The M/V Estonia sank in the Baltic 1994. 852 persons drowned or which 502 were Swedes. It was the biggest accident in North Europe since the second world war. Evidently the accident was investigated by the authorities. It took them three years and three months.
The official cause of accident was that a bow door in the superstructure 2.5 meter above waterline was ripped open due to big waves. How then the ferry actually sank was not explained 1997. This lack of information disturbed survivors and relatives of victims. In 2005 the Swedish government decided that the outstanding question ‘how did the ferry sink?’ should finally be clarified by scientific research. Two consortia were given the task.
The SSPA consortia consisted of Swedes, Scotsmen and Dutchmen and was given $ 1 million. The German HSVA consortia was given $ 400,000. In 2008 the results were ready.
The SSPA consortia explained that when the bow door was ripped open, 2 000 tons/minute of water entered the superstructure and the ferry heeled 47 degrees in less than three minutes. Then the ship floated on the deck house for 20 minutes, then it capsized and floated upside down and then it sank during 20 minutes with stern first. Both model tests and computer simulations showed this. In the model tests SSPA had to release air from the hull via two valves, otherwise the ship would not sink. In computer simulations the air in the was apparently slowly compressed during 20 minutes, so that water could flow up into the hull and reduce buoyancy causing sinking. How this phenomenon actually took place, SSPA could not really explain. Capsized vessels floating upside down normally do not sink.
The HSVA consortia produced a completely different scenario. Much less water entered the superstructure according the HSVA research and the vessel suddenly heeled >30 degrees but then the heel was reduced to 40 degrees after about 30 minutes, and then ventilation openings in the side 8 meters above waterline were submerged and the hull was flooded. Thus the ship sank without capsizing. If the ventilation openings actually existed and were open, HSVA could not confirm. They must have been there, otherwise the ship would not sink.
In October 2008 the Swedish government announced in the Parliament that both consortia had confirmed the official cause of accident and had explained the sinking and that the case was finally closed. The research had provided valuable information to improve safety at sea.
However, the case is still not closed. In Estonia the investigation goes on led by chief prosecutor Margus Kurm. Crew members have told a completely different story to him. The vessel was leaking below waterline, the crew was standing to their knees in water in the engine room below waterline. They started bilge pumps to pump the engine room dry. As soon as the ferry heeled, they escaped to open deck to survive. The Kurm report is awaited early 2009. Maybe there will more scientific research to explain the sinking?