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 asdic control room on the starboard side of 1 deck between 35½ and 39 stations looking aft along the starboard side. The three chairs on the left are for the Type 177 asdic range operator, bearing operator and doppler operator. On the aft bulkhead is the pitometer log speed indicator with retransmission and range unit to the right behind the doppler operator. On the extreme right are the Type 170B asdic dome controls and the stabiliser indicating lamp box.