GB165308A - Improvements in and relating to ship raising devices - Google Patents

Abstract

165,308. Green, J. A. May 26, 1920. Sunken ships, raising. - A lifting-device for raising sunken ships provided with means for generating gas in its interior to expel the water comprises a cylinder having a spring-controlled outlet valve, and a valve opened by the pressure of the gas acting on a piston to allow the water under pressure to act on and open the outlet valve. The device consists of a cylindrical body 1, Fig. 1, and a cap 2 comprising a closed air chamber 6 and a central cylinder 5, the upper part of which has a flared extension 7 closed by a cover-plate 8 carrying a spring-pressed valve 12. The lower end 4 of the body is provided with a central tubular extension 16 with outlet ports 17 normally closed by a spring-pressed valve 18. The sides of the body are extended downwardly and flanged, the flanges having holes for the attachment of lifting-chains 43. A cage 21, consisting of a piston 22 which slides in the cylinder 5, plates 23, 24, and rods 25, slides in the body, and carries the acid-container 26. The piston 22 has ports 28 in its walls which allow gas to pass when the piston rises into the extension 7, and carries a projection 30 adapted to be engaged by spring-controlled catches 31 to retain the cage in raised position. The lower plate 23 of the cage carries a rod 33 to which is secured a valve 34, Fig. 3, consisting of a body 36 with a stem 37, a perforated valve plate 39 sliding on the stem 37 and adapted to rest on a seating 35 formed in the extension 16, and a spider 38 secured to the lower end of the stem. A guideplate 40 on the rod 33 slides between pins 41 integral with the body 1 and prevents lateral movement. Before sinking and attachment to the sunken ship, the cylinder 1 is filled with a solution of soda through the valve 48. The filling-cap 45 of the container 26 holds a capsule 46 of soluble material containing soda, and the sulphuric acid in the container dissolves the capsule and acts on the soda, producing carbon dioxide. The pressure blows out the stopper 47 and the acid mixes with the soda solution in the cylinder, generating more gas which acts on the underside of the piston 22, which is thus raised and held up by the catches 31. The first movement of the cage lifts the body 36 of the valve 34 off the valve-plate 39, permitting the pressure to open the valve 18, discharging the water and rendering the cylinder buoyant. Further movement causes the spider 38 to lift the plate 39 off its seat 35 and permit a greater opening. Excess pressure is relieved by the valve 12, the gas passing through the ports 28 in the piston.