On board the Type 12 general purpose frigate Plymouth (1959) alongside the south side of number 3 basin in Chatham Dockyard at the end of a modernization which commenced in August 1966. The ship is berthed starboard side to the quay. The photographer is in the electronics maintenance room between 39 and 42 stations on the centreline of 1 deck looking into the starboard forward corner showing a bench with drawers under and a portable speaker on top. Against the forward bulkhead is a sliding door cupboard with four leather cases, a canvas bag and a large tin labelled "Radioactive source type 'B'" on it. Three suppressor units manufactured by Aish & Co Ltd of Poole, three lighting fuseways and two fire extinguishers are also against the forward bulkhead.