Failure of automatic release hook during fast rescue craft deployment from royal fleet auxilliary vessel Mounts Bay

Location: Lyme Bay, England.

Completed PE Summary: Mounts Bay

A short summary of the accident and action taken:

Merchant Vessel/Accident Details
Vessel Name Mounts Bay
Registered Owner/Manager UK Government, Commodore RFA
Port of Registry London
Flag UK
Type Landing Ship Dock (auxiliary)
Built 2004
Classification Society Lloyds Register
Construction Steel
Length Overall 176m
Gross Tonnage 23569
Date/Time 08/02/2007, 0937 (UTC)
Location of Incident 5050º 34’N 3º 16’W
Incident Type Machinery failure
Persons Onboard 2 onboard the fast rescue craft
Injuries/Fatalities None
Damage/Pollution None


At 0937 UTC on 8 February 2007 the Royal Fleet Auxilliary Vessel (RFA) Mounts Bay deployed the port Fast Rescue Craft (FRC) for training in Lyme Bay on the South Coast of the UK. The wind was Westerly Force 5 with a moderate WSW’ly swell. The two man crew of the Pacific 22 MkII FRC were expelled from the boat as the boat was lowered into the water with a ship’s speed of 7.5 Knots.

During the launch the RFC Automatic Release Hook (ARH) did not release as the weight came off the fall wire and, as the crew released the painter and applied power to the fast jet boat engine, they did not check that the ARH had released.

Restrained by the fall wire, the FRC listed to starboard and the crew jumped from the boat. The two men, wearing immersion suits, were recovered on board by the second FRC after 10 minutes. They were transferred to the ship’s hospital cold but uninjured.

When the Port FRC was recovered the ARH could not be released from the boat by cocking the hook in the usual way and the hook was forced apart to replace the ARH. The manufacturer’s inspection of the ARH stated that the failure appeared to be due to the build up of sea salt contamination internally and externally causing the mechanism to lock and not release properly.

Action taken

The Chief Inspector has written to the Chief of Defence Materiel, the Commander-in-Chief Fleet, and the Technical Director, recommending that they undertake an urgent review of FRC operations, with particular emphasis on the Bay Class RFAs.

Published 23 January 2015