The military began work on Sunday to salvage the sunken corvette Cheonan after family of the missing sailors requested that search operations be halted to prevent further casualties among divers as the likelihood of finding any survivors disappeared.
Civilian companies will be tasked with salvaging the sunken ship, which was split in half due to an unexplained explosion on March 26. A crane will drop four anchors and chains will be wrapped around the pieces of the hull to pull them to the surface. The hulls will be emptied of water and placed on a barge to look for bodies inside. Then the pieces will be transported to Pyeongtaek base.
The center of the hull's mass must be pinpointed in order to lift it up without tilting. Then a water jet is used to dig a tunnel under the surface of the ocean through which a 90 mm chain will pass to be wrapped around the hull. The chains will then be connected together by wires and tied to the crane. If all goes smoothly, the entire process will take 15 to 20 hours, but bad weather could mean indefinite delays.
Lee Chung-kwan of 88 Underwater Development, one of the civilian contractors, said, "We could be done with everything in five days if the weather allows us to work four hours a day, but it could take months if weather conditions are bad. Fast currents, high waves, low temperatures and low visibility underwater could make work difficult."
The military is keen to prevent leakage of oil from the sections of the ship during the salvage operation. Seven tanks in the Cheonan are filled with 136,000 liters of fuel. Authorities plan to set up a barrier to prevent oil from spreading in case of a leak and deploy ships capable of mopping it up.
The military also believes that guided missiles, torpedoes and depth charges that were stored on the ship's deck have been lost. Mine sweeping vessels and a ship operated by the Korea Ocean Research and Development Institute, equipped with high-tech sonars have already been deployed to take three-dimensional pictures of the sea floor and recover the weapons. A net will also be placed around the Cheonan to prevent the loss of any bodies remaining in the ship.