FEATURES
 

DEEPWATER HORIZON

Deepwater Horizon - What Have we Done to Deserve This
Deepwater Horizon - After the BP Report
Deepwater Horizon - The Investigation
The Deepwater Horizon and the Late MMS.
The Deepwater Horizon - PR and Politics
The Deepwater Horizon - Forces at Work
The Deepwater Horizon - Where Are We Now?
ROVs, Risers and Mud
The Deepwater Horizon - Later
Something about the Deepwater Horizon Accident
Channelling the Oil Leak
Preventing Fires and Explosions on Offshore Installations

OTHER ACCIDENTS
The Costa Concordia Grounding
The Loss of the Normand Rough
The Bourbon Dolphin Accident
The Loss of the Stevns Power
Another Marine Disaster
Something About the P36
The Cormorant Alpha Accident
The Loss of the Ocean Express

OPERATIONS

The Life of the Oil Mariner
Offshore Technology and the Kursk
The Sovereign Explorer and the Black Marlin
 

SAFETY
The ALARP Demonstration
PFEER, DCR and Verification
PFEER and the Dacon Scoop
Human Error and Heavy Weather Damage
Lifeboats & Offshore Installations
More about PFEER
The Offshore Safety Regime - Fit for the Next Decade
The Safety Case and its Future
Jigsaw
Collision Risk Management
Shuttle Tanker Collisions
A Good Prospect of Recovery

TECHNICAL

The History of the UT 704
The Peterhead Connection
Goodbye Kiss
Uses for New Ships
Supporting Deepwater Drilling
Jack-up Moving - An Overview
Seismic Surveying
Breaking the Ice
Tank Cleaning and the Environment
More about Mud Tank Cleaning
Datatrac
Tank Cleaning in 2004
Glossary of Terms

CREATIVE WRITING

An Unusual Investigation
Gaia and Oil Pollution
The True Price of Oil
Icebergs and Anchor-Handlers
Atlantic SOS
The Greatest Influence
How It Used to Be
Homemade Pizza
Goodbye Far Turbot
The Ship Manager
Running Aground
A Cook's Tale
Navigating the Channel
The Captain's Letter

GENERAL INTEREST

The Sealaunch Project
Ghost Ships of Hartlepool
Beam Him Up Scotty
Q790
The Bilbao OSV Conference

THE LOSS OF THE OCEAN EXPRESS (Extract from "Supply Ship Operations 2008")

On 15th April 1976 the mobile drilling unit Ocean Express sank in 167 feet of water in the Gulf of Mexico while under tow. Almost all the crew evacuated from the unit in two Whittaker capsules moments before it disappeared beneath the waves. Subsequently one of the capsules capsized and sank with the loss of 13 lives. In hindsight it appears that the findings of the court of enquiry were extraordinarily predictive, but despite them the tragedy set a pattern which was to be repeated on many occasions in subsequent years. The only lesson learnt has been that these objects, which are normally elevated on stilts above the waves, become unacceptably vulnerable when afloat, and that therefore when things go wrong the best thing to do is to call for help. A number of vessels were involved in both the disaster and the recovery of survivors, principally the three tugs owned by the Gulf Mississippi Marine Corp.

The tugs were all about 100 feet long, and ranged in power from the Gulf Explorer at 3600 bhp to the Gulf Knight at 2400 bhp. The third tug was the Gulf Viking. A survey vessel, the Nicole Martin rescued survivors from the sea. Also briefly involved was the supply vessel M L Levy which was used to transport six offshore workers to the rig when it was under way, in readiness, one assumes, for the next job. Four of the six were to lose their lives when the survival capsule, in which they had evacuated from the rig, capsized.

The Ocean Express was owned by Odeco, a name which is to appear again in this chapter, and the rig move was carried out more or less under the control of an Odeco barge-mover. Also involved in the management of the unit was a Marathon Oil company representative and the tool-pusher for Odeco, who had been in charge of the rig when it was jacked up on the previous well and was to be in charge again when it reached its new location, which was only 33 miles away.

The Ocean Express was a mat supported unit. It was designed to operate on the level soft mud of which much of the seabed of the Gulf of Mexico is composed. When in its drilling position the mat, a rectangular structure with a slot in the after part, which mirrored the slot in the hull of the rig itself, was lowered to the seabed on the three tubular legs. When the mat was on the bottom, the hull could be elevated above the sea surface, and in this position drilling could be carried out.

The mat was of cellular construction, composed partly from tanks which were filled with water, and partly from tanks which remained buoyant. Since the mat contributed to the buoyancy when mated with the hull, as it was lowered towards the seabed, the stability of the unit would be reduced.

On the morning of 14th April 1976 the hull was lowered into the water and the mat recovered until it became essentially part of the hull. The most powerful tug, the Gulf Explorer was designated as lead tug. The rig was rectangular and the points where the towing gear was attached forward were small triangular areas on the port and starboard sides, approached through doors from the deck structures. The Gulf Viking and the Gulf Knight were attached to the towing point on the port bow and the Gulf Explorer to the towing point on the starboard bow, and in this configuration the 33-mile tow was accomplished.

About one mile from the new location, at about 2300 on 14th, the Gulf Knight was relocated from the starboard bow to the port quarter and the Gulf Explorer from the starboard bow to the starboard quarter. The Gulf Viking remained on the port bow. The rig was now positioned with the stern towards the location but was being held bow to the weather by the Gulf Viking, and in this position the mat was lowered until it was 148 feet below the hull.

During the lowering operation the weather had deteriorated and so the relocation was not completed. Instead the rig was held in position by the ships. At 0630 on the following morning the seas had increased in height to 10 to 12 feet and the wind was correspondingly stronger. Obviously there was no alarm at this point because the supply vessel M. L .Levy arrived and discharged the six Offshore Hammer employees by personnel basket. One assumes that at that time it was still dark, and almost certainly the rig was pitching and rolling and moving randomly in the seaway. It must have therefore taken considerable bravery and skill on behalf of both the Ocean Express crane driver and the M. L. Levy captain to accomplish the task, although, in view of how things were to turn out, it would have been better if they had been unsuccessful.

Mid-morning on 15th the weather was really getting up. Spray was blowing across the deck of the rig and seas were occasionally boarding. There had been concerns about the freeboard of the unit, which should have been between seven and eight feet, but the rig had a natural list to port which required counter-flooding, and the derrick was not positioned as far forward as was possible so ballasting forward had probably taken place, reducing the freeboard to as little and five and a half feet. At this time the barge-mover instructed the tugs on the aft corners to head forward to hold the rig on location. Some water was entering the through apertures in the deck, and uncomfortably for those in the accommodation, this resulted in leaks into the living quarters through the light fittings. Other spaces on the rig were also filling up, particularly the mud pits.

If one accepted that water dripping out of the light fittings is more or less normal, the first sign that things were seriously going wrong was the loss of one of the engines of the Gulf Knight. The barge-mover asked the ship if it wanted to recover its tow wire and return to port, but the Master opted to remain attached and to continue to hold the rig up to the weather. At this moment the tugs on the port and starboard quarters were steaming in the same direction as the rig was facing, the tow wires angled outwards from the sides.

Despite the optimism of the Gulf Knight’s master, he was unable to hold the ship head to wind with only one engine and he dropped back until he became part of the tow rather than one of the ships doing the towing. The Gulf Viking was now talking the weight on the port bow, with the most powerful tug, the Gulf Explorer doing what it could to assist from the starboard quarter.

The weather continued to get worse so that there was no question of the mat being put on the bottom. By late afternoon the tugs and tow were experiencing wave height of up to 25 feet and wind speeds of up to 50 knots, far in excess of the relatively benign conditions which would be required to land the mat and elevate the rig.

At 1930 the tow line of the Gulf Viking parted, and although the Gulf Explorer was still attached, the rig wallowed in the seaway while the deck crew attempted to re-attach the tow line. The break had occurred in the towing spring, and the three men on the tiny deck area found it impossible to recover the heavy nylon. The seas which kept swamping the space knocked the men down, and flooded the Welder’s Shop from which access to the area was gained, and eventually they gave up the unequal struggle and retreated. Shortly thereafter some of the pipe on the deck shifted, causing the rig to list, and efforts to re-secure it were soon abandoned due the danger to the crew.

At this time some-one sounded the general alarm without instruction from the person in charge, who was, depending on one’s viewpoint, either the barge-mover, the toolpusher or the Marathon company man. The barge-mover also asked the tool-pusher to drop the anchor but this was not done, so the rig continued to be at the mercy of the weather, the deck being under water for most of the time, the pipe on the main deck rolling from side to side and various compartments gradually filling up. After the sounding of the alarm most of the crew gathered on the upper deck wearing their lifejackets and waited for instructions.

At about 2115 the derrick shifted to starboard, increasing the starboard list, and immediately the toolpusher gave the instruction to abandon the rig using the Whittaker capsules on the starboard side. The capsule on the port side had already been washed away. The two capsules got away from the rig, leaving the barge-mover on board. He gave the Gulf Explorer and the Gulf Knight instructions to release their tow lines and was rescued by helicopter from the helideck at about 2120. Very soon afterwards the rig, continuing the list over to starboard, disappeared beneath the waves. 

Surprisingly, as the emergency developed during the early evening the M. L. Levy was lying at anchor, and after the crew had eaten supper they got under way. This was at about 1900. At this time they were told that the port capsule from the rig had been washed overboard and they were instructed to keep an eye on it. When the coastguard cutter Point Baker asked for the position of the stricken rig, the Captain of the M. L. Levy provided it.

Whittaker capsules were, and still are more or less circular lifeboats whose principal advantage is the ease of launching. The makers also claim that they are easy to manoeuvre due to their shape. Inside there are seats around the periphery and seats around the centre so the majority of the people are seated facing inwards from the outside, and a small number face outwards from the centre. Each of the capsules on the Ocean Express had a capacity of 28 and once inside it was necessary for the passenger to do up seat belts for stability purposes.

 There were 14 men in No 1 capsule, which motored away from the location, lookouts keeping an eye out for lights, but after a while those inside were assailed by paint fumes as the engine overheated, or appeared to. And during a period of stopping and starting the engine the capsule landed heavily against the side of the survey vessel Nicole Martin. This capsule was tied on to the survey ship by light lines from various points and despite the extremely rough weather, which resulted in the capsule landing heavily against the ship at times and in variations in height of up to ten feet, all the survivors in the capsule were successfully transferred to the survey ship.

There were problems releasing No 3 capsule from the falls, but eventually it got away from the side of the rig and motored downwind until the smell of paint and hot exhaust began to nauseate the crew. After about twenty minutes the Gulf Viking closed with the capsule and over time, with some difficulty, ropes were attached. However there was considerable vertical motion between the vessels and in a confused exchange between the survivors in the capsule and the crew on deck it was decided that the tug would tow the capsule to calmer waters. One of the ropes was released and unavoidably the second rope gradually slid through the fingers of the one crewman who was trying to hold on to it, until finally it disappeared over the stern. At the time when the capsule was alongside several people released their seat belts, and shortly after the line was lost the capsule flipped over.

After this the tug backed up to the capsule and efforts were made to right it. These were unsuccessful and it appears that the efforts made by the tug’s crew increased the rate at which the water was entering the inverted capsule. At any rate, after some minutes the confusion in the capsule resulted in some of the survivors being propelled through the doors which up to that time had been held shut by two men. The Captain of the Gulf Viking radioed for assistance and the Gulf Knight responded, picking the last two survivors from the sea.  The remaining thirteen men were drowned.

A late participant in this drama was the aircraft carrier the USS Lexington, which arrived on the location at about 0230 on 16th, in time to assist with the recovery of the capsules.

The board of enquiry found much wrong with the manner in which the rig had been operated, both in general and on that particular occasion, aspects singled out for mention being the difficulties of making the tow fast on the tiny triangular decks, and the lack of information contained in the stability book. There was also considerable discussion as to what constituted a “field move” and what might constitute a “short move”, which would be amusing but for the tragedy which resulted from the confusion created by such distinctions. The board had something to say about the qualifications of the tug’s personnel, suggesting that offshore tugs should be subject to the same regulations as other vessels of a similar type, and that the chosen language to be used at such time should be English – the Louisiana tug crews tended to speak French. In all, this disaster should have resulted in changes which would in the future make the moving of jack-ups safer, whether it did or not remains debatable.

Victor Gibson. October 2008.

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