Crane ship Sea Troll at Statfjord AStatfjord B contracts for NC

Fire in the shaft

person by Trude Meland, Norwegian Petroleum Museum
The fire alarms sounded constantly on Statfjord A during the hook-up stage, and in virtually every shift. False alarms were sometimes caused by hot work, but small blazes also broke out several times a month – generally started by sparks from welding or flame cutting.
— From the press conference a day or two (possibly March 1, 1978) after the fire in the shaft on the Statfjord A platform. The press conference was held at Lagårdsveien 78 Since Statoil had the press responsibility, the press conference was held at Lagårdsveien 78 (even though Mobil was the operator). Photo: Unknown/Norwegian Petroleum Museum
© Norsk Oljemuseum

These incidents were usually without major consequences, but things turned serious on 25 February 1978. A fire broke out in one of the Statfjord A shafts at 21.30. Welding was taking place, something was ignited and an explosive fire spread with great speed and intense heat.

The flames and the thick smoke were sucked up the shaft along the stairwells and around the open lift. Five people were killed. Two tried to escape in the lift, but it stopped before they reached the top. The question was how it could have happened.

This was the first major working accident on a Norwegian offshore platform. The police began an investigation the following morning together with representatives from the Norwegian Petroleum Directorate (NPD). At the request of the latter, Mobil also appointed a committee to investigate the incident.

The following sequence of events was established. The fire began in the platform’s utility shaft. This was split into 13 levels linked by a system of stairs and four lifts, none of which went all the way from top to bottom. Equipment was installed on the decks, and piping criss-crossed all the way up the shaft.

Located 50 metres above the seabed and 125 metres beneath the cellar deck, the 49.5-metre deck was the site of the fire. Four men were working to reinforce the steel foundations for ballast pumps to be installed there, while a fifth acted as the guard. He was in a control room on the 55.5-metre deck.[REMOVE]Fotnote: Nilsen, B., & Eggen, B. (1979). Det brutale oljeeventyret. Oslo: Oktober: 133.

Standing on a temporary scaffolding of wooden planks and plywood, the workers were engaged in flame cutting, grinding and welding. What actually happened remains unclear, since there were no surviving witnesses to the outbreak.

The 49.5-metre deck was the lowest in the actual shaft. Beneath it was a concrete cylinder called a minicell, which also contained two decks with various pumps and was encircled by an annular chamber filled with water.

On one side of the annulus was a sump tank – a steel cylinder open at the bottom where liquids from other levels accumulated. Before the fire, it was generally known that hydrocarbons floated on the surface of the annular chamber after at least two instances of contamination with waste diesel from the sump tank.

To prevent things which fell down and floated on the oil layer from being ignited during cutting or welding work, the surface was regularly doused with foam. A number of small fires had broken out in the days before the big blaze, involving gloves, rags and the like which had dropped into the annular chamber.[REMOVE]Fotnote: Stavanger Police Station archive. Investigated cases 1978. Case 872/78. National Archives in Stavanger.

A temporary control room installed on the 55-metre deck was to be staffed by an operator around the clock, in part to serve as a fire guard. Swift action was particularly important should a fire break out in the shaft. An extra fire guard was also supposed to be on duty during work which posed a risk of ignition.

Operator Mobil used various sub-contractors to carry out the different jobs required during the construction of Statfjord A. The main contractor for the work was Brownaker Offshore A/S. This company had engaged four of the accident victims, who came from various other companies. The fifth was employed by Mobil and served as the fire guard in the control room.

Jogger spotted the fire

Fifteen minutes before the fire started, a man came jogging down the stairs. The run up and down the 175-metre shaft was a popular form of exercise, and the jogger went past the workers and then back up again. He could later report that everything appeared to be normal.

On the way down for the second time, however, he encountered smoke at the 100-metre level – in other words, 50 metres above the work team. He continued down, but the smoke became too thick and he ran back up to report a possible fire. Finding a fire alarm on the 128.5-metre deck, he activated it. The time was 21.35. One minute later, at 21.36, a verbal notification was given over the public address system.[REMOVE]Fotnote: Nilsen, Bjørn, and Bernt Eggen. Det brutale oljeeventyret. Oslo 1979: 122.

Three minutes after the first fire alarm had sounded, another alarm was activated on the cellar deck (CD14) after somebody had spotted smoke. This turned out to originate from the fire in the shaft, and had spread through the vents. The fact that two alarms went almost simultaneously caused a good deal of confusion and hampered the initial response at the actual site of the blaze.[REMOVE]Fotnote: Stavanger Police Station archive. Investigated cases 1978. Case 872/78. National Archives in Stavanger.

Serious faults and deficiencies

Serious deficiencies in routines, fire alarms and fire extinguishing equipment were exposed after the event. Three firefighting teams totalling 12 people were supposed to be available on Statfjord A, but several of these were not notified in accordance with instructions. Two of the members were in their cabins and left undisturbed, while three were not on the platform at all. In addition, the fire chief, his deputy and two of the three fire teams went out to the CD14 area first before continuing to the shaft.

Nor did equipment accord with the procedures. Fire hoses on reels were in place, but a length of these was supposed to have been unreeled and readied for use while hot work was under way. This had not been done.

There were two hoses, for seawater and for an aqueous film forming foam (AFFF) solution respectively.[REMOVE]Fotnote: AFFF is a synthetic substance which, mixed with salt, fresh or brackish water forms a foam very well suited for extinguishing hydrocarbon fires. The latter had been closed off at the valve – probably because of a leak. Opening the valve would not have been difficult, but nobody did it.

Fire extinguishers had been positioned, but there were indications that they were empty. A halon extinguishing system installed on the 55-metre deck had not been activated.

When the firefighters descended the shaft, they encountered intense heat. It was not until 22.50 ¬– 75 minutes after the fire started – that the deluge and sprinkler system was activated. This operated on the 49.5-metre deck but not at the 55-metre level, where it had been disconnected. After the system had operated for about 20 minutes, the flames were largely extinguished and the firefighters could get down.[REMOVE]Fotnote: Stavanger Police Station archive. Investigated cases 1978. Case 872/78. National Archives in Stavanger.

The fire guard was found on the deck where the fire started, while two of the other dead were located in the lift. This had stopped between the 55-metre and 61-metre decks. The control room operator was found on the deck outside, while the last body was inside the room. All the victims were covered in soot, but none had been badly burnt.

Failures at several levels

Since the platform remained under construction, the permanent fire alarm system was under installation and inoperative. A temporary automatic warning system was in place and ready, but no detectors has been positioned on the 49.5-metre deck.

An alarm panel was placed in the temporary control room on the 55-metre deck, but alarms which should have been activated were disconnected before the work started. Welding fumes had previously activated the smoke detectors on the 55-metre deck.

Stavanger Aftenblad reported on 27 February that the fire was not registered by the advanced alarm systems on the platform. “During particular types of work in the shaft, some of the warning systems have to be switched off,” reported Jan Isaksen at Statoil. “That’s because these installations are activated by such operations as welding, and they’re turned off to avoid constant alarms.”[REMOVE]Fotnote: Stavanger Aftenblad, 27 February 1978. “Brannen oppdaget ved en tilfeldighet”.

Manual fire alarms were installed, but had not been activated. The alarm on the 49.5-metre deck was placed by the stairs, where the fire was at its most intense. That on the 55-metre deck was activated, but disconnection of the detector system meant it was not registered by the main control room.[REMOVE]Fotnote: Stavanger Police Station archive. Investigated cases 1978. Case 872/78. National Archives in Stavanger.

The platform management did not alert the joint rescue coordination centre (JRCC) at Sola outside Stavanger about the fire until it had been brought under control.[REMOVE]Fotnote: Nilsen, Bjørn, and Bernt Eggen. Det brutale oljeeventyret. Oslo 1979: 133. Mobil was sharply criticised for this failure. The operator claimed that reporting the fire at 23.50, almost two hours after the alarm was raised, was early enough because it was only than that an overview of the position had been established.

Mobil did not take account of the possibility that the fire could have developed into a major disaster. Had that happened, external emergency assistance would not have fully mobilised. The JRCC picked up reports of the fire itself via radio messages between Statfjord A and other platforms on the UK continental shelf.

Oslo daily VG reported on 25 February that “Police chief Oscar Wergeland Falk takes a very serious view of the fact that Mobil failed to notify the [JRCC] about the fire on the Statfjord platform.”[REMOVE]Fotnote: VG, 27 February 1978. “Mobil varslet ikke redningssentralen”.

Nobody knows for certain what happened in the shaft before and during the fire, but the commission of inquiry assumed that the acetylene hoses used during welding were damaged. That caused a leak with consequent ignition of the gas. The hose ends were directed at the surface of the annular chamber, and the acetylene flame ignited the diesel oil floating just under the wooden boards on which the workers were standing.

A very intense fire than developed, with dense smoke which covered the walls and objects in a thick coating of soot. The lift stopped because of soot deposition on the contacts. The heat was intense where the flames were strongest, but none of the five victims suffered serious burns. They were killed by a combination of carbon dioxide poisoning and lack of oxygen.[REMOVE]Fotnote: Stavanger Police Station archive. Investigated cases 1978. Case 872/78. National Archives in Stavanger.

First application of the WEA

The Norwegian director general of public prosecutions resolved on 24 April 1979 that “oil company Mobil Exploration Norway Inc (Mobil) would be fined for breaches of the Act on Worker Protection and the Working Environment, etc, of 5 February 1977 (the Working Environment Act)”.

Underlying this decision was a finding that the operator’s management of the work did not comply with the intentions and provisions of the Working Environment Act (WEA), and was therefore a contributory cause of the accident. Mobil as operator had principal responsibility for safety on Statfjord A. No penalties were imposed on any individuals or on Brownaker.

This was the first time a company had been penalised for breaching the WEA, which came into force in 1977. A new element in this statute was that the public prosecutor merely had to establish that an objective responsibility existed, and did not need to prove a breach of the law by an individual in order to penalise a company.

Mobil was sentenced for breaching section 8, sub-section 1, and section 14, sub-section i, and fined NOK 1 million as operator. This ranked as the biggest fine imposed in Norway until that time.

The company was found to have contravened the requirement to provide a safe workplace for employees and to have been negligent in providing employees with information about and instructions on particular hazards associated with work in the utility shaft.[REMOVE]Fotnote: Bergens Tidende, 27 April 1979. “Enkelt-personer ikke ansvarlig”.

Working Environment Act of 1977
Section 8. The workplace

1. The workplace shall be arranged in such a manner that the working environment is fully satisfactory with regard to the employees’ safety, health and welfare.

g) that the threat of fire and explosion is prevented, and that adequate escape routes are provided in the event of fire, explosion or other accidents.

Section 14. Employer’s obligations
i) ensure that employees are informed of accident risks and health hazards that may be connected with the work, and that they receive the necessary training, practice and instruction.

Mobil took time to decide its response to the fine. The company’s top management in New York found it unacceptable that the company as a whole had been penalised, rather than individuals. The argument was that, with more than 100 people on board and many sub-contractors, it would be impossible in practice for an operator to know whether the regulations were being observed. The company had to be able to rely on individuals.[REMOVE]Fotnote: Arbeiderbladet, 30 April 1979. “Jurister skal vurdere boten til Mobil”.

After several postponements, Mobil Exploration Norway nevertheless recommended that the top management in the USA should pay the fine. It was finally accepted with reservations on 8 June 1979:

“Mobil Exploration Norway has now informed the public prosecutor for Rogaland, G Fr Rieber-Mohn, that the company accepts the fine of NOK 1 million with reservations and without admitting legal culpability … Mobil has chosen to accept the fine because the company believes that it will benefit progress with the Statfjord development that the company now concentrates on future operations.”[REMOVE]Fotnote: Stavanger Aftenblad, 9 June 1979. “Mobil vedtok boten uten å føle skyld”.

The company also resolved to pay the fine itself, and not to divide it between the other licensees.

Mobil made ex gratia compensation payments in 1980 to two of the widows, with one and two children respectively, who had lost their breadwinner in the fire. Each was paid more than NOK 500 000 in compensation by the company and the insurers.

In addition, the relatives of another victim received NOK 10 000 in compensation from Mobil. All three of those compensated were members of the Norwegian Confederation of Trade Unions (LO), which pursued the compensation claims on behalf of the relatives.[REMOVE]Fotnote: Stavanger Aftenblad, 18 February 1980. “Mobil gir erstatning”. The families of the last two deceased received nothing.

Crane ship Sea Troll at Statfjord AStatfjord B contracts for NC
Published November 14, 2019   •   Updated December 5, 2019
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