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 mortar handing room between 67 and 71 stations on the port side of 2 deck looking forward from the aft end on the starboard side showing the mortar weapon control panel Mark 2, serial number 34, manufactured by Park Bros Ltd of Blackburn, mounted on the end of the projectile loading rack. A fire extinguisher is on the right. A vertical format negative.