GB191328186A - Improvements in or relating to Submarine Mines. - Google Patents

Abstract

28,186. Vickers, Ltd., and Elia, G. E. Dec. 6. Mines. marine.-Relates to mines which are anchored at a predetermined distance below the surface of the water, and consists in a construction whereby the mine can readily be converted, before launching, into one adapted to be supported so that it will float unanchored beneath the surface. In the form shown in Figs. 3 and 4, the anchor B is provided with readily detachable air-chambers E and with a readily detachable weight D. The air-chambers E are provided with screwed plugs E<1> which are removed when the mine is to be anchored. In the weight D is formed a groove d having a narrow top opening d<1>; an attaching-bolt D' has opposite flat surfaces which allow the bolt to pass through the narrow part d<1> when turned through 90 degrees from its locking position. The cable B<1> connecting the anchor to the mine A is wound upon a drum b, which is normally locked by a pawl F<2> engaging ratchet teeth on the drum. The pawl is controlled by a lever F' connected to the usual depth-regulating ball F and also by a spring-actuated plunger f' which holds the pawl F<2> out of action until the upper end of the plunger is released from a nut f on the shaft b<xx> of the drum b, the plunger allowing the nut to move longitudinally but not to rotate. This device prevents the pawl F<2> from locking the drum b during the vibration of the sounding-ball F and before the weight of the ball is taken off the lever F', and also forms a brake for the drum b. In operation, when the mine is to be anchored, the plugs E' are removed, and the weight D is not detached. The ball F falls from the anchor at the moment of launching and controls the depth of immersion in the usual manner. When the mine is to be supported so that it floats unanchored beneath the surface, the plugs E' are not removed, but the weight D and ball F are removed; an additional float C is attached to the mine by a cable c, and the mine is launched. The anchor descends relatively to the mine until the plunger f<1> releases the pawl F<2>, which then locks the drum b. The mine and anchor further descend until supported by the float C. In each case, the pawl F<2>, when free to lock the drum, moves to a position in which the lever F<1> cannot re-engage it, so that water currents cannot cause disengagement of the pawl.