The Sea Empress was a single-hull tanker completed in Spain in 1993 , which wrecked the coast of south-west Wales in 1996 and caused widespread heavy oil pollution .
Course of the accident
On February 15, 1996, the Sea Empress , fully loaded with 130,018 t of crude oil , was coming across the English Channel from the North Sea oil terminal Hound Point in the Firth of Forth , on its way to the refinery site in Milford Haven in Wales. At 8:07 p.m. Western European time , the ship ran on rocks south of Dale immediately in front of the port entrance, the mouth of the Daugleddau , due to a mistake by the pilot . The hull was torn open over almost its entire length, three of the 14 cargo tanks as well as the two empty starboard ballast tanks and the pump room were damaged. The ship came to a standstill on the opposite side of the fairway with a list of 18 ° and a flooded forecastle. During the night it was possible to reduce the list to 10 ° and to tow the ship free again by partially flooding the port ballast tanks with water from the starboard tanks without pumping. The increased draft would have required a barge to bring the ship further into port. On the afternoon of February 16, work began on emptying the five-meter-high flooded pump room with mobile pumps. Because the weather was beginning to worsen, the ship was turned seaward with the bow at high tide on the afternoon of February 17, as the heavy weather could be weathered more easily and the lightening would have been possible. During this maneuver, the ship was moved seaward at the same time, so that without the knowledge of those involved in the rescue, including the pilot still on site, it was in the area of a strong tidal current running across the fairway. When the tide set in, the tugs could no longer hold the ship and it ran aground again around 6 p.m.
Cleaning an inaccessible beach near the scene of the accident, West Angle Bay
As a result, numerous attempts at towing with an increasing number of tugs failed in sometimes stormy weather. The Sea Empress ran aground several times on both sides of the fairway, with additional tanks being damaged and the existing damage being increased. In the end, the pump room could no longer be emptied, which finally prevented lightening at sea. Only with twelve tugs was it possible on February 21st to tow the ship, whose tanks had previously been partially emptied with compressed air or inert gas , accepting further release of oil, to the unused Herbrandston jetty in the port, where it was finally emptied by March 2nd has been. On March 27, the tanker was towed to a dry dock in Belfast for repairs.
71,800 t of crude oil had leaked from the damaged vessel. The ship also lost 480 t of heavy fuel oil. The tidal current transported the releases far into the natural harbor and along the coast. Dispersants have been used on a large scale to combat oil . The surrounding coast was nevertheless over 200 km, mainly located in the Pembrokeshire Coast National Park, with an estimated 3,000 to 5,000 tons of oil. The interior of the natural harbor up to the Cleddau Bridge above Pembroke Dock and the east coast to the Pendine Sands east of Pendine in Carmarthen Bay were most affected . But pollution also occurred westward to the island of Skomer and a little into St. Brides Bay .
Milford Haven Port Authority: Passage Plan (map of the port entrance, scene of the accident marked with Mid Channel Rocks , oil terminal with Chevron , Herbrandston Landing Bridge with South Hook Jetty )
