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 GWS21 power room between 60½ and 62 stations on the port side of 1 deck. The photographer is looking aft through the open door. A small electric motor is on the deck just inside the door and two larger units are in the centre of the room. A vertical format negative.