Underwater signalling unit - has buoy released from concrete block by explosive device on receipt of actuator signal

摘要

An underwater signalling device which transmits data to the surface, and from which afterwards a buoy is released on receiving a signal through a hydrophone, is made in a single compact unit to simplify handling. An outer casing (24, 26) acts as a mould in which the concrete weighting block (23) can be made, and a drum carrying a cable (21) is housed inside, with the buoy (1) mounted above it. The buoy which contains batteries (5), and an electronic control system (4) carries the hydrophone device (2) at the top. When a signal is received an explosive bolt (16) is severed, the force being sufficient to remove any marine growth etc. and the buoy is released while remaining attached to its cable.