A roll film negative. On board the submarine Sealion (1959) towards the end of a long refit at Portsmouth. The photographer is in the forward torpedo compartment looking to port, aft and down at 29 to 31 stations from the centreline showing units marked 'T.C.S.S. 9 socket for battery heating and monitoring' and labelled Port M.I., Port L.O., Port L.C. and Port L.I.. An electric fire and oxygen candle stowage are against the port side. In the foreground is the torpedo loading track.