MO-2014-203 Fatal injury, Purse seine fishing vessel, Captain M. J. Souza, 24 August 2014

1. The Captain M. J. Souza is a New Zealand-registered purse seine fishing vessel that was operating in the Pacific Ocean approximately 650 nautical miles north of Samoa.
2. On 24 August the vessel was engaged in a routine fishing operation when a nylon rope sling that was securing one end of the fishing net to the vessel broke. The weight of the net was then transferred to an approximately 48-millimetre-diameter nylon rope called a safety choker line, which was designed to retain the net end in the event of the rope sling failing.
3. The crew rigged another rope to alleviate the load on the safety choker line, then continued to close the net around the school of tuna. Soon afterwards the safety choker line broke at a bowline knot that had been tied in the rope and recoiled, striking one of the deck crewmembers in the head. The crewmember died instantly.
4. The Transport Accident Investigation Commission (Commission) found that the safety choker rope broke because it was in a deteriorated condition and was further weakened by the bowline knot that had been used to attach it to the net end.
5. The Commission also found that the broken rope was about as likely as not to have begun its life in service at a lower-than-typical breaking load for a rope of that size and construction. However, it could not be determined why, because the rope management plan on board was not effectively managing the purchase, storage, inspection and retirement from service of the ropes on board.
6. The Commission also found that the safety management system on board the Captain M. J. Souza provided good guidelines for the management and use of ropes on board. However, neither the crew nor the skipper nor shore management were ensuring that the safety management system was being adequately followed.
7. The Commission made a recommendation to the operator of the Captain M. J. Souza regarding improving its internal auditing procedures on board.

8. The key lessons arising from this inquiry included:

   • tying a knot in a fibre rope will reduce its strength. It is therefore important to factor in this reduction in strength when tying a knot in a rope for a specific operation

   • fibre ropes can fail due to cyclic tension loading, a form of fatigue damage that can be difficult to see in braided ropes. Mariners must look beyond rope surface appearance alone when deciding whether to retire ropes from service.

Purse seine fishing operation

1. Purse seine fishing aims to surround a school of fish quickly by means of a large net, then impound the fish by closing the bottom of the net. The net is cast vertically (Figure 1, 1.1) and has buoys attached to a float line at the top to keep the net afloat. The remainder of the net is then dropped into the water using a weighted line (Figure 1, 1.2). A steel cable (a cable is a thick wire rope) running through a series of purse rings at the lower end of the net is tightened or pursed to close the bottom of the net and prevent the fish escaping (Figure 1, 1.3).
2. The operation or ‘set’ starts by surrounding the school of fish with a net. One end of the net remains on board the fishing vessel while the other end is secured on a small boat called the net skiff. On the master’s command the net skiff is launched from the ship, signalling the start of the set.
3. The skiff drags one end of the net into the water and holds it in position while the vessel quickly circles the fish, paying the net overboard as the vessel comes around to retrieve the skiff end of the net. The bottom of the net is then closed or pursed, trapping the fish inside.
4. The skiff end of the net is attached to an ortza (an ortza is a triangular metal frame to which one end of a net is attached. Various shackles and slings may be attached to the ortza) (see Figures 3 and 4). When recovering the net from the skiff, the ortza is hauled on board using a winch (a winch is a hauling or lifting device). When the ortza is within reach, a double-braided nylon sling, already attached to the ortza, is secured to a stainless-steel post on the port side of the ship. The weight of the ortza and the net is transferred from the winch to the post.

Narrative

1. The Captain M. J. Souza is a New Zealand-registered purse seine fishing vessel that operates predominantly in the Pacific Ocean.
2. On 24 August 2014 the vessel was fishing in the Pacific Ocean about 650 nautical miles north of Samoa. At about 1430 that day the crew detected a school of fish and manoeuvred the vessel into position to begin the purse seine operation.
3. Eight deck crew assembled on the deck and the skiff was launched. The crewmembers gathered at the forward end of the upper deck and stayed clear as the net was payed out.
4. Once the skiff had been manoeuvred into position the Captain M. J. Souza circled the fish and came back alongside the skiff to retrieve the end of the net.
5. Three crewmembers recovered the ortza and secured it with a sling to a stainless-steel post located on the port side of the ship (see Figure 2).

1. The crew also attached a 48-millimetre (mm) diameter double-braided nylon rope (double-braided nylon rope is nylon rope consisting of a braided inner core and a braided outer sheath) called the ‘safety choker line’ (choker line) to the ortza as a backup in the event that the sling parted.
2. One end of the choker line was attached to the ortza using a bowline knot (a bowline knot is used to form a fixed loop at one end of a rope) (see Figure 5). The other end was attached to the choker winch on the starboard side of the vessel (see Figure 2).
3. Once the sling had been secured to the post and the choker line attached to the ortza, the winch operator started pursing in the cables to close the bottom of the net (Figure 1, 1.4).

4. About one minute into the pursing operation the sling parted and the weight of the net pulled the ortza outboard until the choker line took up the weight of the net. The ortza was at that point close to the sea surface.

   

5. The winch operator stopped the pursing operation as soon as he heard the sling part. A crewmember took a spare three-strand nylon rope, dived into the water and attached one end of the rope to the ortza. The other end of the rope was attached to a winch located on the forward port side of the upper deck to provide a better lead to pull the ortza back to the ship’s side.

6. The surge drum winch was then used to raise the ortza as high as possible. The weight of the ortza and the forward end of the net were now being shared between the choker line and the three-stranded nylon rope.

7. While the ortza was being recovered the master, stationed at the crow’s nest (a crow’s nest is a platform specially designed with protective railing and fitted on the tallest mast of the ship, where a crewmember stands and visually scouts for fish), ordered the winch operator to restart the pursing operation.
8. Five crewmembers stepped over the choker line, which was running transversely across the upper deck, and walked towards their stations on the port aft side of the vessel. They had been tasked with releasing dye bombs (dye bombs are bottles of dye released into the sea to stop the fish swimming through as the net is closed, ensuring they do not escape) into the water to stop the fish escaping beneath the hull of the vessel.
9. Two crew members who crossed over the choker line noticed that it was unusually tight and the rope’s diameter appeared to have shrunk. This indicated that the rope was under severe strain.

10. A few minutes after the pursing operation had restarted, the crew heard a loud bang. The choker line had parted at or near the bowline knot and snapped backwards, striking a crewmember, one of the deckhands, in the head. The deckhand died instantly.

     

1. The vessel’s operations manager was notified of the accident and gave instructions for the vessel to proceed to Western Samoa.

Choker line and sling

1. The choker line (the SMS/Metallurgical and Industrial Consultants report (Appendix 1) initially identified the choker line to be consistent with a double-braided polyester rope, but on further inspection confirmed that the choker line was of double-braided nylon construction) was of double-braided nylon (the rope consisted of a braided inner core and a braided outer sheath) construction and about 48 mm average diameter. One end of the rope was attached to the choker winch (Figure 2) while the other end was attached to the ortza by a bowline knot. The choker line was a backup for the sling and intended to support the weight of the ortza and the forward end of the net if the sling failed.
2. The ortza end of the choker line had originally had an eye splice (an eye splice is a method of creating a permanent loop in the end of multi-stranded rope by means of splicing), which had parted a few weeks prior to the accident. The broken eye splice was replaced with a bowline knot before the same choker line was put back into service, which was a departure from the procedures outlined in the Talleys safe working practice document.

1. The sling was of double-braided nylon rope construction, about 50.8 mm in diameter and spliced (splicing is a method of making a join in a rope by intertwining its individual strands) together at the ends to form a loop. The sling was only a few weeks old at the time of the accident.

Rope testing

1. The Commission retained the broken choker line, the broken sling and a reported new sample rope from on board the ship.
2. SMS was engaged by the Commission to examine the choker line, sling and new ropes and determine the cause of the failure.

Choker line inspection and testing

3. SMS made the following observations in its report (Appendix 1):

   The incident break started at approximately the same axial location all around the circumference of the rope, indicated by the red rectangle in Figure 2a [Figure 7]. No evidence of deliberate cutting, as might have occurred with a knife for example, was observed. No evidence of severe or localised abrasion was observed on the outer strand fibres.

   Deconstruction of the ropes for testing confirmed that they were of a double braid type with a braided cover over a braided core.

   The general damage morphology of the choker line was consistent with predominantly cyclic tension loading, a form of fatigue (fatigue is the tendency of a material to fracture under repeated cyclic stresses) damage.

   It is clear from the evidence that the choker line was in a deteriorated condition at the time it broke. Visual examination of the rope revealed extreme cyclic tension damage and the outer surface also resembled abrasion category 5-6. The ultimate failure was most likely caused by overload of the remaining relatively intact strands, after many fibres had already broken in service. This in service damage substantially reduced the strength of the rope, to the point that it exhibited a small fraction of its original breaking strength.

   The cover strands, and core strands, of an untested section exhibited tangled fibres and broken fibres, consistent with cyclic loading damage (cyclic loading damage is a form of fatigue damage that results in a reduction of strength due to repeated cyclic stresses).

   The choker line could not be tested as a complete rope, owing to its condition and the sample being too short to accommodate effective splicing, which is required to attach the rope to the testing equipment [the length of the recovered choker line was 3.7 metres; the minimum length required to attach the rope to the testing equipment was about 7 metres]. Instead, testing was performed on strands removed from the ropes, in accordance with international standard BS EN ISO 2307. This standard allows the testing of de-stranded ropes and applies a correction factor in a calculation of the realised breaking load (the realised breaking load of a rope is the calculated, approximate breaking load of the intact rope, using an adjustment factor, after having breaking-load tested individual strands of the rope) of the full-thickness rope.

1. The realised breaking load of the choker line was 10,036 kilograms (kg), which is about 19% of the expected breaking load of 52,752 kg (116300 Pounds) (Cordage Institute High Performance Double Braid Nylon Fiber Rope Standard: CI 1310-97. See Appendix 2 for details of the referenced standard).

2. The report also estimated that the bowline knot further reduced the breaking load of the already weakened rope by about 33%, indicating that the breaking strength of the choker line may have been as low as 6,700 kg at the time of the accident.

Testing methodology and limitations

1. Owing to the condition of the damaged choker line and the difficulty of disassembling it, there is a possibility that the number of strands identified in the inner core of the choker line was 24, not 25 as identified in the test report (see Appendix 1). If the number of strands in the core was 24 and the average strengths of the outer braid strands and core braid strands were calculated separately, then the realised breaking load may have been as low as 8,584 kg, which is about 16% of the expected breaking load of 52,752 kg.
2. When the choker line parted at the bowline knot it recoiled. The Commission was unable to quantify what effect this had on the condition of the rope.

Inspection and testing of the sling

1. The following observations were made in the test report (see Appendix 1 for details).

   The strands were relatively intact at their initial separation but the fibres became more separated from each other towards the ends of the strands.

   The general outside condition of the rope appeared to be relatively free from damage, compared with the choker line, but exhibited some broken fibres protruding from the otherwise smooth surface. The sling had a very soft and supple feel. It could easily be squeezed in the circumferential direction by hand and move axially.

   The rope had 4 tying cords at various locations along its length [refer Figure 8]. Two of these had been made by tightly wrapping and finally tying many turns of black cord around the rope and these two cords appeared to be intact. The other two were loose and did not constrict the rope significantly. The core could easily be pulled out of the cover except where the two tight constrictions held it.

Inspection and testing of a brand-new sample rope from a known supplier of ropes to the Captain M. J. Souza

1. The Commission contracted SWOS, synthetic rope testing experts based in the United States, to test a new two-inch (50.8mm), double-braided nylon rope manufactured by a known supplier of ropes to the Captain M. J. Souza. To test the rope, it was cut into three lengths. Each length had an eye splice at both ends. The test results showed that the ropes parted at an average breaking load of 53,8700 kg, which was more than the Cordage Institute standard’s expected breaking load of 52,752 kg (see Appendix 3 for details).

Inspection and testing of a reported new sample rope of similar construction to the choker line, sourced from on board the Captain M. J. Souza

2. The sample rope was 32 metres in length and sourced from on board the Captain M. J. Souza. Visually the rope appeared to be in good condition compared with the choker line, but there was some indication of possible crushing and heat damage (see Figure 9). To test it, the rope was cut into five lengths, each six metres long. Two lengths had an eye splice at one end and a bowline knot at the other end. The remaining three pieces had eye splices at both ends.

Testing methodology and limitations

1. Owing to the elastic nature of the double-braided nylon rope, the rope’s elongation during testing exceeded the maximum travel of the hydraulic ram that was used to stretch it to its breaking point. There was no testing equipment with appropriate test result graphing capability available in New Zealand that had a hydraulic ram of sufficient size. Therefore a low pretension load had to be applied at the early stages of testing to take up some stretch in each sample rope. A rope expert engaged by Talleys stated that this method may have produced inaccurate results. However, the opinion of the rope expert who conducted the tests was that pretensioning of the rope would have been very unlikely to introduce any appreciable error to the final test results. The Commission acknowledges the views of both experts. However, any error resulting from pre-tensioning the test rope during the test procedure is not significant to the result, which was that the rope failed at less than half its expected breaking load. The test results are tabled below:

The test results are tabled below:

General

1. There are more than 1,200 New Zealand-registered commercial fishing vessels engaged in coastal and deep-sea fishing operations. Commercial fishing is a high-risk occupation that often takes place in a hostile and unpredictable environment, and involves working on the deck in the vicinity of winches, ropes and cables in tension.
2. The purse seine fishing vessel Captain M. J. Souza was one of nine deep-sea fishing vessels operated by Amaltal Fishing Company Limited. At the time of the accident the vessel was transitioning from the now-redundant Safe Ship Management (SSM) system to the new Maritime Operator Safety System administered by Maritime New Zealand.
3. The analysis discusses why the choker line and sling parted, the effectiveness of internal audits (an internal audit is an examination of a company’s activities by its own employees) in detecting and preventing deficiencies, the importance of having a rope management plan and the effect of fatigue on fibre ropes.

Why did the sling and choker line fail?

1. The breaking load tests conducted on the choker line showed that the realised breaking strength of the choker line may have been as low as 6,700 kg, which is significantly lower than the typical 52,700 kg breaking strength of a new 50.8 mm double-braided nylon rope (taken from the Cordage Institute Standard. The Cordage Institute is an international association of rope, twine and related manufacturers, their suppliers and affiliated industries. Its mission is to educate on the proper use of industry products through the dissemination of standards) (see Appendix 2)
2. SMS observed in its report (Appendix 1) that the damage sustained by the choker line was generally consistent with fatigue damage, but the ultimate failure was most likely caused by overloading the remaining intact strands.
3. The report referred to fatigue as “the weakening of a material subject to cyclic stresses”. The material, in this case a fibre rope, typically fails at an intensity considerably below its normal breaking strength. The SMS report stated:
4. It is clear from the evidence that the choker line was in a deteriorated condition at the time it broke. Visual examination of the rope revealed extreme cyclic tension damage and the outer surface also resembled abrasion category 5-6. The ultimate failure was most likely caused by overload of the remaining relatively intact strands, after many fibres had already broken in service. This in service damage substantially reduced the strength to the rope, to the point that it exhibited a small fraction of its original breaking strength.
5. A rope of the diameter and construction of the choker rope has thousands of individual strands. A number of broken strands within the core of a rope is an indication that it is fatigued. The greater the percentage of broken to intact strands, the more advanced the stage of fatigue of the rope. Although the number of unbroken strands can give the appearance that the rope is still in good condition, the remaining unbroken strands will have a reduced strength due to cyclic fatigue.
6. When using a rope on board a ship it is important to know how long a rope can be safely used before fatigue sets in and degrades the rope’s load-bearing capacity. The problem with braided-fibre rope that has an outer sheath is that it is virtually impossible to detect broken strands within its core, making it difficult to assess its overall condition visually. Therefore other means of assessing when to retire a rope from use are needed. The fatigue life of a rope can be predicted by modelling the life of the rope based on the load applied to it and the frequency of usage.
7. SMS also found that the bowline knot on the choker line may have considerably reduced the strength of an already weakened rope. A National Transportation Safety Board safety alert (Alert removed by website owner) reported that the strength reduction due to a bowline knot tied in a rope may be as much as 70%, even on a brand-new rope. These studies were based on nylon rope of much smaller diameter than the choker rope. The SMS report considered a strength reduction of as much as 33% for the larger ropes tested in this case.
8. It is not possible to say definitely what the actual strain on the choker rope was when it broke on board the vessel. It was necessary to use the realised breaking load method for testing the rope because there was insufficient rope to conduct a full breaking test. This method has a recognised limitation in accuracy. Also, it is not possible to say with any accuracy what the effect of using a bowline knot had on breaking strength.

The sling

1. The sling failed at the splice. The SMS report stated that it was difficult to determine whether the splice had been constructed in accordance with general industry guidelines. However, the presence of the tying cords (whipping line to constrict the relative movement of the inner core and the outer sheathing in a double-braided rope) (see Figure 10) suggested that it had not. The report also stated that there were breaks at both ends, not straight cuts, indicating that a splice might have come apart gradually while in service. The sling then most likely experienced loads sufficient to cause the observed predominantly tensile breaks (tensile breaks are breaks that are sustained when a material is being stretched or pulled).

Rope management plan

1. At the time of the accident there was no formal recording or registering of ropes on board the Captain M. J. Souza and there was no requirement to do so. There was some generic advice on rope care in its Safe Working Practices document (this is a document prepared by a vessel’s owner to set the standards and norms that should be used to create a safe working environment. The document is to be read in conjunction with the vessel’s Safe Ship Management manual), but essentially the inspection and requisition of ropes were delegated to the ship’s bosun. The shore management relied on the bosun’s judgement and the skipper’s oversight when evaluating the condition of ropes on board and making recommendations for the further use of those ropes.
2. It was reasonable to expect a person to be competent in examining the condition of a rope for what they could see. However, as mentioned above, visual examination alone will not provide a robust measure of rope deterioration. Guidelines on when to retire a rope from service as part of a rope management plan could have assisted the crew in this regard.
3. The company safety management system referenced the Cordage Institute standard as a guideline. The Cordage Institute states that an important tool for rope evaluation is a log, which includes data on the type of rope and the time in service and descriptions of the intended use and the established retirement criteria. The Cordage Institute also suggests that details of every inspection be entered into the log.
4. At the time of the accident there was no log or retirement standard documented in the safe ship management documents kept on board the ship.

5. The choker line and a reported new sample rope of similar construction were removed from on board for testing and examination. The test results showed that the choker line was only about 19% of the expected breaking load (52,700 kg) and the sample rope, which appeared to be in relatively good condition, was only about 40% of the expected breaking load.

6. There are a number of possible reasons for the reported new sample rope suffering a significant reduction in its strength. Manufacturing inconsistencies, ultraviolet degradation, heat abrasion, damage from previous usage and exposure to water or chemicals are all possible reasons.

7. Neither the crew nor shore management were able to determine with any certainty the origin of the choker line and the reportedly new sample rope. They were also unable to determine whether both the ropes originated from the same coil. There was no record of how long the choker line had been in use or how long ropes should be used prior to retirement. Consequently the origin of the sample rope was not able to be traced.
8. If the choker line originated from the same coil from which the sample was taken, it is very likely that it started its life in service at about 40% of the expected breaking load. The onset of fatigue due to cyclic tension was therefore very likely to have been accelerated because the ratio of the rope’s breaking load to the normal service loads would have been significantly lower.
9. Since the accident the operator has started a rope register to log ropes’ usage.

Ship safety management system

1. At the time of the accident the Captain M. J. Souza was transitioning its safety management from the now redundant SSM system to the new Maritime Operator Safety System administered by Maritime New Zealand. Under the SSM code a ship’s owner was required to engage a Maritime New Zealand-approved organisation to administer its SSM system. The Maritime Operator Safety System was introduced on 1 July 2014, about two months prior to this accident. On 1 July 2014 any vessel with a valid SSM certificate received a ‘deemed’ Maritime Transport Operator Certificate. At the time of the accident the Captain M. J. Souza held a valid deemed Maritime Transport Operator Certificate.
2. The Safe Ship Management documents provided extensive guidance on the safe working practices expected on board the ship, including working with various types of rope and twine and the breaking characteristics of synthetic ropes. All crewmembers were required to ensure that ropes were in good condition and had strength appropriate to their applications. Ropes were to be examined for abrasions and broken, deteriorated or displaced fibres.
3. Maritime rule Part 21 required an SSM organisation (an organisation approved by Maritime New Zealand to administer a vessel operator’s SSM system) to carry out an external audit of a ship prior to it gaining an SSM certificate. A subsequent external audit was required as part of the SSM certificate renewal process to ensure the vessel’s continued compliance with the requirements of the SSM code25. In addition to the external audit requirements, the Captain M. J. Souza was internally audited by the vessel’s shore managers when it berthed in New Zealand or American Samoa while discharging cargo.
4. The operator said that internal audits were conducted several times each year. An internal audit would normally consist of a ‘walk around’ the vessel and the subsequent compilation of a work list in consultation with the master and crew. The work list was actioned at the vessel’s next suitable port of call.
5. An internal audit is a good tool for measuring the effectiveness of safety management implementation on board a ship. However, to be effective an audit should be well documented, deficiencies should be clearly identified and corrective actions agreed, and progress should be monitored until deficiencies have been closed out.
6. However, the operator was unable to produce documents for the audits, such as findings and any safety actions taken as a result of the audits. Lack of audit documentation had been an observation made during the previous SSM renewal audit in 2012 by the organisation responsible for administering the vessel’s SSM system.
7. The Captain M. J. Souza was 35 years old at the time of the accident. There is evidence to suggest that the upkeep of the vessel was a matter of priority for the owners. For example, the SSM organisation was contracted by the owner to inspect the vessel annually, even though the SSM code only required surveys to be carried out twice in every five-year period.

8. The Safe Working Practices document, which was part of the ship’s SSM system, was regularly updated and covered vessel-specific activity. The following extracts contained in the Safe Working Practices document are relevant to this accident.

   Crewmembers should be familiar with the various types of ropes and twines and their special uses on board and in particular with the breaking characteristics of synthetic ropes.

   Crewmembers should always ensure that they use ropes only for the purpose for which they are intended. Care should be taken that all ropes in use are in good condition and have strength appropriate to their application.

   Ropes should be examined frequently for abrasions and broken, deteriorated or displaced fibres or strand and other defects.

   A splice should be used where possible in place of a knot, which weakens rope to a greater extent.

   During the handling of mooring lines or other wires or ropes, crewmembers should take care not to stand in a bight26.

   During the pursing operation, crewmembers should avoid standing in a position where they will be endangered should a wire break out from a sheave or roller for any reason.

9. However, contrary to the Safe Working Practices document:
   • There were no documents on board to confirm the origin of the choker line and sample rope, or how long these ropes had been on board.
   • The reported new sample of rope removed from the vessel was tested and found to break at an average breaking load of 22,993 kg, less than half of its expected breaking load of about 52,752 kg.
   • The choker line had broken a few weeks previously while in use. The failed rope was in poor condition and should have been replaced, but instead it was put back into service.
   • The broken splice at the end of the rope was replaced with a bowline knot.
   • The location on deck where the crew routinely stood to throw dye bombs into the water was within the swinging radius of the choker line, which could come under sudden tension in the event of the sling failing.
10. The operator’s Safe Working Practices document covered five topics that included safety on deck and safety in fishing operations. It described purse seining as a particularly dangerous method of fishing and outlined steps to reduce the risk of an accident. The document advised crew to avoid standing in positions where they would be endangered should a wire break out from a sheave or roller, and also to take care not to stand in the bight of a rope.
11. However, given the position from which the crew were required to stand and throw dye bombs into the water, this was practically unachievable (see Figure 4).
12. The Captain M. J. Souza had procedures and instructions for carrying out fishing operations safely, which included not standing in the vicinity of ropes. However, the instruction was generic and did not discuss vessel-specific risks, which in this case should have included the inherent risks faced by the person tasked with releasing dye bombs.
13. Since the accident the operator of the vessel has mitigated the risks by changing the location of the choker line. In doing so it has been moved away from the position where crewmembers would be expected to stand when releasing dye bombs into the water.

General

1. The Commission classifies safety actions by two types:

   (a) safety actions taken by the regulator or an operator to address safety issues identified by the Commission during an inquiry that would otherwise result in the Commission issuing a recommendation

   (b) safety actions taken by the regulator or an operator to address other safety issues that would not normally result in the Commission issuing a recommendation.

Safety actions addressing safety issues identified during an inquiry 

Safety action taken by the operator of the Captain M. J. Souza

1. Since the accident the operator of the Captain M. J. Souza has mitigated the risk of the choker line parting and striking crewmembers by removing the rope from its current location and attaching it closer to the net and away from the position where crewmembers would stand while releasing dye bombs into the water.
2. The operator of the Captain M. J. Souza has started a rope register to identify the various ropes on board the ship and log their usage. This safety action partially addresses the safety issue relating to the requirement for an appropriate rope management system on board the ship.
3. The operator has reported that it has increased oversight of the vessel at turnarounds.
4. The operator contracted a consultant to carry out a comprehensive safety systems audit and report findings to management.

5. The operator updated the on-board Hazard Register to include the following amended sections.

   It is necessary that gear be checked on a regular basis and that as far as possible, crewmembers remain out of the likely path of travel of breaking gear, referred to as the Snap Back Zone.

   Try and anticipate where the force will go if a rope or line breaks. This area is referred to as the ‘Snap Back Zone’ and crew should be aware of where these zones are during fishing and other operations. Normally a rope or line under tension snaps back with a corkscrew motion - so stay out of the direct line of pull. Never apply tension to a kinked wire or line. 

   Splices are much stronger than knots and should be properly matched to the lines or ropes with which they will be used. Listen for warning sounds that indicate excessive strain.

Safety actions addressing other safety issues

7. None identified.

1. The choker line broke, partly because it was in a deteriorated condition caused by extreme cyclic tension (fatigue) and some degree of abrasion, and partly because the bowline knot almost certainly caused a reduction in breaking strength.
2. The rope that was used to make the sling was reasonably new and in good condition. It is likely that the sling failed due to the splice coming apart in service, to a point where the strands ultimately parted under tensile load.
3. The rope management plan on board the Captain M. J. Souza was not effectively managing the purchase, storage, inspection and retirement from service of the ropes on board.
4. It is about as likely as not that the choker rope that broke on board the Captain M. J. Souza began its life in service at a lower-than-typical breaking load for a rope of that size and construction.
5. The safety management system on board the Captain M. J. Souza provided good guidelines for the management and use of ropes on board. However, neither the crew nor the skipper nor shore management were ensuring that the safety management system was being adequately followed.

General

1. The Commission may issue, or give notice of, recommendations to any person or organisation that it considers the most appropriate to address the identified safety issues, depending on whether these safety issues are applicable to a single operator only or to the wider transport sector. In this case, a recommendation has been issued to Talleys Group Limited, with notice of this recommendation given to Talleys Group Limited.
2. In the interests of transport safety, it is important that this recommendation is implemented without delay to help prevent similar accidents or incidents occurring in the future.

Recommendations

3. Despite internal audits being carried out several times each year, a damaged rope was reused and a bowline knot used to replace a broken splice. These were clear departures from the SSM system guidelines. Also, the instructions and guidelines available on the SSM system did not adequately address the issue of rope fatigue and the requirements for a retirement criterion and a usage log.

4. On 29 September 2016 the Commission recommended that the operator of the Captain M. J. Souza: review its internal auditing procedures to ensure that auditors make realistic assessments based on actual practices observed on board; and seek verification that documented procedures are being followed by the crew and they are appropriate for the task. Audit findings should be recorded together with any safety actions taken as a result of the audit. (020/16)

   On 20 October 2016, the Chief Executive Officer of Talleys Group Limited replied:

   Since August 2014 we have implemented a programme to improve the Health and Safety culture on this vessel. This started wit an internal review of our Health and Safety Systems (ashore and on board) governing the Capt M J Souza and following that review, we have taken several steps to improve Health and Safety outcomes which include:

   • Heightened oversight of the documented H & S procedures on the vessel at turnarounds by the vessel manager and operations manager including debriefing key staff on the vessel on H & S compliance and addressing any new hazards that may have been identified during the trip;

   • Implementation of a revised assurance process on the vessel and ashore to provide evidence to shore based management that Talley’s H&S protocols in fact being applied on board the vessel;

   • We have provided additional third party H & S training to the officers and crew of the vessel to ensure that they are aware of Talley’s health and safety procedures, the hazards associated with their tasks and that they are operating safely;

   • Addressed and improved communication structures between senior management and senior vessel staff;

   • Setting out company expectations regarding H & S aboard the vessel and the consequences of departure from these expectations;

5. Further, when the vessel returns to NZ after its current Pacific Season in December 2016, we have identified an independent Health and Safety expert who will take a trip on the vessel to audit its compliance and to report to management on the H&S culture on the vessel, their compliance with the Talley’s & S programme and thereafter, if appropriate to put in place an effective change management programme.

1. Tying a knot in a fibre rope will reduce its strength. It is therefore important to factor in this reduction in rope strength when selecting a knot and rope for a specific operation.
2. Fibre ropes can fail due to cyclic tension loading, a form of fatigue damage that can be difficult to see in braided ropes. Mariners must look beyond rope surface appearance alone when deciding whether to retire ropes from service.

1. On 25 August 2014 Maritime New Zealand reported a fatal accident on board the purse seine3 fishing vessel Captain M. J. Souza. The Transport Accident Investigation Commission (Commission) opened an inquiry under section 13(1) of the Transport Accident Investigation Commission Act 1990 and appointed an investigator in charge.
2. On 27 August 2014 two investigators from the Commission flew to Apia, Samoa, where the Captain M. J. Souza was berthed. In the next three days the investigators interviewed the crewmembers and gathered evidence.
3. A failed rope, a sample rope of similar construction and a sling were removed from the vessel for forensic testing. The Commission engaged Scrase Metallurgical Solutions (SMS) in association with Metallurgical and Industrial Consultants Limited to determine the failure mode of the ropes and sling. SMS subcontracted to Bridon Cookes, which operates one of New Zealand’s largest and most modern test beds, to conduct rope-related testing.
4. On 21 April 2015 the Commission obtained a new coil of rope from a known supplier of ropes to the Captain M. J. Souza, and engaged synthetic rope specialist, SWOS, based in the United States, to carry out tests to determine the rope’s breaking strength.
5. On 26 June 2015 an interview was conducted with the operator’s operations manager and evidence gathered in support of the investigation
6. On 23 June 2016 the Commission approved a draft report for circulation to interested persons. The Commission received and considered a substantive submission from the vessel’s owner Talleys Group Limited. Any changes as a result of that submission have been included in this final report.
7. The Commission approved the report for publication on 29 September 2016.