By Lee Tae-hoon
Staff Reporter
The salvaging of the sunken frigate Cheonan may take a month or possibly longer as considerable time will be needed to attach chains and cable to the two parts of the ship prior to lifting operations, military officials said Sunday.
Due to the difficulty in balancing the weight in the strong tidal currents of the West Sea, the refloating process will have to start from scratch if the wreckage slips and falls to the sea bed, the officials said.
It took 53 days for the Navy to retrieve the 130-ton Chamsuri patrol boat in 2002 after it was sunk in a surprise attack by North Koreans near the inter-Korean maritime border in the West Sea.
Two massive floating cranes from private companies have been mobilized for the recovery of the Cheonan that sank last week near the sea border, military officials said.
The measure was taken as the Navy's existing equipment is only capable of lifting ships below the 130 tons in weight out of the water, according to an official.
A 2,200-ton crane from Samho Industry and Development arrived at the scene of the tragic accident Sunday, hours before a 3,300-ton crane from Daewoo Shipbuilding and Marine Engineering departed from its ship yard in Geoje, South Gyeongsang Province.
The former began preparations for hoisting the stern section of the 1,200-ton frigate, Cheonan, to the surface; the latter is expected to arrive on Thursday or Friday, to lift the bow part ― as the tug boats pulling the cranes can only sail at a maximum speed of four knots (about 7.4 kilometers per hour).
Most of the 45 missing crew are believed to have drowned, trapped in the rear section of the Cheonan, which sank near the Northern Limit Line (NLL), the de facto sea border between the two Koreas.
Experts say that the two massive cranes are capable of pulling up the two parts of the Cheonan, despite the fact that they are two to three times heavier to lift up underwater compared to when they are afloat.
They noted that the bow section would require a crane with a capacity of pulling up more than 2,000 tons of weight, while the lighter stern section would need a 1,000-ton crane.