A roll film negative. On board the submarine Sealion (1959) towards the end of a long refit at Portsmouth. The photographer is in the generator room between 77 and 92 stations looking aft, to starboard and up from the main flat at 79 station showing an emergency equipment locker unit on the left. Also seen is the upper part of the starboard 16 cylinder Admiralty Standard Range diesel engine including the instrument panel at the forward end. All of the cylinders are fitted with temperature gauges. A large number of handwheels and gauges are under the deckhead. A vertical format negative.