer VT & CT up to 220 KV class.

8. Diesel electric locomotives up to 2600 HP.

9. AC/DC locomotives 5000 HP.

10. Over Head Equipment cum Test Car

11. Well wagon 200 tone.

12. Rail cum road vehicle

13. Dynamic track stabilizer

BHEL PERFORMANCE (CORPORATE LEVEL)

MAJOR UNITS TURNOVER (In Rs. /Crores)

PARAMETER 2011 - 12 2012 - 13Turnover (Rs. /Cr.) 49510 50015

Order Inflow (Rs. /Cr.) 22096 31528

Net Profit (Rs. /Cr.) 7040 6485

Net Worth (Rs. /Cr.) 25373 30315

Megawatts Commissioned 9270 10340

R & D Investment (Rs. /Cr.) 1199 1248

Patents/Copyrights Filed (Nos.) 351 385

DIVISION 2011 – 12 (Actual)

2012 – 13 (Provisional

JHANSI 1300 1365

CFFP HARDWAR 506 523

HEEP HARDWAR 5415 6375

BAP RANIPET 4210 3703

HPBP TRICHY/SSTP 14571 14970

EDN BANGALORE 2301 1650

BHOPAL 4790 4703

HEEP HYDERABAD 7072 6408

BHEL NET 49301 50015

FABRICATION :

Fabrication is nothing but production. It comprises of 3 bays i.e., Bay0, Bay1 &Bay 2.

BAY-0

It is the preparation shop while the other two bays form the assembly shop.

This section has the following machines:

1. Planner machine – To reduce thickness

2. Shearing machine

3. CNC / ANC Flame Cutting machine – To cut complicated shaft items

using Oxy-Acetylene flame

4. Bending machine

5. Rolling machine

6. Flattening machine

7. Drilling machine

8. Nibbling machine

9. Pantograph flame cutting machine

BAY-1

It is an assembly shop where different parts of tank come from bay 0.Here

welding processes are used for assembly, after which a rough surface is

obtained Grinder operating at 1200 rpm, is used to eliminate the roughness.

BAY-2

It is an assembly shop dealing with making different objects mentioned below:-

1-Tank assembly 5-cross feed assembly

2-Tank cover assembly 6-core clamp assembly

3-End Frame assembly 7-pin and pad assembly

4-foot assembly

Before assembly, short blasting (firing of small materials i.e., acid pickling) is done on different parts of jobs to clean the surface before painting.

After assembly some tests are done known as NON DESTRUCTIVE TEST

1. Ultrasonic test: to detect the welding fault on the CRO at the fault place

high amplitude waves are obtained.

2. Die Penetration test: Red solution is put at the welding and then

cleaned. After some time white solution is put. Appearance of a red spot

indicates a fault at the welding.

3. Magnetic crack detection: Magnetic field is created and then iron

powder is put at the welding. Sticking of the iron powder in the welding

indicated a fault.

4. X-Ray Test: It is same as human testing and the fault is seen in X-ray

film.

BAY-3

Here are basically three sections in the bay:

1. Machine section

2. Copper section

3. Tooling section

MACHINE SECTION:

The operations to form small components of power and traction transformer are

done in this section. The shop consist of following machines:

CENTRAL LATHE: it consist one tailstock, headstock, lower part of tailstock is

fixed and tail stock spindle is moving. On this machine facing, turning and

threading is done

TURRET LATHE: its function is same as central lathe but it is used for mass

production. Here turret head is used in presence of tailstock because turret

head contains many tailstocks around six.

CAPSTAN LATHE: It is belt drive.

RADIAL ARM DRILLING MACHINE: It is used for drilling and boring.

HORIZONTAL BORING MACHINE: It is computerized and used for making

bore, facing etc.

MILLING MACHINE:-

a) Horizontal milling machine: It is used for making gear and cutting operations.

b) Vertical milling machine: By the machine facing cutting, and T-slot cutting is

done

COPPER SECTION:

All the processes related to copper are done here.

Machines used in this section are:-

TUBE SLITTING MACHINE: This machine is developed here and is used for

cutting the tube along its length and across its diameter. Its blade thickness is

3mm.

SHEARING MACHINE: It is operated hydraulically and its blade has V-shape

and a thickness of 15mm

DIE AND PUNCHING MACHINE: It is also hydraulically operated and has a die

and punch for making holes.

HYDRAULIC BENDING MACHINE: It is used for bending the job upto 90°.

SHEARING MACHINE: It is fully mechanical and is used to cut the job along its

width.

FLY PRESS MACHINE: It is used to press the job. It is operated mechanically

by a wheel, which is on the top of the machine.

BEND SAW MACHINE: This machine is used for cutting job having small

thickness. It has a circularly operated blade, around 5.1 meters long.

WATER COOLED BRAZING MACHINE: It contains two carbon brushes. The

sheet is put along with a sulfas sheet and the carbon brushes are heated. A

Lap Joint is formed between the sheets as the sulfas sheet melts.

LINCING BELT MACHINE: It creates a smooth surface.

HYDRAULIC PRESS MACHINE: To press the job.

SOLDER POT MACHINE: It has a pot that contains solder. Solder has a

composition of 60% Zn and 40% Pb.

TOOLING SECTION:

In this section the servicing of tools is done.

Machines used for servicing and maintenance are

BLADE SHARP MACHINE: It sharpens the blade using a circular diamond

cutter. Blade of CNC cropping line machine is sharpened here.

MINI SURFACE GRINDER MACHINE: It serves grinding purposes. It has a

grinding wheel made of “Aluminum Oxide”.

TOOL & SURFACE GRINDING MACHINE: This is specially used to grind the

tools used in Bay 7.

DRILL GRINDING MACHINE: To grind the drills.

BAY 4:

This is the winding section.

TYPES OF WINDING : 1. Reverse section winding.

2. Helical winding

3. Spiral winding

4. Interleaved winding

5. Half sectional winding

There are four TYPES OF COIL fixed in a transformer, they are:

1. Low voltage coil (LV)

2. High voltage coil (HV)

3. Tertiary coil

4. Tap coil

The type of winding depends upon job requirement. Also, the width and

thickness of the conductors are designed particulars and are decided by design

department. Conductors used for winding is in the form of very long strips

wound on a spool, the conductor is covered by cellulose paper for insulation.

For winding first the mould of diameter equal to inner diameter of required coil

is made .The specification of coil are given in drawing. The diameter of mould is

adjustable as its body is made up of wooden sections that interlock with each

other. This interlocking can be increased or decreased to adjust the inner

diameter of coil.

The moulds are of following types.

1. Belly types

2. Link types

3. Cone type

BAY-5

It is core and punch section. The lamination used in power, dry, ESP

transformer etc. for making core is cut in this section.

CRGO (cold rolled grain oriented) silicon steel is used for lamination, which is

imported in India from Japan, U.K. Germany. It is available in 0.27 and 0.28

mm thick sheets, 1mt wide and measured in Kg .The sheets are coated with

very thin layer of insulating material called “carlites”.

For the purpose of cutting and punching the core three machines are installed

in shop

1. SLITTING MACHINE: It is used to cut CRGO sheets in different width. It has

a circular cutter whose position can be changed as per the requirement.

2. CNC CROPPING LINE PNEUMATIC: It contains only one blade, which can

rotate 90° about the sheet .It is operated pneumatically.

3. CNC CROPPING LINE HYDRAULIC: It is also used to cut the CRGO sheet.

It contains two blades, one is fixed and the other rotates 90° above the sheet. It

is operated hydraulically .M4 quality sheet 0.23-0.33 mm thickness is used

BAY-6Single-phase traction transformer for AC locomotives is assembled in this

section. These Freight locomotive transformers are used where there is

frequent change in speed. In this bay core winding and all the assembly and

testing of traction transformer is done.

Three-phase transformers for ACEMU are also manufactured in this section.

The supply lines for this transformer is of 25 KV and power of the transformer

is6500 KVA.

The tap changer of rectifier transformer is also assembled in this bay. Rectified

transformer is used in big furnace like the thermal power stations / plants

( TPP).

BAY-7 :

This is the insulation shop. Various types of insulations are

1- AWWW: All Wood Water Washed press paper.

The paper is 0.2-0.5mm thick cellulose paper and is wound on the

conductors for insulation.

2-PRE-COMPRESSED BOARD: This is widely used for general insulation &

separation of conductors in the forms of blocks.

3-PRESS BOARD: This is used for separation of coils e.g. L.V. from H.V. It is

up to 38 mm thick.

4-UDEL: UnDemnified Electrical Laminated wood or Permawood

This is special type of plywood made for insulation purposes.

5-FIBRE GLASS: This is a resin material and is used in fire prone areas.

6-BAKELLITE

7-GASKET-It is used for protection against leakage.

8-SILICON RUBBER SHEET-It is used for dry type transformer.

The machines used for shaping the insulation material are

1-Cylindrical machines

2-Circle cutting machine

3 Scarping machines

4-Punching press machine

5-Drilling machine6-Guilletin machines

7-Bench saw (spl for OD)

8-Jig saw (spl for ID)

9-Circular saw

10-Linesin machines

BAY 8:

It is the instrument transformer and ESP transformer manufacturing section.

INSTRUMENT TRANSFORMER -

These are used for measurement. Actual measurement is done by measuring

instruments but these transformers serve the purpose of stepping down the

voltage to protect the measuring instrument. They are used in AC system for

measurement of current voltage and energy and can also be used for

measuring power factor, frequency and for indication of synchronism. They find

application in protection of power system and for the operation of over voltage,

over current, earth fault and various other types of relays.

They are of two types.

1-Current transformer (CT)

2-Voltage transformer (VT)

CURENT TRANSFORMER-

It is a step down transformer. High current is not directly measured by the CT

but is stepped down to lower measurable voltages.

BODY:

The main body is a bushing, which houses the winding and also acts as an

insulator.

The CT has a bottom and top chamber.

The top chamber is a cylindrical tank of mild steel. It has

terminals for connection of HV coils. It also has a glass window to

indicate the oil level.

Below the top chamber is the bushing made of porcelain. It

has several folds or “rain sheds” to provide a specific electric field

distribution and long leakage path. Some bushings are cylindrical

while modern ones are conical as amount of oil porcelain used is

reduced without any undesirable defect.

Bottom chamber houses the secondary winding. There is

also connection box to which the connection of the low voltage

(LV) coil is made.

WINDINGS:

The primary winding consists of hollow copper/aluminum pipe bent in form of a

‘U’. Aluminum is used for low rating. For higher rating a set of wires is passed

through the pipe. For still higher ratings, a copper pipe is used and for highest

rating copper pipe with copper wires passing through it is used. This

arrangement depends on the current carrying capacity. The bent portion of

primary as in the bottom chamber whereas the free end is the top chamber. The

straight portion lies inside the bushing.

The primary is wound with crepe paper insulation. The thickness of the insulation

goes in increasing as we go downwards in the bottom chamber. The free ends

are provided with ‘ferrules’, which are, small hollow cylinders through which wires

can pass connection to the primary are made through these ferrules.

The secondary is divided in a number of coils for different set of tapings.

Connections are different tapings are made in connection box. Each coil has an

annular core of CRGO (silicon steel). The wire use is insulated copper wire. The

winding may be done both manually and by machine. After winding the coils are

covered with paper tape insulation. The coils are then slipped into both the legs

of the primary winding and connections are made in connection box for different

tapping.

VOLTAGE TRANSFORMERS:

This is also a stepped down transformer. The outer construction is same as that

of the CT that is this also has a top chamber, bushing and a bottom chamber.

The difference is only in the winding.

WINDINGS:

The primary winding is of the thick wire having a few turns. The winding is heavily

insulated with paper insulation. It has a hollow cylinder passing centrally through

it, which houses the secondary winding. The clean and painted with either

enamel or epoxy paint. The customer gives the choice of paint. Epoxy paint is

generally used in chemical plants and seashore installation. Terminals are then

mark and ratings and diagram plate is fixed.

The job is then sent to the shipping department, which takes care of its dispatch

by packing it in the wooden boxes.

ESP TRANSFORMER :

The Electrostatic Precipitator transformer is used for environmental application. It

is used to filter in a suspended charge particle in the waste gases of an industry.

They are of particular use in thermal power stations and cement industry.

The ESP is a single-phase transformer. It has a primary and secondary. The core

is laminated and is made up of CRGOS. It is a step up transformer. An AC

reactor is connected in series with primary coil. The output of the transformer

must be DC that is obtained by rectifying AC using a bridge rectifier (bridge

rectifier is a combination of several hundred diodes). A radio frequency choke

(RF choke) is connected in series with the DC output for the protection of the

secondary circuit and filter circuit. The output is chosen negative because the

particles are positively charged. The DC output from the secondary is given to a

set of plates arrange one after the others. Impurity particles being positively

charged stick to these plates, which can be jerked off. For this a network of

plates has to be setup all across the plant. This is very costly process in

comparison with the transformer cost. A relive vent is also provided to prevent

the transformer from bursting it higher pressure develops, inside it. It is the

weakest point in the transformer body. An oil temperature indicator and the

secondary supply spark detector are also provided. One side of the transformer

output is taken and other side has a ‘marshalling box’ which is the control box

of the transformer.

BAY-9

In this bay power transformer are assembled. After taking different input from

different bays 0-9 assembly is done.

Power transformer is used to step and step down voltages at generating and

sub-stations. There are various ratings –11KV, 22KV, manufactured, they are

Generator transformer.

System & Auto transformer.

A transformer in a process of assemblage is called a job. The design of the

transformer is done by the design department & is unique of each job; depends on

the requirement of customer. The design department provides drawing to the

assembly shop, which assembles it accordingly.

The steps involved in assembly are:

1. Core building

2. Core Lifting.

3. Unlacing.

4. Delacing and end-frame mounting.

5. High voltage terminal gear and low volt terminal gear mounting.

6. Vapor phasing and oil soaking

7. Final servicing and tanking.

8. Case fitting.

TECHNOLOGY

This department analyses the changes taking place in the world and suggest changes

accordingly. This is very important because the products must not get obsolete in the

market otherwise they will be rejected by the customer.

FUNCTIONS:

Technology functions can be classified as:

Processing Sequence: The sequence of process of manufacturing is decided

for timely and economic completion of the job.

Operation time estimate : It includes incentive scheme management

Allowed operation time: It includes incentive amount

Facilities identification: It includes looking for new equipment or plant or tools

to increase productivity

Special process certification: Special processes are the ones requiring

expertise for example identifying errors, cracks, air bubbles in welding

Special tools requirement: Special tools are allotted, if possible, when required

else the design has to be reconsidered.

Productivity projects compilation: It includes the initial analysis of the problem

and their appropriate solution to enhance productivity.

The principle of working is that

“IF YOU DO NOT MAKE THE CHANGES IN YOUR COMPANY, THE CUSTOMER WILL CHANGE YOU”.

QUALITY CONTROL

CENTRAL QUALITY SERVICEFew terms concerning this department are:-

QUALITYIt is the extent to which products and services satisfy the customer needs.

QUALITY ASSURANCEAll those plants and systematic action necessary to provide adequate confidence that a

product or service will satisfy the given requirement is called quality assurance.

QUALITY CONTROLThe operational technique and activities that are used to fulfil requirement for quality are

quality control.

QUALITY INSPECTIONActivities such as measuring, testing, gauging one or more characteristics of a product

or service and comparing these with specified requirement to determine conformity is

termed quality inspection.

OTHER TRACTION DEVICES MANUFACTURED AT BHEL

BHEL is not only into manufacturing electric locomotives but also some various other

devices required to cater the need of transportation sector. We would be discussing

these devices in brief here as the next section would be dedicated to electric

locomotive’s technical know-how completely.

OHE Inspection Car (Tower Wagon)

This is the recording cum test car for the overhead equipment used for maintenance of

OHE and for attending to break downs. It carries necessary tools for maintenance and

break downs such as tackles, straining screws, clamps, ropes, ladders, adequate stock

of insulators, length of contact and catenary wires and other OHE fittings.

These are of two types:

– Four Wheeler (speed potential upto 75 KMPH)

– Eight Wheeler (speed potential upto 110 KMPH)

RRV

RRV stands for Rail cum Road Vehicle. It is a type of track equipment which can be run

both on rail and the road.

BALLAST CLEANING MACHINE

This is used for cleaning of the tracks after some accident or incident has occurred on

the railway tracks.

DYNAMIC TRACK STABILIZER

This is used for track stabilization after ballast cleaning.

OTHER USEFUL EQUIPMENTS

The various other useful equipments are shown below with their descriptions just below

them

a) UTILITY VEHICLE

b) WELL WAGON

Well wagon are manufactured at BHEL Jhansi for BHEL Haridwar for the transportation

of turbines manufactured there. Presently, two types of well wagons have been

manufactured and they are:

PROJECT REPORT ON

LOCOMOTIVES

LOCOMOTIVE MANUFACTURING

A locomotive or engine is a railway vehicle that provides the motive power for a train. The word originates from the Latin loco – "from a place", ablative of locus, "place" + Medieval Latin motivus, "causing motion", and is a shortened form of the term locomotive engine,[1] first used in the early 19th century to distinguish between mobile and stationary steam engines.

BHEL deals with the two types of locomotive-

1. Diesel locomotive

2. Electric locomotive

BHEL has subsequently diversified into manufacturer of rolling stock products-

1. Diesel Electric loco

2. Electric locomotive (AC,AC/DC)

3. Special wagon (200 T well wagon)

OHE Recording Cum Test Car

Diesel loco further classified as follows-

1. Diesel Electric

2. Diesel Hydraulic

In diesel electric an alternator is used where as in diesel hydraulic a torque converter is used.

The report is concerned with an electric loco i.e. WAG- 7A

Which is a crew friendly loco.

W - Broad Gauge

A - Running in AC mode

G - Hauling goods train

BHEL Jhansi has got order to develop WAG-7 of 5000 HP in quantity of 50 by Indian Railways.

LOCOMOTIVE MANUFACTURING

A locomotive can be broadly classified as:

a) Superstructure

b) Under frame

c) Bogie

FABRICATION

This shop does not come under Loco Unit but manufactures all the basis parts

necessary for locomotive manufacturing like Shell, Traction Transformer etc.

PARTS MADE IN THE SHOP

To manufacture the structure following Machines are used in fabrication shop.

BUTLER Milling Machine : It is a PLANO Milling machine with multiple cutting

tools. It is used for milling operation. Its milling head is universal which does

angular movement for chamfering.

STRUCTURE

SHELL

UNDERFRAME SUPERSTRUCTURE

CABIN SIDEWALL ROOF

BOGIE FRAME

Bending Machine : It performs bending operation on thick metallic sheets of

thickness up to 32mm and of length up to 3200mm approx. tonnage of capacity

is 500 tones stroke of machine (height up to which tool is lifted) is 15mm.

shut height from top is 250. max pressure which can be applied is 140kg/cm2

Rolling Machine : It contains one power generating roller, below two are driving

rollers. This is used to roll the sheet.

Roller arm drilling machine : it has a fixed bed. If job cannot be fixed on the bed it

can be rotated to work directly on the job. Its movement is controlled hydraulically

in vertical direction.

Hydraulic press Machine or flattening Machine : It flattens the thick metal sheets

in the shop. It has a max. capacity of 100 tones.

CNC Flame Cutting Machine : It is used to cut various shapes on thick sheets of

metal. This is done by suitable program feed in machine.

WELDING PROCESS IN FABRICATION SHOP

Welding is a process of joining together of two metal pieces to produce essentially a single piece of metal.

BASIC ARC WELDING PROCESS

1. Shielded Metal Arc Welding(SMAW)2. Gas Tungsten Arc Welding(GTAW)3. Gas Metal Arc Welding(GMAW)4. Flux Cored Arc Welding(FCAW)5. Submerged Arc Welding(SAW)

Two types of Welding used in BHEL Jhansi:-

GMAW

SUBMERGED ARC WELDING:- • Submerged Arc Welding is an arc welding process where weld is produced by

heating with an electric arc between a bare metal electrode and the work.• The welding zone is shielded by a blanket of granular fusible material on the

work.• Pressure is not used.• Filler metal is obtained from the electrode wire.

ELECTRODES

Electrodes classification as per AWS A 5.1.

1. The prefix E refers to Arc welding electrodes.

2. The first two digit indicate minimum tensile strength in psi,

Ex: E60XX indicate minimum tensile strength 60,000 psi.

3. Second last digit indicates the welding position.

1- All position.

2- Flat position and horizontal fillets.

4. The last two digit together indicate the welding position giving coating type current and polarity.

POLARITY

• When the power source is DC the work is connected with positive pole of the machine, it is called Straight Polarity or DCEN(DC Electrode Negative).

• When the work is connected with negative pole of machine it is called Reverse Polarity or DCEP(DC Electrode Positive)

• The Positive Pole generates two third of heat produce.

Common Electrode used in BHEL, Jhansi:-

• E6013 suitable for all welding position can be used with AC and DC negative.• E7018 low hydrogen electrode suitable for all welding position can be used with

AC and DC(+)• E7024 iron powder electrode suitable for flat position can be used DC and AC

both.• E309 for welding mild steel and stainless steel.• E308 for welding stainless steel.

WELDING CHECKS & TESTS

• LPT/DPT ( Liquid/dye penetrant test)• MCD / MPI ( Magnetic Crack Detection/ Magnetic particle detection)• UT ( Ultrasound Testing)• RT ( Radiographic test )

WAG-7:

INTRODUCTION:-

WAG-7 built by CLW to RDSO specifications, these represent the next indigenous design step up from the WAG-5 locomotives. Used primarily for goods haulage, these locos have a co-co wheel arrangement with high adhesion bogies (shared with WCAG-1, WCAM-3, and WDG-2/3A) and Hitachi motors providing 5000HP. The higher tractive effort compared to the WAG-5 locos allows them to attain higher balancing speeds under load. The first 71 of these all went to the mughalsarai shed, Kanpur was the second shed to get these locos.

Traction motors are permanently coupled in parallel and speed control through the use of transformer taps. Maximum speed is 100 km/hr. Air brakes and dynamic brakes for loco, dual train brakes. MU operation with up to 4 units is possible. Traction equipment such as the smoothing reactor etc. are all higher rated than in WAG-5 due to the higher currents this loco draws. A number of these locos have been retrofitted with static converters to power the auxiliaries, replacing the older Arno rotary converters. These

static converters are more efficient and require less maintenance, besides having self-diagnostic systems to make troubleshooting easier.

NEED & SPECIFICATION OF WAG-7AC

With the ever increasing freight traffic and the need for hauling heavier loads in 1in 200 grades at increased balancing speeds, BHEL JHANSI went into for the design of an upgraded version of WAG-5 locomotive with high capacity transformer, rectifier, traction motor, compressor and other matching associated equipment.

These are six axels loco with axel and nose suspended drive. DC series motors, controlled by a tap changer are used in this locomotive. Indian Railway is going to achieve 700Million tones of traffic; WAG-7 is the stay of loco main. In the locomotive vehicle market WAG- 7 is more economical option and one of the cheapest in the world.

SPECIFICATION

TRACTION MOTORS: Hitachi HS15250-G. Motors built by CLW and BHEL.

GEAR RATIO: 65:18(65:16)

TRANSFORMER: CCL India, type CGTT-5400, 5400 KVA, 32 TAPS.

RECTIFIERS: Two silicon rectifiers, cell type S18FN350 (From Hind Rectifier), 64 per bridge, 2700A/1050V per cubicle.

AXLE LOAD: 20.5T

BOGIES: Alco High-adhesion bogies, fabricated bogie frame assembly with unidirectional mounting of traction motors, primary and secondary suspension.

HAULING CAPACTIY: 3010 T

PANTOGRAPHS: Two stone India (Kolkata) type AN-12.

CURRENT RATINGS: 1350A/2MIN, 1200/10MIN, 960A,HR, 900A continuous.

LOCOMOTIVE MANUFACTURING UNIT

Here is the locomotive manufacturing unit .It has been divided in two shops:

1) Bogie shop

Step by step process carried out in Bogie shop:

Machining of axle: Axle is prepared in bogie shop out of thick cylindrical raw material.

Facing and drilling operation is done on the axle. Turning operation is done on the axle to get the required diameter, by

CNC machine. Grinding operation is done on the axle to make the surface smooth.

1. Preparation of collar and wheel

The collar and wheel are machined to get the desired accuracy. Collar contains a small hole inside which helps in releasing of oil. It is provided across the gears so that it doesn’t move on axle and forms a firm grip.

2. After machining these parts are assembled on pressing machine. The collar, gear, wheel are pressed on the axle via pressing machine.

3. Tube is fitted on the axle and traction motor is assembled on it. Tube supports the traction motor and keeps it stationary while axle is rotating. The gear and pinion (gear of traction motor) are meshed together (the teeth’s are in ratio 64:16 respectively).

4. Axle box is assembled. It has tapered bearing system.

5. After the assembly is complete following test is performed as per the specification:

Wheel Testing : In this process the testing of the assembly of traction motor and wheel (with gears and axle box) on axle is done. This test is called traction motor run test. In this test servo-57 or ENCLO-68 oil is used. It ensures clean commutater.

Specification:

Axle caps of TM-4906 and TM-4605 AZ

Traction motor supply-Voltage 30-40 V DC

Current 70-90 Amps

Duration 2hrs

Backlash test : Any backlash if occurred is recorded and any abnormality like bearing noise is also noted. Backlash limits 0.3-0.8mm.

1. Bogie frame is prepared by achieving desired accuracy. Accuracy is achieved by machining it through CNC machine (COOPER machine).

2. After final machining bogie fitting is done. Bogie fitting includes following steps:

Liner mounting. It is done so that the shell of the bogie can be mounted at this place. The shell structure is pivoted at this place, and liner provides a smooth joint.

Pneumatic brake system is installed. a) Bush brake system is assembled.b) Brake rigging is done.

Wheel axle system is mounted. Suspension arrangement is done which includes mounting of springs

and linkages. Beam mounting is carried out by mounting two equalizer beams.

These beams maintain the alignment of the train by transmitting the suspension motion equally.

Bogie trail load is applied for coupling of Axle with Bogie by tightening of Horn Stay to the Bogie. By applying load the vertical gap between the axle box and padstle reduces and thus the gap can also be maintained. Horn stay provides a support to the axle mounted in the padestle, so that if frame assembly is lifted the Wheel Axle arrangement does not run out.

Rubber is mounted on the frame which is connected to the Traction motors for giving a vibration absorbing support caused due to the suspension of Wheel and Axle system.

After bogie frame is ready it is send to the assembly shop.

2. Assembly shop: The shell is received from fabrication shop. Dismantling of roof Transformer marking drilling

Main reservoir &Aux. reservoir mtg.

Battery box mtg.

After cooler mtg.

SL-30 1st,2nd mtg.

Cattle guard mounting at both end.

Pivot mtg.

AC-2 panel mtg.

MVMT 1st mtg.

Roof sub. Assy.

a) Roof line & Panto insulater mtg.

b) Lightening Arrester

c) Earthing on roof.

Compressor (MCP)-1,2,3 mounting.

Baby Compressor mtg. with its oil tray.

AC transformer mtg

Power cable termination

Painting

Chequred plate in cabin-1&2

Cable laying

General Inspection

Testing

TESTING

Testing is carried out after all the assembly is complete. Following steps are performed in testing:

1. HV & IR (High Voltage and Insulation Resistance) Test: In this testing the insulation of the cabling is tested. Whether there is any leakage of current and its resistance fits the required limit.

2. Sequence Test: This is to check whether the wiring is done accordance with the drawing or not and supply circuit is working properly.

3. Under Catenary Test: 100V supply is provided through battery to baby compressor (8 kg/cm2) then Pantograph is lifted. VCB (Vacuum Circuit Breaker) is closed so that the supply gets transferred. Supply goes to the Rectifier, SL etc. and the circuit is thus tested completely.

4. Axillary Run Test: MVMT (for cooling of motors), MVRH (cooling of circulated oil), MVSL (cooling of smoothening reactor), MVSI (cooling of rectifier), MVMP (cooling of motors) run test.

5. Pneumatic Test: This is to check the working of brake system.

6. Traction Motor Test: To check the direction of rotation of traction motor.

7. Rain Test.

8 Long Run Test: Final Bogie is tested by running 4-5 km in nearby station and DBR test is performed during the run.

Various machines employed in the shop:1) HOESC –pressing machine –wheel, axle, collar, and gears are pressed

together on this machine. Pressing limit (95 – 132 tones)

2) Cooper machine: wheel turning CNC machine .

Specification Travel along x-axis – 1000mm

Travel along z-axis – 3000mm

Swing over bead – 760mm

Spindle nose – 5mm

Spindle power – 20 kw

3) Asquith CNC machine (bogie machining center): Bogie after being prepared

from fabrication shop comes to bogie shop for machining. In machining of bogie,

various processes like boring drilling, milling, facing etc. is done through

ASQUITH CNC MACHINE

Specification:-

travel in x –axis 8000 mm

travel in y- axis 4000 mm

travel in z- axis 800 mm

spindle dia. - 180 mm

spindle power 40kw

auto tool changer 40 tools

4) Hydraulic arm drilling machine

5) Radial arm drilling machine

6) Turret lathe:

Specification:

Swing over saddle- 596mm (max)

Swing over cross

Slide-317mm

Flange to turret

Face – 1500mm

7) Axle drilling machine

8) Centre drilling and facing machine:

Specification:

Work holder – 160*3000 HID

Stock removal – 5.5mm

Gang drilling – 3no UNC 98mm PCD/100mm PCD

Motor power – 10.5 – 5.5 HP

9) Axle turning machine

10) Churchill machine tool: CNC vertical milling m/c

Specification:

1. Travel in x-axis – 1200mm

2. Travel in y-axis – 600mm

3. Travel in z-axis – 400mm

4. Spindle dia – 180mm

5. Spindle nose – ISO 50

6. Spindle power - 30 kw

7. System – SINUMARIL 80Omm

11) Hydraulic Pipe Bending Machine: This machine is in Assembly Sop and it is

used to bend pipe of various diameter at various angles.

Specification:

Max. capacity 65mm OD*6mm thick ferrous tube

Max. bend radius - 300mm

Length over mandrel - 6mtr

Hyd. Tank capacity - 200 ltr

Total H.P- 100

Types and product ranges:

a) Electric Locomotives :WAG-9,WAG-7,WAG-5,WCAM-2,WCAM-3,WCAG-1

b) Diesel Electric Shunting Locomotives :350 hp,450 hp,700 hp(TPP),1150

hp(SPP),1350 hp(SPP),1400 hp(SPP),2600 hp(SPP)

c) New Products :

1. OHE (Recording and Testing car)

2. UTV (Utility vehicle)

3. RRV (Rail cum Road vehicle)

4. DETV (Diesel Electric Tower car)

5. BPRV (Battery powered road vehicle)

6. BCM (Ballast cleaning machine)

7. Metro Rake-Kolkata Metro Railways

8.200 T Well wagon for BHEL Haridwar

The main parts of the locomotive are Under frame : The frame on which a locomotive is built

Super structure : The body of locomotive is called superstructure or Shell and

is made of sheet of Mild steel

DC motor

Alternator

Compressor

Flower

Static Rectifier-MSR

Static Converter-SC

Exchanger

Bogie -The wheel arrangement of a loco is called a bogie. A bogie essentially

contains

1-wheel axle arrangement

2-Suspension

3-Brake rigging

Traction transformer: It is fixed on under frame and gets supply from an overhead

line by equipment called pantograph. The type of pantograph depends on supply.

This transformer steps down voltage and is fitted with a tap changer. Different taps

are taken from it for operating different equipment. One tap is taken and is rectified

into DC using MSR and is fed to the DC motor.

Railways has two types of power supplies – 25 KV, 1 Phase, 50 Hz AC

-1500 V DC

An AC/DC loco is able to work on both of these supplies. For e.g. WCAM-3.

EQUIPMENTS AT A GLANCE

Figure 1.1 BLOCK DIAGRAM OF ENGINE ROOM LAYOUT

CAB-1 Compressor

↓

MVMT Blower: Cooling of traction motors.

↓

BA-1 Panel: Speeding control through shunt resistance.

↓

Triplate pneumatic console

↓

RS-1 {Rectifier}

↓

DBR {Dynamic Brake Resistance}

↓

SL-42 {Smoothing Reactor}: Removes pulses from DC signal.

↓

Transformer

↓

SMGR{Tap Changer}

↓

SL-42{Second}

↓

ATFEX Transformer

↓

BA-3 Panel

↓

BA-2Panel

↓

RSI-2

↓

RC Damping

↓

Static Converter: Converts single phase current to 3 phase.

↓

MVMT Blower-2

↓

Baby Compressor

The above flowchart clearly gives us a handy look at the equipments used in the

locomotive WAG-7.

BROKEN code for the present locomotive.

W- BROAD GAUGE A- RUNNING IN AC MODE G- HAULING GOODS TRAIN

So, this locomotive is basically made for hauling goods train or we can say its freight

carrier.

1. COMPRESSOR (MCP):-

Three compressors are used to produce compressed air to transmit force in an air brake system. Compressor is designed to pump air into reservoir, which result in pressurized air. The compressor in constant drive with engine. A governor controls the maximum & minimum air pressure in the system. The compressor is of reciprocating type. The compressor must be able to build reservoir air pressure 50-90 P.s.i within three minutes.

SPECIFICATION:-

It is reciprocating type compressor.

a. It has three cylinders.

b. 14 HP

c. 900 RPM

d. Working pressure 18.5kg/cm2.

e. Air supply 1000 liter/minute.

2. BLOWER:-

Three types of centrifugal blowers are used in the engine room for cooling purpose.

(i)MVMT BLOWER-

They are two in numbers & one is assigned for each bogie to cool the three traction motor mounted on each bogie.

(ii)MVSL BLOWER-

They are small in size & two in numbers. They are used in cooling of smoothing reactor i.e. SL-30.

(iii)MVRS BLOWER- It is a single unit mounted in a transformer assembly. Its purpose is to provide forced in air for cooling of radiator in which hot transformer oil is circulated.

3. BA PANEL:-

The WAG-7 consists of three BA panels i.e. BA panel 1, 2&3.

It is controlling device of traction motor, sl-30 &other minor equipments.

It controls the traction motor.

4. TRIPLATE PNUMATIC CONSOLE (TPC):-

It is system of valves which is responsible for braking in bogie of locomotive engine. This system of console takes the compressed air from air reservoir 1 & 2 and supply further to different valves for various operations to be occurred.

It contains various types of valves having different characteristic.

Some of them are-

(i) SA9 valve

(ii)C2W valve

(iii)F 1 Selector valves

5. RECTIFIER (RSI 1&2):-

Locomotive is provided with two set of air cooled silicon rectifier connected in Graetz Bridge. Each of these rectifier shall be supplied by separate secondary of main transformer. Its job is to convert AC current to DC current.

6. DYNAMIC BRAKE RESISTNCE (DBR):-

A locomotive shall be equipped with rheostat braking arrangement capable of breaking during event of failure of electric brake on the train & air brake on locomotive. It shall be applied automatically. Braking effort regulating shall be obtained by adjustment of traction motor excitation.

The field of all the motor will be connected in series & lead by one of the two silicon rectifier bridge connected by mean of intermediate transformer to one of the two secondary winding of transformer. The control of excitation shall be provided by tap changer.

7. SL-42:-

It is a smoothing reactor and it is two in number. It is located blow under frame. Converted by its casing. Its function is to smoothen the DC current.

8. TRANSFORMER:-

The main transformer shall be oil submerged type. The oil will be forced circulate through winding by an electric pump & cooled in a radiator with a blower the transformer will have the combined winding on a combined core in a same tank.

(i). A variable order transformer winding incorporates various tap changer, the normal voltage being 22.5 to 27.5kv.

(ii). A fixed ratio transformer the primary winding of which it is connected to auto transformer, tap changer heaving a variable voltage from 0 to 22kv. This transformer will have 2 separate secondary winding.

Transformer consist mainly 5 parts

1. Radiator

2. Conservator

3. Rps

4. Blower

5. Smgr

(I)RADIATOR:-

In radiator hot oil circulate for cooling purpose for increasing surface area for heat transformer.

(II)CONSERVATOR: - Its role is to maintain the level of oil in the transformer tank.

(III)RPS: - It is a resistance parallel to a motor winding.

(IV)BLOWER: - Blower blows the cooling air through the radiator cool the oil through it.

(V)SMGR: - It is a panel which helps in tap changing.

9. ATFEX TRANSFORMER:-

Its main purpose is to provide electric braking. Low voltage supply is received from this transformer. Secondary winding which is feed to the field winding of traction motor. As soon as current flows in secondary winding the motor works as a generator & the voltage produced is consumed by a resistance due to loading (resistance) on the motor. Its speed decrease & finally it stops in this way it acts like an electric brake.

10. RC DAMPING:-

The main purpose of RC damping is to remove voltage dampness i.e. to produce pure dc.

11. STATIC CONVERTOR:-

It is an electric device used to convert single phase as to 3 phase ac. This 3 phase supply is used for running for the auxiliary devices.

12. BABY COMPRESSOR:-

It is compressor used to develop air pressure to lift the pantograph. It operates at 110 volt provided by a battery supply.

13. TRACTION MOTOR:-

(A) The traction motor shall be series d.c. pulsating current. The motor shall be designed as to fit properly in the bogie having adequate margin and reliability levels.

(B) Traction motor armature shall be vacuum pressured impregnated solvent less resins per procedure adopted for manufacture of traction motor by BHEL.

(C) The motor shall be taken for manufacture only after the manufacture of design by R.D.S.O.

(D) The motor shall fulfill the following parameters broadly.

Mounting: - Axel hung nose suspended

Rating: - RPM =895; VOLTAGE=750

CURRENT=900; O/P=630Kw

(MADE IN BHEL BHOPAL)

14. PANTOGRAPH:-

The locomotive shall be equipped with two pantographs. Normally the trailing end pantograph shall be used. The pantograph selector switch shall be provided in the driver’s desk. For raising, either of pantograph or both of the pantograph at a time. Raising &lowering of the pantograph with locomotive in motion will not cause any un-due disturbance to OHE.

(A) It shall be possible for each of these pantograph to be disconnected from the roof equipment &earthed in case of damage.

(B) The metallized carbon strips to be used as pantograph as is being used in IR.

15. TAP CHANGER:-

(i) The tap changer shall be of on load type oil immersed with circulating pump and filter and shall have 32 running taps controlled by an electro pneumatic servo motor.

(ii) In case of failure of the tap changer control circuit it shall be possible to operate the electro valve of tap changer directly from the driver’s cab. Also a manually operated handle shall be provided to move the tap changer.

(iii) A notch repeating device in each cab shall be indicated the position of the tap changer.

(iv) The tap changer shall be complete with switching contractors and resistance.

PANTOGRAPH

The pantograph is the collector used to slide along the contact wire as has been

explained in section 3.6.3.1. It has a conducting strip which is pressed against the

contact wire by springs. The collector strips are usually of steel with grease lubrication,

or of carbon, in which case no lubrication is needed. Function of the pantograph is to

maintain as constant a pressure as possible between the collector strip and contact wire

and to prevent any vertical oscillation of the collector strip; as these will produce arcing

due to braking of electric contact. When the pantograph is not in use, it is maintained in

lower position with the help of stiff springs. The collector strip is raised by compressed

air when it is to be used.

As per the specifications, the WAG-7 locomotive shall be equipped with two pantographs having the metallized carbon strips. Normally, the trailing end pantograph will be used but a selector switch should be provided on the driver’s desk so that either or both of the pantographs can be raised. The raising up or down of the pantograph while in motion should not cause any disturbance in the OHE.

MAIN CIRCUIT BREAKER

An electro pneumatically operated single bottle vacuum circuit breaker is mounted on

the roof of the locomotive to connect the transformer to 25 KV AC overhead line

through the pantograph and to clear any fault in traction power circuit. The breaker

should be operational via a switch located in the driver’s cab. The circuit breaker should

have a rupturing capacity of 400MVA and a continuous rating of 1000Amps at 25 KV.

The suitable interlocks are provided for tripping the circuit breaker in case the air

pressure becomes low to a value at which the raised pantograph leaves the contact

wire.

LIGHTENING ARRESTOR

A gapless lightening arrestor of proven design similar to those working in three phase

locos is provided for protection against the line voltage transients caused by lightening

or system switching.

TRACTION MOTOR

Traction motor refers to an electric motor providing the primary rotational torque of a machine, usually for conversion into linear motion i.e. traction.

Traction motors are used in electrically powered rail vehicles such as Electric multiple

units and Electric locomotives, other electric vehicles such as electric milk floats,

elevators and conveyors as well as vehicles with electrical transmission systems such

as diesel-electric and electric hybrid vehicles. Additionally the electric motors in other

products such as the main motor in washing machines are described as traction motors.

Before the mid-20th century, a single large motor was often used to drive multiple

driving wheels through connecting rods that were very similar to those used on steam

locomotives. It is now standard practice to provide one traction motor driving each axle

through a gear drive.

Usually, the traction motor is simply suspended between the truck (bogie) frame and the

driven axle; this is referred to as a "nose-suspended traction motor". The problem with

such an arrangement is that a portion of the motor's weight is unsprung, increasing

forces on the track.

In WAG-7 the traction motor used is of series DC pulsating current type. The

armature is vacuum pressure impregnated solvent less resin. The motor fulfils the

following parameters broadly:

Mounting: Axle hung nose suspended

Rating: One hour: 750V, 960A, 870RPM, 670 kW

Continuous: 750V, 900A, 895RPM, 630kW

Weak field: 40%

Maximum permissible Ripple 28%

at continuous current of 900A

Starting current: 1350A for 2 minutes

Short time rating: 1200A for 10 minutes

RHEOSTATIC BRAKING

Dynamic braking is the use of the electric traction motors of a railroad vehicle as

generators when slowing the vehicle. It is termed rheostatic if the generated electrical

power is dissipated as heat in brake grid resistors and regenerative if the power is

returned to the supply line. Dynamic braking lowers the wear of friction braking

components and additionally regeneration can also lower energy consumption.

During braking the motor fields are connected across either the main traction

generator (Diesel-electric loco) or the supply (Electric locomotive) and the motor

armatures are connected across either the brake grids or supply line. The rolling

locomotive wheels turn the motor armatures, and if the motor fields are now excited, the

motors will act as generators. For a given direction of travel, current flow through the

motor armatures during braking will be opposite to that during motoring. Therefore, the

motor exerts torque in a direction that is opposite from the rolling direction. Braking

effort is proportional to the product of the magnetic strength of the field windings, times

that of the armature windings.

The locomotive WAG-7 is equipped with rheostatic braking arrangement

capable of braking effort of around 20T over a speed range of 25 to 50 km/h. In the

event of failure of the electric brake brakes on the train the air brake on the locomotive

will be applied automatically. Braking effort regulation are obtained by adjustments of

the traction motor excitation. The field of all the motors are connected in series and fed

by one of the two silicon rectifier bridge connected by means of an intermediate

transformer to one of the two secondary windings of the transformer. The control of the

excitation is provided by the tap changer. The dynamic braking resistance is forced cool

by AC motor blower set (AC MVRF). In case of emergency brake application by the

driver, the electric brake, if applied will be automatically cut off.

BATTERY

Batteries of adequate capacity are provided on the locomotive to feed the equipment for

three hours starting with a half charged battery when the locomotives are coupled in

multiple. The battery can be of lead acid type or latest with PPCP containers.

CONTROL EQUIPMENT & SAFETY DEVICES

The LED flashers light are provided in the locomotive. The microprocessor based

control and fault diagnostic systems are there which can even indicate the availability of

OHE power supply through capacitive coupling.

The safety devices include a new feature in the locomotives manufacturing. The

Vigilance Control Device (VCD) has been installed on WAG-7. The driver has to

acknowledge to periodic vigilance check by pressing a push button. In case the driver is

not vigilant with the first step then the device will flash an indication. If even now, the

driver does not respond then an audio-visual warning will be played and in case of no

response automatically the emergency brakes will be applied and the whole loco has to

be started all again.

PNEUMATIC BRAKING SYSTEM

In the air brake's simplest form, called the straight air system, compressed air pushes on a piston in a cylinder. The piston is connected through mechanical linkage to brake shoes that can rub on the train wheels, using the resulting friction to slow the train. The mechanical linkage can become quite elaborate, as it evenly distributes force from one pressurized air cylinder to 8 or 12 wheels.

The pressurized air comes from an air compressor in the locomotive and is sent from car to car by a train line made up of pipes beneath each car and hoses between cars. The principal problem with the straight air braking system is that any separation between hoses and pipes causes loss of air pressure and hence the loss of the force applying the brakes.

SPECIAL FEATURES OF WAG- 7AC1. Air conditioned driver’s cab.

2. Vigilance control device to monitor driver’s alertness.

3. Stick type master controller for operation by driver in sitting position.

4. Ergonomically designed driver’s desk in FRP.

5. Improved aesthetics using FRP panels for walls, roof & floors.

6. Fire retardant paint for engine room interior.

7. State of art-cable management system-epdm modules.