diploma in marine surveying. module e marine engineering ... · marine surveying. module e marine...

51
1 DIPLOMA IN MARINE SURVEYING. MODULE E Marine Engineering Surveying Paul Russell MSc, BA (Hons), MIMarEST Marine Engineer and Education Specialist Managing Director and Founder Thamesview Maritime Limited, Updated December 2017 by Allan T Larsen Managing Director Larsens Marine Surveyors & Consultants Ltd.

Upload: others

Post on 13-Mar-2020

36 views

Category:

Documents


9 download

TRANSCRIPT

Page 1: DIPLOMA IN MARINE SURVEYING. MODULE E Marine Engineering ... · MARINE SURVEYING. MODULE E Marine Engineering Surveying Paul Russell MSc, BA (Hons), MIMarEST Marine Engineer and Education

1

DIPLOMA IN

MARINE SURVEYING.

MODULE E

Marine Engineering Surveying

Paul Russell

MSc, BA (Hons), MIMarEST

Marine Engineer and Education Specialist Managing Director and Founder Thamesview Maritime Limited,

Updated December 2017 by

Allan T Larsen

Managing Director

Larsens Marine Surveyors & Consultants Ltd.

Page 2: DIPLOMA IN MARINE SURVEYING. MODULE E Marine Engineering ... · MARINE SURVEYING. MODULE E Marine Engineering Surveying Paul Russell MSc, BA (Hons), MIMarEST Marine Engineer and Education

2

PLEASE NOTE

Directed Learning has been provided at the end of each chapter. These questions are designed to help

you with your study. The questions are for your personal study only; do not send in your answers to these questions as they will not be assessed.

Please note that reference numbers in square brackets are provided throughout the text. These relate to the references section at the end of this module (before the appendices).

© Copyright IIR Limited 2017. All rights reserved. These materials are protected by international copyright laws. This manual is only for the use of course participants undertaking this course. Unauthorised use, distribution, reproduction or copying of these

materials either in whole or in part, in any shape or form or by any means electronically, mechanically, by photocopying, recording or otherwise, including, without limitation, using the manual for any commercial purpose whatsoever is strictly forbidden without prior written consent of IIR Limited.

This manual shall not affect the legal relationship or liability of IIR Limited with, or to, any third party and neither shall such third party be entitled to rely upon it. All information and content in this manual is provided on an “as is” basis and you assume total responsibility and risk for your use of such information

and content. IIR Limited shall have no liability for technical errors, editorial errors or omissions in this manual; nor any damage including, but not limited to direct, punitive, incidental or consequential damages resulting from or arising out of its use.

Page 3: DIPLOMA IN MARINE SURVEYING. MODULE E Marine Engineering ... · MARINE SURVEYING. MODULE E Marine Engineering Surveying Paul Russell MSc, BA (Hons), MIMarEST Marine Engineer and Education

3

CONTENTS

1. INTRODUCTION. ..................................................................................................................... 5

1.1 Scope of Marine Engineering Surveys. ................................................................................... 5

1.2 Preparation for Survey ........................................................................................................ 6

1.2.1 Your Principals .............................................................................................................. 6

1.2.2 Reasons for Survey ....................................................................................................... 6

1.2.3 Working with Other Surveyors ........................................................................................ 7

1.2.4 Equipment to be Used ................................................................................................... 7

1.2.5 Document Search ......................................................................................................... 7

1.3 Techniques Used by Marine Engineering Surveyors .................................................................. 8

1.3.1 Analysis of Oil and Water Samples ................................................................................... 8

1.3.2 General Condition of the Engine Room and the Equipment .................................................. 8

1.3.3 Planned Maintenance Systems (PMS) ............................................................................. 10

1.3.4 Shock Pulse Monitoring ................................................................................................ 12

1.3.5 Vibration/Noise Monitoring ........................................................................................... 13

1.3.6 Oil-in-Water Detector (Oily Water Separator) .................................................................. 13

1.3.7 Oil Mist Detector ......................................................................................................... 14

1.3.8 Machinery Condition Monitoring .................................................................................... 14

1.3.9 Non-Destructive Testing (NDT) ..................................................................................... 15

1.3.10 Engine Room Record Books ........................................................................................ 16

1.3.11 Prevention (Case Study) ............................................................................................ 16

2. THE ROLE OF THE CLASSIFICATION SOCIETIES. ....................................................................... 20

2.1 The Main Role of the Classification Societies is ensuring that the ship and machinery conform to the

rules developed by the society and, the Classification Certificate issued by it. ................................. 20

2.2 Surveying Powers of the Chief Engineer ............................................................................... 21

2.3 Prevention of Detention by Port State Control (PSC) .............................................................. 21

2.3.1 Anchors, Cables and Windlass ....................................................................................... 23

2.3.2 Protection of Personnel ................................................................................................ 23

2.4 Type Approval of Equipment .............................................................................................. 24

3. THE WORK OF THE INDEPENDENT MARINE ENGINEERING SURVEYOR. ......................................... 25

3.1 Introduction .................................................................................................................... 25

3.2 Discussions with Engine Room Staff .................................................................................... 25

3.3 Repair of Machinery .......................................................................................................... 25

3.4 Prime Movers and Power Transmission ................................................................................ 26

3.4.1 Diesel Propulsion Units ................................................................................................ 26

3.4.2 Piston Rings ............................................................................................................... 30

3.4.3 Turbochargers ............................................................................................................ 30

3.4.4 Compressed Air Starting Systems .................................................................................. 31

3.4.5 Steam Turbine Plant .................................................................................................... 32

3.4.6 Gas Turbine Propulsion ................................................................................................ 33

3.5 Auxiliary Machinery (Including HVAC Systems) ..................................................................... 36

3.5.1 Air Compressors ......................................................................................................... 36

3.5.2 Fresh Water Generators (Evaporators) ........................................................................... 37

Page 4: DIPLOMA IN MARINE SURVEYING. MODULE E Marine Engineering ... · MARINE SURVEYING. MODULE E Marine Engineering Surveying Paul Russell MSc, BA (Hons), MIMarEST Marine Engineer and Education

4

3.5.3 Steering Gear and Hydraulic Equipment ......................................................................... 37

3.5.4 Refrigeration and Heating, Ventilation and Air Conditioning (HVAC) .................................... 38

3.5.5 Fuel and Lubricating Oil Treatment ................................................................................ 40

3.5.6 Waste Management ..................................................................................................... 41

3.6 Pumps and Pumping Systems (Including Filters, Strainers and Heat Exchangers) ....................... 41

3.7 Electrical Equipment ......................................................................................................... 44

3.7.1 Electrical Generators ................................................................................................... 44

3.7.2 Switch Gear and Distribution Systems ............................................................................ 45

3.7.3 Motors ...................................................................................................................... 46

3.7.4 Control Equipment ...................................................................................................... 46

3.7.5 Batteries ................................................................................................................... 46

3.8 Deck Machinery................................................................................................................ 47

3.8.1 Hatches ..................................................................................................................... 47

3.8.2 Cranes and Lifting Gear ............................................................................................... 48

3.8.3 Containers ................................................................................................................. 49

4. Ballast Water Management ..................................................................................................... 50

5. RECOMMENDED READING AND USEFUL INTERNET SOURCES ...................................................... 51

Page 5: DIPLOMA IN MARINE SURVEYING. MODULE E Marine Engineering ... · MARINE SURVEYING. MODULE E Marine Engineering Surveying Paul Russell MSc, BA (Hons), MIMarEST Marine Engineer and Education

5

1. INTRODUCTION.

1.1 Scope of Marine Engineering Surveys.

Ships are becoming ever more technical in their design with new technology emerging to improve efficiency, reduce pollution, increase safety and to meet with the demands of new and updated regulations. The Marine Engineer and, the Ship Surveyor, must remain knowledgeable and competent

with regards to these changes. This module on marine engineering surveys will primarily focus on the main propulsion system and the

auxiliary machinery required to keep the ship, and the people sailing in her, safe. Also, the new Ballast Water Treatment regulations which entered into force on 08th September 2017 will be discussed. Surveying the hull, cargo, safety equipment and environmental impact may be the objective of different

surveys. However, each of those surveys could also have a direct impact on marine engineering and will, therefore, be of interest to the marine engineering surveyor. For example, if the hull has been damaged in the general area of the main engine bedplate and holding down arrangement, then the main engine

may or may not have been damaged as a result and, the alignment of the shaft line could have been adversely affected. Extensive investigation will ensue, that could involve a number of different surveyors.

The marine engineering surveyor, for example, may have to work closely with the hull surveyor to determine the full extent of the damage and the event timeline. The marine engineering surveyor must also be aware of a continually changing industry in order to keep

fully up-to-date with the latest industry standards. For example, a marine engineering surveyor may have to find the root cause of engine damage due to poor fuel oil injection (see case study in Section 1.3.6) caused, possibly, by the poor quality of the fuel. Therefore, he or she will need to know the latest

equipment being used and the “normal” practices that should be in place on the ship that is being submitted to survey.

During the 1970s and 1980s the industry started to use progressively heavier fuel oil to reduce fuel costs; currently there is a move towards Low Sulphur Fuels (LSF) with the MARPOL 73/78 Annex VI

(Regulations for the Prevention of Air Pollution from Ships), NOx Technical Code, very much in force. Now, in 2017/2018 the industries use of LPG as a fuel for ships becoming increasing evident.

This NOx Technical Code now requires that ships retain samples of fuel oil used for twelve months and the bunker receipts must be retained for 36 months. This is an example of recent legislation with which

the marine surveyor must be familiar. The marine engineering surveyor will also need to have a broad range of knowledge covering several

disciplines. Modern machinery is a complicated combination of electronics, pneumatics and/or hydraulics working in conjunction with mechanical systems. The maritime world is due to expand in this area as the advantages of condition based monitoring and “mechactronics” become more widely appreciated by shipowners and designers.

Surveyors should also pay attention to the qualifications and the experience of the engineers on board. So many problems with modern machinery can be traced back to the lack of correct care or operation of

the equipment due to the lack of knowledge and competence of the staff. On paper, everything may look in-order but that may not be the case and, the surveyor should be ready to question the validity of official certificates (certificates of competency or certificates of equivalent competency) and other

qualifications. This means that the modern surveyor must have a good appreciation of the interaction between these different areas of engineering. For example, the interaction between Low Sulphur Fuels (LSF) and the

lubricating oil used is a complicated one. The engine manufacturers’ recommendations are to be followed carefully. This is because the way the fuel is blended or, the fact that the sulphur has been removed, has an effect on its interaction with the lubricating oil, or the reduced lubricating properties can cause a

blockage or seizure of the fuel pumps. Special consideration must be paid to two stroke engines where

the interaction between the cylinder oil and the different types of fuel oil can cause considerable damage if there is a lack of compatibility.

Page 6: DIPLOMA IN MARINE SURVEYING. MODULE E Marine Engineering ... · MARINE SURVEYING. MODULE E Marine Engineering Surveying Paul Russell MSc, BA (Hons), MIMarEST Marine Engineer and Education

6

1.2 Preparation for Survey

Prior to undertaking a commission, the independent marine engineering surveyor running his or her own business would have to take care to gain assurances about payment and work ethics from a prospective customer. This calls for a sound business sense and the following sections are intended to provide brief

guidance in this respect.

1.2.1 Your Principals

The starting point is to be aware of exactly who your principals are. If you work regularly for a customer

then you will have already built up an understanding and trust of one another. However, it is still good professional practice to obtain written authorisation for the survey that you are undertaking.

The authors of other modules in this course have stressed the need for clarity before you embark on a surveying task. This is especially true of marine engineers because they have a tendency to concentrate on the technical problems and, as a consequence, they might put less emphasis on being absolutely sure

about the reasons for attending a vessel for inspection. If the person requesting the survey is a long-standing client there may not be a problem. However, accepting a new request for survey from someone you do not know will always carry an element of risk.

For this reason, your standard contract should carry clear statements about what action you will take in the event of the client defaulting on the undertaking. If, for example, your terms carry an interest penalty for late payment this should be stated clearly in your original contract.

It would also be a good idea to produce a pro-forma document, listing all the basic information that you require, to be completed by the person or company for whom you are undertaking the work. This will

ensure that you receive accurate information or, if the information is not forthcoming and you have some research to carry out, then you will at least have evidence for claiming the additional cost you incur for that research.

A pro-forma document will also help to overcome any language or cultural difficulties that may arise and will allow even non-technical people to find the correct answers to your questions.

Your principals can be asked to agree to any request for an initial payment to cover your own up-front costs such as travel and accommodation.

If there is no up-front payment then make sure that you record all the costs and make a claim later, or offset these costs against your tax payments as expenses. You will also need details such as the “invoice address” and who your principal is representing, whether it

is a direct employment or whether a third-party is involved. The politics involved in this profession may not be obvious to the marine engineer, but it must be

understood that a survey may be carried out for a whole variety of reasons and these reasons may not, at first, be clear.

Don’t forget that your Personal Protective Equipment (PPE) should be of a good standard and in good condition, as you cannot always rely on good PPE being available on board every ship. It is also a good idea to carry out some research relating to the place where the survey is to be carried

out. This not only helps you to know how to get to the vessel but it also means that you can find local

resources where you might be able to have any repair work completed or lab tests carried out on oil or water samples.

I still think that building your own website full of technical information and links is a good idea as you will have all your needs in one place. This technique has been used by many of our former students and seems to work well.

1.2.2 Reasons for Survey

There are a number of reasons why a marine engineering survey maybe performed. These could be as part of a pre-purchase survey, a machinery condition survey, breakdown or failure survey or class survey. However, to complete the task that has been assigned to them, the surveyor must take into

consideration all manner of other related factors before coming to a fair conclusion.

Page 7: DIPLOMA IN MARINE SURVEYING. MODULE E Marine Engineering ... · MARINE SURVEYING. MODULE E Marine Engineering Surveying Paul Russell MSc, BA (Hons), MIMarEST Marine Engineer and Education

7

Although the final report will be about the primary reasons for the survey, the surveyor must build up a general picture in their mind about the background to the main reason for their attendance.

There will be several techniques to use, though not all will be required every time. These will include observations, interviews, reading notice boards, log books and instruments in the machinery space.

The general information and techniques have been explained during your progression through this

course. However, the marine engineering surveyor must now also bring their diagnostic and technical ability into the process.

If you think that faulty fuel injection is the cause of damage to an auxiliary engine, explanations for arriving at the correct conclusion are important because your evidence could be used as the basis for an

insurance claim. The liability for settling the claim may vary depending upon the conclusion of the cause of the damage, namely, whether due to faulty manufacture or poor quality of fuel or lack of proper maintenance.

1.2.3 Working with Other Surveyors

From time to time the marine engineering surveyor has to work with other surveyors and, as with other human activities, personalities will inevitably be brought into the equation. However, there are some

common-sense ideas and processes that will help you to complete a professional job. It is always a good idea to know exactly why the other surveyors are involved. This will determine your

overall approach. As with so many things, communication is the key to the successful completion of a survey.

You might have to discuss and agree on a sequence for dismantling equipment so that all parties are comfortable that vital information will not be lost. This approach also promotes a professional trust between the different parties.

If samples of oil or water are needed for testing, each surveyor may have their own selected laboratories and, therefore, several samples will be needed from the same source. These should be sealed in the presence of the other surveyor(s) and the labels checked.

1.2.4 Equipment to be Used

Do not forget that you will not be able to take an unlimited number of items or equipment with you to survey a ship. It will be prudent to check with the company or the vessel about the availability of any

specialist equipment. Your own Personal Protective Equipment (PPE) is a matter for your own decision, but you should ensure

that you invest in your own high-quality equipment. If you need to use more specialist equipment such as dye penetrant or non-destructive testing equipment then you should check that these are available on board or, you may have to have them delivered to the

vessel prior to your arrival. Alternatively, you may only find out that you need extra equipment when you arrive on board in which

case the equipment may have to be sourced through the local ships agent. It is also important to remember that you cannot carry sharp objects on a flight, especially as hand

luggage. Customs clearance may be a vital issue. The author has had an experience of a significant disruption to the ability of a vessel to discharge its cargo because a vital spare part was not released from the customs

house, which was at the end of the quay. The ship’s agents might play an important role in solving these kinds of problems, especially if the agents

are local and know the local procedures.

1.2.5 Document Search

Before travelling to the vessel, it will be beneficial to collect information from the original equipment

manufacturers (OEM) about the equipment on board. Building up a contacts list will be an important part of building your business.

Page 8: DIPLOMA IN MARINE SURVEYING. MODULE E Marine Engineering ... · MARINE SURVEYING. MODULE E Marine Engineering Surveying Paul Russell MSc, BA (Hons), MIMarEST Marine Engineer and Education

8

During April 2005, the International Chamber of Shipping submitted a paper to the International Maritime Organization detailing how a system might work for holding certificates online.

This system has still in 2017 / 2018 not yet been adopted but it may well be in the near future. The UK’s MCA have plans to operate a “cloud” based system for example, but the lack of low cost access to the internet is still a major disadvantage to the industry. However, Appendix 1 of the paper contains a list of

the documents that are required to be carried on board including a breakdown of which certificates

should be carried by which type of vessel.

Don’t forget also that you might need to brush up on the latest regulations relating to the type of vessel that you are going to work on. For example, passenger ships built under the “safe return to port” criteria will now be in the survey cycle but this will only apply if they the vessel was built after 1 July 2010.

1.3 Techniques Used by Marine Engineering Surveyors

1.3.1 Analysis of Oil and Water Samples

Analysis of oil and water taken from inside machinery is not only a useful tool to the marine engineering surveyor but it is also becoming increasingly important in monitoring the ongoing condition of machinery

as part of a condition monitoring planned maintenance system (PMS). For example, a crankcase explosion could be, in part, due to fuel being present in the lubricating oil. This

might be detected by smell and also by sending a sample of the oil for analysis. Finding the reasons for the fuel entering the oil might prove more of a challenge. The first obvious

component to look at would be the fuel injectors, but there could be other reasons. For example, if fuel pumps are operated from a cam on the camshaft then the seals in the fuel pumps themselves might be leaking fuel into the engine oil drain tank/sump via the camshaft space.

Monitoring some of the chemical components in the engine cooling water has for a long time been a good indicator of the condition of diesel engine cooling spaces.

It is a sharp reminder that accidents can happen to the best of ships. The Marine Engineers Review(MER),

the technical publication of the Institute of Marine Engineering Science and Technology (IMarEST), gave a technical explanation of the explosion that occurred on the passenger vessel SS Norway, formerly the SS

France. [www.cruiseshipfires.com/Fires/SS_Norway_Fire_May_25_2003.html Last accessed 12th December 2017] &

[https://www.ntsb.gov/investigations/AccidentReports/Reports/MAB0703.pdf Last accessed 12th December 2017 refer] This incident showed how vital it is to ensure that correct boiler water testing and treatment is carried out

on a regular basis.

1.3.2 General Condition of the Engine Room and the Equipment

It is very useful for surveyors to take a detailed look at the general condition of the ship and then the engine room and its equipment.

One of the first observations you should make as you approach the vessel and make your way on board is to take a good look at the general condition of the outside. In addition to the general condition you

should note the condition of the paint, the gangway, watertight doors leading to the accommodation entrances, the condition of the engine exhaust, the cleanliness of the funnel and the condition of the bunker station.

Page 9: DIPLOMA IN MARINE SURVEYING. MODULE E Marine Engineering ... · MARINE SURVEYING. MODULE E Marine Engineering Surveying Paul Russell MSc, BA (Hons), MIMarEST Marine Engineer and Education

9

Figure 1 – A clean and tidy engine room and a very untidy engine room.

[Photographs courtesy of Larsens Marine Surveyors & Consultants Ltd. 2017]

The exhaust will tell you a lot about the condition of the engine and will, therefore, give an insight into the extent and effectiveness of the maintenance that is being carried out.

A clean and well-kept machinery space, such as that shown in Figure 1, will mean that time and effort have been spent on the area. If you can see that the machinery is running well and not in various states

of repair then you can start to have confidence in the people who are operating the technical aspects of the vessel.

The surveyor should look for evidence of general good practice, such as whether all the guards are in

place to protect people against rotating machinery and, if the local thermometers and pressure gauges fitted are in working condition. You must also check whether all the hand tools have been replaced on shadow boards or in drawers from where they cannot fly about in rough weather conditions.

There are essential items of main engine spares that are recommended, by the International Association of Classification Societies (IACS), to be carried on board. Some of these spares could be large and heavy

and should always be stowed in a fixed position so that they are not damaged in rough weather conditions. The surveyor must check that this is the case as this could have a cost implication for the owner if expensive spares have to be transported around the world to replace critical spares that have been damaged in rough weather.

If you are to carry out a routine machinery survey, you must independently, check to ensure that the equipment is in good condition and that the engineers have prepared the equipment so that you can also

see that the component parts are in good condition. In addition, class surveyors or surveyors acting for insurance companies will be required to inspect the

components of, for example, a hydraulic pump or the main or big end bearings of the main propulsion engine(s). Good engineering staff should be available to assist the surveyor. If, for example, some components in a

pump need replacing then the engineers should have the new parts ready alongside the old ones so that the surveyor can easily see the problems that have been uncovered.

However, if the surveyor is investigating some machinery failure then it is most desirable that machinery is NOT moved, cleaned, dismantled or worked on in any way until the surveyor requires it to be so or, the investigation has concluded.

In fact, if damaged machinery has been interfered with before the surveyor has had a chance to look and record the initial condition, then the surveyor must determine the reasons why such an action has been taken.

Page 10: DIPLOMA IN MARINE SURVEYING. MODULE E Marine Engineering ... · MARINE SURVEYING. MODULE E Marine Engineering Surveying Paul Russell MSc, BA (Hons), MIMarEST Marine Engineer and Education

10

It is important to find out whether it is because the ship staff have something to hide or, if it is because they are just inexperienced or, are being overenthusiastic in their efforts to help.

The surveyor’s knowledge of cultural differences will help him/her to determine the reasons for the actions of the ship’s staff. The management of cultural differences within a team is becoming crucial for the safe operation of machinery and the surveyor should be alert to any problems in this area that may

have contributed to accidents or machinery failure.

1.3.3 Planned Maintenance Systems (PMS)

Planned maintenance systems are vital for the safe and efficient management of the shipowner’s asset.

The evidence produced by these systems is very important to the marine engineering surveyor. Traditional systems have evolved from breakdown maintenance through time-based planned

maintenance systems to the modern condition based maintenance systems. Reasonable systems could be:

Time-based (numbers of hours run or calendar periods etc).

Consumption of an item (consumable) required to maintain the machine in service (e.g. lubricating oil).

Lifetime of a filter (e.g. where the differential pressure is out of range). Condition monitoring, where a chosen performance indicator exceeds a pre-set level and triggers

the relevant maintenance procedure. Trend analysis of a set of chosen performance indicators (e.g. the main bearing temperatures in a

diesel engine), where the trend in temperature pattern (from one bearing to the others) or a rate

of change (e.g. when a gradual temperature increase suddenly accelerates). This is an area that is increasingly being overlooked by the ship’s staff and as a consequence

some equipment manufacturers are offering this as a service to the shipowner or manager.

For cheap, non-essential items run-to-failure systems could be employed. If you think about the maintenance carried out on a diesel engine then it is general good practice to change the oil before it deteriorates to the stage where it can no longer protect the engine. However, the exhaust trunking, for example, will only be changed if it is damaged. The oil is thus subjected to

a planned maintenance system while the exhaust comes under a “run-to failure” system. A recording and identification system will need to be put in place so that all properly authorised

structures and equipment are easily apparent. If this facility register is computerised then information produced from it will be readily available to authorised managers at a level of complexity appropriate to their management function.

Then, as the systems associated with this register are constructed, the real-time senior management control, in their areas of responsibility, will begin to emerge and become apparent as the system grows.

For the business to be successful, it is necessary for all the functions to be available at maximum efficiency and at the most profitable time. There will be an optimum economic balance between, availability, operational downtime, cost and safety; the main requirement is to constantly reduce

operational downtime risks that threaten this economic optimum. Very good systems will have a maintenance strategy that concludes that not all machinery will be

maintained to the same planned maintenance system. For example, some items will be on a calendar or running hours based system. Critical items might have been moved to a condition based system and small non-critical machinery might even be run until it fails.

However, in this fast-moving area of business and, with a degree of variable requirement of equipment and, with many of the functions in the United Kingdom and European Union (EU) subject to legislative control, historical data is no longer adequate to keep the vessel’s maintenance on track.

It is essential to install a system to provide comprehensive real-time information that will allow all levels of management to monitor performance in relation to the optimum requirement, and to constantly

update the availability demand of equipment operation in relation to the maintenance requirement of this.

Therefore, there is now a move towards condition-based maintenance. One of the reasons for this being

the fact that time-based systems could result in equipment being submitted to ‘over-maintenance’ in some circumstances.

Manufacturers have to ensure that their recommendations for the maintenance intervals are for a worse- case scenario. So, if the operating conditions were light then the maintenance interval could be extended. Operators would however, often be reluctant to do this, as it would leave them open to criticism.

Page 11: DIPLOMA IN MARINE SURVEYING. MODULE E Marine Engineering ... · MARINE SURVEYING. MODULE E Marine Engineering Surveying Paul Russell MSc, BA (Hons), MIMarEST Marine Engineer and Education

11

If condition-based maintenance systems are adopted, then a whole new set of circumstances will exist. For example, an operator could claim that the machinery was running well just before a failure, in an

attempt to justify an insurance claim. In the past, the maintenance would have had to have been completed at set time intervals or based on the machinery’s operating hours. Under a condition-based system much more rigorous testing and

monitoring systems must be utilised to justify extending the maintenance periods.

It must also be remembered that maintenance periods might need to be shortened if the machinery is

subjected to adverse conditions for a period of time. It is vital that the marine engineering surveyor pays attention to the maintenance system that is used on

board any vessel that they are to work on. This would be a good question to ask the shipowner before travelling to attend the ship. Don’t forget that not all machinery needs to be subjected to the same maintenance strategy.

For example, critical items such as main engine crankshaft bearings might be subjected to rigorous inspection and maintenance while a small non-essential pump might just be run until it shows signs of imminent failure. It will be necessary for the marine engineering surveyor to satisfy him/herself that the

ship’s staff understand the system that is in operation and that they show themselves to be diligent in carrying out their duties.

Companies such as MAN and Wärtsilä are looking to take the system further and have all the data about the operation of one of their engines sent back to them on a regular basis by electronic (cloud based) means. In this way, they can ensure correct operation and advise about the maintenance required.

IACS produce a very good “Guide to Managing Maintenance” that gives a clear statement about the objectives of maintenance, the link to International Safety Management (ISM Code), class and flag state. It makes sense to collect data about the machinery and place it into one system. The system should then

produce the reports to satisfy the following requirements: Safe operation of the machinery. The ISM system.

Classification society.

The maintenance system is set up initially around the maintenance schedule recommended by the original equipment manufacturers (OEM). The intervals can be modified by the following condition

monitoring techniques such as: lubricating oil analysis; vibration analysis;

analysis of engine performance data; monitoring pressure and temperature trends; and pulse monitoring.

Please see [http://www.jfmimic.co.uk Last accessed 7 August 2017] for more information about integrated condition monitoring systems.

Condition monitoring, when applied to planned maintenance is sometimes referred to as “predictive maintenance” and when used to initiate maintenance procedures it is also closely linked to “machinery

performance monitoring”. Condition monitoring (CM) means tracking any measurable condition that may be used as part of a

maintenance routine. However, there are practical limitations and for CM systems to work, the condition being monitored must be convenient to read with repeatable results being achieved. For example, it might seem to be a good idea to measure the surface roughness of a main bearing

journal and use the result as a means of regulating the planned maintenance on that bearing. However, at the moment, given the current techniques available, the bearing would have to be dismantled before the reading of roughness could be made, thus making the roughness useless as a condition upon which

to make the decision about whether maintenance is required. However, it may be possible to embed a small wire in the material of the shell bearing below the surface,

so that when and if the bearing material wears away, then the wire surface is worn and an open circuit made that triggers an alarm. This is similar to the warning that is built into the braking systems of motor vehicles.

Page 12: DIPLOMA IN MARINE SURVEYING. MODULE E Marine Engineering ... · MARINE SURVEYING. MODULE E Marine Engineering Surveying Paul Russell MSc, BA (Hons), MIMarEST Marine Engineer and Education

12

MAN prefer to monitor the height of the piston rod with a proximity meter placed on the engine casing just below the lowest travel of the guides on the cross-head bearing, this is accurate enough to measure

the wear on either the cross-head or bottom end bearing in any one unit on an engine. Condition monitoring can apply to items such as filters where only if the condition is poor is a maintenance routine executed.

However, this is also difficult to quantify so as to be useful in everyday situations. Engineers would normally say that a filter with debris in it means that the associated machinery needs some sort of

examination: How do we judge when the filter is in a “poor” condition so that a maintenance routine is carried

out?

Do we extract and weigh the debris? Can we separate out rubber debris from any other sort?

Possibly, under abnormal conditions, a lube oil sample would be sent for analysis.

Usually, condition monitoring is a term that is applied to monitoring in real time, that is, some property is monitored as the machine is operating or running. This is what the operator would ideally want.

A condition monitoring record can also be used to present to surveyors. If experience with the equipment is positive, a good record can be used to show that a particular item of machinery (e.g. pumps) is in good

order and does not need to be dismantled for the survey. This approach can have considerable savings in terms of spares and down time, as well as a saving in terms of the human resource necessary to carry out the stripping down and re-assembly. Some

manufacturers of machinery will offer such systems as bolt-on enhancements. A very dramatic influence on this area of monitoring will be wireless technology. For example, at present

it is difficult to monitor accurately the temperature of the bearings in a diesel engine due to the need to transmit a reading from the moving bearing to the static casing of the engine where it can be read or sent to a remote gauge.

Some efforts have been made to measure the temperature of the oil as it sprays from the bearing but by using wireless technology the manufacturers will be able to send the bearing temperature information to a remote pickup via a wireless signal.

The following section offers information about some of the methods on the market at the present time.

1.3.4 Shock Pulse Monitoring

Shock pulse monitoring (SPM is a registered trademark) [http://www.spminstrument.com/methods/ Last accessed 12th December 2017] is a system where tiny high

frequency shocks from a bearing are measured by a sensor located as close to the monitored surface as possible.

The “shock pulse” describes the specific vibration pulse that is set up when a small protrusion on one moving surface comes into contact with a small protrusion on another moving surface when the oil film, designed to keep the two surfaces apart, does not completely separate the two.

The website [http://www.marineinsight.com/guidelines/condition-monitoring-techniques-what-is-shock-pulse-monitoring-spm/ Last accessed 12th December 2017] gives more detail about how this technology is used.

An electronic circuit is used to filter out the background machinery “noise” and translates the shock frequency into a meter reading. This reading can be measured either by a hand-held unit, or by means of

a hard-wired continuous monitoring installation. In the latter case, it is usual to include some form of automatic alarm function.

A full installation will usually comprise both the hand-held instrument and the permanently cabled system

for critical machinery, so that this can be part of the continuous monitoring programme of maintenance. The hand-held meter would be used by a member of the maintenance crew who will regularly take

readings and keep a log. The system comes with a decision-support system, which will assist the operator to arrive at a decision concerning when maintenance or repair is needed.

Page 13: DIPLOMA IN MARINE SURVEYING. MODULE E Marine Engineering ... · MARINE SURVEYING. MODULE E Marine Engineering Surveying Paul Russell MSc, BA (Hons), MIMarEST Marine Engineer and Education

13

One of the disadvantages of the system is that the pickup is very sensitive and can be prone to false signals (loose pipe clamps being one source). This is particularly important if used in online systems

where alarm functions are included. Therefore, interpretation must be carried out with care, and a visual inspection is necessary before any action is taken.

1.3.5 Vibration/Noise Monitoring

Vibration/noise monitoring is similar to the SPM system whereby the vibration of the machinery (as a whole) is measured and monitored, as opposed to filtering out some of the unwanted “noise”. Alarm hard-wiring possibilities and making a systematic record of levels of vibration are the same as for shock

pulse monitoring. In both shock pulse and vibration/noise monitoring the readings are taken by the same methods. Either

the hand-held meter is plugged into a transducer, which has been permanently installed on the machinery being monitored, or it is applied directly to a designated part of the machine casing/bedplate.

This position is indicated by a distinctive marking that ensures that the instrument is applied as close as possible to the same point on the machine. However, it is difficult to place the instrument precisely in the same position for every reading; there is a consequent loss of accuracy when trends in the readings are observed using this method.

The analysis does require sophisticated software and sometimes the harmonics set up with engines running mean that care has to be taken about when to take the readings.

1.3.6 Oil-in-Water Detector (Oily Water Separator)

The equipment monitors the water content in oil giving a reading (display and recorder if required), with an alarm function, if required. It is suggested that a warning alarm be fitted when installing this.

Meters using a “light scatter” method of detection might have difficulty in distinguishing between oil and dissolved solids. Both scatter the ordinary light and the detector cannot tell the difference between the

two.

Similarly, if the oil is emulsified in the water the detector may not give an accurate reading. Another possibility for a false reading is that the optical detector might become dirty.

Another type of meter on the market measures the wavelength of the light reflected from hydrocarbons that are suspended in a flow of the water to be sampled. The light source is transmitted at one

wavelength and detected at another. Therefore, light reflected from solids will not be detected as the wavelength remains the same.

Page 14: DIPLOMA IN MARINE SURVEYING. MODULE E Marine Engineering ... · MARINE SURVEYING. MODULE E Marine Engineering Surveying Paul Russell MSc, BA (Hons), MIMarEST Marine Engineer and Education

14

1.3.7 Oil Mist Detector

Figure 2 – Oil Mist Detector

The oil mist detector has seen some serious development in recent times, after many years of only a

single producer’s standard instrument being available. The equipment is used to detect the presence of oil mist that might be in explosive/flammable mixtures with air. This is done by comparing the optical

properties of one compartment within the engine with the optical properties of the other compartments.

For many years “Graviner” reigned supreme in this field (see Figure 2). However, there are alternatives available now:

Product Innovations.

LOS Oil Mist Detector by Wormald Fire Systems. Quality Monitoring Instruments (QMI).

1.3.8 Machinery Condition Monitoring

Some of the equipment to be mentioned in this section is the same as that used for monitoring performance. The difference is that for “condition monitoring”, we are looking for faults in machinery/plant, whereas for “performance monitoring” we are looking to measure the efficiency of the machinery.

The purpose in the former case would be to initiate maintenance and in the latter case, we would be (normally) looking to make adjustments to the machinery to bring it back to full efficiency.

Engine/machine performance monitoring means that the actual performance of the machinery is monitored, rather than a specific parameter. There really is no limit, apart from a financial one, to what

can be achieved by this method. However, few shipping owners will go as far as the power producing industry. Most modern power stations are fully instrumented, and as such, the manager can directly view an

instantaneous reading of the plant performance as a whole. Any lack of performance that leads to a reduction in plant efficiency is immediately highlighted, thus allowing remedial action to be taken

straightaway, if required. Alternatively, the machinery can be left to operate, but within set boundary

conditions. When the particular property being measured reaches a set point, then maintenance is performed on that

component thus restoring the plant to full efficiency again. This system of monitoring and maintenance is very efficient and is in widespread use in the bulk power generation industry.

Page 15: DIPLOMA IN MARINE SURVEYING. MODULE E Marine Engineering ... · MARINE SURVEYING. MODULE E Marine Engineering Surveying Paul Russell MSc, BA (Hons), MIMarEST Marine Engineer and Education

15

However, the operation of marine machinery does not generally reach the steady-state conditions experienced in the large-scale power generation industry. For this reason, there is a limit to what is

achievable on a ship using such equipment, and, therefore, the additional costs are not justified. The limited human resource usually available on board is a drawback for the kind of instrumentation that can be fitted to ship’s machinery.

Fitting more instrumentation that is increasingly complicated leads to a maintenance penalty, namely, the cost of maintaining the instrumentation. If specialist staff are not available it can lead to the

instrumentation not being used, or the maintenance being “left for someone else to do”, or worse still, to a situation when maintenance isn’t carried out at all. However, there is much to recommend this type of equipment if it can be fitted and operated correctly.

1.3.9 Non-Destructive Testing (NDT)

Detection of surface cracking would generally be by:

Visual inspection. Magnetic particle testing. Liquid penetrant testing.

Figure 3 – Crack Detection Using a Dye Penetrant

The International Association of Classification Societies’ (IACS) state in their Recommendation 20 (3), that any personnel carrying out a visual inspection must have sufficient knowledge and experience. This should be demonstrated by the qualification of personnel involved in non-destructive testing to a

nationally recognised standard. This standard should be equal to Level II qualification against ISO9712, SNT-TC-1A or EN463. Any person undertaking magnetic particle testing or liquid penetrant testing must be qualified to the IACS

acceptable standards. Such persons will require to hold certification to prove their qualifications. IACS give further information about the testing and repair of crankshafts, propeller shafts and rudder

stocks. The following link will guide the student to the IACS guidelines No 68 & 69 relating to Non-Destructive

Testing (NDT) operations – [www.iacs.org.uk/publications/publications.aspx?pageid=4&sectionid=5 Last accessed

12th December 2017]. Magnetic particle inspection (MPI) works on the principle that a defect in the metal, which could be below

the surface of the metal, causes a distortion in a magnetic flux at the point of the defect. The distortion of the magnetic flux is disproportionately large and extends to the surface of the metal. This leakage of magnetic flux can then be used to attract coloured iron particles suspended in a solution.

Liquid penetrant testing is a low-cost method of testing for cracks that break the surface of a non-porous material. It relies on the penetrating ability of a low surface tension fluid such as paraffin to carry a dye

into a surface crack that may not be visible under normal circumstances. Figure 3 shows how this could be used on cracks in a tank or prefabricated bedplate.

Page 16: DIPLOMA IN MARINE SURVEYING. MODULE E Marine Engineering ... · MARINE SURVEYING. MODULE E Marine Engineering Surveying Paul Russell MSc, BA (Hons), MIMarEST Marine Engineer and Education

16

Ultrasonic testing is commonly associated with discussions about NDT. However, this is more a technique for detecting the thickness of metal than to determine the extent of any corrosion taking place. This

method of testing has the added advantage of being open to a high degree of automation and, therefore, slightly less training is needed to carry out the tests successfully. More information about NDT techniques can be found at [www.ndt.org/ Last accessed 12th December 2017].

1.3.10 Engine Room Record Books

All ships should keep proper records about their engineering operations. The main log should record the: performance of the main and auxiliary machinery;

time of the stop/start and the running hours of machinery; transfer of fuel; use of any lubricating oil;

operating state of the main propulsion motors.

The oil record book must be kept on board for at least three years and, therefore, should be available for the surveyor to examine. If the ship has recently changed ownership then the original book might be with the previous owners.

However, a “certified” copy covering the previous six months should be retained on board. The book must record all movements of oil or oily liquids, whether the movement is by gravity, pump or

hand. MARPOL 73/78 (consolidated edition 2011) gives a list of the operations that should be recorded. Bulletin

84 also gives more information about the oil record book and what should be recorded [www.bahamasmaritime.com/bulletins.php Last accessed 12th December 2017].

Figure 4 – Split to the Furnace of a Boiler The Kongsberg group produces an electronic logbook that can be used instead of the paper version. Also,

for smaller companies, Maritime Applications Limited are working to develop several different products where the data can be collected on a tablet and downloaded to a computerised record keeping system. More information can be found by visiting [www.maritimeprinting.com Last accessed 12th December 2017]

These records could be very important to the marine engineering surveyor. They are a source of evidence to be used as part of any survey. Surveyors will be able to cross-reference these documents against

others on board at the time and also against different statements from crew members.

1.3.11 Prevention (Case Study)

In Figure 4 you will see the result of damage to an auxiliary steam boiler. There is a lot of emphasis put

on the care of boilers in all the engineering certificates of competency (CoC) at officer of the watch, second engineer and chief engineer levels.

Page 17: DIPLOMA IN MARINE SURVEYING. MODULE E Marine Engineering ... · MARINE SURVEYING. MODULE E Marine Engineering Surveying Paul Russell MSc, BA (Hons), MIMarEST Marine Engineer and Education

17

The reason for this emphasis is that boilers are considered a potential source of danger. Auxiliary Boilers keep water under around 7 to 10 times atmospheric pressure and main propulsion boilers at pressures of

over 80 times atmospheric pressure , therefore, if that pressure is released for any reason then the expansion of the water into steam due to the reduction in pressure will be enormous. In the past, explosions have occurred with steam boilers that have resulted in loss of life. The burners of the boilers are also a potential fire source. Oil residue not cleaned up properly from

previous repairs can become hot enough to self-ignite.

It has been proved, time and again, that prevention is much better than cure. However, effective prevention needs time, expertise and resources to be made available in the appropriate amounts.

If we look at the example of the split boiler furnace, it would be common sense to say that this situation is not normal, desirable or expected. So why did it happen?

Figure 5 – Broken Valve

Normally, the furnace would be cool because it is surrounded by the water inside the boiler. The author has seen the back end of a boiler glowing red due to the poor combustion at the front of the boiler and

the fuel taking longer to burn as it travelled the length of the exhaust path. This meant that combustion was still taking place when there should only have been exhaust gases.

However, this would be unlikely in the case illustrated here because the top of the furnace has split and should have had sufficient cooling if the water was still surrounding the metal.

That leads us to ask what caused the possible loss of water in the boiler. Was the feed pump in good working order? They are prone to having the water turn into steam and the pump, therefore, not working. Gassing up could have occurred, or a loss of water to the pump.

Figure 5 gives a further clue pointing in the direction of a problem with the feed water.

The investigation would lead further because even with the loss of feed water the boiler should have been protected. So, were these protection devices working and when were they last tested by the ship’s staff?

If the valve has broken due to corrosion, then you would have to ask if the quality of the feed water was being checked and any chemicals added. Was this process recorded and are the records up-to-date and available for inspection?

Further checks would be carried out on the water level indicators (the gauge glass – see Figure 6); sometimes there are remote indicators that show the water level on a gauge in the control room.

It would also be necessary to interview the ship’s staff to find out if they knew how to operate and maintain the boiler correctly.

Page 18: DIPLOMA IN MARINE SURVEYING. MODULE E Marine Engineering ... · MARINE SURVEYING. MODULE E Marine Engineering Surveying Paul Russell MSc, BA (Hons), MIMarEST Marine Engineer and Education

18

The owners might ask for an independent assessment of the situation. The classification society would want to have a surveyor present and the insurance company may also wish to have their own surveyor

present. In general, cracking in the internal parts of a boiler is due to:

thermal stressing;

mechanical movement; and

chemical imbalance.

Figure 6 – Water Level Indicator (Gauge Glass) The thermal stressing can be caused by a short-term and/or a localised loss of water. Boiler tubes or, in

the case above, the actual furnace, expand rapidly due to the localised overheating and eventually burst. Long-term overheating can promote small creeping cracks. This type of cracking may well cause less distortion than the short-term overheating.

Mechanical movement might be induced by the vibrations from the main engine or from fluctuating

thermal loads.

Before boilers of welded construction, caustic embrittlement was much more common. However, even with a welded construction, localised build-up of caustic soda can occur. Concentrations can arise if there is a leakage. The boiler water evaporates leaving a high concentration of salts that are suspended in the

boiler water. High concentrations of dissolved oxygen will cause pitting which will weaken the tubes.

Page 19: DIPLOMA IN MARINE SURVEYING. MODULE E Marine Engineering ... · MARINE SURVEYING. MODULE E Marine Engineering Surveying Paul Russell MSc, BA (Hons), MIMarEST Marine Engineer and Education

19

The key to avoiding cracking in boilers, and something for the marine engineering surveyor to check for, is the efficient operation of the boiler.

The water composition should be continuously monitored and the treatments added as required. There should be no gaps in the monitoring or extra chemicals added to make up for a lapse in testing. The logbook should reflect this continuous testing and treating of the boiler water.

The boiler should be warming up correctly and fluctuations in load kept according to the manufacturer’s recommendations.

Vibrations from other machinery can cause problems with the operation of the boiler. I have come across a situation where excessive vibrations emanating from the main engine caused the controls of the boiler

to become loose. The primary and secondary air control levers would not work as they were designed to do and as a consequence the air/fuel ratio was not correct, and the flame impinged on the boiler casing causing it to glow red, which was visible from the outside.

The overall continuous care of the boiler will be the responsibility of the ship’s technical staff and how well they carry out their duties will have a direct impact on the overall condition of the boiler.

Page 20: DIPLOMA IN MARINE SURVEYING. MODULE E Marine Engineering ... · MARINE SURVEYING. MODULE E Marine Engineering Surveying Paul Russell MSc, BA (Hons), MIMarEST Marine Engineer and Education

20

2. THE ROLE OF THE CLASSIFICATION SOCIETIES.

2.1 The Main Role of the Classification Societies is ensuring that the ship and

machinery conform to the rules developed by the society and, the Classification

Certificate issued by it.

MSN 1672, Amendment 3, introduces new legislation relating to the common rules and standards for ship

inspection and survey organisations, and Appendix 5 outlines the common system that can be adopted. The owner will want to keep their ship “in class” as this will help to preserve the residual value of the

vessel and, therefore, the ship will have to satisfy the classification society rules. There are three basic types of periodic classification surveys:

Annual survey.

Intermediate survey. Special survey (also referred to as renewal Survey)

Annual surveys are carried out each year by the class surveyor, the survey being performed within a window of +/- three months of the class certificate anniversary date. The surveys are carried out with the ship afloat, and the parts examined are:

side shell plating as is visible; loadline marks; structural arrangement and conditions relating to maintenance of structural integrity, and

weathertight and watertight integrity of the hull, weather decks, exposed bulkheads and tops of

superstructures and deckhouses; fittings and appliances relating to safety of those on board; closing appliances for hatches,

openings in the shell, exposed decks and exposed bulkheads of deckhouses and superstructures;

windows, portlights, ventilators, air pipes, guard rails and bulwarks; rudder stock, rudder, shaft struts and propellers as far as can be seen; anchors and anchor cables; and

chain plates.

Intermediate surveys are carried out between the second and third annual surveys (within a window of

+/- nine months of the date calculated as being 30 months prior to the definitive class certificate expiry date and, subsequently, at no more than five-yearly intervals, from the first and subsequent intermediate surveys. Intermediate surveys are carried out with the vessel afloat unless a survey of the bottom in dry

condition is required as a part of the survey scope – this varies by ship type and ship age. In general, the intermediate survey is an annual survey plus examination of additional potential problem

areas such as the structure that is prone to corrosion or subject to high stresses and novel features. The following are the parts to be examined:

parts required to be examined at annual surveys; all protective coatings, internally and externally, in tanks, void spaces and in all accessible

spaces; all areas subject to corrosion; locations subject to high stresses; and

much of the internal surface of the shell is covered by linings or fitted furnishings. Surveyor’s judgment is to be used with due regard to the age of the vessel and the general conditions of the hull elsewhere.

Special surveys are to be carried out at the fifth year after delivery and at five-yearly intervals thereafter. They are carried out with the vessel in dry dock or in other suitable out-of-water locations. The special survey window opens 15 months before the expiry date of the definitive classification certificate.

The following are the parts to be examined:

parts required to be examined at annual and intermediate surveys;

all accessible parts of the vessel; shell plating, externally and internally; Exterior of the bottom of the ship

decks, external and internal; superstructures and deckhouses, externally and internally; tanks, double bottoms and void spaces; machinery spaces;

Page 21: DIPLOMA IN MARINE SURVEYING. MODULE E Marine Engineering ... · MARINE SURVEYING. MODULE E Marine Engineering Surveying Paul Russell MSc, BA (Hons), MIMarEST Marine Engineer and Education

21

chain lockers; hatch covers, doors, windows, portlights in external bulkheads and shell;

rudders, rudder stock, pintles, shaft struts and propeller; ventilators, vent pipes, air pipes; bulwarks and guard rails; chain plates;

all protective coatings; and

depending on age, level of maintenance and condition of protective coatings, gauging’s may be required to verify plating thickness.

Upon successful completion of a survey the surveyor would, then, issue a “definitive certificate” or an “interim certificate”, if the definitive one is not available for a little while.

If the ship has a “deficiency” it will not be meeting its class or statutory obligations and then the class surveyor can, with the agreement of the flag state, issue a “conditional (statutory)certificate” and, depending upon the severity of the condition, the ship may or may not be able to continue in service.

If the deficiency is a “minor” deficiency then the ship will still be allowed to proceed to sea. A minor deficiency will be caused by things that are not considered to pose a danger to the ship, the environment

or the people on board. The ship’s staff/company will be given a time frame to complete any necessary repairs.

If the deficiency is a “major” deficiency then no certificate will be issued until the deficiency has been rectified. Major deficiencies include items such as the following:

failure of the propulsion machinery, electrical equipment and other essential machinery; excess oily water in the bilges; failure of the emergency generator and/or lighting;

main and auxiliary steering gear failure; defective or absent personal life-saving equipment; defective fire detection, alarms, firefighting and other equipment;

failure of the proper operation of the cargo deck area in tankers;

absence or failure of radio equipment; and failure of the inert gas system.

The flag state can delegate their survey work to responsible and suitable qualified bodies. This usually means one of the classification societies. In the United Kingdom, the Maritime Coastguard Agency (MCA)

have the alternative compliance scheme, which is detailed in MGN 537 (June 2015). Part of these checks increasingly involve advice on improving efficiency and reducing the ship’s

environmental impact. For example, the Italy based Classification Society ‘RINA’ has developed a “Green star certificate”. This system was initially developed to enable cruise ships to prove that they have reached the standard where they have little or no impact on the environment.

The standard exceeds the requirement of Maritime Pollution (MARPOL) and makes the passage of the ship through areas of environmental sensitivity easier to organise.

Other types of vessels are now working towards gaining the “Green star certificate”.

2.2 Surveying Powers of the Chief Engineer

Appendix 2 details Lloyd’s Register’s account of the extent that chief engineers can survey machinery in lieu of the classification society surveyor. For suitably qualified, experienced and confident chief engineers this is an excellent way for the chief to

become experienced in surveying techniques, as well as for the company to operate their ships much

more cost effectively.

2.3 Prevention of Detention by Port State Control (PSC)

The classification societies are expanding their business by offering to give advice to the shipowner at regular intervals to prevent the cost of the vessel being detained by port state control.

Page 22: DIPLOMA IN MARINE SURVEYING. MODULE E Marine Engineering ... · MARINE SURVEYING. MODULE E Marine Engineering Surveying Paul Russell MSc, BA (Hons), MIMarEST Marine Engineer and Education

22

This advice will be about the machinery spaces and the independent marine surveyor with a good trusted track record could also give the same advice. In fact, the marine engineering surveyor is in a good

position to give advice about almost any part of the ship. The Merchant Shipping (Port State Control) Regulations 2011, MSN 1832 (replaces MSN 1775), sets out clearly the port state detention procedures and reasons for detention (see Appendix 3).

Ship risk profiles

Frequency of inspections Notice requirements for ships requiring an expanded inspection.

Requirement for ships to remain in port during expanded inspection Detention Refusal of access to port or anchorage

Rights of appeal Follow up inspections and detentions Ships detained or released to a repair yard Complaints

Reports from Pilots Reports from Port Authorities Ships which fail to comply

MSN 1832 makes reference to the Directive 2009/16/EC of the European Parliament. This directive concerns Port State Control issues. notice covers the flag state’s requirements under the Paris

Memorandum of Understanding: the scope of the memorandum; the procedures for inspection and detention; details of the mandatory expanded inspection;

follow-up inspections and detentions; banning vessels; rights of approval;

reports from pilots; and contact details of UK offices.

Annex IV of the Directive 2009/16/ details the “in date” certificates that are to be carried on board the vessel and will be subject to inspection by the flag state.

Annex V of the Directive 2009/16/ gives examples where the flag state would have “clear grounds” for a more detailed inspection; for example:

oil record book not kept up to date;

evidence of unsafe cargo operations; and excessively unsanitary conditions (see Figure 7).

Figure 7 – Unsafe Food

Annex X V of the Directive 2009/16/ lists the deficiencies that could result in detention under SOLAS, MARPOL and STCW etc. This area will include the following:

Page 23: DIPLOMA IN MARINE SURVEYING. MODULE E Marine Engineering ... · MARINE SURVEYING. MODULE E Marine Engineering Surveying Paul Russell MSc, BA (Hons), MIMarEST Marine Engineer and Education

23

The closing appliances for openings in the shell, weather deck, exposed bulkheads, tops of superstructures and deckhouses.

Doors: condition of securing devices, hinges, gaskets, proper operation and the proper fit in the closed position.

Windows, portlights and skylights: condition of glazing, framing, securing means, deadlights and storm shutters where required.

Hatch covers: condition of securing devices, hinges, gaskets and coamings.

Ventilators, air pipes and vent pipes: condition of fittings and attachment to shell, deck or bulkhead, existence of closing means.

Freeing ports in bulwarks, handrails and stanchions (see Figure 8).

Figure 8 – Hatch Cover Not Watertight

[Photograph courtesy of Larsens Marine Surveyors & Consultants Ltd. 2017] For compliance with the safe construction of a vessel the following should be examined for their

condition: Condition of hull, superstructures, deckhouses and internal sub-division bulkheads. Structural fire protection – refer to fire safety plan on board showing structural fire protection,

check condition of deck and bulkhead insulation, note any changes to the general arrangement and uses of compartments.

Means of escape – refer to the general arrangement plan and verify that the required means of

escape exist and are not obstructed. Refer to the fire safety plan on board and verify that the fire detection, fire alarm and fixed fire

extinguishing systems exist as indicated on the plan and are in good condition.

For compliance with the safe construction of equipment the following should be examined: Fire appliances – refer to the fire safety plan on board and verify that:

o fire hoses, power-driven fire pumps, fire mains, and fire hydrants are all as indicated on

the plan, in number, location and in good condition; o portable fire extinguishers in accommodation and machinery spaces are in the same

locations and of the same number, type and capacity as shown on the plan. Check

records to ensure there is the required means of charging, that they have been charged as required and that any dates of required replacement have been complied with.

2.3.1 Anchors, Cables and Windlass

Verify required number and mass of anchors are on board and at least one anchor is installed ready for immediate use, check condition of anchors and cables for wear, deformation and fracture. Examine

windlass for operation and condition, including close-up inspection of brake linings (as far as can be seen), foundation and connections to deck and underside of deck.

2.3.2 Protection of Personnel

Examine condition of bulwarks, guardrails and stanchions; check for corrosion, especially where there are dissimilar metals and stanchion bolted connections to deck. Check handrails on bulkheads and conditions

of gangways.

Page 24: DIPLOMA IN MARINE SURVEYING. MODULE E Marine Engineering ... · MARINE SURVEYING. MODULE E Marine Engineering Surveying Paul Russell MSc, BA (Hons), MIMarEST Marine Engineer and Education

24

2.4 Type Approval of Equipment

The reason for the classification societies being approached to carry out an approval of equipment is because they can provide an independent verification of the producers’ claims. This provides a “third- party” certification for the benefit of the end user.

The IACS sets the recommendation for the minimum spare parts to be carried for the main engine on a

ship that is on unrestricted service. This information is contained in IACS Recommendation 26.

The list covers the following:

Main engine bearings.

The main thrust block. Cylinder liner. Cylinder cover. Cylinder valves.

Connecting rod and bearings. Pistons. Piston rings.

Piston cooling connections and telescopic. Cylinder lubricators. Fuel injection pumps and piping.

Scavenge system components including blowers and turbochargers. Reduction and/or reversing gears.

On a ship with a large two-stroke cross-head engine, the storage space for the spares can be

considerable. However, these items will be checked during the annual survey to ensure that there has been no

deterioration since the last survey. Figures 9 and 10 show a spare tail shaft and a spare cylinder liner to show the difficulties of carrying

even the minimum spares required by the classification society.

Figure 9 – Spare Tail Shaft Figure 10 – Spare Cylinder Liner

Page 25: DIPLOMA IN MARINE SURVEYING. MODULE E Marine Engineering ... · MARINE SURVEYING. MODULE E Marine Engineering Surveying Paul Russell MSc, BA (Hons), MIMarEST Marine Engineer and Education

25

3. THE WORK OF THE INDEPENDENT MARINE ENGINEERING SURVEYOR.

3.1 Introduction

We have seen earlier in this course, methods for carrying out interviews so that an accurate view of events can be built. We have also seen how the surveyor will be building a picture about the competence of the crew by careful observations of the general condition of the ship.

We can now have a closer look at the procedure to be used when a surveyor arrives on board and has to gain information about an incident or machinery failure.

3.2 Discussions with Engine Room Staff

It will be important to obtain as many views from as many different technical staff as possible. This will enable the surveyor to cross-check the sequence of events leading to any failure.

This strategy together with a scrutiny of the documents on board should prove effective in tracking down the real causes; bearing in mind that some of the staff may want to mask actual causes to avoid any

blame for the cost of repairs. It is not the job of the surveyor to apportion any blame for what has happened. They should concentrate on the facts and let others deal with the staffing issues.

However, it is important to interact with the staff, especially where co-operation is essential. The staff should be made aware, as soon as possible, that an outside investigation is underway.

They should also be instructed not to undertake to move any equipment before the surveyor has had a chance to review the situation.

3.3 Repair of Machinery

The debate about the cost effectiveness of repairing machinery as opposed to replacing machines or components is highly complex.

The judgement about which will be the most suitable must be taken on a case-by-case basis. The same problem may have a different outcome depending upon the location of the vessel. For example, it may be

more cost effective to replace a pump if the vessel is close to a source of supply but it may be cheaper to repair the old pump if the vessel is close to workshops that have skilled staff and is in a location where the labour costs are low.

To be able to repair machinery, you will have to find out about the availability of local workshops, engineering companies and testing facilities.

If specialist repairers, manufacturers or approved repairers are required then they will probably not be available locally. The additional cost of specialist people attending the ship will have to be allowed for. There are bound to be logistical problems in shipping spare parts, especially if the time scales are short.

The operating conditions of machinery may have a dramatic effect on the condition of the internal components. This may, in turn, determine whether components are continually replaced, repaired or upgraded. For example, the use of high sulphur fuel means that when the exhaust gases cool down to the dew point, the moisture combines with the sulphur to form acids.

I have come across a situation where an engine working on a ship with a cross-Atlantic operation was fine with no acid erosion of the internal components.

However, when that same engine was driving a vessel on a short-sea service the exhaust valves were wasting away. The valve stems were being eroded where they operated through the valve guides.

The final repair was to change the base metal that the valves were made from. But it might be found that poor operating practice is to blame or that the ship was just on the wrong route for the specification of the engine employed.

Page 26: DIPLOMA IN MARINE SURVEYING. MODULE E Marine Engineering ... · MARINE SURVEYING. MODULE E Marine Engineering Surveying Paul Russell MSc, BA (Hons), MIMarEST Marine Engineer and Education

26

3.4 Prime Movers and Power Transmission

3.4.1 Diesel Propulsion Units

The most common forms of main propulsion power for ocean going vessels are the large, slow-speed two-stroke cross-head engine and the medium-speed trunk type engine.

Large two-stroke cross-head diesel engines are becoming more and more powerful as the advancement

of material science helps us to develop bigger and more powerful vessels.

The most important guide to the safe running of any engine still applies to these engines. That is: clean air; clean oil;

clean fuel; and clean water.

Efficient combustion is essential to any engine but a two-stroke engine is more sensitive to poor combustion than the four-stroke engine. Damage shown in Figures 11 and 12 were both due to poor injection of the fuel into the combustion

chamber.

Figure 11 Figure 12 Damaged Pistons Due to Fuel Injection Problems

The damage to the smaller piston was caused due to the faulty refurbishment of fuel injection nozzles which meant that the movement of the needle in the nozzle assembly was 1.1 mm instead of a maximum of 0.8 mm (see Figure 13).

Figure 13 – Cut Away View of Nozzle Assembly

Page 27: DIPLOMA IN MARINE SURVEYING. MODULE E Marine Engineering ... · MARINE SURVEYING. MODULE E Marine Engineering Surveying Paul Russell MSc, BA (Hons), MIMarEST Marine Engineer and Education

27

The correct and effective maintenance of fuel injectors is probably the most important single job for the efficient running of any diesel engine.

It is normal practice to have the nozzle assembly reconditioned separately from the main body of the injector. The nozzle assembly is shown in Figure 14.

Figure 14 – Nozzle Assembly

The specialist engineering company would machine the needle to match the landing in the body of the nozzle assembly (see Figure 13). The seat and the tip of the needle should make an edge contact and,

therefore, the two cannot be lapped in using grinding paste. This process will slightly reduce the effective length of the nozzle compared to the body of the nozzle assembly.

Therefore, the body of the assembly should also be machined to ensure that the maximum “lift” of the needle is kept within the manufacturer’s tolerance. As in the case aforementioned, this maximum was 0.8 of a millimetre. The nozzle assemblies were returned to the ship and fitted to the engine. The

assemblies arrived encased in a moulded plastic protective covering and it was assumed that the work carried out was correct and, therefore, the vital tolerance of needle lift was not checked. Due to the extra lift, the needle was travelling at a higher speed and the additional force generated on

the tip of the nozzle was much higher than it could stand. The tip of the nozzle assembly broke away and the fuel was then injected in an abnormal spray pattern. In this instance, the spray pattern was to one side and aimed directly at the cylinder liner.

The liner was overheated and developed a crack in the area of the overheating which propagated down the liner to the bottom allowing the hot products of combustion to enter the crankcase. The result was a

crankcase explosion and damaged internal components of the engine. Given that the marine engineering surveyor might be presented with a variety of damaged components you can see that it will be difficult tracking down the cause to 0.3 mm extra lift of the fuel injectors

especially if the nozzle tip had been damaged along with the other components of the engine. Damaged exhaust valves can restrict the power output of an engine. They have to be kept in good

condition. Modern engines burn residual fuel oil rather than diesel oil. To prolong the life of the valves it is common practice to turn the valve relative to the cylinder head. This is done using “rota caps” which are devices fitted to the top of the valve. As the camshaft operates the valve the rota cap rotates the

valve as it leaves the seat. The introduction of NIMONIC exhaust valves (see Appendix 6 for the metallic composition of this material) gave the diesel engine the ability to operate using the heavier fuel oil. However, as Figure 15

shows the valves can burn through in one place. The hard face is cut and the base metal cannot

withstand the high temperatures and the valve develops a hole such as the one in Figure 15.

Page 28: DIPLOMA IN MARINE SURVEYING. MODULE E Marine Engineering ... · MARINE SURVEYING. MODULE E Marine Engineering Surveying Paul Russell MSc, BA (Hons), MIMarEST Marine Engineer and Education

28

Figure 15 – Burnt Exhaust Valve

A reason for the exhaust valve burning out could be that the rota cap has stopped working. The valve then does not turn and if a small particle of carbon becomes trapped between the valve’s face and the valve seat the hammering effect will work its way through the hardened face of the valve.

Invariably, the valve seat in the cylinder head will become affected as well as the valve. Figure 16 shows the effects of faulty fuel injection and how the exhaust valve seat can become damaged.

Figure 16 – Damaged Cylinder Head

If the parent metal that makes up the cylinder head is not damaged, then the old seats can be carefully removed and new hardened seats inserted into the cylinder head. A way to do this is to carefully break

the old seat with a chisel and clean up the recess. Then cool the new insert using an environmentally friendly refrigerant gas. The new seat slides into position and expands into a tight fit as it warms up.

The new valve seat will then have to have the face ground at the correct angle. The Chris Marine grinding equipment (Figure 17) will be able to carry out the task on board the vessel.

Page 29: DIPLOMA IN MARINE SURVEYING. MODULE E Marine Engineering ... · MARINE SURVEYING. MODULE E Marine Engineering Surveying Paul Russell MSc, BA (Hons), MIMarEST Marine Engineer and Education

29

Figure 17 – Chris Marine Grinding Equipment

The designs of modern engines are an improvement on older ones. However, the cross-head bearing still needs special consideration. The bearing oscillates instead of rotating and, therefore, the oil does not build up the classic oil wedge as a barrier between the two surfaces.

Therefore, it is the pressure of the lubricating oil entering this bearing that keeps the moving surfaces apart. It follows that any reduction in the lubrication oil pressure could result in damage to this bearing.

Modern shell-bearing construction helps the situation but on older engines the white metal surface can break up and give the look of a jigsaw puzzle. Spare cross-head bearings should be carried on board (see Figure 18). The minimum list of spares for the main internal combustion engine on a ship sailing on

unrestricted service is given in Section 2.4, Type Approval of Equipment.

Figure 18 – Spare Cross-head Bearing

A reduction in lubricating oil pressure could be for a number of reasons. Some of these might be attributable to human error. If the quality of the oil is allowed to deteriorate in any way then the cross- head bearing could be the first to suffer damage. This is because this bearing is oscillating back and forth

instead of rotating in a complete circle.

A reduction in pressure could be due to dirty filters. They may not have been changed as regularly as they should have been. Possibly the oil purifiers are not working as they should be. Heavy weather can

stir up the sediment at the bottom of the lube oil drain tank.

Page 30: DIPLOMA IN MARINE SURVEYING. MODULE E Marine Engineering ... · MARINE SURVEYING. MODULE E Marine Engineering Surveying Paul Russell MSc, BA (Hons), MIMarEST Marine Engineer and Education

30

If the oil becomes dirty then the lube oil pump might not be able to push out at the pressure that it should. Does the engine log record a reduction in pressure? Have the staff noticed this?

The surveyor should not trust the log record or the remote readings; if they suspect the lube oil pump then the local discharge pressure gauge should be checked and then, if needed, removed and tested or replaced. One quick check that can be done with the pump running is to slowly and only partially close

the discharge valve and note the effect that this has on the gauge reading.

3.4.2 Piston Rings

The piston ring in its free state has a slightly larger diameter than the liner. A ring in service springs out

against the liner, but not with sufficient force to maintain an adequate seal. Combustion gas pressure acting behind and on top of the ring provides the sealing pressure.

The top ring is subject to the rising compression, then firing pressure and continuing but reducing load as the gas in the cylinder expands. It is pressed against the liner hardest, at the top of the stroke, in the area where the oil film is less than perfect because it is furthest above the delivery point and also the

area most affected by combustion (i.e. oil is burned away by the flame of combustion). The very heavy wear and ridge at the top of the liner can be accounted for by the less effective lubrication, burning of the oil and high gas pressure on the rings.

A large two-stroke engine is big enough for an internal inspection to be carried out to determine the condition of the piston rings. The ship’s staff should be checking inside the scavenge space and inspecting

the piston rings through the scavenge ports. Figure 19 (broken piston rings) shows the view of the side of the piston. A person may gain this view by

looking through the scavenge ports from inside the scavenge space. By carrying out this inspection early warning of poor combustion due to low compression can be gained. The piston rings that appear dull in colour will not be rubbing against the cylinder wall. This will most likely be due to the ring being broken.

Figure 19 – Broken Piston Rings

3.4.3 Turbochargers

Turbochargers are magnificent pieces of machinery. Their internal components are machined to very fine tolerances and the clearance between components is very small. They are essential to the running of the engine. There are very few marine engines on ocean-going vessels that are not turbocharged.

The water-cooled turbo-charger has, typically, a cast iron casing at the turbine end and an aluminium casing at the compressor end.

The cast iron casing between the exhaust gas area and the cooling passage is prone to wastage and

failures have resulted in the leakage of water into the gas side.

Inspection to establish casing thickness is advisable but ultrasonic methods with cast iron may be questionable. A flexible bellows piece for attachment of exhaust trunking to the turbo-charger gas inlet permits thermal expansion and contraction without stress. The charger may be mounted on flexible pads to damp down vibration.

Page 31: DIPLOMA IN MARINE SURVEYING. MODULE E Marine Engineering ... · MARINE SURVEYING. MODULE E Marine Engineering Surveying Paul Russell MSc, BA (Hons), MIMarEST Marine Engineer and Education

31

Both the exhaust gas side and the compressed air side can be cleaned in service. The ship’s staff should be able to carry out this function and record the fact in the engine room logbook. Care must be taken and

if the ship’s staff are not diligent in carrying out this activity problems can occur. For example, the turbo-charger speed must be reduced before water washing the gas side of the machine. If this is not done then the force of the water hitting the blades will be high and breakage of the internal parts could occur.

Figures 20, 21 and 22 (Turbo 1, 2 and 3) show just what can happen if the turbocharger is part of an

engine suffering from faulty fuel injection.

Figure 20 Figure 21 Figure 22

Turbo 1, 2 and 3

The internal parts of the turbo-charger become dirty and eventually fail as a result. Failures of turbo- chargers are expensive; not just for parts replacement, but also for the associated costs of possible loss of charter and the associated loss of reputation of the shipping company.

Fouling of the exhaust system and turbine happens due to the build-up of the products from the combustion of fuel, used cylinder oil and its additives, ash, and any other non-combustibles present in

the fuel. These will create hard deposits that interfere with gas flow, may cause local overheating, reduce turbine efficiency and even destroy balance of the rotor.

Soon the marine engineering surveyor will be more involved with environmental equipment. Surveyors

could find themselves being asked to report on suspected malfunction of equipment that has resulted in a fine imposed upon the owner. This could include scrubbing technology, ballast water treatment or the malfunction of a bilge pumping system.

3.4.4 Compressed Air Starting Systems

Air start systems are designed to deliver starting air at about 30 bar (435 lb/in2) to those cylinders of an engine in which the cranks and pistons are between 5° past top dead centre and about 15° before

exhaust opening. The pressure of air is required briefly in one or two cylinders, to rotate the engine, giving it the momentum to compress the air in the other cylinders.

The fuel is then delivered to the cylinders in the correct firing order and ignited by the heat of compression. There are safeguards intended to reduce the likelihood of air and fuel being delivered to a cylinder simultaneously. Compressed air starting systems should be treated with the greatest respect due

to the severe consequences of a malfunction of this system. The marine surveyor has plenty to check when examining the compressed air starting system if it is suspected that this is causing a problem. Faulty air start valves could be responsible for the engine not

starting well. But they might also be the cause of an explosion if hot products of combustion have entered the starting air inlet pipes via a leaking air start valve. Such explosions can be fatal for persons in the engine room.

A safety or relief valve must be fitted to the main air manifold. Flame arresters or bursting caps or discs must be fitted to each cylinder valve connection from the manifold in reversible engines. Non-reversing

engines require one only, fitted between the non-return valve and the engine. Checks must be made that cylinder starting air valves do not leak.

These can be carried out while the engine is running by checking the temperature of the air pipe adjacent

to the valve. Care must be taken when carrying out this operation as the pipe can become very hot and could cause serious injury. Discussions with the staff and inspection of the logbook will give clues as to whether good engineering practice has been carried out.

It is important that the drains are checked to give an early warning of any oil or oily water that has entered the system. The main point here is that any oil together with compressed air and possible heat

Page 32: DIPLOMA IN MARINE SURVEYING. MODULE E Marine Engineering ... · MARINE SURVEYING. MODULE E Marine Engineering Surveying Paul Russell MSc, BA (Hons), MIMarEST Marine Engineer and Education

32

from the engine could cause a nasty explosion. In the past, loss of life has occurred due to explosions in air start systems. There should be an interlock fitted to prevent the engine from starting if the turning

gear is engaged.

3.4.5 Steam Turbine Plant

The steam turbine plant is usually a very reliable propulsion plant. The ships that have a steam plant are

now very much in the minority and probably restricted to gas carriers. However, the plant needs careful

operation by well qualified and experienced staff. The clearances between the stationary and rotating components are so small that if the machine is not

warmed up evenly internal components can come into contact with each other causing damage. Therefore, it is easy to see how good watch-keeping and engineering practices are vital. However, it is not just the turbines that need care, the whole system must be carefully maintained and operated.

Figure 23 – Turbine Motor – Water Figure 23 shows the damage that can be done if the boilers are not operated correctly and water is

allowed to carry over with the steam. The turbine must be operated correctly and the “barred speed” strictly observed. Also, if the turbine is subjected to too much vibration from the adverse operation of other machinery in the engine room then

the turbine could suffer damage.

Figure 24 – Labyrinth Gland 1

Figure 24 shows the labyrinth gland of a steam turbine. The clearances in this gland are very close and

any incorrect operation of the system or excessive vibration will affect this area of the machine.

Page 33: DIPLOMA IN MARINE SURVEYING. MODULE E Marine Engineering ... · MARINE SURVEYING. MODULE E Marine Engineering Surveying Paul Russell MSc, BA (Hons), MIMarEST Marine Engineer and Education

33

Careful control of the boiler water treatment is also very important. Not only from the point of view of the feed water system, but if the treatment is not correct then chemicals can enter the turbine and block the

small passageways and clearances between the internal parts.

3.4.6 Gas Turbine Propulsion

Gas turbine power plant (Figure 25) is very reliable equipment. However, it will be prone to being

damaged if dirt or other foreign bodies get past the air intake filters.

Some very high-tech processes are being used to search for metal fatigue and the servicing intervals. For example, an inspection system using eddy currents has been developed to check for cracks on turbines

with very small blades. The reliability of the gas turbine engine is due to the very high standards imposed during the frequent

inspections that must be carried out. Some manufacturers are also fitting very sophisticated vibration monitoring equipment to ensure that any faults that might be developing are detected in the early stages.

Figure 25 – Gas Turbine Arrangement

3.4.7 Power Transmission (Including Gearboxes, Shafting, Stern Tubes and Propellers) Ship propulsion can be by:

• Metal shafting.

• Azimuth thrusters. • Electrical podded drive system.

• Water jets.

• Tunnel thrusters.

The information brochure from Rolls-Royce shows more detail about each of these types of propulsion systems (Appendix 4). Manual transmission of power is still the most common form of connection between the prime mover and

the propeller. On the faster engines, this drive train will include a gearbox and usually a pneumatically operated clutch.

This means that the engines can be run and tested without any transmission of power to the gearbox and

Page 34: DIPLOMA IN MARINE SURVEYING. MODULE E Marine Engineering ... · MARINE SURVEYING. MODULE E Marine Engineering Surveying Paul Russell MSc, BA (Hons), MIMarEST Marine Engineer and Education

34

propeller shaft. Although this system of transmission is generally reliable it will be the subject of failure if there are manufacturing defects or if there has been careless operation.

The transmission of power through a gearbox will cause stress to the teeth on the gear wheels. These teeth have a layer of case hardening which is highly resistant to wear. The lubricating oil is aimed to flow directly into the mesh of the teeth.

There are a number of faults that can occur with gearing. These will either be due to design or manufacturing defect or due to a problem that has come about due to operational mismanagement.

The lubricating oil will be a critical factor in the correct and efficient operation of the gearbox. The teeth in the gearbox are literally tearing the oil apart and for the oil to resist this it must be in good condition.

If the oil has been allowed to deteriorate in any way then the teeth will be allowed to come into contact with each other, wear through the case hardening and start to wear the softer metal underneath.

The oil could be contaminated by water from condensation that has built up inside the gearbox casing. If any dirt is allowed to enter the system the flow of oil to the bearings could become disrupted. This could also mean that the oil did not carry out its lubricating function correctly.

If the quantity of oil is diminished then the amount of heat removed will also be reduced and a build-up of heat could have a further adverse effect on the viscosity of the oil.

Engine and shafting alignment is another critical factor in the smooth running and transmission of power to the propeller.

If the components have been fitted correctly when initially assembled, then the reasons for

deterioration in performance will be due to: bolts becoming loose, causing fretting on the coupling faces; extensive wear in one of the intermediate bearings;

loose engine holding down arrangements; excessive bending due to the cargo loading pattern; and vibration from some part of the system, for example from the propeller due to damage.

The marine engineering surveyor may have to climb down to the bottom of the engine room to inspect the holding down arrangements of the engine. The bolts can become loose or break due to excessive

stress (Figure 26). The main reason for the resilient mountings is to reduce any shock loading coming from the hull of the

vessel and not to compensate for misalignment. Therefore, the holding down arrangement is subjected to constantly fluctuating forces and could well

become damaged. Regular inspection is essential and may reveal a number of problems.

Figure 26 – Holding Down Arrangements 1 and 2 Shaft bearings will bed themselves in, in one direction. If the bearing is removed for inspection it must be

returned exactly as it came out.

Page 35: DIPLOMA IN MARINE SURVEYING. MODULE E Marine Engineering ... · MARINE SURVEYING. MODULE E Marine Engineering Surveying Paul Russell MSc, BA (Hons), MIMarEST Marine Engineer and Education

35

There will be small differences in the wear of the shaft over the length of the bearing. If the bearing is reversed then the differences will be accentuated and the bearing will run hot when returned to service.

The bearing cap is only there to hold the top half of the shell and allow the oil to circulate. This circulation will give the necessary rotodynamic oil lubrication needed to support the heavy weight of the shaft which is all on the lower section of the bearing.

The stern tube bearing is subject to considerable stress because it must support the weight of the propeller as well as act as a watertight seal around the rotating propeller shaft.

Figure 27 shows the result of dirt getting into the bearing.

Figure 27 – Scored Tail Shaft

This could be a very difficult item to change. Figure 28 shows a method that can be used during a drydocking process.

The propeller is removed first and the tail shaft is drawn into the hull of the vessel after first removing an intermediate section of shafting.

A hole is cut in the side of the vessel and the tail shaft passed out through the hull. Fitting the new shaft is a reversal of the removal process.

Some manufacturers are now producing “lightweight” transmission shafts that are threatening to take the industry by storm.

At the moment, these are fitted to super yachts and fast ferries. Please see [www.centa.info/?show=

products&c=&nr=61&what=marine Last accessed 12th December 2017] for more information.

Page 36: DIPLOMA IN MARINE SURVEYING. MODULE E Marine Engineering ... · MARINE SURVEYING. MODULE E Marine Engineering Surveying Paul Russell MSc, BA (Hons), MIMarEST Marine Engineer and Education

36

Figure 28 – Removal of Prop

3.5 Auxiliary Machinery (Including HVAC Systems)

3.5.1 Air Compressors

Compressed air is very important on-board ship and is used for a variety of reasons. The lack of compressed air to start a large two-stroke engine (or to change its direction of rotation), for example, could be the cause of the ship running aground.

The starting air compressors must be in good condition so that the safety of the ship is maximised at all times. A danger is that when you compress the air and pass this to a piping system you are also raising

the proportion of oxygen within the associated pipe work and holding receivers. Therefore, if the conditions for a fire or explosion become right then the resultant effect will be greater than in normal atmosphere due to the higher concentration of oxygen.

Safety valves for the protection of receivers are given an accumulation test by the surveyor when they are set initially, but the test can only be applied by using the air compressors. The rise of pressure that would result from a fire cannot be simulated and the fitting of fusible plugs, even where each receiver has

its own safety valve, must be considered prudent. Air receivers are pressure vessels and as such will be the subject of statutory inspection. Any failure when full of compressed air will be violent. As a consequence, they should be treated with care.

The internal surface of an air receiver is likely to rust because water condenses and clings there when it cools. Any salt content of the moisture or presence of other contaminants in the compressed air could

result in other forms of corrosion. Protection is usually provided by coating the internal surface. Ideally the coating should remain flexible after application so that expansion and contraction do not cause it to flake. Epoxy coating is favoured in

modern applications and in all cases spirit-based coatings should not be used. It follows on then that any raise in temperature within the system could contribute to the conditions needed for a fire or explosion.

Dirty air filters, for example, will reduce the air intake and cause air compressors to run hot. This will tend to increase valve deposits when mineral oil lubrication is used and can produce dangerous

conditions. Inefficient cooling due to blocked cooling passages will also cause overheating of the machine.

Air compressor valves are operated by the changes in pressure caused by the movement of the piston. The plates open and close very rapidly and, therefore, any defect is likely to be a starting point for failure. Plates can be slightly damaged by:

scraping to remove deposit (use a cleaning agent); erosion due to moisture or particles in the air, which flows past at 30 m/s or more (ensure

efficient air filtration);

Page 37: DIPLOMA IN MARINE SURVEYING. MODULE E Marine Engineering ... · MARINE SURVEYING. MODULE E Marine Engineering Surveying Paul Russell MSc, BA (Hons), MIMarEST Marine Engineer and Education

37

corrosion due to salt or other contaminants in the air, by a damaged seal; and foreign objects.

Figure 29 – Air Compressors Spring pressure must be correct, and failure is likely if springs are broken or weakened by prolonged high

temperature or corrosion. Springs will lose strength over a period of time. Plates should be renewed rather than reground and new valve plates should have new springs. If the marine engineering surveyor

suspects that the air compressor is inefficient then the valves may be suspected.

The valves can become damaged due to inappropriate storage. The original protective wrapping should not be removed until the valves are fitted. Valves sometimes fail due to incorrect assembly or fitting.

Sometimes retaining screws in the cover are not slackened back before replacing the cover after fitting a new valve. There are small dowels that hold all the plates and springs in line. Sometimes these are not lined up or are a very loose fit due to wear in the hole that the dowel fits into.

Design or manufacturing errors are occasionally responsible for problems.

3.5.2 Fresh Water Generators (Evaporators)

These machines can be desalination plants using electricity, steam or “waste heat” as the heating source

and the machine would usually boil the salt water under low pressure. Alternatively, fresh water generators can be of the Reverse Osmosis (RO) type. Plate heat exchangers are now being used, in desalination plants, to improve efficiency.

The desalination plants can easily lose efficiency because they fail to keep a low pressure inside due to a leak in the casing. If the heating surfaces become scaled up then they will also contribute to a loss of

efficiency. The RO plants are fairly simple in their operating concept; however, the components are made very carefully and need care and understanding. More information about RO plants can be found at [www.derwentwatersystems.co.uk/reverse-osmosis.html Last accessed 12th December 2017].

3.5.3 Steering Gear and Hydraulic Equipment

The steering gear is one of the most important pieces of equipment on board the vessel. It has also been the cause of some dramatic accidents.

The loss of the Amico Cadiz might well have been due to a complete loss of oil in the steering gear. This

incident led to ships being forced to carry a fresh charge of oil for the steering gear. It is very important that the ship’s staff know the operation of the steering gear very well.

Page 38: DIPLOMA IN MARINE SURVEYING. MODULE E Marine Engineering ... · MARINE SURVEYING. MODULE E Marine Engineering Surveying Paul Russell MSc, BA (Hons), MIMarEST Marine Engineer and Education

38

The marine engineering surveyor should check in the log book that a record has been made about testing the correct operation of the steering gear before all voyages. It would also be useful to cross-check a

corresponding entry in the deck log book. The telemotor system can also be the cause of problems with the steering gear. I know of an incident that sent a ship towards the river bank due to the malfunction of the steering gear. The steering gear did

not work properly because the telemotor failed to operate the hydraulic pumps. The reason for the failure

was that the hydraulic pressure from the telemotor pistons was causing the housing to flex and stopping the operating rod from working that controlled the main pumps to the steering gear.

It has not been unknown for steering gear to be fitted out of alignment. This could cause oil leaks or allow the ingress of water. I know of a super tanker that had a twin rudder system with the rudders

placed 5° from the vertical. The rudder shafts were fitted slightly out of alignment, which resulted in sea water which had found its way through the steering flat doorway actually entering the oil powering the pistons through the seal.

The same problems can be associated with steering gear as with any other hydraulic system. Hydraulic systems are manufactured very accurately and, as a consequence, operate with very fine tolerances, as can be seen in Figure 30, which shows the internal components of a piston pump.

Figure 30 – Piston Pump Figure 31 – Hydraulic Pump Photo Courtesy of Mr Robert McClintock

Therefore, if a new pump is fitted (see Figure 31) the people fitting the pump must ensure that no debris enters the system.

Filters in the system should protect it to some extent but if the oil is contaminated in any way then further damage could result.

The ship’s staff must keep a regular check on the condition of the oil in a hydraulic system. This will give an early warning of potential damage or failure.

3.5.4 Refrigeration and Heating, Ventilation and Air Conditioning (HVAC)

HVAC systems are now an essential part of every ship and not just passenger ships. The main work of a surveyor that relates to air conditioning and refrigeration will be, if the unit fails, in

some way or another to check whether the system complies with the latest environmental requirements for the use of non-CFC (Chlorofluorocarbon) gases. The surveyor should be looking for a good record of continued maintenance for the equipment.

Generally, the applications of refrigeration are such that it is vitally important that the plant should not fail in any way. For example, in food storage, a prolonged failure can result in spoilage and consequent loss, and in many air conditioning applications work cannot continue if the plant fails.

Thus, it is essential that some form of planned maintenance is adopted in an attempt to anticipate any failure before it occurs or to detect the failure, as early as possible, so that it may be rectified quickly

before further damage results. The engineering surveyor would look for evidence of this work from the search of the maintenance system on board. Where this is not evident and equipment failure has occurred, then further research can be conducted

using the lack of maintenance as a guide.

Page 39: DIPLOMA IN MARINE SURVEYING. MODULE E Marine Engineering ... · MARINE SURVEYING. MODULE E Marine Engineering Surveying Paul Russell MSc, BA (Hons), MIMarEST Marine Engineer and Education

39

The routine that cannot be over-emphasised is the necessity of keeping a regular record of the various temperatures, pressures etc existing in the plant.

It is only by the regular logging of this information that deviations from normal running conditions can be observed and, consequently, an early diagnosis of any fault may be made. All possible information should be logged at least once a day (preferably more frequently) and, as a general guide, the following list

indicates some of the more important items:

Date and time of log. Compressor hours run, speed, number of operating cylinders and motor power (kW).

Compressor discharge, intermediate and suction gauges and temperatures. Evaporator gauge. Condenser water temperatures and flow.

Liquid refrigerant temperature leaving condenser. Secondary refrigerant/air temperature on evaporator. Secondary refrigerant/air temperature off evaporator. Secondary refrigerant/air temperature flow.

If the system is part of a refrigerated cargo plant then the various temperatures in the hold will be automatically logged by the data logger.

Fault-finding on a refrigeration plant requires a thorough knowledge of what should be going on throughout the circuit and the ability to apply logical reasoning to the symptoms observed. Most faults

will result in an out-of-the-usual behaviour of the compressor in that it may: not run at all; run for a short period and stop; or run for a longer period than usual or continuously and not perform the required cooling.

If the compressor is not running then you should first see if the area being examined has cooled down to

the correct temperature and, if the system should be running, has it just been stopped by the thermostat.

If, after resetting the overload, it fails to restart then check the power supply to the control panel and if

this is “live” check the starter. If the compressor restarts and continues to run normally then the fault was probably due to a fluctuation in power supply voltage. If the compressor restarts but stops again after a short period this leads to the second basic symptoms.

If the space being cooled is not at the desired temperature then one of the cut-outs could be the cause. If the pressure cut-outs have caused the shutdown this will be apparent by observing the cut-out reset lever or knob.

If the high-pressure cut-out has tripped the excessive pressure may have been caused by a lack of condenser cooling, a rise in the temperature of the cooling medium, a dirty condenser, excessive charge

backing up in the condenser or perhaps air in the system. The low-pressure cut-out could be operated by refrigerant starvation in the low side of the system. This could be for a number of reasons, such as a loss of refrigerant from the circuit, a choked liquid strainer or

a faulty expansion valve. If the differential oil pressure switch is suspected, then the compressor should be restarted and the oil

and crankcase gauges observed. If a sufficient differential pressure is not established within the time allowed then this is the reason for the shutdown. Insufficient oil pressure could be caused by a shortage of oil in the crankcase, excessive dilution of the oil in the crankcase by the refrigerant, a choked oil

strainer or filter. A shortage of oil will be observed in the sight glass, that is, a low level or no oil visible at all. Excessive dilution by the refrigerant would also be observed in the sight glass as an excessively high oil level, and

foaming, on starting the compressor. If the motor overload is the cause of the shutdown then this may be a result of a partial seizure within

the compressor or excessively high suction and/or delivery pressures. We have already considered high delivery pressures but the high suction pressure could be due to an excessively high evaporator load. If these observations prove negative then the fault may lie in the starter itself.

If the compressor runs for longer than is usual a number of faults could be the cause. If the compressor has unloading gear, first check that it is fully loaded. If it is, then check the suction and delivery gauges; if the suction gauge is low then suspect a shortage of refrigerant in the evaporator.

Page 40: DIPLOMA IN MARINE SURVEYING. MODULE E Marine Engineering ... · MARINE SURVEYING. MODULE E Marine Engineering Surveying Paul Russell MSc, BA (Hons), MIMarEST Marine Engineer and Education

40

This can be confirmed by an excessively high suction superheat (a low-suction gauge but a normal superheat in a plant having direct expansion air coolers suggests a frosted air cooler or a cooler fan has

stopped). The suction strainer could be choked and give a low-suction gauge and reduced duty. A back-pressure valve jacked in the closed position would also give a similar effect.

If the suction gauge is higher than usual, then this could be caused by compressor valve breakage or perhaps a fractured bursting disc. In either case the discharge temperature will be higher than usual.

3.5.5 Fuel and Lubricating Oil Treatment (Including Centrifugal Purifiers, Fuel Quality and Lubricating Oil Derogation from Microbes)

The marine engineering surveyor must check the bunker samples if they suspect a problem with the fuel oil.

Information about the quality of fuel, which has been bunkered in the vessel, is obtained from the supplier’s specification and/or from samples of the fuel analysed in a laboratory ashore. A limited range of on board test equipment is also available.

The shore analyst’s report is compared with a standard specification used when ordering and the standard is based on the specification given in the engine instruction book. Care of the fuel once it arrives

on the vessel is most important for good performance of the engines. Water in the fuel is a big danger. Water can enter tanks through open vents on deck; in heavy weather, it can also be the result of condensation in the ship’s bunker and daily service tanks. Condensation is

influenced greatly by climatic conditions. A leak in the steam heating coils is another source of contamination by water.

Figure 32 – Centrifugal Purifiers, refurbished and ready for fitting onboard.

Photograph courtesy of Mr Robert McClintock. Fuel and lubricating oil defects are one of the biggest single causes of machinery defects and malfunction (see case study earlier).

The use of the centrifugal purifier (Figure 32) is the most effective method for cleaning the fuel. The

machine can be used as a clarifier or a purifier but if not operated carefully can create more problems than it solves.

Water can enter the fuel system from the purifier if the machine: is not cleaned regularly; the wrong “paring” or “Gravity” disc is used for the density of the current oil; or too much water in the oil entering the purifier inlet.

Page 41: DIPLOMA IN MARINE SURVEYING. MODULE E Marine Engineering ... · MARINE SURVEYING. MODULE E Marine Engineering Surveying Paul Russell MSc, BA (Hons), MIMarEST Marine Engineer and Education

41

So much care has to be taken with this area of the ship’s overall operation. If the marine engineering surveyor steps on board a vessel to be confronted with a bunkering station as shown in Figure 33, then

more problems can be expected. New legislation and the changing economic environment can have a dramatic effect on decisions taken with the quality and specification of oils.

For example, the new drive towards bio-fuels will probably have an effect on the specification of the lubricating oils used. This is already happening with the current practice of moving towards LSF.

It is important that, to combat crank chamber corrosion, water should be removed from the oil as rapidly as possible by centrifuging. As it is not always possible to remove all the water, it is advisable to keep the

oil circulating for a period after stopping the engine and also recirculating once per day in port.

Figure 33 – Bunkering Station Periodic turning of the crankshaft with the turning gear is also helpful in preventing settled water from

remaining on the crankshaft at any one point of time.

The oxidisation of lubricating oil produces, in its earlier stages, acidic and other completely soluble oxidisation products, but higher temperature deterioration can produce oil insoluble carbonaceous

materials. Emulsification can be the result of severe oxidation. Contamination by fuel as the result of leaks from fuel

pumps or pipes, can lower the viscosity of the oil and reduce its lubricating value. Such contamination will cause a fall in the flash point of the crankcase oil.

The closed flash point of new lubricating oil must be not less than 204°C. If a test shows that the figure has dropped to 177°C or less, the oil must be replaced. Fuel oil cannot be removed from the lubricant by settlement or centrifugal treatment since the fuel is entirely miscible, being from the same source, that is, derived from crude oil. Badly contaminated oil must be discarded.

3.5.6 Waste Management

Sewage plants, waste disposal units and exhaust gas emissions are all currently the subject of much debate. The maritime regulatory bodies are pushing ships towards being “zero emission” entities. Fuel

cells, photovoltaic panels, sails and wave power are just some of the new technologies being explored by the company Wallenius Wilhelmsen. Their aim is to have the technology perfected by the year 2025.

3.6 Pumps and Pumping Systems (Including Filters, Strainers and Heat Exchangers)

Machinery cannot operate without pumping systems supplying lubrication, cooling water or fuel to prime movers and auxiliary engines.

Damage to main plant can easily be caused by the malfunction of this equipment. Where pumps are

external to the plant being serviced (see Figure 34) access to the equipment might make the job of the marine engineering surveyor easier; however, pipework leading to machinery could be difficult to trace if

that is necessary to any investigation.

Page 42: DIPLOMA IN MARINE SURVEYING. MODULE E Marine Engineering ... · MARINE SURVEYING. MODULE E Marine Engineering Surveying Paul Russell MSc, BA (Hons), MIMarEST Marine Engineer and Education

42

Figure 34 – Centrifugal Pump and Valve Figure 35 – Damaged Impeller

For example, it has been known that a new joint has been fitted, to make a leaking pipe coupling watertight, where the centre hole has not been cut. Therefore, there is a complete blockage in the

system. This could prove difficult to find and may include tracing a line and looking through the records to find

any record of work being done on that system, especially if this work has been carried out by sub- contractors or dry dock staff. Wear inside centrifugal pumps will lead to loss of performance; this will be especially so if the pump is

being used for pumping abrasive material such as any sand in ballast water.

Figure 36 – Scrolls – Fridge Compressor Figure 35 shows the damage that can be done if a pump is operated with no liquid going through it. This

pump is a small ‘Jabsco’ type cooling water pump that has been running dry. The rubber impeller has overheated and started to break up making the pump unable to carry out its function.

Gear pumps and scroll pumps are also prone to damage from debris that is held within the medium that is being pumped or compressed.

Figure 36 shows a set of scrolls from the inside of a refrigeration compressor. The scroll pump used for hydraulic oil will be of similar construction. The medium being pumped will act as a lubricant. If the system is kept in good order and the pump is running well then, the two scrolls should not touch each other.

During a routine annual survey, you should still be able to see the original machine marks from the manufacturing process.

Shaft sealing arrangements have always been a source of leakage. Older pumps will have a gland filled with packing. The packing becomes hard and starts to leak. Further “turns” can be inserted as a

temporary measure. However, the packing does put pressure on the rotating shaft which will then wear due to the erosion.

Page 43: DIPLOMA IN MARINE SURVEYING. MODULE E Marine Engineering ... · MARINE SURVEYING. MODULE E Marine Engineering Surveying Paul Russell MSc, BA (Hons), MIMarEST Marine Engineer and Education

43

Metal spraying techniques using plasma arc equipment can be used to build up the eroded area and then the shaft can be machined back to the original dimensions.

The latest pumps will be fitted with mechanical seals. These should not leak at all. If the seal does leak the loss of fluid will be excessive and the seal will need replacing as soon as possible. The different types of heat exchangers bring different problems.

Tube heat exchangers are designed to cope with a high differential pressure between the medium being cooled and the medium carrying out the cooling.

The O-rings separating the tube stack from the casing will eventually wear out and allow leakage of one medium into the other. If the heat exchanger is an oil cooler then the oil should be at a higher pressure

than the cooling water. This will mean that the oil will leak into the water and not the other way around. If the cooling system is a closed loop fresh water system then it may become contaminated with oil. Taking samples and having them analysed will confirm to the surveyor that this is the case.

Scale build-up and corrosion can be a problem but a more serious problem and one that is underestimated is that of electrolysis.

Sometimes, especially where salt water is used as a cooling medium, sacrificial anodes are fitted to the casing of tube heat exchangers; these will waste away due to electrolytic action. The anodes need to be

replaced from time to time. If not then the internal parts of the heat exchanger will waste away instead. This can be a particular problem on large yachts where more alloys and plastics are used in the construction of the vessel.

Figure 37 – Stainless Steel Plate

The correct flow of liquid through a heat exchanger is very important. The control of temperature must be arranged so that the flow of liquids through the heat exchanger is kept around the design recommendations.

Page 44: DIPLOMA IN MARINE SURVEYING. MODULE E Marine Engineering ... · MARINE SURVEYING. MODULE E Marine Engineering Surveying Paul Russell MSc, BA (Hons), MIMarEST Marine Engineer and Education

44

Figure 38 – Plate Heat Exchangers

The normal control mechanisms will take this into account. However, if the ship’s staff have operated manual valves incorrectly then the flow through the exchanger could change outside of this

recommendation. The metal surfaces might, then, become damaged due to erosion or due to any sediment or excess

chemicals in the system. Plate heat exchangers are size for size more efficient than tube heat exchangers. However, they are not designed to operate with a large differential pressure between the two liquids. The plates (see Figure 37)

are made from special metals such as stainless steel or titanium. The joints are of a rubber suitable to resist any reaction with the different liquids. Leaks can occur with

these units if the tie bolts have not been tensioned correctly or if excessive vibration has caused the nuts to come loose (see Figure 38).

The plates are made in a corrugated shape to assist a turbulent flow of liquids which assists the heat exchange from one medium to the next. This is why the plates need to be made from an erosion resistant material such as stainless steel.

This does not mean that they will be very resistant to mechanical damage. The plates are fairly thin and are quite fragile.

3.7 Electrical Equipment

3.7.1 Electrical Generators

The efficient operation of this equipment can be vital to the correct operation of the vessel. The variation in the load required from the generators can be quite wide. Diesel electric systems powering passenger

ships, for example, will have times when all the generators will be required to operate at a high load. At other times, some of the generators may be stopped. During these periods, when the engines are stopped, it is very important that the routine maintenance is carried out.

If the work is not carried out during this down time, then the alternators might not be able to deliver enough power when required.

Ships carrying a full load of bananas, for example, will need maximum power to cool the cargo down to just 4°C 48 hours after loading. If this is not done, then the cargo could be damaged.

In the case of damaged bananas, the marine engineering surveyor may be called in to identify why the cargo has been damaged. It will take an extensive investigation to track down a lack of maintenance to the auxiliary engines as the main cause of the temperature of the cargo not falling quick enough.

The data log of the cargo’s temperature would have to be examined carefully to track down the rate of fall of that temperature. If the rate of fall was not steep enough then suspicion would fall upon the following:

Page 45: DIPLOMA IN MARINE SURVEYING. MODULE E Marine Engineering ... · MARINE SURVEYING. MODULE E Marine Engineering Surveying Paul Russell MSc, BA (Hons), MIMarEST Marine Engineer and Education

45

Poor operation of the refrigeration system. Mechanical malfunction of the refrigeration system.

Lack of performance of the auxiliary generators. Operational logs and maintenance records will be vital in tracking down the actual cause. The system will have to be run on load and performance data taken and checked against the manufacturer’s original

data.

Discussions with the technical staff will ascertain the extent of their knowledge and understanding of the

maintenance and operation of the machinery. Failure of the alternators could be due to lack of care by the ship’s staff. Engine rooms can be hot and

dirty places and the alternators need a lot of air to keep them cool. The air drawn from the engine room will cause the windings inside the alternator to become dirty. If the insides are not cleaned regularly then the insulation can breakdown, which could cause a fire.

If the alternator has been stopped for any length of time and especially if the engine room has become cold then moisture can form on the insulation of the internal windings which could cause a breakdown in the insulation or could increase the earth leakage current.

Heaters might have to be used to raise the insulation value of the windings before the use of the alternator. Parts of the rotating sections of the alternator might work loose. Regular inspections would

identify any fault such as this at an early stage.

3.7.2 Switch Gear and Distribution Systems

Switchboards are usually built from standard parts. Each alternator has a section or panel on the main

board containing a circuit breaker, protection equipment and possibly the constant voltage unit, together with the means for isolating the machine when necessary. Parts are made accessible by withdrawal arrangements or by attachment to panel doors, which can be

swung open. Instruments, switches, indicator lights and controls are door-mounted with flexible leads. Each panel may be fitted with synchronising and paralleling equipment or there may be a special synchronising panel. The load panels can also be made of similar standard units containing the breakers,

switches and indicators as required. The board should be arranged so that essential services are maintained until the last possible moment. Three-phase systems are currently the most common systems with voltages being limited by the

controlling bodies. For lighting, accommodation and other services, voltage should not exceed 250V. The general limit for generation, power, cooking and heating equipment permanently connected to fixed wiring is 500V.

In large AC installations, generation and limited distribution at higher voltages might be used especially for cruise ships, dredgers and other vessels where high voltage AC can be used to advantage for the

propulsion motors. As with all electrical circuits, the correct type and efficient operation of protection devices is the key to

safe operation. If the cabling and equipment has been installed correctly, is not overloaded or has not been subject to mechanical or chemical damage, then the electrical systems should give a long trouble- free service.

A recent development in electrical engineering is performance monitoring and fault diagnosing by the use of thermal imaging technology.

The temperature of electrical components and connections can be compared with similar components that are next to and under similar load conditions.

Carrying out these checks could identify broken cables, weak insulation, corroded, loose or over tight connections, as well as the possible detection of an electrical imbalance.

A component that is cooler than surrounding components could indicate a malfunction of that component.

[www.maib.gov.uk/publications/investigation_reports/2011/qm2.cfm Last accessed 12th December 2017] shows what can happen when thing go wrong with the latest “High Voltage” systems and why IMO has just introduced a new “high voltage” endorsement to the engineering certificates of competency.

Page 46: DIPLOMA IN MARINE SURVEYING. MODULE E Marine Engineering ... · MARINE SURVEYING. MODULE E Marine Engineering Surveying Paul Russell MSc, BA (Hons), MIMarEST Marine Engineer and Education

46

3.7.3 Motors

The accumulation of dirt inside the cooling ducts and between the rotator and stator windings can easily cause a breakdown in the insulation properties needed for the motor to work properly.

Moisture is another substance that can have an adverse effect on the insulation properties of the machine. A breakdown in the insulation properties of the motor could first show up on the earth leakage gauges located on the main switchboard.

Isolating the fault will be carried out by switching off the service to different items at the isolating switch on the switchboard until the earth leakage gauge responds by showing an increase in insulation for the system.

It is a peculiarity of the maritime environment that moisture in the atmosphere can affect the insulation of the motor to such an extent that if the motor were started it would burn out.

Some motors that are particularly vulnerable will have a heating circuit built into the windings. This will keep out the moisture that breaks down the insulation of the motor.

Any machinery on board a ship that has not been used for a long period is susceptible to defects or breakage due to the vibration of the running machinery. For example, if a ball or roller bearing has been in the same position for an extended period then the balls or rollers will be moving against the same

place in the bearing carrier possibly without any lubrication. An indentation will start to appear, and when the equipment is started, and the bearing rotated, the small

indentation suddenly becomes a big problem and could lead to the failure of that bearing. The effect is called brunelling and can easily be overcome by running the equipment on a regular basis. It

is good professional advice to ensure that the running or operation of machinery for this purpose is recorded. If bearing failure is suspected the marine engineering surveyor should search the ship’s records and

conduct interviews to ascertain if the ship’s crew know about this effect.

3.7.4 Control Equipment

Electronic control equipment is now becoming more and more reliable. However, the harsh marine

environment will always be a challenge for the designers. Vibration, heat and moisture are the big contributors to the malfunction of electronic equipment.

Components can fail due to manufacturing defects. Dry joints or breaks in the circuit due to the flexing of a circuit board are the most common. Where electronics are required to work in extreme conditions they can be completely encased in resin.

This will hold the components securely, but sufficient heat dissipation must be designed into the system. Pneumatic control equipment is probably more suited to the harsh environment of the main machinery

space where it is not possible to cool the area with air conditioning. The single most important factor with pneumatic systems is the supply of clean, dry air at the correct pressure. Solid particles larger than five microns can cause blockages or damage diaphragms and/or O-rings.

The correct operation of dryers (chilled water or absorption types) is very important. The ship’s staff should be aware of this importance and of the consequences if the system is not maintained.

The incorrect operation of the control system will have a knock-on effect and means that the machinery is vulnerable to damage due to the systems having the wrong temperatures and pressures.

3.7.5 Batteries

The safe use of batteries is well documented, and their careful maintenance is the key to long trouble-free service.

Cleanliness must be the overriding concern, with consideration given to the following: ventilation (especially with large banks of lead acid batteries); cleanliness of the terminals;

any spilt acids or top-up water cleaned up immediately; electrolyte levels are correct; and records of maintenance complete and kept up to date.

Page 47: DIPLOMA IN MARINE SURVEYING. MODULE E Marine Engineering ... · MARINE SURVEYING. MODULE E Marine Engineering Surveying Paul Russell MSc, BA (Hons), MIMarEST Marine Engineer and Education

47

The surveyor must ensure that they take personal safety seriously where batteries are concerned. Even with low voltage batteries, sparks can still be generated. These are hot and can either burn or become

the source of ignition if flammable vapours are present.

3.8 Deck Machinery

The marine engineering surveyor might be brought in to investigate deck equipment or watertight

integrity where mechanical failure might be suspected. For example, the watertight integrity of the vessel is the subject of the safety and load line survey. However, the marine engineering surveyor may be requested to join a team if mechanical damage has occurred which has led to a compromise in the

watertight integrity of the vessel. Lack of maintenance and/or misuse will be the major contributing factors to the failure of deck

machinery.

Figure 39 – Chain – No Oil Figure 40 – Worn Teeth – No Oil

Figures 39 and 40 show the classic problem if machinery is neglected due to lack of lubrication. These

pictures show a serious situation and possibly show that the mechanism has never been lubricated.

3.8.1 Hatches (Watertight Integrity) Figures 41 shows the stains from the ingress of water. This could be highly dangerous for the vessel concerned because the vessel’s stability could be compromised as well as cause damage to the cargo or

equipment stored below the inspection hatch. Obviously, the vessel’s deck and cargo equipment are subjected to a most corrosive environment. Coatings are vital to protecting these areas and equipment. Figures 42 and 43 shows how badly corrosive the marine environment can be.

Figure 42 – Corroded Deck Figure 43 – Corroded Step on Deck

Page 48: DIPLOMA IN MARINE SURVEYING. MODULE E Marine Engineering ... · MARINE SURVEYING. MODULE E Marine Engineering Surveying Paul Russell MSc, BA (Hons), MIMarEST Marine Engineer and Education

48

Figure 44 – Corroded Hatch Cover Drive

Similarly, Figure 44 shows how the hydraulic drive to operate the hatch has become corroded. It is only a small step before the equipment fails and then the vessel will struggle to fulfil its trading agreements.

The hydraulic pipes leading to the motor can also become corroded to the extent that they leak hydraulic oil. Clearly this could lead to a whole host of different problems for the ship, its crew and its owners.

The defects could lead to: people on board slipping over; oil entering the dock and the ship being subject to a fine; or

equipment failing and delaying the loading or discharge of cargo. Should the marine engineering surveyor point these defects out to the owners as part of their

survey? If this area is relevant to the original commission then by all means include it as part of

the report. If not, then it might be prudent to send a private note to the owner pointing out the

defects.

3.8.2 Cranes and Lifting Gear (Including Different Power Sources) Corrosion will always be the biggest problem to overcome with machinery on deck (Figures 45 and 46).

Figure 45 Figure 46 Deck Equipment 1 and 2

Mistreatment of the equipment by the operator will also be a factor for the marine engineering surveyor to consider when coming to a conclusion about any damage that might have occurred.

Page 49: DIPLOMA IN MARINE SURVEYING. MODULE E Marine Engineering ... · MARINE SURVEYING. MODULE E Marine Engineering Surveying Paul Russell MSc, BA (Hons), MIMarEST Marine Engineer and Education

49

3.8.3 Containers

The IMO Convention for Safe Containers was adopted in December 1972 and came into force on 6 September 1977. Amendments include the following:

Plating of containers (1981).

Examination scheme (1983). Approval of modified containers (1991). Standardisation of the information contained on the CSC approval plate (1993).

Figure 47 – Stacking of containers ready for loading.

A large number of containers are refrigerated. The refrigeration machinery is housed at one end of the container.

However, from time to time the machinery stops working. If this happens during a passage, then the contents of the container could be lost.

The question of who pays for the failure of the machinery may well become the issue for surveyors to sort out. Ship’s staff are often called upon to carry out repairs. Sometimes the answer might be simple but on

other occasions more extensive work may be required. These are complete refrigeration systems and, therefore, there could be problems with the following:

Compressors.

Electric or, on occasion, diesel drive motors. Drive belts.

Loss of refrigerant gas. Blocked cooling of the condenser. Restricted cool air movement around the evaporator. Restricted air movement around the container.

Page 50: DIPLOMA IN MARINE SURVEYING. MODULE E Marine Engineering ... · MARINE SURVEYING. MODULE E Marine Engineering Surveying Paul Russell MSc, BA (Hons), MIMarEST Marine Engineer and Education

50

Non-refrigerated containers are also a source of problems. Sometimes containers are filled with dangerous goods but are not labelled or declared as such. Containers are also poorly “stuffed”, in other

words, the contents are not put into the container carefully. Therefore, for example, the centre of gravity might not be where it is expected. This might lead to an accident when lifting or maybe the container might not fit into the locking mechanism directly due to the

unequal forces of the unequal weight distribution.

If the ship’s staff do carry out any repairs then they must record exactly what has been done and the

exact reasons for taking the action that they have. This is very important because they may have to defend their actions in the event of any claim for loss of the contents inside the container.

CMA CGM are the third largest container company in the world according to their web site, they also produce very interesting information about the specification and different types of container that are used.

Have a look at [www.cma-cgm.com/products-services/containers for more information Last accessed 7 August

2017].

4. Ballast Water Management

On 13th February 2004 the International Maritime Organization adopted the International Convention for

the Control and Management of Ships’ Ballast Water and Sediments (BWM). This convention recently. On

08th September 2017, entered into force.

According to the convention, ships must comply with the Ballast Water Management Convention not later

than the first renewal survey after 08th September 2017.

Ships may comply with the convention in one of several ways:

Ballast Water Exchange method

o Constant flow through tanks of ballast water.

o Sequential exchange of ballast water

o Dilution of ballast water.

Ballast Water Treatment method

o Process/ mechanical treatment

o Chemical treatment

Ballast Water Isolation

o Ballast water is loaded and discharged in same geographical area.

o Ballast water is pumped to a reception facility

o Ballast water is held on board

When performing on board surveys in relation to Ballast Water management, the surveyor should in the

first instance determine which of the above methods is in use. This information will be included in the

Ballast Water Management Plan which should have been reviewed and endorsed by the Flag State

Administration or a Recognised Organisation (RO) acting on their behalf.

The Ballast Water Management Plan must include the following information:

Ship name

Ship type

IMO Number (Ship)

Ballast water capacity

Call sign

Classification Society details, including registration number

Flag

Gross Tonnage

Main Dimensions

Number of ballast tanks on board

Number of pumps dedicated to ballast water system

Page 51: DIPLOMA IN MARINE SURVEYING. MODULE E Marine Engineering ... · MARINE SURVEYING. MODULE E Marine Engineering Surveying Paul Russell MSc, BA (Hons), MIMarEST Marine Engineer and Education

51

Owner

Port of Registry

Once the methodology has been ascertained, and it has been confirmed that the Ballast Water

Management Plan has been reviewed as required, then the surveyor should review the Ballast Water

Record book to ensure that the appropriate entries have been made by the ships staff.

Following the documentation review, and depending upon the method of ballast water management

which is in place, the surveyor should inspect the ballast water system including treatment plant where

fitted. These treatment plans should be type approved with traceability between a certificate and the on-

board equipment being available.

During the survey, the marine surveyor should confirm that the on-board arrangements are in line with

the Ballast Water Management plan and associated system diagrams.

5. RECOMMENDED READING AND USEFUL INTERNET SOURCES [All links below last checked 07 August 2017]

https://www.ntsb.gov/investigations/AccidentReports/Reports/MAB0703.pdf

www.dieselduck.net

www.marinediesels.co.uk - General site about the construction of engines

https://ww2.eagle.org/en.html - American Classification Society

www.marisec.org - International Chamber of Shipping

www.imo.org - International Maritime Organisation

www.iacs.org.uk - International Association of Classification Societies

www.sulzer.com - Marine engineering support services

www.internationalpaint.com - Marine coatings

www.alfalaval.com - Centrifugal purifiers and plate heat exchangers etc

APPENDIX 1

http://www.imo.org/en/OurWork/Facilitation/FormsCertificates/Pages/Default.aspx IMO forms

and certificates. [Last accessed 12th December 2017]

APPENDIX 2

https://www.cdlive.lr.org/information/Documents/Chief%20Engineer%20Procedures/The_examin

ation_of_machinery_items_by_chief_engineers_V101.pdf - The Examination of Surveyable

Machinery Items by Chief Engineers [Last accessed 12th December 2017]

APPENDIX 3

https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/440596/1832.pd

f - The Merchant Shipping (Port State Control) Regulations 2011 (replacement for MSN 1775 (M))

[Last accessed 12th December 2017]

APPENDIX 4

https://www.rolls-royce.com/~/media/Files/R/Rolls-Royce/documents/marine-product-

finder/propulsion-brochure.pdf - Rolls-Royce, Moving your business in the right direction [Last

accessed 12th December 2017]

APPENDIX 5

https:// https://www.gov.uk/government/publications/msn-1672-amendent-3 finder/propulsion-

brochure.pdf - Rolls-Royce, Moving your business in the right direction [Last accessed 12th

December 2017]

APPENDIX 6

http://www.specialmetalswiggin.co.uk/pdfs/products/NIMONIC%20alloy%2080A.pdf -

NIMONIC® alloy 80A [Last accessed 12th December 2017]