MAIB has completed its preliminary investigation into the fall of an FRB from the Viking Discovery in December 2007:
The crew of Viking Discovery were carrying out a regular launching drill of the Fast Rescue Craft (FRC), when it dropped approximately 30 feet into the water, injuring the boat’s three crew. Weather conditions were good at the time, with little wind and a slight swell. The three injured men were taken ashore by helicopter, where one man was found to have broken the bones in both feet, requiring reconstructive surgery. Injuries to the other two men were slight.
The ship was new, and during previous drills carried out on board the crew had noticed that the steel ring at the end of the fall, used to attach the boat for lifting, was at the same height as the boat coxswain’s head when the quick release hook was released. To overcome the danger of the coxswain or other crewmen being hit by the ring, a tripping rope was attached to the ring so that it could be pulled up to deck level once the boat was released.
The davit in use was a “Caley” type, and the fall led through a docking head to the boat. In the boat, the lifting hook equipment included a cruciform arrangement, designed to mate with the docking head on the davit to securely hold the boat in position as the davit was topped and lowered. With the boat in the stowed position, the tripping rope led through the docking head and cruciform arrangement.
The onboard standard procedure was to cock the release hook with the boat still docked in the davit, and then begin lowering. The boat would then enter the water, the hook would release, and the ring would be pulled clear. However, on this occasion the tripping rope had jammed between the cruciform arrangement and the jaws of the docking head. The hook was cocked for off-load release, and lowering commenced. The jam in the docking head stopped the boat from moving immediately, reducing tension in the fall. This tension reduction was sensed by the hook, and it consequently released. The only support for the boat was now the rope jam, which then released and the boat fell.
- On the day of the accident, the owner published a safety alert advising that when launching boats, the hook should not be cocked until the boat is approximately 1m from the water.
- The hook manufacturer intends to amend its operating instructions to the effect that the hook should be cocked only when the boat is close to the water.
- The Chief Inspector of Marine Accidents has written to the owner of Viking Discovery to endorse this practice of not cocking the release hook until the boat is close to the water, and strongly advising a reassessment of other options for keeping the lifting ring clear of the boat when the hook is released. He has also written to the hook manufacturer to endorse the change intended to be made to its standard operating instructions and to encourage this practice to be passed to other manufacturers.