A roll film negative. On board the submarine Sealion (1959) towards the end of a long refit at Portsmouth. The photographer is in the control room between 59 and 69 stations looking forward and to starboard from 63 station showing the Mark 17 T.C.C. unit manufactured by Laurence Scott & Electromotors on the left with the Mark 1 torpedo order firing unit next to it. A junction panel and fuse boxes are on the forward bulkhead. The battery compartment hatch is in the deck on the right. The hinged ladder leading up into the conning tower has been lowered into position. On the left is the passage outside the sound room with a curtain separating the control room from the forward crew accommodation. A vertical format negative.