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 conversion machinery and radar power room on the starboard side of 3 deck between 31 and 35½ stations. The photographer is looking aft showing a row of rectifiers on the left. A telephone and emergency lamp are mounted on a pillar and beyond them are two generators. To the right of centre is a rack of 12 volt batteries under a work bench. On the right are two generators with contactor units above them. Immediately above the nearer of the two generators is a change over switch panel. In the left foreground is tandem machine No. 1.