Connecting an underwater vehicle to a tether

摘要

Apparatus for connection of an underwater vehicle (102 fig. 2) by a tether 109 comprises a drum 302 which stores the tether 109 so that the tether 109 is unwound from the drum to allow the underwater vehicle (102 fig. 2) to move away from the apparatus, a pulley system 303 which engages with the tether 109 and which also unwinds the tether 109 from the drum 302, a pulley-drive operable in a forward mode to drive the pulley system 303 for the unwinding of the tether 109 and operable in a braking mode to resist the re-winding of the tether 109 and a drum-drive operable in a forward mode to drive the drum 302 for the re-winding of the tether 109 and operable in a braking mode to resist the unwinding of the tether 109. The drum 302 may have a helical surface such as a helical sleeve applied over a smooth drum. The pulley-drive and drum-drive may include first and second hydraulic motors (501, 502 fig. 5).