Patent GB-389553-A (GB)
Title: Apparatus for controlling liquid masses in stabilising tanks
IPC: B63B39/03
Filed: 1931-10-22
Abstract: 389,553. Anti-rolling tanks for ships. HARGREAVES, T. F., 28, Southampton Buildings, London.-(Ges. f³r Elektrische Apparate; 44, Wilhelm v Siemensstrasse, Marienfelde, Berlin.) Oct. 22, 1931, No. 29400. [Class 113 (i).] Relates to apparatus for stabilizing or minimizing rolling of ships in which side tanks 2, 3 in communication with the sea are connected by a 'thwart-ship pipe 4 provided with a valve 5 which at the extremities of the roll is opened to establish pressure equality in the tanks, thus producing a sudden alteration in the respective liquid contents of the tanks, the syphon effect during the roll being increased by a pump 18 extracting air from the rising side and supplying it to the falling side. According to the invention, the supply pipes 6<1>, 6<11> from the pump are arranged in parallel to the pressure equalizing pipe 4 so that the pump remains unaffected by the pressure equalization which occurs on the opening of the valve 5. The main valve 15<1> for reversing the supply of air to the tanks on reversal of direction of roll communicates with the pump 18 through the leads 16, 17 and is operated by the rack 26, Fig. 2, gearing with the sector 25 and operated by the piston-rod 27 working in the cylinders 28<1>, 28<11>. The main distributing-valve 32, provided with pressure and suction ports 33, 34, 34<1>, is connected with the main cylinders 25, 25<1> through the valves 30<1>, 30<11> and the movements of the pistons therein and hence the reversal of the pump leads through the valve 15 is synchronized with the rolling of the ship through the angle of roll indicator operating the one or the other of solenoids 36<1>, 36<11> which in turn reverse the position of the pressure and suction leads in the pipes. At the same time the pressure is reversed in cylinders 39<1>, 39<11>. The pistons working in these cylinders are provided with extensions which alternatively block the possible movement of the valve 5 in one direction or the other. The valve is therefore free to swing in the opposite direction to effect pressure equality in the tanks on the reversal of roll. The tanks are further provided with float valves 19 which at the limiting positions operate the switch 22, thus energizing the solenoid 46. The valves 30<1>, 30<11> are thereby reversed. A second distributing-valve 43 is thereby actuated and being in connection with the cylinders 28<1>, 28<11> brings them into a central position, thereby closing the valve 15<1> from the pump until the water level in the tanks rises or falls. The control apparatus for the supply arrangement shown in Fig. 2, comprises a rolling angle indicator 71 the movements of which are conveyed by gear actuated by the motor 75. to a pair of damping arrangements 80, 81 which are adjusted in accordance with the conditions of roll and list of the ship which it is desired to correct. These movements are finally communicated to a cam 90 which operates the switch 37 controlling the solenoids 36. In further modifications, an independent electric motor is provided to control the flap valve whilst the main distributing valve is controlled bv an electric motor actuated from the main control solenoids.