Defence system for harbours and waterways - uses floating strips attached to anchorage blocks to wind around propellers of enemy craft

摘要

The marine defence system for harbours and canals etc., uses blocks (10) resting on or anchored to the bottom of the waterway, each with a set of strips (11) attached. These strips float under the surface of the water and become entangled in the propellers of enemy vessels. The blocks can be of concrete, and can be combined with explosive mines, actuated by the strips when tensioned. Explosive devices can be mounted on the strips themselves. These strips, which can be of textile, metal foil or plastics material can be embedded in holes in the blocks by a suitable hardenable material. They can be installed so as to operate a warning signal.