I remember a true tale about a RFA Rover class tanker at Chatham. As she was coming out of the locks into the basin, she suffered a C.P. shaft failure, she locked into slow ahead as default setting for CP props. No one noticed the pilot asked for astern, but she carried on and before anyone noticed what was wrong, it was too late she rammed HMS Triumph moored in the basin pocket and broke several of her mooring wires, I think it was Gold Rover.. Another one was when the last paddler in Portsmouth finished her last job she moored up in the Basin for the Port Admiral to ceremoniously ring off her engines for the last time when the Confiance came in, suffered a CP prop failure and went to slow ahead, before they could stop her engines, she rammed the paddler and smashed up her paddle box.