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. In the sonar instrument compartment between 16 and 27½ stations on 3 deck. The photographer is looking forward and slightly to port from just inside the doorway showing nine racks of electronic equipment, including some that are shown to be 5000 volts units. Against the bulkhead just inside the door on the right are a telephone, an automatic emergency lantern and a fire extinguisher. A vertical format negative.