Gondola in free fall

The flotel which had lain alongside the B platform since its arrival on the field in 1981 was no longer needed. But that unit had also been used as an extra “lifeboat” as well as for accommodation. Before it could be removed, Mobil as operator was required by the government to establish a new evacuation system. It opted for a solution used by the British navy to transfer personnel between ships.

This involved shooting a line from the platform to a standby ship, which was then used to pull across a cable. A lifeboat-type gondola attached to the latter could then shuttle back and forth between installation and vessel. The unions were sceptical about this system. “Don’t take the flotel away from us, it’s the best lifeboat we’ve got,” the Norwegian Oil and Petrochemical Workers Union (Nopef) wrote in its membership magazine.

It took the view that the system was insufficiently secure and would take too long to evacuate personnel in a crisis. About 300 people could be taken off the platform in 10 minutes by crossing the bridge to the flotel. The gondola system would take an hour to achieve the same.

Mobil had joined forces with other partners to participate in developing and testing the new evacuation system. It maintained that, in the present position, helicopters were the only option for taking people off should an emergency arise during a hurricane. When the weather was very bad, the flotel had to be drawn away from the platform and could therefore not be used as a lifeboat. Flotels had never been intended to be a permanent fixture on Statfjord.

The rescue system was developed and tested. It was installed on Statfjord B and subjected to testing in all kinds of weather and conditions, both unoccupied and with people and cargo on board. Results from about 850 runs were good. However, the first trial operation after a final overhaul revealed a fault in the hydraulic system. The gondola failed to stop as intended at the receiving station on the topside. It struck the platform leg, jumped off the cable and fell into the sea, where it floated until being retrieved to the standby ship. Nobody was on board and nobody in the vicinity was injured.

The final test run was witnessed by representatives from Mobil, the Norwegian Petroleum Directorate (NPD) and Det Norske Veritas. After the accident, the Statfjord division resolved to abandon plans to use a gondola-based system. Contracts were cancelled with General Electric in the UK, which was developing the system, and with Brattvåg Hydraulic outside Ålesund, the intended manufacturer of the equipment under licence.

Sources:
Nopef-nytt , 1986.
Oral report from Oddbjørg V Greiner, former platform manager on Statfjord.