GB191205672A - Improvements in Explosive Booms for the Defence of Ports and other similar purposes. - Google Patents

Abstract

5672. Elia, G. E. May 30, 1911, [Convention date]. Mines, marine.-Relates to a boom or network of explosive mines, comprising a taut lower cable, a floating upper cable, and a number of connecting-cables, each containing an explosive element, and consists in so constructing the boom that the connecting-cables are not detached from the main cables when a ship strikes the floating cable, thereby causing the mines adjacent to the ship to be brought as low as possible under the ship, the other mines remaining laterally remote therefrom. In the preferred form, the boom comprises a series of explosive elements f, Fig. 1, attached by cables b, c to a series of taut cables a, and maintained at the water surface by suitable floats g. The separate elements f are connected by cables d, which are longer than the cables a. In one type, intended for the destruction of crusiers having a draught of about 9 metres, the cables b, c are 10 metres long, the cable a 12 metres, and the cable d 60 metres. For harbour defence, the boom is attached to floats such as h suitably anchored; while for use on the high seas, the floats h are replaced by drift anchors, or the two ends of the boom may be towed by boats. On striking the boom, a ship first carries away one of the floating cables d. When this cable becomes taut, it drags the adjacent pair of explosive elements f below the surface, until the two sections of the cable d are collinear with the corresponding connecting- cables, and the two elements f lie under the side of the ship. These two elements are then exploded by the continued motion of the ship, but the remaining elements of the boom are unaffected owing to the slackness of their upper cables. The elements f are preferably of the known kind in which the striker o, Fig. 2, is held by a pin p which is sheared by a pull on the cable, thereby allowing the spring r to project the striker upon the detonator. A safety soluble plug w holds a key v in position to prevent the firing of the mine while it is being placed in position. To maintain the boom in a suitable position in currents, the cables d are supported at the surface by means of known sentinel hydroplanes. In a modification, intended for the destruction of submarines, the boom is inverted, the cables a being maintained on the water surface by floats.