On the Repairing Work of a Damaged Liberty Type Ship

Abstract

The repairing work consuming about 300 tons of steel of Liberty type ship, the "D0NG HAE", which ran aground off Imaharu, Shikoku, on account of a dense fog, was done in the space of time from the 20th of May to the 3rd of August, 1957, in Kawasaki Dockyard. In order to shorten the docking period and to save the repairing cost, the damaged double bottom construction, which was the major damaged part of the ship, was renewed in the following manner. At first, as far as the strength of the hull permited, the damaged part of the inner bottom was removed while the ship was afloat for the purpose of shortening the docking time. At the same time, renewed double bottom parts, including bottom shell, were assembled on assembling platform in the form of four double bottom blocks which weighed about 16.8, 38.6, 31.7 and 72.5 tons respectively. After assembling, these blocks were arranged beforehand in the position which would be directly under the damaged part of the ship when it was docked in. The damaged part being removed, these four blockes were lifted up one after another by a 200 ton floating crane, and fitted on to their proper positions. As a result of this method, the time the ship spent in the dock including the days of docking in and of undocking was actually 23 days, and man-hours were also saved by 52%.