Patent GB-245304-A (GB)
Title: An improved method of and device for raising sunken and other damaged vessels
IPC: B63C7/06
Filed: 1925-02-24
Abstract: 245,304. Aktiebolaget Tolfvan O. Y. Jan. 5, 1925, [Convention date]. Sunken ships, raising.-In raising sunken or waterlogged ships lifting tanks are used which are connected by pipes and emptied of water simultaneously. The tanks are cylindrical with pointed ends and are constructed of iron plate or of wooden planks sheathed with iron, reinforced by internal annular frames 2, Fig. 3, placed closetogether. Rings 3 are located on the axis of the tank, each ring being between two adjacent frames and connected thereto by tie-rods 4. Longitudinal channel irons 7 and circumferential bands 6 are also provided, the bands 6 being provided with shackles for the attachment of the lifting ropes. The tanks may be made from units assembled as required where salvage operations are to be carried out. The two tanks used are connected at each end by flexible conduits 13, Fig. 1, which permit free flow of water to equalize the levels in the tanks. These tubes comprise sections attached to each tank which are connected up after the tanks are submerged. To bring the tanks close to the sunken ship, the ends of the tanks are connected by means of a steel rope 16, Fig. 2, using compound tackle and fastenings attached to the stem and stern of the ship. Other steel ropes, 12, Fig. 1, attached to the shackles on the tank pass under the hull. The fastening by means of which the ropes 16 are kept in position comprises two metal plates 17, Fig. 7, kept at a suitable distance apart by means of bolts 19 arranged in pairs and having holes through which extends a pin 20 forming a hinge. Set screws 18 pass through the plates to one side of the row of bolts 19, and serve to adjust the angle between the plates to correspond with that of the stem or keel of the ship. Passing through the plates on the other side are setscrews 22 having drill points which penetrate the stern 21 of the ship when tightened. A recess 24, Fig. 5, rounded off at the corners and furnished with a latch bar 23 is formed at one side of the plates for the reception of the rope 16. The valve for filling the tanks with water consists of a casing with holes 25, Fig. 8, and is secured to the bottom of the tank partly projecting therethrough. The projecting part is cylindrical, and the interior part conical. A conical float 26 fits tightly inside the conical part of the casing when the valve is closed. Movement of the float is controlled by a weight 27 attached to a rope 28 which is secured to the top of the float, and by a second rope 29 which is attached to the bottom of the float and led to the surface. The valve is thus opened from the salvage ship by pulling on the rope 29 and closed by slackening the rope. The tanks are emptied by pumps 30, Fig. 2, in the tanks and driven by steam, compressed air or electricity supplied from the surface through conduits or cables 32. Pipes 33 and 34 for discharge of water and inlet of air respectively are provided and lead into tanks 36, 25 at, the surface which permit working when the sea is rough. When steam is used the supply pipe 33 is arranged within the exhaust pipe, which opens into a tank 37. The water may be expelled from the tanks by the generation of gas therein.