Flooding of UK Fishing Boats

8/14/2019 Flooding of UK Fishing Boats

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Banff and Buchan College The Universities of of Further |Education Glasgow and Strathclyde

FLOODING OF UK FISHING BOATS

by

BANFF & BUCHAN COLLEGEAND

THE UNIVERSITIES OF GLASGOW AND STRATHCLYDE



Banff and Buchan College The Universities of of Further Education Glasgow & Strathclyde




THE FLOODING OF UK FISHING BOATS

Contents

Executive summary

EXECUTIVE SUMMARY...............................................................................................VI BACKGROUND ................................................................................................................... VI

R ESEARCH METHODS .......................................................................................................VII

SUMMARY OF THE MOST SIGNIFICANT FINDINGS..............................................................IX

GENERAL FINDINGS .......................................................................................................... IX

FLOW DESIGN ................................................................................................................... XI

MATERIALS AND FITTINGS ............................................................................................... XII

E NGINE R OOM LAYOUT, LOCATION OF EQUIPMENT AND ACCESS...................................XIV

OPERATION .....................................................................................................................XIV

I NSPECTION OF SYSTEMS..................................................................................................XV

FREQUENCY AND COST OF FLOODING .............................................................................XVI

CONCLUSIONS AND RECOMMENDATIONS....................................................XVIII

CONCLUSIONS ...............................................................................................................XVIII

R ECOMMENDATIONS ......................................................................................................XXII

ACTIONS TO MEET THE R ECOMMENDATIONS...............................................................XXIV




BACKGROUND.................................................................................................................. 5

OBJECTIVES AND ACHIEVEMENT ............................................................................ 6

OBJECTIVES........................................................................................................................ 6

FOCUS OF THE STUDY ......................................................................................................... 6

SOURCES OF INFORMATION....................................................................................... 9

GOVERNMENT I NFORMATION............................................................................................. 9

I NSURERS I NFORMATION .................................................................................................... 9

BANFF A ND BUCHAN COLLEGE PREVIOUS STUDY ............................................................. 9

SURVEYS OF VESSELS AND PERSONNEL............................................................................. 9

SKIPPERS A ND OWNERS R EACTION TO SURVEY/R ESEARCH ............................................ 10

FLOODING HAZARDS IN FISHING BOATS............................................................. 12

OVERVIEW OF SYSTEMS .................................................................................................. 12

SOURCES OF FLOODING ................................................................................................... 14

SUMMARY OF FLOODING HAZARDS ................................................................................. 16ENGINE ROOM VOLUMES .......................................................................................... 17

MATERIAL (CORROSION) & FLOW (EROSION) PROBLEMS ........................... 18

GENERAL ......................................................................................................................... 18

GALVANISED STEEL ......................................................................................................... 19

OTHER PIPE MATERIALS A ND FLOW R ATES .................................................................... 20

MATERIALS FOR FITTINGS ............................................................................................... 21FLOW EROSION: LIMITS O N FLOW SPEED ........................................................................ 21

LOCATIONS OF PIPE FLOW TURBULENCE......................................................................... 22

THE PIPE MATERIALS FOUND I N THE SURVEYS ............................................................... 23

TESTING OF PIPING & SYSTEMS.............................................................................. 24

THE TIME REQUIRED TO SURVEY VESSELS ........................................................................ 24

ULTRA-SONIC TESTING ..................................................................................................... 24

FLEXIBLE HOSES AND COUPLINGS........................................................................ 26

HOSES .............................................................................................................................. 26

FLEXIBLE (VIBRATION) COUPLINGS ................................................................................. 27

BULKHEAD INTEGRITY.............................................................................................. 30




SYSTEM DESIGN PROBLEMS..................................................................................... 31

SEA I NLETS ...................................................................................................................... 31

CONDITION OF SEA INLETS ............................................................................................... 32

BILGE SUCTIONS .............................................................................................................. 33

OVERBOARD DISCHARGES ............................................................................................... 33

COOLING SYSTEMS........................................................................................................... 34

AUTOMATION AND VIGILANCE......................................................................................... 34

BILGE ALARMS ................................................................................................................ 35

ANALYSIS OF REGULATIONS.................................................................................... 36

METHOD........................................................................................................................... 36

SAMPLE ............................................................................................................................ 36

SUMMARY ........................................................................................................................ 38

FINDINGS ......................................................................................................................... 39

FINDINGS FROM GOVERNMENT A ND I NSURERS I NFORMATION ........................................ 39

SUMMARY OF FINDINGS FROM DATABASES ...................................................................... 41FINDINGS FROM SURVEYS OF ACTIVE FISHING BOATS.................................................... 41

SUMMARY OF FINDINGS FROM SURVEYS........................................................................... 42

DISCUSSION, CONCLUSIONS, RECOMMENDATIONS AND ACTIONS ........... 45

DISCUSSION AND CONCLUSIONS ...................................................................................... 45

R ECOMMENDATIONS ........................................................................................................ 49

ACTIONS TO MEET THE R ECOMMENDATIONS.................................................................. 51




APPENDIX A SUMMARY RESULTS......................................................................... 54

CORRELATIONS ................................................................................................................ 54

TABLES ............................................................................................................................ 55

APPENDIX B FREQUENCY AND COSTS ................................................................. 57

APPENDIX C TYPICAL REPORT............................................................................... 58

APPENDIX C TYPICAL REPORT............................................................................... 59

VESSEL DETAILS .............................................................................................................. 59

FINDINGS.......................................................................................................................... 62

R ECOMMENDATIONS: ....................................................................................................... 62

APPENDIX D TYPICAL INTERVIEW......................................................................... 63

CRITICAL PIPE WORK AND SYSTEMS/ PROCEDURES I NTERVIEW....................................... 63

APPENDIX E..................................................................................................................... 66

EXAMPLES OF R EGULATION A NALYSIS ............................................................................ 66

SCUPPERS, I NLETS AND DISCHARGES ............................................................................... 66

COOLING WATER AND OTHER SEAWATER SYSTEMS......................................................... 70

APPENDIX F EXAMPLE OF INFORMATION BOOKLET .................................... 77

TYPICAL LIST OF MATERIALS ........................................................................................... 77





Banff and Buchan College of Further Education1 and

Glasgow & Strathclyde Universities2

After a survey by the team a main sea water pipe, that had been identified asbeing thin although it looked “in sound condition”, was replaced at the request of

the skipper. Inspection by a shore based engineer showed that it was indeed

“dangerously thin and if left would have caused flooding”.

EXECUTIVE SUMMARY

The most effective ways to cut down losses and damage due to flooding are

1 To fit means to close sea inlet valves that would be operable in theevent of significant flooding of the Engine Room.

2 To have functioning bilge alarms that can be tested and maintained.

3 To use flexible hoses and vibration couplings correctly.

4 To close all sea valves in harbour to avoid flooding and to confirm

their operational effectiveness if they need to be used at sea.

BACKGROUND

As part of their drive to improve safety at sea in the fishing industry, theFishermen’s Safety at Sea Working Group commissioned a study of water ingressinto fishing vessels, specifically with regards to critical pipe work. The aim was to

identify and quantify crucial areas of deficiency and to make proposals that wouldhelp correct them.

In the UK as a whole, foundering and flooding accounts for over 50% of all losses to all lengths of fishing boats and, in recent years, for Scottish boats, a rather higher percentage with Engine Room flooding as a significant source of loss3. The




The resulting study has focussed on flooding of fishing boats and, in particular,concentrated on raw sea water systems as these have most potential to causelarge scale flooding.

The study was sponsored by The Corporation of Trinity House, Maritime andCoastguard Agency (MCA), North East Fishermen’s Training Association(NEFTA), the Royal National Lifeboat Institution (RNLI) and Sunderland Marine

Mutual Insurance Company.

Additional assistance in carrying out the project was received from the MCA,Marine Accident Investigation Branch (MAIB) statisticians, Sunderland MarineMutual Insurance Company, Scottish Boatowners Mutual Insurance Association,Pirie and Smith Ship Surveyors, vessel agents, skippers, owners, engineers,designers and boat yards.

The project team are most grateful for all assistance given and wish to thank theindividuals involved for their time and efforts.

The study set out to answer two main questions:

•

•

Why do fishing boats flood so often?

What can be done to reduce the number of these floodings?

RESEARCH METHODS

The work centred on practical surveys of 40 fishing boats and, in particular, their seawater piping systems as this was shown to be the most significant cause of

flooding. Interviews were carried out with experienced fishermen on the issue of flooding and flooding related topics. Additional information was utilised from aprevious project carried out by Banff and Buchan College1; “The Development of aReliable Bilge Monitor and The Loss of UK Fishing Vessels Through Flooding”.

This was coupled with a review of insurance claims2 related to flooding incidents




• at what stage the faults occur in the life of a boat:

o do they derive from the initial design of the pumping and seawater systems on the vessel?

o are any problems “built” into these systems at the constructionstage?

o are problems introduced as a result of modifications or repairs?

• the reason for these faults occurring

o is the system being used as designed?

o is the system being maintained appropriately?

o are any modifications to the system being monitored and checked?

• whether the faults that occur could be found in conventional MCA or insurance surveys and indeed, what sort of survey could be used to findthese faults?

The vessels sampled were typical of the UK fleet as possible sources of bias were

minimised. The boats were not self-selected, nor were they subjectively chosenby the investigators from a wider pool of possibilities. They were selected fromthose that were available in the time available and against sponsors’ requirementsto survey vessels of a certain size, age and also from different geographicalregions within a given time period. It was not possible for the investigators toinfluence the selection. This lack of bias and the numbers surveyed are enough togive confidence that any commonly occurring faults will be typical of the fleet as awhole. At no time did any owner refuse to take part in the survey, thus underlining

both the impartiality of the survey and the willingness of ordinary fisherman to workfor a safer industry.

The average age of the boats surveyed was 17 years – ranging from just under ayear to well over 40 years old. Eleven (27.5%) had wooden hulls the remainder were of steel hull construction The age and length distributions are shown in




SUMMARY OF THE MOST SIGNIFICANT FINDINGS

This research has quantified many problems that have been previously highlightedby the MCA in their guidance to Seafarers. In particular many of the findingssupport recommendations that have previously been passed on to all the relevantplayers in the maritime industry via M Notices1 and some have been incorporatedin recent Regulations for the 15 to 24 metre vessels2. Prior to this research it wasdifficult to quantify these problems, but an opportunity now exists for thecommissioners of the research to plan their strategy to lessen losses at sea due to

flooding through critical pipe work failure.

To put the probability of flooding in perspective, consider a fleet of 1000 fishingboats. In an average year the vast majority (930) of these would not have aproblem with flooding. Fifty boats out of the remainder would have a floodingincident that they controlled effectively without bringing in any outside help.Fifteen boats, however, would have to call in others for assistance and five boats

would sink because of flooding.

GENERAL FINDINGS

1. Faults and deficiencies are common across age and size groups.

2. The most significant faults are those that could lead to full bore pipe failure or

slower flooding that is undetected.

3. Most fishing vessel pumping systems cannot cope with potential floodingrates.

4. There is a need for a pumping capacity outside the Engine Room.

5. Bilge alarms and the means of closing sea inlets and discharges are often

deficient.

Distribution of Common FaultsFault % of vessels surveyed

associated with flow design 62 5




This photograph show a very simplecable attached to the valve handle and

fed through the deck plates.A red plastic ring is attached to the upper end of the cable. A sharp tug on this redring then quickly closes the valve. Thisis simple, cheap, reliable and effective,

i ll ith th hi h i ibilit f th




MATERIALS AND FITTINGS

10. Incompatibility of metal components, causing corrosion due to galvanicaction, is common.

This photograph shows mildsteel studs being used tosecure an aluminium brasspipe, flange and housingtogether. They were tuckedout of sight; should they failthe flange and housing couldseparate resulting in a “fullflow” incident. If the flangewas sealed watertight andthe studs kept dry, the

situation would be greatlyimproved.

11. Galvanised steel as a general piping material on fishing boats is questionablein its effectiveness due to difficulties in making modifications and repairs.

This shows the reason whygalvanised piping is notpreferred. Repairs are notalways performed correctly.

Here, the pipe has not

been re-galvanised after welding.




These photographs: show:

On the right correct use of materials and coupling

(although the quantity used

seems excessive).

But, to the right the couplingwas taking up the

misalignment of the pipework




14. Poor support and fastening of pipe work is relatively common.

Poor support

The pipe was rattling onthe support and thewhole assembly was

supported at one end bya hose!

ENGINE ROOM LAYOUT, LOCATION OF EQUIPMENT AND ACCESS

15. Equipment is not always positioned with due regard to the consequences of potential flooding and, in particular, bilge alarms could be placed with moreaccessibility for testing and repair.

16. The potential ability to close sea inlets after even quite limited flooding was

often lacking – this could make potentially dangerous situations irrecoverableand catastrophic.

17. Frequently valves and pipes were fitted in locations that made inspection andmaintenance extremely difficult.

OPERATION

18. The common failure to close sea inlets and discharges in harbour is bad

practice and sometimes costly.

If this seacock wasused regularly in

harbour to close down




20. Identification marking of piping systems is limited making use by

inexperienced crew/ persons difficult.

INSPECTION OF S YSTEMS

21. Ultra-sonic inspection of pipes is a valuable component of an overall vesselsafety scheme.

This photographshows the researcher

using ultra-sonicequipment to test a

pipe.

This photograph

shows the samesection of pipe butthis time take frombelow floor plate

level showingperforations that

were undetected by

the ultra sonicsampling above thedeck plates. Thissection is directly

connected to one of the main sea water




These two photographs weretaken on similar age and type of vessels. The one on the left with the red ring around theconnecting piece shows that allthe materials used in itsconstruction are compatible andno materials problems are beingdisplayed (although there are

nasty right angled bends).

The pipe work below has thecentre section replaced withsteel (magnet stuck ontosection). This section wasfailing over its entire surface.This is the main discharge from

the pump and failure would leadto sea water being pumped viathe sea suction into the vessel.This would have disabled thisparticular vessel’s main systemsin a very short space of time.

Magnet




CONCLUSIONS AND RECOMMENDATIONS

Most critical flooding problems derive from thedesign, installation, operation or maintenance

of raw sea water piping systems.

CONCLUSIONS

General wear in pipe systems is to be expected as boats get older, but this wasnot always found. General pipe deterioration will usually cause leakage but rarelycauses catastrophic flooding unless it goes undetected.

The most critical defects are those that that could produce full bore failure - that is,catastrophic flooding. The types of failure that produce the largest flooding ratesare defects that accelerate wear (corrosion/erosion), cracks that propagate and

cause pipe work to shear, and failure of flexible/rubber connections or inserts.

A critical evaluation should be made, during the initial design and constructionstages of a vessel’s life; into the effects that catastrophic flooding would have onthe vessel’s ability to cope with these situations. This risk assessment shouldguide the design and location of vital equipment and systems.

There is inconsistency in the positioning of components, equipment and in the

selection of materials for engine room systems. There is also evidence, from theboats surveyed, that suggests ‘repairs’ are performed with little regard for materialcompatibility and potential consequences.

Over-seeing inspections during construction or in service are not picking up all thepossible deficiencies. It seems that information about and understanding of fluidflow systems is not being adequately applied or disseminated in all situations.

We conclude that there will always be incidents that are beyond the capability of avessel’s systems to control. This places an emphasis on ways to detect and limitflooding. Despite this:

i) the overwhelming majority of the boats surveyed (87.5%) did not have




Most of the boats surveyed were built in accordance with the 1975 Fishing VesselsSafety Provisions Regulations and associated guidance. It is clear that these

Regulations are in many instances unclear and ambiguous, requiring builders andsurveyors to use their own interpretation. Because of this, the rules naturallyevolved to set minimum requirements / standards and in most instances vesselssurveyed were constructed to comply with these minimum requirements.Alarmingly, few owners were aware that their vessels were only meeting aminimum standard and that they were free to modify - and improve - their vessels.Many vessel operators were under the impression that their UK Fishing Vessel

Certificate was definitive evidence of the vessel’s seaworthiness and thatmodifications / improvements could only be made if advised by the MCA. Thus,the Regulations, themselves are enforcing an artificial ceiling on good practice. Itis felt that this should be made clear to the industry.

We have found, moreover, that the recent Code of Safe Working Practice for theConstruction and Use of 15 metre length overall (LOA) to less than 24 metre

registered length (L) Fishing Vessels is not as clear and unambiguous as it couldbe about minimum requirements so as to avoid ‘individual interpretation’.

It is very important that Regulations should be clear and that the requirementsshould be enforceable and enforced.

Among the most immediately critical defects discovered on vessels was themisuse of flexible fittings such as hoses and flexible expansion pieces. Thesewere frequently used as repairs and were also used in fairly new boats as ameans of dealing with poor pipe alignment and fitting. Failure of these flexiblefittings would usually lead to rapid flooding. The MCA have pointed out through MNotices that that these fittings should be replaced regularly as a matter of course,but a date of fitting is seldom apparent and no date of manufacture is impregnatedinto the fabric and, therefore, operators are unaware of the age of the item. Use of these items should be logged within a safety system and key players should be

made aware of the correct way of using them. It must be stressed, however, thatthese fittings were never seen under floor plates in live sea water pipelines.

The number of missing or broken pipe supports is also of major concern (37.5% of vessels surveyed). Failure to repair these seems to be due to lack of awarenessof the consequences These may be catastrophic as vibration induced fractures




Whilst the surveys detected numerous thin pipe walls (25% of pipes were inexcess of 25% average pipe wall thinning, of these 10% in excess of 40%

thinning), it is felt that very few of these would have resulted in catastrophicflooding provided that bilge alarms functioned properly and gave adequate earlywarning. In most cases the application of an epoxy bandage would allowoperations to continue until the vessel made shore and had a permanent repair made.

Many deficiencies discovered during our surveys were probably found simply by

“fresh eyes” specifically targeting pipes and flooding related areas. That impliesthere is a need for the vessel’s own engineer to devote time specifically to theseissues in addition to normal operational effort.

In some cases video footage and photographs were taken. These recordingswere found to be invaluable for review and occasionally allowed previously unseendeficiencies to be detected either by a ‘second look’ or other opinion.

In the following recommendations an attempt is made:

i) to solve immediate problems;ii) to produce systems and a regime that will reduce the number of

floodings.

Our recommendations are a mixture of prescription, to set a base level of safety,and procedures / requirements that are intended to raise the amount of informationavailable and to increase awareness of critical flooding issues.

The recommendations are followed by actions for each part of the Industry.

Flexible coupling

Misaligned to stretch andbend. Also under torsion.

These must never bet i d i t d!




RECOMMENDATIONS

1) In the short term,

1.1 A major effort should be made to inform all sectors of the industry of thehazards associated with misuse of flexible hoses and flexible expansion joints.

1.2 MCA Inspectors should be informed of the limits of, and correct use of,flexible expansion joints and hoses and should enforce removal of hazardous fittings.

1.3 Skippers should (again) be reminded of the potential consequences of failing to close sea inlets and discharges in harbour and Insurers shouldconsider means of persuading operators to close inlets and overboarddischarged in harbour.

1.4 All boats 12m and over should be required to fit means of closing sea inletsand discharges from a position that can be accessed when there issignificant flooding of the engine room - say 30% of the volume of thespace.

2) In the medium term,

2.1 All boats 12m and over should have an independently powered pumpsituated above the main deck level in a position accessible in normaloperations that can take suction from the engine room and fish room bypiping that is permanently installed and independent from other pipingsystems.

2.2 All boats 12m1 and over should be required to carry a document that

describes their engine room pumping systems in terms of layout, equipmentpart numbers, especially the specification of all piping. There should be aschematic of the engine room systems displayed within the engine roomand there should be associated marking and colour coding of pipes andequipment. Any subsequent alterations to any one of these systems should




ACTIONS TO MEET THE RECOMMENDATIONS

The Maritime and Coastguard Agency should:

1. Consider carrying out spot safety inspections on fishing vessels specifically toinclude bilge alarms, sea inlets and remote closure systems for sea inlets.Target time for spot check 30 minutes.

2. Consider how best to ensure that a risk assessment might be carried out oneach vessel that includes risks associated with flooding. Once risks areidentified and quantified effective action may be taken to reduce the overallrisk.

3. Consider setting up a working party to evaluate the Code of Safe WorkingPractice for the Construction and Use of 15m (LOA) to Less Than 24m (L)Fishing Vessels (and associated Guidance to Surveyors), with particular regardto clarity in the rules for sea inlets, bilge pumping capacities, materials andcomponents.

4. Examine the viability of new builds installing an auxiliary engine and bilgepumping arrangement in a dry space out with the main engine space.

5. Consider requiring all vessels 12m and over to prepare and carry on board a

schedule of piping, pumps and associated equipment which includes materialspecifications, system drawings and recommended replacement intervals for short life fittings. The intention being to allow transfer of design intent andrelevant information through the vessel’s life.

6. Consider requiring all vessels to display within the engine room a schematicdiagram of the bilge and cooling water systems to assist the crew.

The Fishermen’s Safety at Sea Working Group could:

7. Consider initiating research into:

a) the degradation of piping systems and preferred best practice in design and




The UK Fishing Industry should:

8. Consider, where possible and practical, carrying an independent portablepump capable of pumping bilges in an emergency.

9. Consider carrying out regular safety drills which involves all members of thecrew in basic bilge pumping and valve isolation operations and use of manualand powered emergency pumps.

10. Make a practice of shutting all sea inlets and discharges when vessels areunattended in harbour.

11. Fit a high bilge level warning system, in a position where it can be readilyinspected and maintained, which would operate an external alarm in

circumstances where the vessel is unmanned, i.e. when in harbour.

12. Fit two independent (and accessible) bilge alarm systems for engine roomprotection.

13. Fit at least one bilge alarm in all major spaces within the vessel.

14. Consider installing a “bilge monitor” system which constantly displays levels of water in bilges.

15. Test bilge alarm bilge switches daily where possible and test fish room bilgealarms by controlled flooding during cleaning operations.

16. Where practicable, install close circuit colour television cameras in the engineroom.

17. Be aware of the potential for electrolytic action associated with installing lowvoltage negative earth electrical equipment.

18. Colour code all pipe work for easy and quick identification and label valvesstating their purpose




Marine Insurance Companies should:

21. Encourage skippers to perform safety checks and drills and include a record of these in a vessel log.

22. Encourage vessel owners to compile video footage and still photographs of vessel’s engine room etc. for ease of visualising components and equipment toassist with potential claims.

23. Consider methods of persuading operators to shut sea inlets and dischargeswhen vessels are unattended in harbour.

24. Carry out safety related spot checks on vessels, to include observation of safety drills, testing alarms and emergency response procedures.

25. Encourage vessel owners to carry portable salvage pumps and other risk

reducing equipment such as bilge monitors and engine room cameras.

Training Establishments are recommended to:

26. Offer training to fishermen in awareness of flooding dangers and in portablesalvage pump operations.

27. Construct courses (certificated) and offer training in basic machinery operation,inspection and maintenance, including valve chests and pumping operations.

28. Offer short Safety and Management courses in Marine Insurance to cover possible implications upon the fishing industry of insurers’ becoming morestringent in their interpretation and application of the Marine Insurance Actclauses, warranties and definitions.

29. Offer technical awareness courses suitable for fishing boat designers andsurveyors to cover fluid system design, degradation and inspection techniques.

The RNLI could:

30 Consider applying their considerable experience and knowledge by becoming



FLOODING OF UK FISHING BOATS

by

BANFF & BUCHAN COLLEGEAND

THE UNIVERSITIES OF GLASGOW AND STRATHCLYDE

MAIN REPORT



B ff d B h C ll Th U i iti f




SYSTEM DESIGN PROBLEMS........................................................................... 31

SEA I NLETS ............................................................................................................. 31

CONDITION OF SEA INLETS ...................................................................................... 32

BILGE SUCTIONS..................................................................................................... 33

OVERBOARD DISCHARGES...................................................................................... 33

COOLING SYSTEMS ................................................................................................. 34

AUTOMATION AND VIGILANCE ............................................................................... 34

BILGE ALARMS ....................................................................................................... 35

ANALYSIS OF REGULATIONS.......................................................................... 36

METHOD ................................................................................................................. 36

SAMPLE .................................................................................................................. 36

SUMMARY............................................................................................................... 38

FINDINGS................................................................................................................ 39

FINDINGS FROM GOVERNMENT A ND I NSURERS I NFORMATION............................... 39

SUMMARY OF FINDINGS FROM DATABASES ............................................................. 41

FINDINGS FROM SURVEYS OF ACTIVE FISHING BOATS .......................................... 41SUMMARY OF FINDINGS FROM SURVEYS ................................................................. 42

DISCUSSION, CONCLUSIONS, RECOMMENDATIONS AND ACTIONS.. 45

DISCUSSION AND CONCLUSIONS ............................................................................. 45

R ECOMMENDATIONS............................................................................................... 49

ACTIONS TO MEET THE R ECOMMENDATIONS ........................................................ 51

APPENDIX A SUMMARY RESULTS ............................................................... 54 CORRELATIONS....................................................................................................... 54

TABLES ................................................................................................................... 55

APPENDIX B FREQUENCY AND COSTS........................................................ 57

APPENDIX C TYPICAL REPORT ..................................................................... 58

APPENDIX C TYPICAL REPORT ..................................................................... 59 VESSEL DETAILS..................................................................................................... 59

FINDINGS ................................................................................................................ 62

R ECOMMENDATIONS:.............................................................................................. 62

APPENDIX D TYPICAL INTERVIEW 63

Banff and Buchan College The Universities of





Banff and Buchan College of Further Educationand

Glasgow & Strathclyde Universities

BACKGROUND

In the two years, 1999 and 2000, 29 Scottish fishing boats in the over 12metres fleet were lost. 20 foundered due to flooding and 14 of these losseswere specifically due to initial engine room flooding – that is 48% of all losseswere caused by engine room flooding.

On most of these occasions the vessels involved sank without loss of life,

but, unfortunately, sometimes there have been fatalities1. Often the vessels

in question sank due to flooding from causes unknown. It is hoped that thefindings from this study will go some way to establish and quantify areas of weakness where such floodings may arise and by doing so, improve safetywithin the fishing industry.

Insurance payments for damage to, or loss of, fishing boats of all sizesexceed £15 million a year on average; insurance payments for boats thatsank in 2001 exceeded £6 million2.

These figures highlight the cost to the fishing industry that stems fromflooding of vessels. There is a clear need for some action to limit the mostdamaging causes.





OBJECTIVES AND ACHIEVEMENT

OBJECTIVES

Contracted objectives of the project were

i) To identify, as far as possible, the most frequent and likely causesof flooding of fishing boats.

ii) To survey or inspect no less than forty, (mostly steel) UKregistered fishing vessels. Ten vessels were to be registered inthe UK, but out with Scotland and two vessels were to be less than2 years old.

iii) The vessels were to be surveyed on the slip where possible andfindings were to be made available to the sponsors. The vesselsand operators names however, were to remain anonymous.

iv) To produce a final report containing firm conclusions andrecommendations.

FOCUS OF THE STUDY

It was clear from prior information assimilated and from sources developed in

the study that the consequential flooding of Engine Rooms constituted by far the largest cause of total loss or damage due to flooding. In addition, pipingsystem failure was indicated as a primary cause of many fish room floodings – generally through "back flooding."

Within the category of flooding/sinking it was possible to identify causes suchas hull failure and rudder or shaft gland leakage that contributed to floodingsand losses. Where information existed, however, it showed that these were

almost completely associated with a shock incident such as grounding or contact with the propeller or rudder. To investigate these was clearly out withthe remit of the study.

An early decision in the study was, therefore, to concentrate on pipe work




Each survey consisted of an inspection of the vessel’s engine room andidentification of the pipes and components within the sea water and bilgesystems. A descriptive narrative and diagram for each boat was prepared.Ultra-sonic testing was performed on pipe sections where wall thinning wouldnormally be expected over time and in certain cases (with the ownerspermission) video footage and still photographs taken of examples of bothproficiency and deficiency.

The descriptions and diagrams were used to consider the flow regimes within

the systems and to help identify deficiencies.

The surveys and other studies of losses have led to a series of conclusionsand recommendations addressed to the Fishing Industry, Marine Insurers,Training Establishments and the Regulators (MCA).




gof Further Education Glasgow & Strathclyde

SOURCES OF INFORMATION

GOVERNMENT INFORMATION

Summarised accident and loss reports for the period from 1990 to the end of 2001 were obtained from MAIB. The main body of this was the informationpresented by MAIB in their report on the Analysis of Fishing Vessel Accident Data 1992 to 2000 . This was modified with more recent information qualitychecked against the raw incident reports. It must be noted that MAIB believeonly their major incident information is complete due to non-reporting from

the fishing industry of what are perceived as lesser incidents.

INSURERS INFORMATION

Information on damage and loss claims were obtained from two major fishingboat insurers who cover the majority of the UK fleet. This data gave thereported causation and the cost of both the claim.. The information allowedextension of the MAIB information to include unreported (to MAIB) incidents

that had caused damage to vessels as well as providing information aboutflooding in harbour. Because the information was given in strict confidence,only summarised information is presented in this report.

BANFF AND BUCHAN COLLEGE PREVIOUS STUDY

Banff and Buchan College had previously, through questionnaire andstructured interview, obtained information and views about various aspects of

flooding and this information was integrated into the study.

SURVEYS OF VESSELS AND PERSONNEL

Each inspection was performed alongside or on the slip/dry-dock. A typicalsurvey of a vessel produced a report that included information on the vessel’sdetails and history, the location of the survey and a description of the vessel’scondition at the time, a description of the engine room and associated

systems, comments on the system design, the extent and results of ultra-sonic testing, the findings and recommendations. The detailed review of theengine room systems was performed by tracking each system along allroutes from inlet to discharge and identifying the function.




of Further Education Glasgow & Strathclyde

Operator survey information from Banff and Buchan Colleges research into‘The loss of UK Fishing Vessels Through Flooding’ and some forty newpersonal interviews were used to assimilate information into this report.The results of the surveys and interviews are confidential and onlysummaries of the results are presented in Appendix A

It must be stressed that the identity of vessels and interviewees were, andwill remain, anonymous, even to the sponsors of this project. Examples of atypical report and structured interview format are in Appendices B & C. Notethat neither of these is a ‘real example’ to preserve confidentiality.

SKIPPERS AND OWNERS REACTION TO SURVEY /RESEARCH

Of the forty different vessels surveyed, not one owner/operator wasobstructive or refused access to their craft, indicating the willingness withinthe industry to improve vessel safety.

Wherever possible boats were surveyed in the dry-dock or slipway as this

allowed us to inspect hull penetrations as well as internal pipelines and,because the vessels were laid up it didn’t interfere with fishing patterns.

Several of the vessels surveyed were actually undergoing their four yearlyMCA survey for their UK Fishing Vessel Certificate. This gave researchersthe opportunity to inspect some pipe walls internally, as often valves werewithdrawn in preparation for MCA survey.

Some consider the fishing industry to be irresponsible and apathetic to safetyissues. We found a very different attitude. Where deficiencies were foundverbal feedback was given to operators. In some cases vessel operatorsobserved the survey work, and in a few instances where deficiencies werefound, they were attended to (upon the owners instructions) before thesurvey was completed. In three situations where the owners could only beinformed by telephone of probable pipe wall thinning, they gave carte

blanche to the survey team to instruct shore engineers to attend to theproblem.

At least one owner is known to have fitted high level extended spindles toships side isolation valves since the survey of his vessel took place.





From this we can sympathise with the MCA and the predicament they findthemselves in regarding perceptions of the UK Fishing Vessel Certificate.Many operators are lulled into a false sense of security by the issue of theCertificate - thinking that their vessels are absolutely safe. In fact their vessels have reached a minimum base line for safety requirements, not theceiling. We found a similar perception with regard to our surveys; whichincluded ultrasonic inspection with random sampling of pipe wall thickness inareas that could be expected to encounter corrosion/erosion. At no timewere components taken apart for internal inspection for integrity or strength.

Some of the failings of ultrasonic testing were pointed out to operators – for example that reliable sampling could not be obtained near flanges or compression fittings. The survey of the vessel’s pipes and ensuing reportcan not be taken as a clean bill of health, just as a car passing its MOT is notguaranteed to be free of defects or the potential to break down.

Banff and Buchan College The Universities of f F th Ed ti Gl & St th l d




FLOODING HAZARDS IN FISHING BOATS

OVERVIEW OF S YSTEMS

The life of an engineering system can be very broadly viewed as design,construction and then operation and the headings of design, build andoperate can also be used to generate a framework of broad objectives for systems on fishing boats that are related to flooding (Tables 1(a) to (c)).These objectives are based on the well known idea of avoiding a risk,reducing the effect of the event if it occurs and providing contingency

measures to deal with the consequences.

Design has to be good. It is expensive to change systems – other than thecomponents – after the system has been built and, thereafter, conflicts withother systems and difficulties with space and access may hinder attempts tochange things. Design, therefore, has to consider the life of the system –how it may degrade and how it may be accessed for inspection and

maintenance. It is the purpose of engineering qualifications and controlssuch as "Safety Regulations" to ensure that a design is, at least, competent.

TABLE 1(a) System Objectives to Avoid Flooding LossDESIGN

WHAT HOW

Avoid flooding As far as possible sources of flooding should beminimised. An obvious example is to minimise hull

penetrations that cause weakness.Limit the extent of flooding

If flooding occurs then the volume that can be floodedshould be minimised. For example the vessel shouldbe subdivided into a number of watertight spaces.

Limit the rate of flooding

If flooding occurs then the rate should be minimised.For example, pipes should be as small as possible.

Limit the effects

of flooding

Essential vessel systems should not be affected by

anything other than major flooding. The rate of floodingwill control the time it takes to put the vessel at risk.

Know aboutflooding

If critical flooding occurs there should be a way of telling the crew before the situation is irretrievable.Bilge alarms are in fighting flooding.

D l ith Th h ld h t d l ith th fl di





A system should be designed so that it can be built and that implies arelationship of some sort between the designer and the builder. At the leastthis requires experience on the part of the designer, and good practice by the

builder. Both the designer and builder should ensure that they do notproduce systems that are going to be difficult to access for operation or for maintenance.

TABLE 1(b) System Objectives to Avoid Flooding LossBUILD

WHAT HOW

Understandthe design

Key building staff should know why systems have beendesigned and why certain materials have been specified.Builders must have the professionalism to use what isrequired rather than what is available to avoid this.

Follow thepurpose of the design

As far as possible, the intent of the designer should befollowed. Changes or corrections should be assessedagainst the original intent. This requires goodcommunication promoting two way transfer of knowledge.

Use goodpractice

Competent tradesmen should be used. Competence impliestraining, understanding and experience.

Controlconstruction

Inspection systems should exist that check and control thecompetence of workers and their work, i.e. quality control.

Clearly, a system also has to be designed so that it can be operated and fulfil

its functions. There are often many ways to make a system work, but only afew will do what was intended, and that implies that the crew need to knowhow the system works and what it should and should not do. Operation alsoincludes regular checking, maintenance and repair. These are intimatelylinked to design in that the purpose of the design has to be communicated to,and understood by all those who are working the system.

TABLE 1(c) System Objectives to Avoid Flooding Loss

OPERATEWHAT HOW

Understandfloodingeffects

The crew should be aware of the effects of flooding and thecritical nature of flooding on fishing vessels. There existrequirements for skippers to understand stability but





SOURCES OF FLOODING

Water ingress into a vessel can be from,

i) boundary failures such as leaks through the hull, bulkheads andtank boundaries.

ii) envelope failures in the fluid system pressure envelope (thisincludes all pipe line systems).

iii) system faults where fluid flow is inappropriate or misdirected.

These are the broadest possible generalised categories and the vessel’s ownpumping and piping systems are involved in two of them – highlighting theimportance of these systems in maintaining the vessel’s integrity.

Boundary failures

The main sources of boundary failures are hull leaks through planking or at

penetrations such as sea inlets and discharges, shaft and rudder glands.

Whereas hull seepage is a fact of life on wooden boats, good maintenancekeeps it in check and careful monitoring of bilges warns of any changes.Shaft and rudder gland failures affect all vessels, but dominate boundaryfailures on steel boats. Our review of insurance information suggests thatshaft and rudder gland leaks are almost always associated with ground or gear contact or shock impact of some kind. Where vessels were in dry dockor slipped at the time of survey their hulls were inspected visually at potentialsuspect areas. Only one vessel inspected reported having this type of damage prior to dry docking and this was being attended to at the time.

At another level are bulkhead and tank penetration leaks and open Weather tight (WT) doors and hatches. Tank leaks are naturally limited in volume sothat, although they can cause damage, they are unlikely to lead to a total

loss.

Down flooding through doors and hatches is not usually the primary event ina flooding. It is clear, however from descriptions and reports of losses, thatflooding through a door or hatch that is designated as ‘closed at sea’ is





Pressure envelope and system faults

Envelope and system failures can affect all boats.

Of a vessel’s envelope systems those with the largest flows present the mostobvious hazard, but it is the size of the leak as well as the flow within thesystem that makes for a catastrophic failure. In a fishing boat the hydraulicand fuel lines may be discounted as they are limited in their effect. Equally,sanitary systems are small bore and should not cause major problems,although faulty installation and improper operation has led to hazardousflooding1. The systems of interest in typical boats that were studied in the

surveys of working vessels are listed in the tables below.

Vessel Sea Water Systems

System CommentCooling water Continuous use from sea inlet when running machinery

Deckwash Sea water pumped when required for deck/gear cleaning.

Process water To clean catch - may be common with deckwash.

Ballast water Occasional use to balance vessel.

Refrigeration Usually continuous sea water supply at sea (if fitted).

Bilge water Although the bilge system is a contingency system todeal with any flooding, there may be regular use of thissystem if there is continuous, known leakage into thevessel – say through a wooden hull.

Flooding due to system failures stems from those systems that areconnected at one point to the sea and at another to a space or spaces –typically at a bilge suction. The potential exists for flow to be misdirected or for gravity/pressure to cause flow if control valves fail or if they are not usedcorrectly. The systems that are most susceptible to this are those that takeentry from or discharge to the sea below the water line





Possible System Failures

System Comment

Ballast Potential to pump to the wrong space, allow gravity flow tothe wrong space from the sea or to allow gravity flowbetween spaces.

Cooling Although generally enclosed, connections may pass water and allow flow through other systems.

Bilge Failure, or trapped debris in a non-return valve can and

often does allow flow directly from the sea into the bilge.

This type of flooding is especially connected to harbour flooding. Of 19claims studied for machinery damage by flooding against one insurer, 12were from flooding in harbour and in 11 of those cases, the sea inlet valveshad not been closed when the vessel was left unmanned. All that is thenrequired is a valve that is passing water for some reason and flow will take

place to a low point – generally the engine room or fish room bilge.Surprisingly, perhaps, the deck wash system can also suffer frommisdirection of flow when the tail of a hose is left in the sea and a siphoneffect arises through a passing valve. It can happen at sea or harbour and,because the backflow suction rate is high the ensuing flooding can be rapid.

Finally, in the study we found that most of the boats surveyed had a bilge

system of the type only protected, from the sea by one non-return valve in avalve chest – making this component absolutely vital to the boat’s integrity.We comment on that later.

SUMMARY OF FLOODING HAZARDS

From the design overview the key words are competence, control,communication and understanding. Mechanisms have to be found that will

i) Ensure competent design of systems;

ii) Transfer knowledge through the life of the vessel so that, for example, correctly specified materials are used in repair;



MATERIAL (CORROSION) & FLOW (EROSION) PROBLEMS

GENERAL

Corrosion

We found a range of problems that could be traced to poor use of materialseither when built or during repair. 70% of all boats surveyed had what we judged to be a material problem that would eventually lead to a pipe failure.25% of vessels surveyed were actually displaying advanced corrosion due todissimilar metal contact. Initially, these could be leaks that would be caughtearly by a functional bilge alarm, however a few may cause a complete pipework section to collapse and in a pumped system this could produce quiterapid flooding.

There was evidence of corrosion and erosion problems within the critical pipework. 11 out of the 40 boats (27.5%) had what we would class as a pure

corrosion problem caused by use of inappropriate materials.

Frequently the problem had been inappropriately repaired by patching andnot replacing the “suspect” pipe. On one vessel there was evidence of multiple levels of patching. In some cases there seems to be a tendencywithin the industry to replace material rather than solve the deep rooteddesign/construction problem that caused the initial failure. We found sevenvessels (17.5%) with patches on their pipe work, including one on a vessel

only fifteen months old. Under such a ‘patch’ erosion continues due to the‘broken’ pipe wall.

The underlying problem is either in the understanding or the implementationin practice of corrosion theory. In the worst cases of repair a dangerousproblem was built into the system.

Galvanic corrosion arises if two different metals are put in contact in a wetenvironment - and sea water is one of the worst. If this happens, there willbe a flow of electrical current from one to the other. Electrical current is aflow of electrons and each electron has to come from one of the metals. Asthe electrons are taken away some metal is also lost and one of the metals

ill d h f hi i b i i l h fl




design systems with dissimilar metals that don’t cause problems, but it’s a loteasier to avoid the problem by keeping metals apart. On one boat we foundthree, possibly four different metals in one length of pipe (the doubt arose

because it wasn’t possible to test the metals in the allotted time and we hadtherefore to rely on observation and experience.).

Erosion

The research found that a majority of boats (62.5%) had what we judged tobe problems associated with flow design of the sea water systems that wasleading to erosion of the pipe walls. Here the problem lies with accelerated

turbulent flow caused by sharp bends, sudden changes in flow and badlydesigned connections. To understand this it must be noted that, in general,materials gain resistance to erosion (and corrosion) by forming a thin film of oxide coating. If this coating is taken away by high speed flow then the metalitself will wear away dramatically.

Some of this erosion was very severe and would eventually have led toreasonably large holes. There is an interaction here. Because erosionusually occurs where flow rates are high, the leaks that result could havehigh flow.

Different materials have varying capabilities with regard to flow and our viewsand findings are discussed in the sections below.

GALVANISED STEEL

The recently issued Code of Practice (issued November 2002) states thatgalvanised steel is generally unacceptable for sea water piping.Correctly fitted and in carefully designed flows, the galvanising has a finite lifeand any deficiencies in practice reduce the life. In practice,

(i) the pipes will at some time require replacing or re-galvanising byremoval ashore, thorough internal cleaning and hot dipping in zinc;

(ii) The zinc wears off at sites of turbulent flow and erosion/corrosionis then enhanced at these sites;(iii) Onboard repair is seldom effective unless a complete pre-

galvanised piece can be fitted between flanges.

W f d l i d t l t b t bl i l di t thi k ll d



and stainless steels do not provide the clear advantage as might beimagined.

As noted above, however, there is also a lower flow speed limit to avoidstagnation and possible fouling. It is because of this lower limit thatredundant piping runs (say for an emergency cooling supply) should beblanked and drained until needed.

LOCATIONS OF PIPE FLOW TURBULENCE

On the vessels surveyed, numerous areas were found where we consider

there had been wall thickness loss due to turbulent flow erosion/corrosion. Ingeneral it is necessary to minimise turbulence in the system by avoidingdesign and fabrication details that cause turbulence. Such details are:

• Small radius bends. We found excessive use of these – particularlywhere engines were shoe-horned into small engine rooms and wherepipes had been poorly aligned. As a general rule, the minimum bendradius should be about three times the diameter of the pipe.

• Bends immediately downstream from a pump where the turbulent flowfrom the pump would bear on the bend.

• Misaligned pipes. See the comment above, but also where pipeswere fitted into the wrong size flanges so that the contact was notsquare.

• Partly protruding joints. Especially where pipes of different diameters joined and in some flanges that we were able to remove.

• Partly throttled valves• Reductions in pipe diameter on full flow.

• Poor welds which leave rough and protruding surfaces inside pipes.

• Internal pipe corrosion – especially with galvanised pipes.

On the limited evidence, the same problem of flow exists from manifolds. It isessential that the flow out of a manifold is through a smooth concentric

reducer welded into the manifold pipe. Directly welded stub pieces producesharp edges and high turbulence just downstream of the entry from themanifold.

It is particularly bad to have two turbulence raisers in close proximity, for


T P M F I T S



THE PIPE MATERIALS FOUND IN THE SURVEYS

The survey team encountered a very wide range of metal pipe material

during the course of the research. By far the most common were galvanisedsteel and aluminium brass. Among the others were mild steel, other aluminium alloys, copper, copper alloys, and stainless steel. It was notpossible with the alloys to identify the exact make up of the metal in anyparticular pipe sample although this can be done very effectively, butexpensively, with portable material analysers. The precise make up can,however, have a great effect on a pipe’s ability to cope with various water speeds and turbulence.

It must be stated that the only materials that were found deficient across theboard were mild steel and galvanised mild steel. There was, however,occasional thinning in sharp bends and 90 degree elbows for all metals -whether steel or copper alloy.

Aluminium brass alloy is a fairly common medium for pipelines and theresearch found few sections that were in immediate need of replacement.

However this does not mean that it is without its faults. Aluminium brassdoes not cope well with water velocities in excess of 3.5 m/sec. If the surfaceof aluminium/brass alloy becomes broken for any reason it looses itsprotective oxide coating and deterioration is then rapid. This was apparent inaluminium brass 90° elbows where the bend caused turbulence andincreased velocity. A good limiting speed (3.0 m/sec) has been quotedabove that includes an allowance for bend speed enhancement.

A small amount of stainless steel piping was encountered in the research andseemed to be in sound condition. Because, however, stainless steel cansuffer from pitting and crevice corrosion in ‘quiet’ areas such as flanges andcouplings it is hard to be relaxed about its use. The methods used in theproject did not have the ability to detect thinning in these areas.




TESTING OF PIPING & SYSTEMS

THE TIME REQUIRED TO SURVEY VESSELS Competent inspectors required about 2 hours to review the system layoutson board a typical vessel surveyed and a further 6 man hours to performultra-sonic testing of samples of the piping. A report with schematic layoutrequires at least a further 4 man hours of effort.

Thus, a competent engine room system survey will take approximately twelve

man hours. The surveys in this project were not exhaustive and thereforecannot be assumed to give a clean bill of health to any vessel surveyed.

There is no doubt these man hour times could be improved if moreinformation was available about the systems. In many vessels, the pipe worksystems were found to have multiple pumps and a multiplicity of sea inletsand cross connections causing confusion over how to use the systemefficiently. These systems were vastly more complex than required and, for example it took over five man hours on one twenty metre vessel to establishthe function of all the valves and pumps within the engine room. Thesecomplexities also have a secondary effect of reducing crew confidence intheir ability to set up the system for emergency pumping. Only one surveyedvessel carried a clear “user guide” to valve settings for pumping the bilges.

ULTRA-SONIC TESTING

The study used ultra-sonic testing as a means of non-destructively identifyingthin areas of pipe work. Sections were found that sounded and looked ingood condition, but were quantifiably thinned by erosion or corrosion. Thiswas confirmed on the removal of the pipe to make repairs. This revealed thathammer testing is not always a reliable means of finding thin sections - other than on large areas. Conversely there have been occasions where hammer testing has disproved ultrasonic results especially on hull inspections.

It was found, however, that ultra-sonic testing is not a panacea for allproblems. It is best deployed as a predictive tool that can be an indicator of problems or be used to monitor wall thickness loss though regular samplingwould be required for it to be of best value.


iii) The range of pipe diameters and materials that have to be tested so



iii) The range of pipe diameters and materials that have to be tested sothat the pipe curvature may not match the probe head. It is difficult toensure the probe is normal to the surface and this can cause the pipe

wall to be measured thicker than it actually is.

iv) The skills and special equipment required to accurately gauge thewall thickness of thin pipes. There is a doubling effect as the probenears its lower limits and this means that the sound double echoes togive a reading of double the wall thickness, this is exacerbated asfurther thinning of the wall will produce a quadrupling effect!

In addition, welds and other non homogeneities in the materials produceunreliable results and both crevice corrosion and pitting - among the mostdestructive forms of corrosion - cannot be detected because of the proximityof flanges and fittings and because it is difficult to detect localised corrosion.It is of course, in the area of flanges and compression fittings that pipedamage frequently occurs.

MCA guidelines are that when the wall loses 25% of the original thicknessthe item should be replaced. Before a true sample of wall thinning can becalculated, however, the original wall thickness must be known. Thisinformation was not available to the researchers; therefore the next best thingwas to sample areas which should not be worn – that is extended straightruns well away from bends or pumps or other turbulence raisers. It has to benoted, however, that even with new pipes wall variations may occur.Samples of bends “off the shelf” gave thickness variations up to 12.5% of nominal - in line with quoted manufacturing tolerances.

The problem of dealing with thin pipes means that any inspector wouldrequire both special training and test equipment with special heads to dealwith the likely piping. When a pipe is very thin and especially if it iscorroding, the sound echoes from front and back wall and from internaldeposits can be hard to separate. This requires training and experience but

can be eased with purpose made equipment.

Allowing for these parameters we still detected some 10% of vessels wherethe general wall thickness loss (weight loss) exceeded 40% of what weexpect to have been the original thickness – a very significant loss of




FLEXIBLE HOSES AND COUPLINGS

HOSES

Theory

Flexible hose can be used to take up vibration and can also be used as aconnector if there is limited space. It is not suitable as a permanent repair for damaged piping because a hose failure is likely to be full bore – or very near full bore. That means the hose is a critical component in any piping system.

Used properly, a flexible hose should not be longer than one metre betweenend fittings that are permanently attached1. If the end fittings are notpermanently attached then metal hose clips are usually used. It is veryimportant that the correct stainless steel material is used and that at least twoclips are used at each end of the hose, with each clip bearing correctly on themetal beneath.

The hose must be specially selected for resistance to the fluid being carriedand aging in the environment of use. Thus, the hose and its connectorsshould be suitable for the design pressure, the design temperature, the fluidbeing carried, the mechanical loads and pressure impulses, contact forcesand abrasion and the environment outside the hose.

Every hose has a manufacturer’s recommended life, but for marine use it is

unwise to take this as any longer than 5 years.

In summary, the use of hoses must be formalised. If they have to be used,then they have to be correct for the purpose and their type and date of manufacture should be impregnated on the hose.

Hoses found

Flexible hoses were often used wrongly to take up severe misalignment inpipe work and as a repair for failed piping. Many such hoses seemed longterm fittings as they were of various indeterminate rubber/polymer materials,were often perished due to heat, age, vibration and oil or paint contamination.


material allowed it to be fitted on incompatible pipe diameters by stretching or



material allowed it to be fitted on incompatible pipe diameters by stretching or squeezing on to the pipe stub in several instances.

As far as length was concerned, we found many hoses that were too short toallow appropriate coupling but only two instances of a flexible hose longer than the recommended maximum length.

Hose materials covered a wide range, unfortunately some were found totallyinappropriate for pressurised sea water use in an engine room with the worstbeing no better than common garden hose. Whilst we appreciate thesethings may be essential for a "get you home," their condition often indicatedfairly prolonged usage.

55% of vessels were seen to have flexible hoses with inappropriateconnections or in need of replacement which included:

• Inadequate number of couplings (jubilee clips);

• Wrong material for couplings (mild steel as opposed to

stainless)• Couplings completely corroded off, leaving a “push fit”

connection.

• Inappropriate hose material

• Hoses too short to allow appropriate coupling.

• Hose of wrong diameter for pipe stretched/ squeezed on topipe.

•

Flexible hoses used to take up severe misalignment in pipework.

• Rubber/polymer material perished due to:o Heato Ageo Vibrationo Oil contamination

12% of interviewees reported flooding caused by flexible pipes either perishing, coming loose at jubilee clip fittings or splitting open to allow in eachinstance full bore flooding.

FLEXIBLE (VIBRATION) COUPLINGS


The coupling, like the hose, has to be of the correct material for its



The coupling, like the hose, has to be of the correct material for itsapplication and it should be fitted to the maker’s recommendations with thepipes cut and positioned to suit the coupling, not the other way around.

Often termed ‘rubber bellows,’ flexible couplings perform just like metalexpansion joints to compensate for axial, lateral or angular movement andthey will expand when under pressure especially if unrestrained. The ‘endthrust’ exhibited on a bellows can be substantial at pressures above 2 bar ona 65 mm nominal bore unit. Generally the thinner the walls of the bellowsbecome the more flexible it becomes. If the bellows become axiallyoverextended this ‘flexibility’ will increase. The immediate pipe work oneither side of the bellows must be anchored to prevent it from extending toofar.

These couplings are made from a range of different materials and all have alimited service life of around 5 years, but the main influence on lifeexpectancy in use is temperature - the higher the temperature the less thelife expectancy. Their maximum pressures should be lowered when the

working temperature exceeds 500

C. Due to the difficult conditions onboardfishing vessels, ship builders and bellows manufacturers normallyrecommend a 4-year replacement cycle for marine use.

When the pipe work cannot be adequately anchored within manufacturer’sguidelines the unit must be tied by support rods (tie bars). In the case of installation on pump suction inlets vacuum support rings may need to befitted. Tie rods limit lateral vibration to +/- 5mm maximum and axial and

angular movement is prevented. Tied units are associated with ‘guided’ pipework and untied bellows are associated with anchored pipe work. Untiedbellows are recommended by manufacturers for bellows up to 150mm borewith pressures of 3 bar (45 psi) in non-engine cooling connections. If a piperises out from an engine and the first anchor is not within a straight run from itthen tie bars should be fitted. These rods are also required where:1. Pump surges occur.

2. Anchoring or pipe supports are not fitted.3. Alignment guides are not fitted (in cases where wide temperaturefluctuations occur)

Best practice


Inspection of bellows in service



p

We consider that these fittings should be renewed after 4 years regardless of operation or condition. However, that requires the date of fitting to belogged.

The problems we found included,

o Profile changes (10% of vessels) – usually associated with excessivemisalignment, torsion or excessive face-to-face dimensions. In this

case the pipe work should be re-aligned and the coupling replaced.o Flange bolts contacting the rubber and causing wear (5% of vessels) –

usually a result of poor fitting.o Painted bellows (20% of vessels) - the solvents in paint destroys the

polymeric material and replacement is needed.o Lack of adjacent support (17.5% of vessels) - causing severe pipe

work vibration problems due to excessive “spring” effect.

Other possible problem with this type of fitting,

o Cracking – usually as a result of overextension, angular or lateralmovements – this requires immediate replacement.

o Blistering, deformation or ply separation so that reinforcement materialwas visible – again this requires immediate replacement.

o Rubber Deterioration – when a bellows feels ‘Gummy’ it should be

replaced immediately.

These fittings were used to mask badly fitted pipes in 4 boats out of the 40surveyed (10%). Most often they were on larger bore pipes which wereprobably misaligned during fitting and the ensuing distortion caused byinserting the bellows was an easy option. They were found stretched,squeezed and twisted to compensate for the errors in the original pipe work.Failure of these items would probably give full bore flooding.


BULKHEAD INTEGRITY



BULKHEAD INTEGRITY

It is a part of any damage control strategy – especially important for flooding

situations – to isolate compartments. For flooding, this means containingwater in the compartment concerned; this is vitally important because anyfree flow of water into another compartment will increase free surface whichmay also produce critical trims which further increase inflows. Floodingbetween spaces can jeopardise a vessels chances of survival by turningrecoverable situations into catastrophic. Review of MAIB and Insurancereports shows that this free flow of water through supposedly watertightbulkheads or conduits has been a contributory factor to many losses.

As part of the vessel surveys, bulkhead penetrations and the condition of watertight bulkheads were inspected. 5% of vessels inspected revealedbulkhead penetrations that would allow water to transfer freely betweencompartments in a flooding situation.

Only one vessel had a watertight bulkhead that showed a small area of

significant localised thinning (by some 40%). This was caused by corrosionin an area that was alternately wet and dry and it affected unprotected steelplate. Although this study did not provide evidence for lack of bulkheadintegrity as a common flaw, it is known from experience that boats have sunkwhen flooding progressed from one enclosed space to another.


SYSTEM DESIGN PROBLEMS



SYSTEM DESIGN PROBLEMS

SEA INLETS

Problems

The most common problems with these were,

i) Multiple inlets so that the chance of a failure is increased.ii) Poor access – so that the valves and filters were difficult to operate

or clean.iii) Under floor plate positioning.iv) Failure to fit methods of closing the sea inlet valves in the event of

moderate flooding.v) Failure to fit a strainer in line before valve chests and pumps.vi) Failure to vent the sea inlet boxes to reduce air locking.

Each inlet should follow established marine practice by having a thick walledpipe section before a screw down isolation valve followed by a strainer and asecond valve (which may be in a valve chest). The thick walled pipe shouldbe of a thickness not less than the hull plating or 12.5 mm whichever is thegreater.

There should be a maximum of two sea inlets for general operations unless avery good case is made for an additional inlet for a specific purpose such as,

vivier or refrigerated sea water (RSW) systems where incompatible flow ratesmay result from mixing functions.

The valves and strainer must be accessible and the ships side valve shouldbe capable of operation when a significant proportion of the volume of thespace e.g. 30% is flooded.

The position of the filter/strainer is important. It should be placed in aposition that will remove solids before any components are reached thatcould be damaged by them. Both pump impellers and non-return valves areseriously impaired by solids or build up of materials.

Th l i ll i di id l b ild h f hi id


they rupture, ensuing flooding could be severe and possibly catastrophic.Thi i k i i i i d b i h i Th d t f



This risk is minimised by using heavy gauge pipe. The advantages of multiple smaller inlets from numerous ships side penetrations and each

serving a dedicated unit are that flooding arising from any one pipe rupturingwould be less severe. The problem arises in quickly identifying which pipe isdamaged and possibly having to close upwards of six valves before completeisolation is achieved. Another downside is that these inlets were in some vessels, spread over the length of the engine room bilge port and starboard,making location equally difficult before isolation can begin. Many sub tenyear old vessels were seen to have this location problem addressed bysimply taking sea in via two main chests or boxes with multiple inletsconfined to these boxes.

We have strong feelings against the multiple sea inlets spread around theengine room due to their inconsistent positioning and because, where smaller bore pipes are used, pipe walls are usually thinner therefore prone to faster erosion.

Access and means of closingClearly, the valves and strainer must be accessible, but there should also bea way of closing the sea inlet valve when a significant proportion of theEngine Room volume i.e. 30% is flooded. This 30% figure is based on thecalculated volumes of the Engine Rooms of the boats surveyed.

Poor access leads to poor maintenance only 17.5% of the boats surveyed

had sufficient access to work easily on the sea inlet valves and filters, thesewere predominantly the newest vessels in the survey. 12.5% of the boats wesurveyed had one or more valves that were excessively corroded. Thiscorrosion rendered them inoperable without a serious risk of them breaking.

MCA have highlighted this problem for years and the industry knows of manycases where boats have been in severe difficulties or lost because the inletscould not be closed. Of the boats surveyed, 87.5% (35 out of 40) did not

have a suitable system for shutting off the inlets in the event of high floodinglevels in the engine room. (The extending of spindles etc.)

CONDITION OF SEA INLETS

Wh ld b bt i d f th t l l f th thi t




In general, flow is continuous through overboard discharges and they canoften be hard to repair due to access We consider that any dispensation to



often be hard to repair due to access. We consider that any dispensation tothe hull thickness in steel vessels is not advisable. The discharge pipe

should be of a certain minimum thickness, but not less than the hull thicknessin way of the discharge. Where accessibility for ultra-sonic samplingallowed, none of the vessels surveyed revealed thinner inlet lines (when theywere new) than the adjacent hull plating.

NRV Valve

Hull

COOLING S YSTEMS

Sea water cooling systems have continuous flow when engines are running.They will probably be the systems that shows wear first and yet the pipes andvalves are often routed with no thought for inspection or maintenance.However, on newer vessels (under five years old) we found these systems to

be more accessible and user friendly.

A particular problem we have found with galvanised steel pipes is where alooped cooling system is used so that warmed water re-circulates with adramatically increased corrosion rate due to this temperature increase.

Problems were found with redundant standby cooling systems and the

connecting pipes into the heat exchangers. These little used items can liedormant for considerable periods, but contain some sea water. Due tostagnation the chemical properties of the sea water changes and increasescorrosion within the pipe. It is advisable to break, drain and blank the pipingand connect it if and when it is needed. It is normal to paint these emergency


BILGE ALARMS



Most bilge alarms were found to be inaccessible with only six vessels (15%)giving easy access for testing and maintenance. These figures are in linewith previous research by Banff and Buchan College which indicated that35% of bilge alarms gave false alerts and that 36% of interviewees hadencountered flooding of which their bilge alarm gave no warning.

This study again highlights the fact that efficient operational bilge alarms areimperative. It is only when adequate early warning is given that successfulremedial action – such as alerting the crew and shutting off flow from the sea

– can be taken.

Although every boat had a bilge alarm as required by Regulation, the fittingposition appeared to have been selected to be as low in the bilge aspossible. Many of these bilge alarms, however, had been sited in positionsrecommended by the MCA or, and some cases, agreed by insurancecompanies. It is unfortunate that, in the effort to achieve optimum placing for earliest warning of ingress, the alarms are often inaccessible. There has tobe a balance between function as an alarm and functionality of the alarm.

No vessel inspected had more than one bilge alarm apparent in the EngineRoom. The November 2002 15 -24 metre Code addresses this issue but of course this does not apply to vessels smaller than 15 metres or over 24metres.


ANALYSIS OF REGULATIONS



METHOD A new Code of Practice for fishing vessels between 15 and 24 metres inlength was published in 20011. Guidance for Surveyors related to the Codeis being prepared at present.

As part of this study we have analysed an example section of the Code of Practice and the results of this are given in Appendix D. The analytical

technique is not new in itself, but has been reviewed and extended by JohnLawson in a recent PhD thesis from Aberdeen University2. Essentially Theaim is to grammatically analyse the text and identify verb clauses andthereby isolate these as clear instructions to take account of information,perform calculations or do things in some way thus removing ambiguity.When set against a clear set of functional requirements we suggest that thisis an extremely powerful way to achieve clarity in Regulations and, fromthere, into Guidance.

SAMPLE

A typical rule analysis taken from the section in the recent Code of Practicethat deals with scuppers, inlets and discharges is given below where theoriginal text is highlighted in bold, discussed and then a proposed new text isgiven, highlighted in bold italics.

2.2.6.2 Each scupper or discharge leading throughthe hull from spaces below the freeboard deck or from withinan enclosed superstructure or deckhouse on the freeboarddeck should have an automatic non-return valve fitted at thehull with a positive means of closure from an accessibleposition. N

This consists of 2 rules and a modifying clause to define wherethey apply. The rules apply to scuppers and discharges fromwater or weather tight spaces leading through the hull and theyare,

) d di h h i


Much of the definition of the spaces is redundant as it is clear that



Much of the definition of the spaces is redundant as it is clear thatit is only watertight or weather tight spaces that require such

discharges. Drainage from open decks to discharges below thefreeboard deck is covered in 2.2.6.7 where an unspecifiedincrease in wall thickness is required. See comments at that rule.

The position of the NRV is not clearly defined with respect toaccess for operation or maintenance. The need to maintain thesenotoriously frequently unreliable valves in fact conflicts with thephrase at the hull . There is a need for an isolation valve near the

hull and a non-return valve inboard of that. This allowsmaintenance of the NRV. Combining isolation with the NRVmakes for complexity and inefficiency and consequentially poor reliability.

Remote closure from an 'accessible position' is also not clear, asaccessible is not defined either in terms of location or for ease of

operation. It could usefully read ‘positioned above the freeboarddeck and within the normal working area of vessel, located so thatit is easy to use.’ If, however, this were accepted then adispensation for engine room overboard discharges would berequired.

Either the isolation valve or the NRV could be subject to the'remote closure' requirement, but it would be best to make this the

isolating valve – again because of the unreliable nature of NRV’s.It would also be necessary to define certain requirements for theclosing apparatus and ensure that there is, a way of specificallyknowing when the valve is closed!

The engine room dispensation would allow the remote closure tobe from a location within the engine room but readily accessible

after significant flooding of the space. This could apply to anymachinery space, but it would be necessary for the space to beprotected by bilge alarms. Significant flooding would be a levelthat would be expected to remove critical bilge pumping capacity –from our studies about 30% of floodable volume.


2.2.6.2(a.2) Notwithstanding the requirements of



( ) g q2.2.6.2(a.1), if the discharge is within a machinery space that

is fitted with a bilge alarm and serves machinery within that space, then the remote means of closure may be operated within the machinery space from a position that is readily accessible after significant flooding of the space. As a guide,significant flooding may be taken as more than 30% of thefloodable volume of the space. N.

2.2.6.2(b) Each scupper or discharge leading through

the hull below the freeboard deck from water or weather tight spaces should be fitted with an automatic non-return valvefitted inboard of the isolation valve to prevent back flow intothe vessel. N

SUMMARY

It should be clear that the Regulations as they exist – even this recent (Nov2002) Code of Practice – can be improved. We consider that this analysisshould be extended to cover all relevant sections of the Code and the resultsfed into the Regulations through Guidance.


FINDINGS



FINDINGS FROM GOVERNMENT AND INSURERS INFORMATION

Causes of flooding

As noted, the main body of data had already been summarised andpresented by MAIB. Additional information extended the results of the MAIBanalysis of 1992 to 2000 incidents to include 2001. These new data werequality checked against raw reports.

The insurance information was used to obtain mean average and upper values of claims for floodings and total losses due to flooding. This allowedthe research to obtain estimates of the financial burden on the industry that isborne through insurance premiums. To avoid infringement of commercialconfidentiality we have presented losses as a percentage of all claims in thefigure below.

Floodings and Sinkings(as percent of overall insured loss for each year)

0.0%

10.0%

20.0%

30.0%

40.0%

50.0%

60.0%

70.0%

1997 1998 1999 2000 2001

Year

% o

f c o s t f o r t h

a t y e a r

Sinking and

flooding

All mechanical

damage

All other

causes

It will be seen that partial loss (repairable damage) due to flooding and total


by bilge system problems. It would be expected that a sinking where theprecise cause was not known would follow the same distribution.



Frequency and costsThe MAIB record flooding as the primary causation for 16 % of all seriousincidents reported to them1. Moreover, flooding and foundering incidentsfrom whatever cause account for 50% of all losses and engine room floodingcan be firmly established in half of those cases. Thus, based on the MAIBreports, Engine Room flooding accounts for more (possibly significantly more) than 25% of all losses.

Because MAIB receive only notification of serious incidents they cannotcomment on the occurrence of other incidents such as flooding at sea whencontrolled by the crew or flooding in harbour. Only compulsory reporting(which is not at present mandatory) of hazardous incidents and near misseswould give specific causes of problems whereas the cause of a sinking mayalways be in question as the vessel is no longer available for inspection.

It is possible, however, to estimate the number of unreported floodingincidents overall using other information2. These unreported events rangefrom leaks that are big enough to be remarked upon to flooding that giveseverybody a reasonably large fright. The method is presented in Appendix E.The average results for boats over 12 metres in length are:

Category (and source) Boats per year

1 MAIB report: losses due to Flooding 1 in 210

2 MAIB report: flooding at sea 1 in 60

3 Uncontrolled harbour flooding (marineinsurance stats)

1 in 115

4 Other flooding incidents (estimate Appendix E) 1 in 20

It can be seen that flooding incidents of some kind are relatively common.3

Many of these, not reported to MAIB, could have had more severeconsequences.

Our survey of insurance claims supports the rates given above.


lead to a need for intervention by rescue services and become visible to theMCA.



Total Losses due to flooding cost the industry at least £6 million In the year 2001 alone.

SUMMARY OF FINDINGS FROM DATABASES

1) Every year about one boat in every twenty (1 in 20) suffers aflooding incident that is more than just a leak.

2) Every year about one boat in every one hundred and fifteen (1 in115) is flooded because the sea cocks or overboard discharges arenot closed.

3) The MAIB only receive reports on severe floodings and losses.They report that, every year, one boat in every sixty suffers floodingat sea and one in every two hundred and ten (1 in 210) is lost due

to flooding.

4) Financial costs to the industry are high – averaging £4.5M everyyear and much more in a bad year.

FINDINGS FROM SURVEYS OF ACTIVE FISHING BOATS

A typical survey report is attached as Appendix B. These surveys were

performed on 40 vessels which included 11 wooden hulled vessels, and 29steel hulled vessels. The vessels varied from just under a year old through tofifty six years old. Lengths ranged from 16m through to 34m. The sampleincluded scallopers, beam trawlers, vivier crabbers, pair trawlers, twin rigtrawlers and smaller pelagic trawlers.

Of the 40 vessels surveyed 60% showed defects that could have been aprime cause of catastrophic flooding in port or at sea. Most vessels surveyedrevealed at least one hazard that if addressed would lessen the chances of flooding or improve the vessels crews ability to cope with flooding. Thesefigures corroborate the findings of Banff and Buchan College’s previous workwhich revealed that some 98% of fishermen interviewed had at some time


Although it is possible to use experience and knowledge to make judgementst th h thi i bl ll th ti



as to the areas where thinning problems usually occur, they were sometimes

found in the most benign of positions, for instance on long straight pipe runs.

The majority of pipe work faults were found in carbon steel. Vessels usingcopper based alloys pipes revealed few localised problems but showed moregeneral signs of “weight loss” degradation. The survey team, however, wereshown samples of these alloys with severe pitting corrosion around the insideof swaged flanges which can not be seen externally or picked by ultra-sonicsampling.

SUMMARY OF FINDINGS FROM SURVEYS

The findings of the inspections of fishing vessels include:

1) 25% of all vessels surveyed showed thinning in pipes that was inexcess of the 25% limit as per MCA replacement guidelines. Ultra-sonic testing is a useful tool for the detection of “weight loss”

corrosion.

2) 20% of all vessels surveyed had perforations (pin holes), withintheir critical pipe work systems.

3) 5% of all vessels surveyed revealed small holes in excess of 2 mmwhich appeared as a result of preparing the pipe for ultra-sonictesting.

4) 17.5% of all vessels surveyed displayed deficiencies in commoncast elbows.

5) One vessel had localised thinning of her engine room/fish roombulkhead.

6) 5% of vessels had bulkhead penetrations which would allow freeflow of water between compartments.

7) Galvanic corrosion (dissimilar metals) was found on 27.5% vessels.


12) 10% of vessels surveyed had deficiencies associated with flexiblevibration couplings.



13) 37.5% of all vessels surveyed revealed inadequate supports to pipework systems.

14) 27.5% of vessels surveyed had misaligned pipe work.

15) 7.5% of vessels had cracked welds in their pipeline systems.

16) 15% had systems that were considerably more complex than

required.

17) 12.5 % of vessels revealed problems with valves.

18) 61% of vessels surveyed in the harbour had left their sea inletvalves open

19) 36% of the wooden vessels had appropriate remote closure fittingson their sea cocks.

20) No steel vessels had a full complement of adequate extendedspindles permanently attached to their sea inlets.

21) 85% of bilge alarms were found to be difficult to reach for testingand maintenance.

22) No vessel inspected was seen to be carrying more than one bilgealarm in the engine room.

23) Only one vessel was seen to carry a competent description of thefluid systems in a conspicuous place.

24) Only one vessel (not the same vessel as above) had pumpingguidelines displayed openly.

25) Only 37.5% of vessels had a consistent and useful system for identifying pipe use.





DISCUSSION, CONCLUSIONS, RECOMMENDATIONS ANDACTIONS



DISCUSSION AND CONCLUSIONS

In this section of the report we bring together our conclusions about the mostcritical things that we found. We then make recommendations for the shortand longer terms that set the priorities as we see them and suggest actionsfor the various parts of the industry.

We consider that the most critical flooding problems derive from the design,installation, operation or maintenance of raw sea water piping systems. Theproblems are often fundamental in nature and it seems to us thatunderstanding and information about these systems is not adequate in theindustry. In some ways, also our findings may reflect the current situationswithin the industry which include;

Financial constraints within the white fish and shellfish sectors of the industry

causing:•

o Vessels to operate continuously allowing little time for maintenance.

o Crews to leave fishing for other careerso Vessels to sail with minimal crews.o In some cases only essential maintenance to be carried out.

• Varying interpretations of regulations:o That encourage operators to build “rule beater” and

“paragraph boats” o A misunderstanding that the four yearly UK Fishing Vessel

Certificate is a definitive statement of vessels seaworthinesscoupled with a misconception that the MCArecommendations and guidelines are a standard to be

achieved rather than a minimum standard to be exceeded where practicable.

o Shipbuilders operating in competitive environment arebuilding vessels to be (capital) cost effective within the rules

d l ti


In reaching these views an important consideration has been that there doesnot seem to be an age relationship with flooding problems – apart from thegeneral decay of materials. For example, a new boat is just as likely to have



general decay of materials. For example, a new boat is just as likely to have

a major corrosion problem as an old boat – in fact, the survival of the old boatmay be because it has good system.

The general uncertainty in design knowledge is also evidenced in theinconsistency in the positioning of components and in the selection of materials for engine room systems. When sister ships were surveyed therewere marked variations in the placing of systems onboard each vessel.There was, however, a thread of evidence from the younger vessels

surveyed that some of these quality control issues are being addressed.

It is clear, however, that over-seeing inspections during construction or inservice are not picking up all the possible deficiencies. It seems thatunderstanding of and information about fluid flow systems is not adequatelybeing applied or disseminated in all situations.

There is, then, a need to concentrate the thoughts of the design/build teamson flooding and we believe this should be led by the Regulatory body,although all branches of the industry can contribute.

A critical evaluation should, therefore, be made, during the initial design andconstruction stages of a vessel’s life, into the effects that flooding would haveon the vessel’s ability to cope with these situations. Such a risk assessmentwould set the basic parameters for safe operation. We consider this sort of

approach essential, but have noted that the present legal positiondiscourages it.

In the short to medium term, therefore, we consider there will be a need for MCA to re-focus their surveys to place more emphasis on critical engineroom systems and bilge systems elsewhere on the vessels. That willprobably (almost certainly) require training and new skills for the surveyors.

On the other hand, there is also evidence, from the boats surveyed, thatsuggests ‘repairs’ are sometimes performed without due regard for materialsand not enough thought of potential consequences. The poor andindiscriminate fitting of flexible hoses and couplings is a prime example of




Among the design flaws we found a common problem concerning sea inletsthat makes back flooding into the bilge(s) more likely. We have suggestedpossible changes, but it is the lack of thought that is most serious. This



p g g

should be addressed within the Code of Practice and Guidance.

Similarly, the problems we found with use of materials are matters for Regulation and the new Code of Practice for 15 to 24 m boats addressessome of them. We have, however, concluded that there is only a limited rolefor galvanised steel piping in sea water – not because of any theoreticaldisadvantage, but because, in practice, it seems never to be repaired or maintained correctly.

Flow problems were common (62.5%) and seemed to us to be evidence of inadequate thought in design. Too many sharp bends and changes in flowspeed leads to erosion of the pipe walls – and in extreme cases not just toleaks, but to full bore failures.

Whilst the research detected numerous thin pipe walls, few of these wouldhave resulted in catastrophic flooding provided that bilge alarms functionedproperly and gave adequate early warning. That highlights all the more theimportance of bilge alarms and the ability to take action to isolate the boat. If the sea inlets can be shut off in time and the pumps operated by someonewho knows what they are doing, then in most cases the application of anepoxy bandage would allow the vessel to make the shore and have apermanent repair made.

The number of broken pipe supports is, however, of rather more concern.We consider there are two main reasons why we found a significant number of boats with this problem (37.5%). Either, at some time the piping has beendisconnected to allow replacement of pipes or other fittings and has not beensecured again, or the supports have broken adrift due to vibration and havenot been re-fixed by the vessels operators. The fact that broken anchor points are not replaced immediately by the operators may not be deliberatenegligence, but rather a matter of casualness and lack of awareness on their part. That is, a sin of omission rather than commission. Usually, when ananchor point comes adrift there is little, if any, damage done at the time.Nothing apparent happens, the equipment carries on functioning as beforeand it is understandable that repair is put off or even forgotten about. The


One of the techniques we used for inspection was ultra-sonic thicknessmeasurement. This helped us, but requires some thought as to how it could



be used to help the fleet as a whole. If this sort of testing was incorporatedfor long term monitoring in a safety system that logged the original thicknessvalues and if the surveyors had the equipment and training to use it then weconclude that it has very real value.

In some surveys video footage and photographs were taken. These werefound to be invaluable for review and occasionally allowed previously unseendeficiencies to be detected. That experience leads us to say that it would be

of benefit to both owners and insurers to hold video records of vessels thatwould assist in identifying problem areas and possibly assist when dealingwith claims.

RECOMMENDATIONS

In the following recommendations an attempt is made to solve immediateproblems and then produce systems and a regime that will reduce the

number of engine room floodings. The recommendations are a mixture of prescription to set a base level of safety and requirements that are intendedto raise the amount of information available and the knowledge of the criticalengine room systems. The recommendations are:

1) In the short term,

1.1 A major effort should be made to inform all sectors of the industry of the hazards associated with misuse of flexible hoses and rubber expansion pieces.

1.2 MCA Inspectors should be informed of the limits of, and correct use of,these items and should enforce removal of hazardous fittings.

1.3 Skippers should (again) be reminded of the potential consequences of

failing to close sea inlets and discharges in harbour and Insurersshould consider means of persuading operators to close inlets andoverboard discharged in harbour.

1 4 All boats 12m and over should be required to fit means of closing sea


2.2 All boats 12m and over should be required to carry a document thatdescribes their engine room systems in terms of layout, equipmentpart numbers and, especially the specification of all piping. There



should be a schematic of the engine room systems displayed withinthe engine room and there should be associated marking and colour coding of pipes and equipment.

2.3 All boats 12m and over should have two independent bilge alarmsfitted in the engine room at positions where they can be tested andmaintained. [Although out with the scope of this study it is clear thatbilge alarms are necessary in any major space such as fish holds.

3) In the longer term,

3.1 The Regulations should be framed such that:

a. The capacity of the bilge pumping systems should be governedby the potential rate of ingress in critical pipe failure and shouldbe defined as a required system flow rate rather than by theexisting system of pump capacity.

b. Both maximum and minimum flow speeds are defined withinsystem pipe work commensurate with the materials used so as tominimise the effects of erosion and corrosion.

3.2 An inspection regime should be implemented that checks pipes andpiping systems and which include sampling by ultrasonic. As part of

this, all owners of fishing boats 12 metres and above in length shouldperform regular inspections of their engine room and other sea water piping systems and arrange an independent audit every two years.Self certification is already accepted by the < 10m fleet.

3.3 A more detailed engine room inspection should be incorporated intothe MCA survey by apportioning the surveyors time so that more timeis spent in the bilges and less time on equipment check lists. Regular

equipment safety checks could be done by the skipper and randomlyinspected by MCA if there was sufficient emphasis on deterrents for non-compliance.


ACTIONS TO MEET THE RECOMMENDATIONS

The Maritime and Coastguard Agency should:



1. Consider carrying out spot safety inspections on fishing vesselsspecifically to include bilge alarms, sea inlets and remote closuresystems for sea inlets. Target time for spot check 30 minutes.

2. Consider how best to ensure that a risk assessment might be carriedout on each vessel that includes risks associated with flooding. Oncerisks are identified and quantified effective action may be taken to

reduce the overall risk.

3. Consider setting up a working party to evaluate the Code of SafeWorking Practice for the Construction and Use of 15m (LOA) to LessThan 24m (L) Fishing Vessels (and associated Guidance toSurveyors), with particular regard to clarity in the rules for sea inlets,bilge pumping capacities, materials and components.

4. Examine the viability of new builds installing an auxiliary engine andbilge pumping arrangement in a dry space outwith the main enginespace.

5. Consider requiring all vessels 12m and over to prepare and carry onboard a schedule of piping, pumps and associated equipment whichincludes material specifications, system drawings and recommendedreplacement intervals for short life fittings. The intention being to allowtransfer of design intent and relevant information through the vessel’slife.

6. Consider requiring all vessels to display within the engine room aschematic diagram of the bilge and cooling water systems to assist thecrew.

The Fishermen’s Safety at Sea Working Group could:

7. Consider initiating research into:

a) the degradation of piping systems and preferred best


f) the merits of introducing damage limitation in to statutorycourses for deck and engineering officers to include suitablecontent and methods of delivery etc.



The UK Fishing Industry should:

8. Consider, where possible and practical, carrying an independentportable pump capable of pumping bilges in an emergency.

9. Consider carrying out regular safety drills which involves all membersof the crew in basic bilge pumping and valve isolation operations anduse of manual and powered emergency pumps.

10. Make a practice of shutting all sea inlets and discharges whenvessels are unattended in harbour.

11. Fit a high bilge level warning system, in a position where it can bereadily inspected and maintained, which would operate an externalalarm in circumstances where the vessel is unmanned, i.e. when inharbour.

12. Fit two independent (and accessible) bilge alarm systems for engineroom protection.

13. Fit at least one bilge alarm in all major spaces within the vessel.

14. Consider installing a “bilge monitor” system which constantly displayslevels of water in bilges.

15. Test bilge alarm bilge switches daily where possible and test fish roombilge alarms by controlled flooding during cleaning operations.

16. Where practicable, install close circuit colour television cameras in theengine room.

17. Be aware of the potential for electrolytic action associated with




Marine Insurance Companies should:

21. Encourage skippers to perform safety checks and drills and include arecord of these in a vessel log.

22. Encourage vessel owners to compile video footage and stillphotographs of vessel’s engine room etc. for ease of visualising

components and equipment to assist with potential claims.

23. Consider methods of persuading operators to shut sea inlets anddischarges when vessels are unattended in harbour.

24. Carry out safety related spot checks on vessels, to include observationof safety drills, testing alarms and emergency response procedures.

25. Encourage vessel owners to carry portable salvage pumps and other risk reducing equipment such as bilge monitors and engine roomcameras.

Training Establishments are recommended to:

26. Offer training to fishermen in awareness of flooding dangers and in

portable salvage pump operations.

27. Construct courses (certificated) and offer training in basic machineryoperation, inspection and maintenance, including valve chests andpumping operations.

28. Offer short Safety and Management courses in Marine Insurance tocover possible implications upon the fishing industry of insurers’

becoming more stringent in their interpretation and application of theMarine Insurance Act clauses, warranties and definitions.

29. Offer technical awareness courses suitable for fishing boat designers


APPENDIX A SUMMARY RESULTS

CORRELATIONS



Correlations show if there are any relationships between variables. For example you would expect age to be correlated with height for teenagers.Correlations were calculated between age and all other variables andbetween hull material and all other variables. The results are:

Positive correlations

The only positive significant correlations are:AGE to CommentHull material The wooden boats sampled were older – as

would be expectedAverage corrosion Average weight loss on older boats was

greater than on younger – again as would beexpected.

Pipe coding and valve tagging Newer boats have better systems – probably

because old boats have lost track of thesystems.

Earthing Newer boats have better bonding systems

HULL MATERIAL to CommentLength Steel boats were longer.Pipe coding and valve tagging Steel boats had better systems but the

correlation was marginal.

Earthing Steel boats had (marginally) better bondingsystems

Sea cocks open Steel boats had their seacocks open moreoften than wooden boats. This, perhaps,represents a greater awareness of flooding ingeneral on wooden boats.

Negative results

The most interesting variables that showed no significant correlations withage are:

AGE t C t


TABLES



Materials and Corrosion Observation

Age(years)

Hullmaterial

HighHazard?

Pipethinning?

AveragePipe

weightloss %

MaxCorrosion

%Leaks?

Crackedweld?

Materialproblem?

Galvanicaction?

Earthingproblem?

Pipesupport

problem?

20 Steel Yes Yes 35 100 Yes No Yes No No Yes

10 Steel Yes No 15 100 Yes No Yes No Yes Yes

34 Steel Yes Yes 45 50 No No No No No Yes

35 Steel Yes No 50 60 No Yes No No No No

35 Wood No Yes 25 45 No No Yes No No No

5 Steel Yes Yes 12 100 Yes Yes Yes No Yes No

5 Steel No Yes 25 70 No No Yes No Yes No

13 Steel No No 20 65 No No Yes No No No

20 Wood Yes No 15 25 No No Yes Yes No No

2 Steel No No 15 30 No No No No Yes No

5 Steel No Yes 25 65 No No Yes No Yes Yes

6 Steel Yes Yes 12 60 No No Yes Yes Yes Yes

1 Steel Yes No 15 20 No No No No Yes No

36 Wood Yes Yes 10 45 No No Yes Yes Yes No

22 Wood Yes Yes 20 100 Yes No Yes Yes No Yes

20 Steel Yes No 25 100 Yes No No Yes No Yes

2 Steel No Yes 15 70 No No No No Yes No

22 Wood Yes Yes 30 66 No No Yes Yes No Yes


28 Wood Yes No 22 25 No No Yes No No Yes

12 Steel Yes No 15 47 No No Yes Yes Yes Yes

33 Steel No Yes 30 52 No No No No Yes No


56 Wood Yes Yes 30 100 Yes No Yes No No No

13 Steel No No 10 10 No No No No Yes No

3 Steel Yes Yes 20 57 No No Yes No Yes Yes

21 Steel No No 10 50 No No Yes No Yes No

22 Wood Yes No 20 23 No No No No No No

15 Steel No No 15 66 No No No No No No

14 Steel Yes Yes 25 100 Yes Yes Yes No Yes Yes

3 Steel No Yes 20 64 No No Yes Yes Yes No

2 Steel No No 5 20 No No Yes No Yes No

12 Steel Yes Yes 25 43 No No Yes No No No

13 Wood Yes No 10 25 No No Yes No Yes No

35 Steel Yes Yes 50 100 Yes No Yes Yes No Yes


Flow and Fittings Problems

Flex



Ageyears

Hull Flowproblem

?

hoseproblem

?

Bellowsproblem

?

Bendsproblem

?

Poor alignment

?

Corrodedvalves?

Poor Access?

Pipescoded

?

Valvestagged

?

Remoteclosure

?

SeaCocksopen?

20 Steel Yes Yes No No No No Poor No No No No

10 Steel No Yes No Yes Yes No Poor No No No On slip

34 Steel Yes Yes No No Yes No OK Yes No No Yes

35 Steel Yes No No No No Poor No No No On slip

35 Wood Yes No No No No No Poor No No No No

5 Steel Yes No No No No No Poor No No Yes On slip

5 Steel No No No No No No Poor Yes Yes No On slip13 Steel No No No No No No Poor Yes Yes No Yes

20 Wood Yes Yes No No No No Poor No No Yes Yes

2 Steel No No No No No No OK Yes Yes No On slip

5 Steel Yes No No Yes No Yes Poor Yes Yes No Yes

6 Steel Yes No Yes Yes Yes No Poor Yes No No No

1 Steel Yes No No Yes No No Poor Yes Yes No Yes

36 Wood No Yes No No Yes No Poor No No No No

22 Wood No No No No Yes No Poor No No No Yes

20 Steel Yes Yes No No Yes No Poor No No No Yes2 Steel Yes No No No No No OK Yes Yes No On slip

22 Wood Yes Yes No No Yes No Poor No No Yes No

1 Steel Yes No No No No No OK Yes Yes No On slip

28 Wood Yes Yes No No No No Poor No No No No

12 Steel Yes Yes Yes Yes Yes No Poor No No No On slip

33 Steel Yes Yes No No No No Poor No No No No

34 Steel Yes Yes No No No No Poor No No No Yes

56 Wood No No No No No No Poor No No No Yes

13 Steel No No No No No No Poor No No No On slip

3 Steel Yes Yes No No Yes No Poor Yes Yes No Yes

21 Steel Yes No No No No Yes OK Yes Yes No On slip

22 Wood Yes Yes No No No Yes Poor No No No Yes

15 Steel Yes Yes Yes No No No Poor No No No On slip

14 Steel Yes Yes Yes No Yes Yes Poor Yes No No Yes

3 Steel No Yes No No No No OK Yes Yes No On slip

2 Steel No No No Yes No No Poor Yes No No On slip

12 Steel Yes Yes No No No No Poor No No No On slip

13 Wood No Yes No No No No Poor No No No No

35 Steel No Yes No Yes No Yes OK No No No Yes

30 Wood No No No Yes No No Poor No No Yes No

15 Steel Yes Yes No No No No Poor No No No On slip

21 Steel No Yes No No Yes No Poor No No No Yes

No


APPENDIX B FREQUENCY AND COSTS

A survey by Banff and Buchan College1, found that 28% of senior crew



surveyed had experienced uncontrolled flooding at sea and a further 17%when in port. Of the same group, moreover, 98% had experienced floodingthat had been controlled, dealt with efficiently and professionally with littledetriment to the vessel. These figures may be used to obtain an estimate of unreported flooding incidents overall.

The MAIB average rate for serious flooding of boats of all lengths in theinterval 1992 to 2000 is 0.042 incidents per boat per year. For boats greater

than 12 metres in length the incident rate is 0.015 per boat per year and thetotal loss rate 0.005 per boat per year. Taken with the average number of boats licensed in the same period, the number of boats affected on average in a year is estimated.

If we concentrate on the >12 m boats we can ratio the events using the Banff and Buchan figures. The underlying assumptions are that:

i) the Banff and Buchan interviews have sampled typical fishermen

ii) any of these fishermen has the potential to be involved in either acontrolled or uncontrollable flooding

iii) the average number of crew per boat doesn’t change over theyears.

On these bases we assume that the serious floodings reported to MAIB andthe uncontrolled floodings reported by fishermen to Banff and Buchan are thesame things and then we ratio to unreported, less serious floodings.

Using all this information, the expected flooding proportions, for a fleet of 1000 boats in an average year, are shown on the figure overleaf. In addition,it should be noted that uncontrolled harbour flooding would affect 9 boats in athousand in an average year.




15BOATS

NEEDHELP

5BOATSSINK

930BOATS

NOPROBLEMS


APPENDIX C TYPICAL REPORT

Document Use. This document is purely for research use to assist theFisherman’s Safety at Sea Working Group – Flooding of UK Fishing Vessels

St d d it i t i f bi di l ( ) t t



Study: and it is not in any form binding upon vessel owner(s) to carry out recommendations offered in the report.Strathclyde University and Banff & Buchan College accept no responsibility or liability as regards these findings and recommendations.

Confidentiality. All findings will be given to the owner or their authorized agent(s). Further disclosure can only be by their permission. All names of people and vessels will remain strictly anonymous and will not be revealed toany third party including the sponsors.

Ultrasonic Sampling:No samples of the original pipe work were available. This means that theextent of thickness loss has been estimated by sampling an area of the samesystem that should not be prone to general thinning.

New pipe bends and elbows have been sampled and gave thicknessvariations of between 1% and 12%. New straight pipes were within 2% of nominal. This uncertainty must be factored in to any practically determined values from the vessel.

MCA guidelines state that a pipe with a reduction in wall thickness of 25%should be considered for replacement. Although this is an exact value it isonly determinable by starting ultrasonic testing in the construction phase and

keeping an accurate chronological record thereafter.

VESSEL DETAILS

Steel vessel built in Scotland.Age 17 yearsLength 25m.

Approximate gross tonnage, 160.Soft nose stem, rounded bilge and transom stern.Hull subdivided from forward into chain locker, forecastle, fishroom, engineroom and cabin.


Abstract

Galvanised steel pipe mostly sampling at less than 25% thinning.Aluminium brass pipe wall thinning found to be 25% loss where sampled at

i i t di h li



main engine seawater discharge cooling pump.Porous pipe by way of the port auxiliary sea suction.Weeping welds in discharge of bilge pump (starboard).Weeping weld at port side bilge pump discharge.No valve tagging or colour coding.No engine room layout schematic.3 Instances of misaligned pipes - Two sections of overboard discharge pipeswere severely misaligned.

Engine Room

The main engine is a Caterpillar 3412 developing 600Hp@ 1800rpm and it islocated within a central well between 2 wing tanks. The total volume withinthis well minus the main engine and associated plant is 16m³. The generatorsare located above to port and starboard.

IntroductionEngine room pipe work was inspected for wall thickness in places deemedlikely to fail through corrosion, erosion or vibration and in general the pipethickness was not in a poor condition.

Systems

The sea water system had the following sea inlets:

‘2 off’ - 3” sea suctions for the main engine‘2 off ’ - 1 ½”’’ Sea inlets serving the ‘2 off ‘ alternators‘2 off ‘ - 3’’ Sea inlets serving the bilge pumps port and starboard and thevalve chest.Other small sea inlets for services.

The system has an inherent weakness in that if the bilge valve leaks thevessel will experience back flooding from the main sea inlets if these areopen to the bilge line valve chest – as is normal on board. Indication of thiswill be the constant operation of whatever bilge pump is used. Conversely,this will also seriously hamper the pumping ability of the vessel, as theleaking bilge valve will draw air when empty


Design

The design of the engine bilge system was sketched and the layoutexamined.

The practice of tagging valves has been missed and there is the possibility of



The practice of tagging valves has been missed and there is the possibility of a mistake due to the complicated array of valve positions which if notmemorised could lead to confusion and delay in an emergency.

Practice

The practical aspects of bilge pumping requires closure of valves and cocks

when alongside - the complexity of the present system, in the hands of unfamiliar personnel, could lead to non-operation of these components for fear of mix-up and subsequent loss of pumping capability.All shipside valves should be closed when plant is shutdown alongside.

Ultrasonic Sampling:

Areas of main seawater suction pipes were sampled at points likely to

experience severe turbulence and erosion:Seawater to the main engine and general service pumps enters the vesselvia 6” diameter stub trunking. This trunk wall gave ultrasonic thickness to beabnormally thick – approximate external measurement from the dry-dockshowed the internal diameter of this trunking to be approximately 3 inches,indicating that the sounding was reasonable.Cooling water to the main engines, gearbox and refrigeration is supplied

through aluminium brass piping, as is raw seawater piping to the starboardvalve chest. Most other piping is of galvanised steel. A seawater pipe(galvanised) was found porous at inlet to the port auxiliary engine coolingsystem.Sampling of aluminium brass pipes to both main engine and showed littleevidence of wall thinning at inlets, although the main engine discharge pumphad 25% reduction in thickness.Both port and starboard valve chests may be suffering from severe external

corrosion. Ultrasonic sampling was attempted on the strainer casings but noresults could be obtained – this usually indicates pitting internally. Thecasting was observed encrusted in rust with a black colouration in severalplaces.


Flexible joints/sections.

Several flexible sections were sighted. These were inserted within the coolingpiping arrangements to compensate for vibration. The sections were either

of reinforced bellows type construction or straight hose In all cases the



of reinforced bellows type construction or straight hose. In all cases theflexible sections were applied with type approved clips with a minimum of twoat each end.Two sections of suction pipes were severely misaligned. In particular the 3”emergency line.

FINDINGS

Aluminium brass pipe wall thinning found to be no greater than 25% wheresampled.Galvanised steel pipe mostly sampling at less than 25% thinning.Porous pipe by way of port valve chest discharge.Colour coding was painted over in many places.Weeping weld by way of first bend after port side bilge pump.Several instances of misaligned pipes with misalignment being taken out by

flexible pipe hose; one of which showing signs of fretting.Three overboard flanges missing nuts on bolts holding valves to ships side.

RECOMMENDATIONS:

Consider fitting extension spindles to all bilge sea suction valves.Align pipe sections on 3” overboard discharge (starboard side) by way of

flexible pipe section – use a purpose made spooled flange before insertingflexible expansion joint if necessary.Replace porous pipe in suction of port auxiliary seawater cooling pumpReplace section of pipe from port side bilge pump.Replace 3” galvanised steel pipe from starboard bilge pump discharge tooverboard.Replace missing nuts on overboard discharge valves (3) at ships side (port).Consider monitoring thickness of pipe walls by having ultrasonic samplestaken at regular intervals.Consider having aluminium brass pipe from main engine discharge pumprenewed.Consider constructing and affixing piping diagrams and bilge pumping


APPENDIX D TYPICAL INTERVIEW

CRITICAL PIPE WORK AND S YSTEMS / PROCEDURES INTERVIEW



Information given in this interview will be treated as confidential.The names of people and vessels will be strictly anonymous andwill not be revealed to any third party, including the sponsors. If itis felt that any question puts you in a compromising situation,simply answer, “pass”.

1 Vessel age 8 years old

2 Hull construction material Steel

3 Fishing type e.g. white fish W.F.

4Fishing method e.g. pair trawl

Pair trawl

5 Fishing routine e.g. weekly Weekly, 1½ crews6 Number of crew 4

7 Your job Engineer

8Crew turnover (1=low;5=high)

4

9Duration onboard of Driver/Engineer

3 years

10 Driver/ Engineer qualifications

None

11 General history of vessel:Ownership 2

nd

Burst pipework Yes – not uncommonRe-engining Original

Comments Flooding due to mis-alignment of pipesinto cooler causing erosion and in onecase cracked pipe. Found during visit toengine room for other reason. Bilge


Is a planned maintenance routine in place for:

12 Pipework None – sort of check it outwhen I can

13 Valves None – when operated

14 Seacocks Monthly to work valves



14 Seacocks Monthly to work valves

15 Strainers Monthly with valves

16 Mud boxes Weekly

17 Anodes;PipesHull

MonthlyAnnually

18 Pumps None – if they stop!

Is a regular visual inspection routine in place for: 19 Pipework Yes

20 Valves Yes

21 Seacocks Yes

22 Strainers Yes

23 Mud boxes Yes

24 Anodes

in pipes;On hull; On engine monthlyYes, annually

25 Pumps Yes – regular check

26 Are seacocks closed in harbour, if vessel is unattended for morethan 12 hours?

Yes

27 Is a sign displayed indicatingseacocks shut?

No but getting one painted

28 Is pipework colour coded? Painted - e.g. green for seawater

29 Is a pipework diagram displayedin the engine room?

No – would be handy

30 Are suction valves clearly markedfor ease of use?

Some

31 Is a pumping diagram/directions

displayed in engine room?

No

32 Have you ever encounteredleaking water pipes?

Yes

33 If “yes”, what caused theCorrosion and misalignment


38 Has backflooding through valvesever been a problem on this boat?

Yes, bilge in harbour – why weshut seacocks

39 Have you encountered flooding

from other sources?

Cooler corrosion

40 If “ ” h h ?



from other sources?40 If “yes” what was the source?

Corrosion & electric leaks

41 Can you suggestanything whichwould improve bilge pumpingsystems andpipework reliability?

Annual non destruction testing of pipework. Galvanised steel pipingseems to be sub standard.

Annual testing for electrical leaks.


APPENDIX E

EXAMPLES OF REGULATION ANALYSIS

In this Appendix sections of the Code of Practice for Fishing Vessels



In this Appendix, sections of the Code of Practice for Fishing Vesselsbetween 15 and 24 metres in Length that was published in 2001 areanalysed as an example of how the Regulations might be clarified thereforeby and leading to more effective guidance.

The analytical technique is not new in itself, and has been well reviewed andextended by John Lawson in a recent PhD thesis from Aberdeen University.

The aim is to grammatically analyse the text and identify verb clauses,therefore isolating these as clear instructions to take account of information,perform calculations or do things in some way thus removing ambiguity.

In the example sections below, the original rule is in bold the discussion innormal font and proposed new rules in bold italics.

SCUPPERS, INLETS AND DISCHARGES

2.2.6 Scuppers, Inlets and Discharges

2.2.6.1 The number of inlets and discharges should be kept to theoperational minimum. N

This consists of 2 rules(a) Discharges to be minimised(b) Inlets to be minimised

This is the first mention in the Code of any of these items so they areundefined. The intention is that openings for these purposes below the upper freeboard deck should be minimised, but o perational minimum is fairly hazyas a concept. A reference to redundancy would be useful so we propose this

should be reworded as

2.2.6.1 The number of openings through the hull below the upper freeboard deck used for inlets and discharges should be the minimum


This consists of 2 rules and a modifying clause to define where they apply.The rules apply to scuppers and discharges from water or weather tightspaces leading through the hull and they are,

c) scuppers and discharges to have an auto non return valve fitted at the



) pp ghull to prevent backstop -flow of sea into the vessel

d) scuppers and discharges to have a means of closure that can beoperated from an accessible position when the non-return valve is notfunctional.

Both rules are ambiguous because hull is undefined. The meaning is ‘hull

below the upper freeboard deck’ because no other section of hull requiresthis protection.

Much of the definition of the spaces is redundant as it is clear that it is onlywatertight or weathertight spaces that require such discharges. Drainagefrom open decks to discharges below the freeboard deck is covered in2.2.6.7 where an unspecified increase in wall thickness is required. Seecomments at that rule.

The position of the NRV is not clearly defined with respect to access for operation or maintenance. The need to maintain these notoriously frequentlyunreliable valves in fact conflicts with the phrase at the hull . There is a needfor an isolation valve near the hull and a non-return valve inboard of that.This allows maintenance of the NRV. Combining isolation with the NRVmakes for complexity and inefficiency. with NRV makes for poor reliability.

Remote closure from an "accessible position" is also not clear, as 'accessibleis not defined either in terms of location or for ease of operation. It couldusefully read ‘positioned above the freeboard deck and within the normalworking area of vessel, located so that it is easy to use.’ If, however, thiswere accepted then a dispensation for engine room overboard dischargeswould be required.

Either the isolation valve or the NRV could be subject to the remote closure requirement, but it is would be best to make this the isolating valve – againbecause of the unreliable nature of NRV’s. It would also be necessary todefine certain requirements for the closing apparatus and in particular, a way


2.2.6.2(a.1) Each scupper or discharge leading from a water or weather tight space through the hull below the freeboard deck should have an isolating valve fitted near the hull. This valve should be

capable of local control at the valve and also be fitted with a positive



means of closure that can be operated from a position above thefreeboard deck and within the normal working area of vessel, located so that it is easy to use. Indication of valve position should be provided at the remote closure position. N

2.2.6.2(a.2) Notwithstanding the requirements of 2.2.6.2(a.1), if

the discharge is within a machinery space that is fitted with a bilgealarm and serves machinery within that space, then the remote meansof closure may be operated within the machinery space from a positionthat is readily accessible after significant flooding of the space. As aguide, significant flooding may be taken as more than 30% of thefloodable volume of the space. N.

2.2.6.2(b) Each scupper or discharge leading through the hull below thefreeboard deck from water or weather tight spaces should be fitted withan automatic non-return valve fitted inboard of the isolation valve to prevent backstop -flow into the vessel. N

_____________

Inlets

2.2.6.3 Each sea inlet valve should be fitted with a positive means of closure from an accessible position. N

2.2.6.4 In machinery spaces, controls for main and auxiliary seainlets essential for the operation of machinery may be controlled locally. The controls should be readily accessible, above the floor plates, and be provided with indicators showing whether the valves areopen or closed. N

2.2.6.3 is a simple rule that but is ambiguous because accessible isundefined It also confuses local control at the valve with remote


2.2.6.3(a.2) Notwithstanding the requirements of 2.2.6.3(a.1), if the sea inlet is within a machinery space that is fitted with a bilge alarmand serves machinery within that space, then the remote means of

closure may be operated within the machinery space from a positionth t i dil ibl ft i ifi t fl di f th A



that is readily accessible after significant flooding of the space. As aguide, significant flooding may be taken as more than 30% of thefloodable volume of the space. N.

______________

2.2.6.5 If valves are not fitted above the floor plates, rapid andpractical means should be provided to allow for the valve to beoperated from floor plate levelIf inlet valves are not fitted above belowthe floor plates, rapid and practical means should be provided to allowfor the valve to be operated from above floor plate level when morethan 30% of the floodable volume of that space is reached. .

E

AND

2.2.6.9 Existing vessel arrangements will continue to be acceptableprovided that valves fitted at hull penetrations remain both accessibleand efficient in service. EExisting vessel will have to meet the requirements of 2.2.6.5 for inletshowever present arrangements will continue to be acceptable for

scuppers and discharges provided that valves fitted at hullpenetrations remain both accessible and efficient in service. E

Rule 2.2.6.9 should be combined with 2.2.6.5 as they both refer to existingvessels.

Rule 2.2.6.5 is intended to bring existing vessels into line with respect toisolation. It stands alone with, perhaps, an implicit understanding that it

covers sea inlets valves because of the position of the rule in this section. Itis not particularly clear which valves are covered, but it is all the valves withina machinery space that can shut off the vessel from the sea or isolate criticalsystems that are intended – not just valves below floor plates.


to be readily accessible for local operation and for maintenance and areregularly checked for operation. E

2.2.6.5(b) Notwithstanding the requirements of 2.2.6.5(a), valves within

a machinery space that control or isolate flow of sea water are to befitted with rapid and practical means of closure that can be operated



fitted with rapid and practical means of closure that can be operated from a position that is readily accessible after significant flooding i.e.30% of the space. E

________________

2.2.6.6 Soil and other waste water drainage should be so arranged and fitted with such water seals, air vents and storm valves as arenecessary to prevent siphoning, blowback or ingress of water. The hull closing arrangements should be as detailed in paragraph 2.2.6.2. N

No change required.

____________

2.2.6.7 If scuppers from open decks penetrate the hull below thefreeboard deck they should be made from piping of substantialthickness.

Allowing such scuppers is poor practicenot ideal, but may be unavoidable in

some cases. Although this rule is relatively clear, the word substantial isundefined. The intention is to defeat corrosion by providing a margin on wallthickness. This is not sufficient on its own and a table of pipe wall thicknessfor given pipe diameters and material should be referenced. The rule shouldbe,

2.2.6.7 Scuppers from open decks should not be led below thefreeboard deck unless no other drainage route is practicable. Where a

scupper from an open deck penetrates the hull below the freeboard deck it should be made from piping of the thickness given in Table X.

_________________


In the example sections below, the original rule is in bold the discussion innormal font and proposed new rules in bold italics.

4 11 1 1 All new or replacement installations of sea water piping and



4.11.1.1 All new or replacement installations of sea water piping andfittings for cooling water systems should be of aluminiumbronze, cupro-nickel or similar corrosion resistant material.

The intention is to ensure that all sea water piping and equipment thatcontains sea water is of material that resists corrosion. An admirable intent,but it must be clear and also coupled with advice on galvanic action and onallowable flow rates. There is a great deal of confusion in the industry aboutthe various causes of corrosion with more apparent emphasis on avoidingstray currents than on correct use of materials.

Aluminium brass is probably intended for piping. Aluminium bronze is not asuitable piping material, but would be correct for valves and other such items.

The requirements for fittings should be separated from the requirements for pipes as these will include valves, and could include polymeric fittings. For example, rubber impregnated with a carbon filler can cause significantdamage to aluminium or copper piping.

It is not clear why replacement installations are specially mentioned and itcauses confusion.

The term or similar corrosion resistant material is imprecise. The intentionshould be to allow either a new material of proven corrosion resistance or analternative lower quality material with increased wall thickness to acceptgreater thickness loss. The latter is not preferred, but may be an effectivestrategy in some cases.

For new boats it should be clear that all sea water systems are to be of

suitable materials.

For existing boats the replacement in a repair should take account of thecause/need for the repair and should be both compatible with existing

f f




iv) Turbulence is avoided where pipes are taken off themanifold by the use of smooth reducing sections.

v) It is demonstrated that flow rates in all normal operating conditions do not fall below 1 m/sec.

vi) Full attention is paid to the avoidance of galvanic corrosion at the junctions between the mild steel pipe



corrosion at the junctions between the mild steel pipeand other pipes or fittings of dissimilar materials in thevessel.

___________

4.1.11.3 Care should be taken to ensure that galvanic corrosion effectsfrom dissimilar metals are prevented, by such means asisolation packing, washers and sleeves between the flangesand fasteners joining pipes.

Almost redundant, but worthwhile to have a catch-all clause here to mentionsuch things as pipe supports. It is also necessary here to bring in theconcept of bonding of similar materials. Reword as,

4.1.11.3(a) Care should be taken to ensure that galvanic corrosion effects from dissimilar metals are prevented, by such means as isolation packing, washers and sleevesbetween the flanges and fasteners joining pipes and in way of pipe supports.

4.1.11.3(b) Care should be taken that where similar materialsare separated by a non-conductive material there is electrical bonding across the junction.

___________

4.1.11.4 Recommendations may also be found in MGN 190 (F): FishingVessels – The Premature Failure of Copper Pipes in Engine

Cooling Water Systems.

No change to this. ___________


the connection must be capable of close inspection and repair withoutremoval of items of equipment other than floor plates.

The rule then becomes,

4.1.11.6(a) Sea water pipes should be connected by means of



4.1.11.6(a) Sea water pipes should be connected by means of bolted flanges. Alternative connections will be considered,but only if they provide the same ease of integrity assessment and replacement as a bolted flange. . Existing vessels should be fitted with such arrangements whenever seawater pipework is renewed. E

4.1.11.6(b) Pipe connections should be capable of closeinspection and repair without removal of items of equipment other than floor plates

___________

4.1.11.6 Where cooling water services are essential for the cooling of the propelling machinery, alternative means of circulatingwater should be provided in the event of failure of the primarysource. Such alternative means should be demonstrated tothe satisfaction of the Certifying Authority.

And

4.1.11.8 New vessels should be fitted with at least two main seawater cooling inlets, with one inlet fitted on each side of the vessel(except when fitted with ‘keel cooling’ arrangements).N

These rules requires redundancy of cooling water supply to propulsion

machinery – and presumably to any other machinery critical to the boat’ssurvival.

4.1.11.8 is primary as it deals with the main cooling system and asks for seai l t t d t b d th l Th i t ti i t id i l t


three inlets are require – the two primary inlets and another that may bealready used for some other purpose.

This is also discussed in 2.2.6.1 where any overall requirement is for the

minimum number of inlets that meets redundancy needs.



Reword as,

4.1.11.6(a) There should be two main sea water inlets –suitably separated to take account of fouling and to provideredundancy in location of supply through the vessel’s hull.

4.1.11.6(b) In addition, where cooling water services areessential for the operation of the propelling machinery and for the operation of any other machinery critical to the vessel’ssurvival, alternative cooling water supplies should be provided to the machinery. These alternative supplies should be from a sea inlet that is independent of the usual cooling water supply and should employ independent pumps and

piping to the machinery – for example, by a cross over fromanother sea water system. Such alternative means should bedemonstrated to the satisfaction of the Certifying Authority.

4.1.11.6(c) Where keel cooling arrangements are fitted, thealternative cooling supply in 4.1.11.6(b) is not required.

___________

4.1.11.7 Sea water suctions of cooling systems essential for internalcombustion machinery should be provided with strainerssuitably arranged so that they may be cleaned withoutinterrupting the supply.

This should be more general in that all sea water inlets should have easilyaccessible strainers. In addition, when a sea inlet comes out of the water thepipes can drain to cause an air inlet in the system. The sea inlet valves,therefore, should be screw down non return valves. It may be that this rule

ld b b tt l d d i l t b t f th t it i t i d i thi


4.1.11.8 New vessels should be fitted with at least two main seawater cooling inlets, with one inlet fitted on each side of the vessel(except when fitted with ‘keel cooling’ arrangements).N

See above under 4.1.11.6. Delete.



___________

Add new Rule to account for MGN 49 that says do not fix flexible sections of piping in cooling water or other systems unless necessary to withstand

movement or vibration.

4.1.11.8 Flexible hose and other flexible fittings should not be used incooling water or other fluid systems) unless necessary towithstand movement or vibration. The fittings must besuitable for the conditions of use and be clearly marked with a part number or other description and the date at which they must be replaced.

___________

4.1.11.9 Refer also to Section 2.2.6 (Scuppers, Inlets and Discharges)

Retain

___________________________


APPENDIX F EXAMPLE OF INFORMATION BOOKLET

T YPICAL LIST OF MATERIALS

Item Description Details Material N. Bore Comments



ItemNº

Description Details Material N. Bore Comments

1 Port Bilge SuctionValve Chest

S.D.N.R – 5ways

CI/GM 80NB

2 Starboard BilgeSuction Valve

Chest

S.D.N.R – 5ways

CI/GM 80NB

7 Diesel EnginePump Suction

ButterflyValve

CI 80NB Bilge/Fire/Deckwash

Pump

8 DieselEngine/Gilkes

Pump Dis

Wafer typeN.R Valve


Pump


Suction

Flexible Joint 80NB Bilge/Fire/Deckwash

Pump


Suction

Flexible Joint 80NB Bilge/Fire/Deckwash

Pump

11 Diesel Engine/Gilkes Inlet

ButterflyValve


Pump

12 Diesel Engine/Gilkes Outlet

Wafer typeN.R Valve


Pump

13 Port Bilge PumpDischarge

S.D.N.R +test Cert,

GM 80NB

14 Starboard BilgePump Discharge

S.D.N.R +test Cert,

GM 80NB

16 Fire / DeckwashIsolating Valve

ButterflyValve

CI 80NB

21 EngineroomEmergency Suction

Whale 4” DKfitting

Brass 100NB Hand Pump

21 Deep Well

Emergency Suction

Whale 4” DK

fitting

Brass 100NB Hand Pump

29 Port EngineroomSuction

Foot ValveC/W Strainer

GS 50NB

30 StarboardE i

Foot ValveC/W St i

GS 50NB

Flooding of UK Fishing Boats

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