MV Derbyshire tragedy

The MV Derbyshire, a 91,655 gross tons bulk-carrier was was built in 1976 by Swan Hunter Shipyard, Teesside, for the shipping company Bibby Line. The vessel was registered at Liverpool and classified by LRS.

On 9 September 1980, during Typhoon Orchid, MV Derbyshire dissapeared off the south coast of Japan, with all hands on board (42 crew and two wives). She was, and remains, the largest UK ship ever to have been lost at sea.

The Report of the Formal Investigation (FI) held in 1987 first concluded that the loss of the MV Derbyshire had been due to a force majeure event, the vessel having probably been "overcome by the forces of nature in typhoon Orchid".

The wreck was eventually found in June 1994, during a search launched by the International Transport Workers' Federation and led by the American shipwreck hunter David Mearns. The search team were also able to deploy a ROV to survey the wreck and collect photographic evidence from the site.

Later on, using evidence from the underwater survey, the Investigation assessors purported - on the basis of a rope seen emerging from the Bosun’s store hatch opening and of an examination of the disposition of that hatch’s toggles - that the loss of MV Derbyshire had been caused by the negligence of the crew, who had allegedly failed to secure the hatch lid, which lead to fore end flooding and structural failure.

The discovery of the wreck prompted the British Government to re-open the Formal Investigation into the sinking of the vessel - investigation which began in April 2000. This time, the investigation reached the conclusion that the ship had sunk because of fore end flooding and structural failure, and as a result of inadequacies in the legislation in force at the time of build, and that the rope emerging from the Bosun’s store hatch opening was nothing more than post-casualty debris, thus absolving the crew of any responsibility for the tragedy.

The Investigation found that damage to the forward vents, hatches and equipment on the upper deck initiated the unfortunate sequence of events that led to the vessel's loss. Flooding of the vessel’s forward spaces through these damaged vents and hatches gave the vessel a trim by the bow, thereafter the main cargo hold hatch covers were subjected to seawater loading and collapsed – flooding number 1 hold first, then number 2 hold, then number 3, and so on until the vessel sank.

Several important questions, however, have remained unanswered:

1. The mushroom vents on the MV Derbyshire obviously failed. Were they therefore adequate?

2. The vessel had been issued with a Load Line certificate. But did the vents comply with the requirements of the Load Line Convention?

3. Did the construction and workmanship of these vents conform to the shipyard's or appropriate British standards?

4. Did the fillet welding on the windlass seat have adequate throat thickness and, was the workmanship satisfactory?

In due course, these questions and several others will finally be addressed.