OSLO, Norway – The Petroleum Safety Authority (PSA) has concluded its investigation of an incident on the Gullfaks B platform this March, in which the boom of the pipehandling crane fell to the pipe deck.
PSA has identified several breaches of regulations.
While transferring materials from the pipe deck to the drill floor, the boom – weighing around 14.4 metric tons (15.9 tons) – dropped 10 m (33 ft) without warning to the pipe deck after a steel rope failed.
On the platform, the horizontal to vertical Eagle crane is used to lift drill pipe from a horizontal position on the pipe deck catwalk to a vertical position on the drill floor.
Two drill floor staff had adjusted the gripper on the crane’s gripper yoke down on the pipe deck immediately before the incident.
The incident caused material damage to the crane and to the cable tray for the traverse crane on this deck, as well as halting activity on Gullfaks B.
No personnel were injured, but under different circumstances, the incident could have caused serious personal injuries or loss of human life.
PSA said the direct cause of the boom falling to the pipe deck was fatigue in the steel rope, while the underlying cause was weaknesses in the design of the crane’s hoisting system, which led to wear and fatigue in the rope over time.
The investigation has identified several nonconformities from the regulations:
- Inadequate identification of risk of equipment
- Inadequate investigation and improvement measures following earlier incidents
- Insufficient use of mechanical handling expertise when specifying crane requirements
- Inadequate follow-up and checks when taking delivery of and operating machinery and equipment
- Deficiencies in the maintenance program for the steel rope.
PSA has asked Statoil to explain how it intends to deal with these nonconformities by Sept. 20.