MAIB Safety Digest 2/1995

Marine Accident Investigation Branch (MAIB) - Safety Digest Contents 1. OBSTRUCTION AT TIDAL BERTH CAUSES POLLUTION ...........................3 Narrative .........................................................................................................................3 Observations ...................................................................................................................3 Comment.........................................................................................................................3 2. INCORRECT SETTING OF GENERATOR RUNNING SEQUENCE CAUSESPOWER FAILURE........................................................................................................................5 Narrative .........................................................................................................................5 Observations ...................................................................................................................5 Comment.........................................................................................................................5 3. INADEQUATE PASSAGE PLANNING LEADS TO LOSS OF A TOW ...........6 Narrative .........................................................................................................................6 Observations ...................................................................................................................6 Comment.........................................................................................................................6 4. PREMATURE RELEASE OF LIFERAFT LIFTING HOOK .............................7 Narrative .........................................................................................................................7 Observations ...................................................................................................................7 Comment.........................................................................................................................7 5. SHIFT OF CARGO ON RO-RO VESSEL DURING BAD WEATHER CONDITIONS 8 Narrative .........................................................................................................................8 Observations ...................................................................................................................8 Comment.........................................................................................................................8 6. CORROSION CAUSES FLOODING TO A STANDBY SAFETY VESSEL......9 Narrative .........................................................................................................................9 Observations ...................................................................................................................9 Comment.........................................................................................................................9 7. LOSS OF CREW MEMBER OVERBOARD .......................................................10 Narrative .......................................................................................................................10 Observations .................................................................................................................10 Comment.......................................................................................................................11 8. ESCAPE OF FREON 22 GAS ................................................................................12 Narrative .......................................................................................................................12 Observations .................................................................................................................12 Comment.......................................................................................................................12 9. THE VITAL IMPORTANCE OF KEEPING AWAKE WHEN ON A BRIDGEWATCH ........................................................................................................................................13

Case 1 ............................................................................................................................13 Case 2 ............................................................................................................................13 Case 3 ............................................................................................................................13 Case 4 ............................................................................................................................13 Comment.......................................................................................................................13 10. LOSS OF A 54 YEAR OLD WOODEN FISHING VESSEL ............................14 Narrative .......................................................................................................................14 Observations .................................................................................................................14 Comment.......................................................................................................................14 11. GALLEY FIRE WHILST ALONGSIDE ............................................................15 Narrative .......................................................................................................................15 Observations .................................................................................................................15 Comment.......................................................................................................................16 12. HEAVY WEATHER FLOODING AND DAMAGE TO FISHING VESSEL.17 Narrative .......................................................................................................................17 Observations .................................................................................................................17 Comment.......................................................................................................................17 13. RAPID CAPSIZE AND SINKING OF A FISHING VESSEL WITH LOSSOF LIFE 18 Narrative .......................................................................................................................18 Observations .................................................................................................................18 Comment.......................................................................................................................19 14. LOSS OF A WOODEN FISHING VESSEL .......................................................20 Narrative .......................................................................................................................20 Observations .................................................................................................................20 Comment.......................................................................................................................20 15. FLOODING AND FOUNDERING OF WOODEN FISHING VESSELS - OFFICIALCONCERN AT NUMBER OF INCIDENTS.........................................21 16. HYDRAULIC OIL LEAK CAUSES EXPLOSION ON FISHING VESSEL..23 Narrative .......................................................................................................................23 Observations .................................................................................................................23 Comment.......................................................................................................................23 17. THE LOSS OF A FISHING VESSEL AND THE STOWAGE OF LIFERAFTS 25 Narrative .......................................................................................................................25 Observations .................................................................................................................25 Comment.......................................................................................................................25 18. ANOTHER WOODEN FISHING VESSEL LOST THROUGH FLOODING28 Narrative .......................................................................................................................28 Observations .................................................................................................................28 Comment.......................................................................................................................28

19. LOSS OF A FISHING VESSEL WITH LOSS OF LIFE ..................................29 Narrative .......................................................................................................................29 Observations .................................................................................................................29 Comment.......................................................................................................................29

1. OBSTRUCTION AT TIDAL BERTH CAUSES POLLUTION

A 60 metre coastal tanker arrived at a tidal berth to load 1176tonnes of light crude oil. Loading was completed in the afternoonand it was then necessary to wait for the next tide and sufficientwater for the tanker to sail. Low water occurred in the earlyevening, during which time the vessel took the ground.

Shortly before midnight, about an hour before high water, thecrew turned out to prepare for sailing. It was then noticed therewas crude oil on the water surface around the vessel. A reportwas made to the harbour authority and the Department of TransportMarine Pollution Control Unit was notified. While the source ofthe leak was being investigated, the crew deployed the buoyantmooring ropes as an emergency containment measure. Oil booms wereplaced downstream of the berth to prevent pollution of other partsof the harbour. At about 0100 hours it was established that theoil had leaked from No 4 starboard cargo tank. The shore hosewas connected and discharge of No 4 tank was commenced. This wascompleted at about 0400 hours.

The tank was opened up and water was seen to be leaking in toit, evidently through a hole in the bottom. The remainder of thecargo was transferred ashore, this being completed by about 1000hours. After gas freeing No 4 starboard tank, an internal inspectionof it revealed a rounded and cracked indentation in the bottomplating. The ship was moved to a nearby slip for repairs.

Observations 1. Fortunately the pollution was not serious. It was calculatedthat less than two tonnes of the cargo was lost and it was allsuccessfully contained in the vicinity of the berth. Much of itwas recovered by skimming equipment. 2. A search was made off the berth during the following low water.A large lump of concrete about one metre square with a lengthof steel rail protruding from it was found. This was without doubtthe cause of the holing and consequent pollution. 3. The berth had been in use for the loading of crude oil cargoesfor only six months prior to the incident, although 37 loadingshad taken place during that time. Prior to the first loading theberth had been cleared of debris and cleaned up. 4. Following the incident the entire berth and swing basin wasdredged, but no further debris was found. The berth operator alsoset up a procedure of routine visual inspections of the berthat low water spring tides and amended the loading procedures toensure that, whenever it is practical to do so, vessels take thebottom in the light condition only.

Comment 1. There are many tidal berths in United Kingdom ports and itis common for coastal vessels of all types to take the groundat low water. However, extremely careful consideration needs tobe given before allowing a loaded vessel to take the ground. Excessivestresses will be exerted on the hull if the ground is irregularor fouled and a dangerous loss of stability can occur in certaincircumstances. 2. All operators of tidal berths should have a system for checkingthat as far as possible the berth is clear of debris, and followthat system regularly. 3. So far as coastal tankers are concerned, in particular thosecarrying dangerous and polluting cargoes, the cargo operationsshould be carefully planned so that the vessel lies on the bottomfor the

minimum amount of time. Should it be necessary to commenceloading before the vessel grounds, the amount of cargo so loadedshould be the minimum quantity as dictated by operational needs.It should be loaded into all the cargo tanks in order to minimiselocal stresses when the vessel takes the bottom.

2. INCORRECT SETTING OF GENERATOR RUNNING SEQUENCE CAUSESPOWER FAILURE

The engineers of a large Ro-Ro vessel had been performing routinemaintenance on No 3 of the vessel's three main generators. Nos1 and 2 generators were running. On completion of the work No3 generator was started and put on the board; No 2 was then takenoff load and shut down. Several minutes later No 3 generator startedto shed its load and shut down, so placing an excessive load onNo 1 generator which then tripped on overload.

The vessel remained without main electrical power for about onehour. This time was spent investigating possible causes of fuelstarvation, however none was found. Power was restored after aboutan hour and the vessel safely reached port a few hours later.

The emergency generator functioned properly.

Observations 1. The main generators were arranged to start automatically andsequentially as load demands changed, a multi position switchfor each generator being used to select whether it should be thefirst, second or third machine in the sequence. 2. In shutting down No 2 generator the engineer inadvertentlyturned the selector switches for both Nos 2 and 3 generators sothat they were both the third machine in the sequence. 3. Although No 2 generator was stopped, and therefore could properlybe the third machine, No 3 was running with only one other generatorrunning. The control logic of the sequential loading system recognisedthat No 3 generator was one of two on load and yet had been instructed,via the selector, to be the third on load. The control systemthus commenced to shut down No 3 generator, so leading to an overloadof No 1 and complete black out.

Comment 1. This incident demonstrates the great care that needs to betaken when selecting the automatic start and stop sequences ofvital machinery such as main generators. 2. Clear and unambiguous instructions, placed adjacent to selectorswitches, are always of assistance with these operations. Withsome installations these can be in the form of a 'matrix' showingswitch positions for desired sequences.

3. INADEQUATE PASSAGE PLANNING LEADS TO LOSS OF A TOW

A pontoon of 15 metres length had been employed for several decadesas an unpowered vehicle ferry on a narrow river crossing. Thehull was subdivided and of riveted steel construction but witha wooden main deck. For vehicle access purposes there was a largehinged ramp at each end of this deck.

In order to employ the vessel at another location, preparationswere made to tow it to another port several miles along the coast.Suitable arrangements were made to satisfy mandatory requirementsfor this operation, including the issue of a Load Line ExemptionCertificate which specified limiting weather conditions, and atug was hired to perform the tow. The pontoon was to be unmannedduring the tow. Two hours after the tow commenced it was observedthat one of the pontoon's ramps had partially broken from itssecuring arrangements. The weather at this time was good and thetow was returned to its port of departure in order to undergoa temporary repair.

Once these repairs had been completed towing started again andproceeded without incident for several hours. However, shortlyafter clearing a headland, which had been offering shelter, thepontoon started to pitch and roll significantly. The deteriorationin conditions, probably coupled with rather too high a towingspeed due to the tug Skipper's wish to compensate for the timelost earlier in the operations, caused seas to break over thepontoon's main deck.

After several hours of these conditions the pontoon capsized andeventually sank.

Observations The lack of any previous seagoing service on the part of thispontoon made the assessment of its ability to withstand sea-inducedmotions rather difficult. Even the moderate motions produced duringthe first tow, when weather conditions were good, were sufficientto generate dynamic loads on one of the ramps which caused itto break free from its securing arrangements.

Comment 1. This incident reinforces the importance of careful preparationfor a tow, and the responsibility of the person in charge to assessall dangers. Satisfying the minimum conditions set out in a LoadLine Exemption Certificate may not guarantee a successful conclusionto an operation; prudent seamanship remains a fundamental requirement. 2. Advice on planning, preparing and performing a tow, togetherwith emergency advice, is contained in Merchant Shipping NoticeNo M.1406 "Safety of Towed Ships and Other Floating Objects".

4. PREMATURE RELEASE OF LIFERAFT LIFTING HOOK

An exercise involving the preparation of a davit-launched liferaftwas conducted on board a passenger/Ro-Ro cargo ferry while thevessel was berthed alongside in port. On completion of the preparationprocedure, the Bosun entered the liferaft which was suspendedover the side, in order to insert three deflation plugs in readinessto lift the liferaft back on board. Still in the liferaft, hewas instructed by the Second Officer, who was in charge of theexercise, to indicate the hook cocking wire.

The prevailing force 5 wind conditions caused the liferaft tomove and to unbalance the Bosun, who then grabbed the liferaftsuspension ropes with both hands for support. In doing so he inadvertentlypulled both the hook cocking wire and the remote brake releasewire which caused the hook actuating mechanism to operate andthe winch brake to lock in the OPEN position.

The winch lowered the liferaft until the load was taken fullyon the bowsing lines and caused the hook to automatically release.Fortunately, the Bosun was able to scramble back on board thevessel without injury.

Observations 1. The liferaft davit lowering mechanism was so arranged thatit could be actuated by one person on the ship's deck or, alternatively,by one person from within the liferaft. 2. Actuation of the lowering mechanism from within the liferaftwas achieved by means of a remote brake release wire which, whenpulled, effectively locked the winch brake in the OPEN position.It was intended that the remote release wire should only be usedwhen launching the last of a number of assigned liferafts. 3. The liferaft hook could be released either manually or automatically.Operation of the actuating mechanism, which allowed the liferaftto be released automatically when the hook was relieved of itsload, was achieved by means of pulling a hook cocking wire fromwithin the liferaft. 4. Although the position of the hook cocking wire rendered itunlikely to be pulled inadvertently by personnel boarding theliferaft, the remote brake release wire was positioned in closeproximity to the liferaft entrance.

Comment 1. The incident was caused by the inadvertent operation of boththe hook actuating mechanism and the winch brake locking arrangementwhen the Bosun attempted to support himself using the liferaftsuspension ropes. 2. A major contributory factor was that the Bosun became unbalancedat a time when he was reaching upwards in order to indicate thehook cocking wire. 3. The close proximity of the remote brake release wire to theliferaft entrance rendered the winch brake liable to inadvertentrelease by personnel boarding the liferaft or by the remote releasewire becoming fouled by the liferaft suspension ropes during theinflation process. 4. The management company concerned has since taken action toprevent a recurrence by installing a short length of line forthe purpose of keeping the remote brake release wire clear ofthe liferaft entrance until required.

5. SHIFT OF CARGO ON RO-RO VESSEL DURING BAD WEATHER CONDITIONS

A Ro-Ro cargo vessel had loaded a total of 37 trailers and onearticulated vehicle. A weather forecast predicted winds of force6 - 7, occasionally 8. In anticipation of a rough passage, unitswere selected as being suitable for the voyage and none containedhazardous goods. Each unit stowed on the lower vehicle deck wassecured using 8 chains; those on the upper deck had 10 chains.

The vessel left port at 0815 hours and by 1300 hours the windhad increased to force 9 giving very rough seas and heavy swell.Course was adjusted to keep rolling to a minimum and cargo lashingswere inspected regularly. At 1550 hours course was altered forthe final leg of the voyage. During this turn the vessel experienceda series of exceptionally violent rolls. As a result two trailersfell onto their sides when the lashings failed and cargo shiftsoccurred in four other trailers. The affected units were stowedon both the upper and lower decks.

The vessel suffered no significant heel and safely made port at1830 hours.

Observations 1. The lashings employed for securing these cargo units wereequal to, or in excess of, the recommendations contained in the"Code of Practice for Roll-on/Roll-off Ships - Stowage andSecuring of Vehicles". 2. The majority of the affected units suffered from shift oftheir cargo. This is indicative of inadequate arrangements forsecuring cargo to the trailer.

Comment 1. This incident again highlights the difficulty of performingan accurate assessment of the efficacy of securing arrangementsof cargoes in trailers. 2. It should be recognised that problems only occurred when weatherconditions were significantly worse than predicted and whilstthe vessel was altering course.

6. CORROSION CAUSES FLOODING TO A STANDBY SAFETY VESSEL

A standby safety vessel with a crew of 12, was on duty in theNorth Sea. The wind condition was force 7 and the sea swell 6/7metres. Whilst on his rounds the Chief Engineer noticed that therewas more water than normal in the bilge system. The cause wastraced back to a leak from the starboard machinery cooling seachest into internal tanks. It was decided to leave attemptingany repair until the morning when the weather was due to moderate.At 0730 hours and before repair had commenced, there was a rapidincrease in the flow rate. One ship's party tried to stem theflow while the other put the salvage pump into action: this wasin addition to the ship's bilge pumping system. This action wassuccessful.

At 1300 hours the vessel received permission to break off herduties and proceeded to Lerwick. During this 15 hour voyage shereported her progress to HM Coastguard every two hours and shemade port safely.

Observations 1. The vessel was 14 years old and of steel construction. 2. She had been dry docked for survey ten months before the accident,when no significant defects to the steel hull had been found. 3. The port and starboard keel coolers were removed and it wasfound that about 50% of the nylon insulators were missing fromthe studs securing the bronze tube plate to the steel mountingplate on both coolers. 4. The absence of these insulators had allowed very high galvanicaction to take place causing extremely heavy corrosion of thesea chest. 5. The plating within the cooler recess area on the sister vesselis to be inspected.

Comment 1. This incident illustrates the benefits of officers' rounds,and having a portable/salvage pump on board and in working order. 2. The Merchant Shipping Notice No M.1361 on "The Dangersof Flooding" provides useful advice. 3. All inlets and recesses should be thoroughly examined duringthe five years periodical hull survey. The cooler should be removedand plating within the recess examined and if in doubt an ultrasonictest on the plating should be carried out. It goes without sayingthat on replacing the cooler all the insulators should be correctlyrefitted.

7. LOSS OF CREW MEMBER OVERBOARD

A dredger, with a full cargo of sand, having weighed anchor atabout 0945 hours was on passage up river making for her dischargingberth. The weather was overcast, force 5, fresh breeze with amoderate swell. At approximately 0920 hours, the Fourth Engineerand the Assistant Engineer discussed details of repair work tobe carried out on the aftermost hopper spillway on the starboardside of the vessel. Subsequently, the Assistant Engineer wentaft to the steering gear compartment to collect some steel barand to assemble the tools necessary to complete the work. Amongstthe tools was an electric welding set. The Fourth Engineer passedthe Assistant Engineer on the catwalk at about 0940 hours wherehe was fitting the lead for the electric welding set into thesupply socket.

At about 1215 hours it became apparent that the Assistant Engineerwas missing. The vessel was immediately searched and all workingspaces and accommodation areas were inspected. The welding equipmentand a steel bar were found on the starboard deck aft of the spillwaybut there was no trace of the Assistant Engineer. The vessel wasby this time in the process of manoeuvring alongside the berthand once secure the Master immediately informed the Thames NavigationService and the Coastguard. A thorough search of the river wascarried out starting at 1254 hours and continuing until 1508 hours,but no sign of the missing man was found.

Observations 1. The area in which the repair work was to be carried out wason the main deck just forward of the accommodation on the starboardside. To reach this point it was necessary to climb down ontothe well deck, move forward to No 3 dredge pipe davit, pass outboardof this and then forward again underneath the dredge pipe to thework area. Lifelines were normally fitted between the aft sideof the dredge pipe davit and the accommodation, and between theforward side of the davit and the aft side of the next davit forward.The dredge pipe davits were about 460 mm wide and to go forwardit was necessary to go outboard of the lifelines using