A half plate sheet film negative. On board the Type 12 frigate Yarmouth (1959) alongside the south-east corner of the fitting out basin in John Brown & Co Ltd's shipyard at Clydebank. In the engine room on 4 deck between 49 and 57 stations. The photographer is at the main platform level looking across the engine room at a mass of machinery and pipework. The precise location and subject of this negative is unknown although the largest piece of machinery appears to be a water pump.