A roll film negative. On board the Tribal class type 81 frigate Mohawk (1962) in Portsmouth Dockyard. She was in a dry dock from 21 March to 11 April 1972 when she moved to the South Railway Jetty. The port GWS 21 missile launcher power room between 54½ and 56 stations on the port side of 01 deck. The photographer is looking forward through the open watertight door. A vertical format negative.