Abstract: A mechanical fuse for a cable connection tail of a submarine repeater in a cable transmission link, said cable connection tail extending from a case for repeater equipment, having a "free" end for connection to the head of a line cable fixed to the repeater when the link is laid, and including a tube which encloses the transmission-providing elements. The mechanical fuse comprises a plug (40) threaded over and fixed to the end of the tube (30) at the free end of the cable connection tail, a ring (41) fitted over the plug (40) and free to escape from the plug (40) in a direction running away from the cable connection tail, and mechanically fixed to the cable head, and a set of pins (42) transversely connecting the ring (41) to the plug (40) and having a cumulative shear strength which is less than the breaking strength of the tube of the cable connection tail.