STOCKHOLM -- Caught in a violent storm, 852 passengers died within minutes after winds ripped off the bow door of the ferry Estonia in 1994, sending icy water gushing through the car deck.
Yesterday, authorities sought clues after another ''roll-on, roll-off" ferry sank in the Red Sea with nearly 1,500 people aboard. The cause was unknown, but specialists said the vessel's design may have been a key factor.
The 35-year-old ferry, Al-Salaam Boccaccio 98, had a similar, but older, door construction to the Estonia, said Johan Franson, a safety specialist at the Swedish Maritime Administration.
''The basic problem with these ships is that if water enters the car deck, it makes the ship unstable and it can then capsize," he said.
Outdated designs and safety measures can quickly turn older ships into death traps.
David Osler, of Lloyds List, the London shipping paper, said ''it would only take a bit of water to get on board this ship and it would all be over."
''The percentage of this type of ferry involved in this type of disaster is huge," Osler said.
But new designs, which could keep stricken vessels afloat for up to 24 hours, could soon be manufactured.
Since the Estonia disaster in the Baltic Sea, Swedish and international specialists have come up with safety improvements aimed at drastically decreasing the risk of flooding.
Researchers at the Chalmers University of Technology in Goteborg and SSPA Sweden, a company focusing on maritime safety, are developing a ship with a double layer of walls that would give it extra buoyancy, said Claes Kallstrom, a SSPA safety specialist.
That would make a ship more resistant to tilting.
Anders Ulfvarson, a maritime technology specialist at Chalmers, said blueprints for the new model will be presented within months. A new fleet could be built within a few years, he said.
Such improved safety may not drastically reduce the number of ferry disasters, however, as most take place in poorer countries that often buy used ships from Western nations.