THE TRINITY II ACCIDENT

This narrative is developed from a US National Transport Safety Board report published on April 9th 2013, plus articles from the Australian press relating to the Mermaid Vigilance.

The Trinity II at work - from Marine Traffic.

PREAMBLE

The Trinity II accident might have passed under the radar of everyone outside the Gulf of Mexico, had it not been for the court case which had involved the Mermaid Marine vessel the Mermaid Vigilance, one of the ships hired by the survey company Geokinetics, and which was apparently assigned to act as a standby vessel in the worsening weather conditions as Hurricane Nate developed.

The Trinity II was a liftboat, one of two hired by Geokinetics to act as a collecting point for some seismic work being undertaken in the south of the Gulf of Campeche, some 15 miles from the coast in 84 feet of water. The process being carried out was for a number of chartered vessels to lay cables containing geophones on the seabed, and then for one of them to fire of an air gun. The resulting seismic information would be collected on board the liftboats. Geokinetics were working for PEMEX the Mexican state oil company.

The Trinity II was a small craft, capable of moving from place to place by means of its own propulsion, and then able to jack itself out of the water on its three legs. There were two legs at the bow and one at the stern, all 145 feet long. It had tankage for water and fuel in the hull, and a deck house on three levels which offered a navigation bridge, accommodation and recreation spaces for the four crew and six contractors who were employed by Geokinetics. The seismic activity was controlled from a container on the deck. Liftboats are much used in the Gulf of Mexico and in the Arabian Gulf for maintaining the small offshore platforms which are the predominant means of recovering hydrocarbons from beneath the seabed. The personnel on board consisted of four crew, the master, the mate, an AB and an ordinary seaman (All Americans). And six Geokinetics contractors, a day navigator (Bangladeshi), a night navigator (Australian), two quality controllers QC1 and QC2, a cook and a cleaner (All Mexicans).

The liftboat carried the following lifesaving equipment, three lifefloats which were buoyant ovals with netting in the middle, one rescue boat (Although listed in the report there is no further mention of this equipment), three lifebuoys, two 25 person liferafts and one EPIRB (Emergency Position Indicating Radio Beacon). The two liferafts were not part of the vessel’s original equipment, but were required to be installed by the US Coast Guard since the two liftboats were to go “foreign”, ie to the Mexican part of the Gulf of Mexico.

The US Coastguard had certified the Trinity II as an ‘offshore supply vessel with moveable legs capable of raising its hull above the surface of the sea”. Because of its limited size it was not required to conform with SOLAS, but the Coast Guard had made the following restrictions on its operation:

• Maximum operation water depth 100 ft.
• Maximum allowable draught 6 ft.
• Maximum wave height when afloat 5 ft.
• Vessel not to be trimmed by the bow at any time.
• Route: Oceans, limited to Gulf of Mexico not more than 12 hours from harbour of safe refuge or location where the vessel may elevate to survive 115 mph winds.

THE TIMELINE

The timeline for the event was as follows. All in 2011:

Late August 2011. The Trinity II is located about 15 miles North of Frontera in the Gulf of Campeche in 84 feet of water and starts work.

September 4th. The marine weather forecast indicated the possibility of a low pressure system forming nearby. The master and the navigator discussed the possibility of moving the vessel closer to the coast, but decided not to carry out the move due to the time involved.

September 5th. There is an increase in wind speed and sea state.

September 6th. The National Hurricane Centre (Located at Florida International University) reports that there is a 20 percent probability that the low pressure system close to Trinity II will deepen. The day navigator on the liftboat determines that the worsening weather will not affect operations.

1200. September 6th. The sea state has become such that the vessel can no longer be moved. Specifically it can not undertake the transit from the elevated to the afloat status. This is limited by US Coastguard instruction to be carried out in no more than 5 foot swells.

Evening. September 6th. The vessel is jacked up further from the sea surface three times. This now the only option for the crew apart from evacuation. The precise extent of the jacking operations were not recorded.

September 7th. NHC predicts that there is a 70% of 8-10 foot seas. There is now no chance of jacking down for at least a couple of days. The vice president of Trinity Liftboats calls the master to discuss the situation. The master also speaks with the president of Trinity and the Geokinetics project manager in Frontera. The project manager tells him that PEMEX can send a helicopter from Ciudad de Carmen to evacuate the crew if necessary.

On this day Geokinetics cease operations due to the weather and the vessels involved apart from the Mermaid Vigilance return to Frontera. The Mermaid Vigilance is instructed to stay in the area and act as a standby vessel “to assist if necessary”. This information conveyed to the Trinity II master.

PM. September 7th. The crew of the liftboat note that the windspeed has increased to more than 50 mph, and the NHC have determined that this is a tropical storm, named “Nate”. The stern leg is sinking deeper into the seabed, probably due to wave action on the underside of the hull.

Evening September 7th. The radio controller for Geokinetics asks that the three vessels still at sea, the Trinity I, the Trinity II and the Mermaid Vigilance report in every 15-20 minutes. The master is determined that it is time to evacuate the unit, and conveys this information to Geokinetics in Frontera. The master of the Mermaid Vigilance is requested to close up with the liftboat, but replies that he may be unable to do so, being unable to turn in the adverse weather.

Night September 7th. The master of the Mermaid Vigilance reports that he will be unable to assist the Trinity II. He says he will be unable to turn his vessel due to the sea state, the vessel has sustained storm damage and he has an injured crew member on board. He returns the vessel to port.

Early September 8th. The master of Trinity II gathers all personnel and discusses the possibility of abandoning ship. Also during this period of darkness in increasingly difficult weather conditions the master is in frequent contact with the president of Trinity liftboats by the satellite phone. They discuss the means by which additional air gap can be gained, but nothing is actually done.

Early Morning. September 8th. The Trinity II stern leg penetrates a further six feet into the seabed. The master attempts to level the hull by lowering it on the forward legs, but this action is unsuccessful. The vessel is stuck about 20 feet above the sea, and the hull is still being buffeted by waves. Discussion takes place between the president of Trinity Liftboats and the master, and the two consider the possibility of the stern legs breaking off. The president thinks that the result of this would be that the vessel would only gradually fall stern first into the sea and, according to the master, tells him to inflate one of the liferafts. The president later denies giving this instruction.

0600. September 8th. Geokinetics in Frontera receives another request that personnel be evacuated from the vessel. Geokinetics contact the PEMEX “Control Marino”, which monitors and directs all PEMEX chartered vessel movements in the Gulf of Campeche. Control Marino dispatches Isla del Toro and Bourbon Artabaze in the direction of the Trinity II. Their ETAs are 1400 and 1500 on 8th.

Morning September 8th. All personnel muster wearing lifejackets. They have collected food, bottles of water and the flares in preparation for abandonment. The AB and others are sent to inflate the starboard side liferaft. They place the container on the deck, tie the painter onto the handrail and inflate it. The high wind immediately carries it away, breaking the painter.

1225 September 8th. The stern leg breaks off after the impact of several large waves resulting in the stern descending towards the sea. The master orders abandon ship, and broadcasts a ‘Mayday” on the ship’s radio. The personnel grab their supplies and head for the main deck. As they approach the second liferaft a wave hits the mate and knocks him to the deck. The master returns to the bridge to recover the EPIRB, but is unable to do so due to the possibility of being hit by the crane.

A wave crashes into the port side liferaft canister, and it inflates on the deck. The crew push it over the side, but despite it being tied on to the rail by its painter, the wind and waves carry it away and it is soon out of sight. (The NHC determined that the wave height at the Trinity II location might have been as high as 36 feet.)

Two of the contractors return to the upper deck and recover one of the three lifefloats and pass it down to the people on the main deck. Shortly thereafter the hull is hit by several large waves, and the master, believing that capsize is probable, orders everyone to abandon. The cook wishes to retrieve a second lifefloat, but everyone else enters the water and he does not want to be left behind. None of the prepared supplies are taken although they do take extra lifejackets and a lifebuoy. The master has a waterproof radio which he loses as soon as he enters the water.

Overnight to 9th September. All 10 personnel cling to the lifefloat as it drifts in heavy seas and high winds. The ignite their chemical lights on the lifejackets.

Morning 9th September. They drift within about half a mile of a platform but the current changes and they drift away again. During the day they take turns at lying across the lifefloat two at a time. For unknown reasons the night navigator keeps untying himself and drifting away.

2330. 9th September. The night navigator becomes separated from the group and despite their efforts he disappears into the darkness.

10th September. The weather improves but the condition of the survivors begins to deteriorate. The day navigator is not making any sense when he speaks.

Evening 10th September. The Ordinary Seaman inexplicably removes his lifejacket and tries to jump out of the lifefloat. The others secure him to it, and check on him periodically. Later they find his face underwater, and their attempts to revive him are unsuccessful. They secure his body on the lifefloat.

Morning 11th September. They see a platform and the master, mate and AB decide to swim towards it, leaving the four weaker personnel still clinging to the raft.

Late morning 11th September. The mate begins hallucinating and sticking his head underwater. And later the AB thinks he sees and orange coloured vessel in the distance and so he and the QC1 decide to swim towards it. The vessel is the Bourbon Artabaze.

1145 September 11th. The Bourbon Artabaze spots the lifefloat still with the cook, the QC2, the day navigator and the cleaner alongside. They recover all four to the ship together with the body of the ordinary seaman.

1242 September 11th. The Bourbon Artabaze recovers the QC1 and the AB just under a mile from the lifefloat.

1500 September 11th. The Bourbon Artabaze recovers the body of the mate. At the same time the Spanish registered support vessel Arbol Grande arrives on scene and rescues the master.

All survivors are airlifted to the PEMEX hospital in Ciudad de Carmen. The day navigator later dies. A week after the accident the body of the night navigator is recovered.

Subsequent to the evacuation the remaining legs of the Trinity II break off and the vessel drifts for several days before being boarded by units of the Mexican Navy and towed back to Ciudad de Carmen. Its AIS system remained operational and this allowed it to be tracked.

THE INVESTIGATION

The report goes into some detail about the manner in which the investigation took place. After some initial problems during which the Mexican authorities refused permission for the team to carry out its task the NTSB team made several visits to Ciudad de Carmen and interviewed members of the Geokinetics team and well as visiting the Trinity II, which was lying alongside in Ciudad de Carmen, more than once. The also went to Lafayette and interviewed the remaining crew members of the vessel and the management of Trinity Liftboats.

The US Coast Guard were also involved and a Coast Guard SAR group went to Mexico City and attempted to interview the members of SEMAR (Secretaria de Marina – Mexican Navy). The NTSB team also requested permission to interview the SEMAR personnel in Ciudad de Carmen who had been involved, but the permission was not granted, and in the end the investigators had to be satisfied with a Powerpoint presentation relating to the processes involved and the equipment deployed. They also unsuccessfully attempted to interview the personnel who had been on duty from PEMEX Control Marino and CRAE (Centro Regional de Atencion and Emergencies – PEMEX emergency response operations centre). The report also goes on to state that the Coast Guard group in Mexico City had produced a report, but that the NTSB had been unable to have a copy of it, although they had been able to view it in Washington DC. This seems quite difficult to understand.

However, regardless of the information made available by the Mexican authorities, during the event there was almost constant interaction between them and the Coast Guard Eighth District who had been contacted soon after the abandonment by the Trinity Liftboats vice president. They offered assistance in the form of a C-130 aircraft, but the offer was refused. SEMAR stated that they had dispatched two 45 ft vessels towards the scene.

On 9th September the Coast Guard applied further pressure on SEMAR who responded with a list of assets deployed these were:

• One MI17 helicopter
• Two Panther Helicopters
• Two motor lifeboats
• Five Interceptor Patrol Vessels
• One fixed wing aircraft.

The Eighth District also received occasional screenshots of the SEMAR search patterns, and this allowed them to validate the process in general. And on September 11th they received permission to deploy the C-130. However about ten minutes after the aircraft had taken off the recovery of the lifefloat was announced.

In terms of cooperation with the investigation the report states:

As a result of the limited information available from Coast Guard SAR personnel, SEMAR, and PEMEX, the NTSB’s investigation of the Trinity II accident was hampered. Neither Coast Guard nor NTSB accident investigators were able to ascertain how the search was planned and coordinated, and how this may have affected the rescue of the Trinity II personnel.

The investigation considered hurricane planning on the part of both Geokinetics and Trinity. Both plans were phased, the phases relating to the approach of a hurricane from outside the area of operation, with the Geokinetics place requiring the complete evacuation of the offshore installations if the hurricane came within 250 kilometres of the location. It also identified ports of refuge for all vessels, but did not account for the time which it would take for the liftboats to get to safety. The Trinity plan also required the evacuation of its units if gale force winds were to be expected within 36 hours.

It is worth noting that the investigators found fault with the weather forecasting which always limited the risk of extreme weather and never forcast the wind strengths actually experienced at the Trinity II location. But in the end neither plan considered the possibility of a hurricane developing in the area of operations.

The Trinity II had a Marine Operations Manual which also contained heavy weather information, and in that manual phase 3 required the master to evacuate the unit in the event that it was in the direct line of the storm. In the end none of the emergency plans were put into operation.

Some of the conclusions of the investigating body were as follows:

• The master’s decision that all personnel on board the Trinity II abandon the vessel once the stern leg failed was understandable, given the context of the situation.
• The actions taken by the Trinity II crewmembers when abandoning the vessel were of limited effectiveness because the stressed and exhausted crew did not make use of all available safety equipment and supplies, and this reduced the personnel’s probability of survival.
• Had the Trinity II crewmembers brought along and activated the emergency position indicating radio beacon when the personnel abandoned the vessel, it would have aided the Mexican search and rescue effort and shortened the time the personnel had to spend in the water, thus increasing their probability of survival.
• The inappropriate decision to inflate the starboard-side liferaft on deck, and the inadvertent loss of the portside liferaft, led to the loss of both of the vessel’s available out-of-water flotation devices and the additional lifesaving supplies contained therein.
• The weather preparedness plans of Trinity Liftboats and Geokinetics in place at the time of the accident did not adequately address weather systems such as rapidly developing surface low pressure systems and nontropical storms, nor the operational limitations of each individual vessel.

The investigating team also made a number of recommendations directed to the US Coast Guard, the US Department of State, the Offshore marine Service Association, Trinity Liftboats and Geokinetics. They were all concerned with the following:

The need to improve co-operation between the US and Mexican authorities in the event of a marine accident, the requirement that proper guidance is provided for the deployment of ‘throw over’ liferafts, and that adverse weather planning take into account locally developing low pressure systems.

THE MEDIA INVOLVEMENT

In early 2012 the Australian press reported on the involvement of the Mermaid Vigilance in the Trinity II accident, probably because some of the families of those who lost their lives were suing everyone involved including the ship and its master. He was accused of abandoning the crew of the liftboat and more extremely “murder at sea”. One of the navigators was Australian, and Mermaid Marine is an Australian company. Mermaid made a statement in March 2012 that the master had made the difficult decision of not going to the aide of the Trinity II because his primary responsibility was to his passengers and crew, one of whom had been said to be injured during the event, and all of whom, were suffering from acute seasickness. Also that the equipment on the deck would have made the any intervention dangerous, starting with problems in turning the vessel.

Mermaid also stated that at no time did the Mermaid Vigilance receive a request from the Trinity II to go to its assistance, although it did receive repeated requests from Geokinetics onshore control.

Also, in 2012 the Australian Seven Network’s “Sunday Night” programme broadcast what it described as an ‘Explosive Investigation” broadly along the same lines that have already been described’. Mermaid Marine had provided the programme with a response but the presentation had ignored it. This resulted in a formal complaint by Mermaid being upheld by the Australian Federal Court in July 2014.

WITH THE ADVANTAGE OF HINDSIGHT

Oh dear, where to start. Those of us who have been involved in the development of processes designed to keep people safe offshore mostly concentrate on the means by which emergency events might be prevented, and then afterwards on the means by which the survival of the personnel in the event of the realization of the hazard can be achieved.

To start with the Trinity II and if it comes to that all its sister vessels, seem to be so small. Their ability to move from place to place is virtually limited to calm conditions and one would think that they would have problems preloading, which for those unfamiliar with the operation of jack-ups is the means by which the footings are tested. Four legged jack-ups can do this by raising all but one of their legs a bit and seeing if the loaded leg goes through the seabed. Three legged jack-ups usually pump a great deal of water into talks surrounding each leg in turn. This simulates extremely high winds impinging on the hull, and ensures that in extreme weather the footings will hold.

But we know now that the footing for the aft leg did not hold. This was as a result of the high winds and waves to which the vessel was subject. By then there was no possibility of jacking down and running for a safe haven. The Captain was extremely experienced, but up until the event might have only operated within the US administered area of the Gulf. Where there were two things different from the situation in Mexican waters. The first is that hurricanes seldom if ever (we might need to check on that) originate in the northern part of the Gulf, and the second thing is that everyone is supported by the virtually unlimited resources of the US Coast Guard.

So firstly should this vessel of very moderate capabilities have been sent into the Gulf of Campeche in the beginning of the hurricane season? Since Geokinetics have, subsequent to the accident, changed its operating process to replace liftboats with monohulls with four point moorings the answer is a resounding no.

Secondly could they have relied on the weather forecasting and their own meteorological skills to jack down and find a port of refuge before the unset of adverse weather? The quick answer if probably not, and we have no idea of what actually passed between the master and the management of Trinity Liftboats during the period before the emergency. Were the president and vice president of the company proffering advice? In which case what were their qualifications and experience such that this might be meaningful. The master seems to have consulted the day navigator about the weather on a number of occasions. What meteorological qualifications did he have? We don’t not know, but it is common practice for the personnel who look into the computer screens and manipulate the software during these sort of operations to be known as “navigators”. In any case it is almost certain, that due to the restrictions on the operation of the vessel, any opportunity to jack down and run for safety would be missed in a rapidly developing local weather system.

The fall back position in the event of extreme weather was considered in all the hurricane preparedness procedures to be evacuation of the unit, but this was never requested until the lives of those on the liftboat were in danger. In any case the standard means of evacuation was apparently by ship, with all the personnel except for the crane driver being lowered onto the deck of a vessel a few feet from the legs and then the unfortunate crane man shinning down a knotted rope, to be picked up from the sea. The Trinity II did not have a helideck, so the crew would have to be winched aboard a helicopter. Had this been considered as part of the routine evacuation for an approaching hurricane, or even as an emergency measure? We have no idea, but we do know that the Mexican navy had at least one helicopter with winching capabilities available because one was used to put people on the unit when it was floating about unattended. But maybe while we, in hindsight are aware that a tragedy was about to occur, the people who organized the operation thought “15 miles out – what can go wrong?”.

As the weather got worse Geokinetics took action to safeguard their fleet sending all back to port but asking the Mermaid Vigilance to remain at sea, either to act as a standby vessel at the Trinity II, or to stand by the Trinity II. It is likely that the owners would say that the it was the latter, since the requirements are different. And anyway how could the Mermaid Vigilance act as a standby vessel? It was not suitably equipped. And here is another unanswered question, what made the Geokinetics marine controller select the Mermaid Vigilance over the other vessels of their fleet. Was it the most suitable, or the largest or what? In any case, when it came to it, the ship was miles away from the liftboat, and the master felt that he would be unable to turn and get close to it without hazarding his ship and its crew. Hence the media interest in Australia. There is not much more to say about this, and a ship master must put his own ship and its crew first. However, we can assume that he did not really think he would be called to do anything, otherwise he might have refused when asked, and this would have given Geokinetics the opportunity of choosing an alternative.

One should bear in mind that the NTSB investigators were unable to interview any of PEMEX marine controllers or the SEMAR personnel who had been directly involved in the incident, and so the most important question remains unposed, and therefore unanswered. This is – why did PEMEX not arrange for a suitably equipped helicopter to fly out and recover the crew of the Trinity II by winching? There may be an answer, and this could be that the master had not broadcast a mayday message, and that therefore the situation could not be deemed to be critical.

So by now the scene was set for the major drama in this tragedy, and the errors made during the time up to the evacuation into the sea are obvious. These errors, mainly on the part of the master, were made, it is suggested by the investigators, by his extreme fatigue. The US Coast Guard made some recommendations to prevent such an occurrence again, particularly that the guidance for the operation of throw-over liferafts should be reinforced. But there is no doubt that the master’s most serious error was not to take the EPIRB with him. If he had the lifefloat and the ten personnel clinging to it, would have been found within hours.

One cannot help thinking that the antipathy between the American and the Mexican authorities did not provide the best opportunity for learning from the event. Some say that this is at least in part due to the fact that an American lawyer spirited the survivors away in his Learjet before the Mexican authorities had the opportunity of interviewing them. It also seems possible that all was not sweetness and light between the NTSB and the Coast Guard, illustrated by the fact that the Coast Guard were reluctant to share the information gained from SEMAR in Mexico City, and that the NTSB chose identify a previous recommendation which had been less than effective.

This related to the liftboat AVCO V which sank in 1989 while trying to return to port during Hurricane Chantal. 10 of the 14 personnel on board died. As a result the NTSB issued a safety recommendation to the Coast Guard. This said:

Require that liftboats have on board a severe weather action plan that is tailored to the operating characteristics and limitations of the vessel.

The Coast Guard issued regulations requiring heavy weather guidance to be included in liftboat operations manuals, in 1996. And there was indeed heavy weather guidance in the Trinity II Operations Manual, but it was of limited value to the master of the vessel since it dealt solely with an approaching hurricane, rather than a developing weather system at the location.

This narrative has required some interpretation from the original report, and also contains the views of the author, it therefore cannot have any legal standing. US legislation also precludes the admission into evidence of the report, or its use in any civil action for damages.

Victor Gibson September 2014

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