MAIB: Capsize and sinking of fishing vessel Joanna C – vessel stability

Early in the morning, in darkness and windy conditions, the crew of a scallop dredger was recovering the dredges, full of catch, back on board. As the gear emerged out of the water, the skipper realised that the starboard dredge bar was snagged on a potting line. At the same time, the vessel started to heel to starboard and rapidly capsized. The mate, who was on deck, was thrown into the sea, but the skipper and deckhand were initially trapped inside the floating, upturned hull. After about 40 minutes, the skipper managed to escape as the boat sank, but the deckhand remained trapped inside.

Only the skipper survived this accident. The deckhand was unable to escape from the upturned boat and his body was recovered from the wreck by divers the following day; the mate’s body washed up ashore sometime later.

The MAIB’s investigation found that through-life modifications, culminating in extensive alterations in 2019, had reduced Joanna C’s previously good stability to a state where she had very low reserves of positive stability and increased vulnerability to capsize. The detrimental effect of the modifications was unknown to the crew and regulator alike because, although a stability assessment had begun after the 2019 modifications, the analysis was never completed, and the vessel was free to continue operation.

The vessel’s life raft did not inflate during the accident because the uninflated life raft had insufficient buoyancy to initiate the inflation mechanism. The absence of a life raft adversely affected the survivability of the crew in the sea after the vessel sank.

Some of the lessons drawn from the MAIB’s safety flyer about this incident:

• Modifications will alter a vessel’s stability characteristics.
  • Post-accident analysis identified that multiple modifications over many years had eroded the fishing vessel’s stability condition from one of being very satisfactory, to that of failing the required criteria by a wide margin.
• Automatic lifesaving appliances need to be arranged so that they float free and aid survivors.
  • After Joanna C sank, the float free life raft was released from its cradle by the Hydrostatic Release Unit (HRU) but did not subsequently inflate.  The life raft did not inflate because it was a model intended for use in the leisure industry and was not manufactured to meet any design standard. At the time of this accident, the carriage of a liferaft that did not meet any industry standard was acceptable under the small fishing vessel regulations.