TWIN-HULL OIL RECOVERY SHIP THOR: DEVELOPMENT, CONSTRUCTION AND TESTING

In the late 1970s, the C. Luhring shipyard began the development of a design for an oil recovery ship having a hull divided into two halves, port and starboard, which are hinged together at the stern and can be opened out to form an angle of 65 deg. The two halves are normally secured together and the vessel then operates as an conventional ship ; for collecting oil spillage, the two halves are unlocked and opened out on arrival at the spillage; oil is drawn in through suction openings in the half-hulls. The design was described in the article summarised in Abs. No. 49896 ; further development has resulted in the building and testing of a prototype, the 34.5 m Thor. The present article describes and discusses this concept, gives a detailed account of its development in model tests and other investigations, describes Thor and her trials, and discusses the trials results. These results, both for the Thor as a ship and for its oil collection, treatment and disposal capabilities, are very satisfactory, and preparations are in hand for building a larger vessel of this type. In addition to the C. Luhring shipyard, the HSVA Schiffko, and Germanischer Lloyd have taken part in this project, which has West German Government support. The article includes general-arrangement drawings of Thor, whose principal particulars are: length 34.5m o.a., 31.1m b.p.; moulded breadth 8.2m; depth 3.1m to main deck, 4.1m to poop deck; draught 2.5m approx; tankage 281 m3; two 220-kW Schottel rudder-propellers for main propulsion; two 44 kW Schottel cone jets for auxiliary propulsion ; speed 9 knots.