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 up at the aft bulkhead at 34 station from the centreline at 33 station. On the aft support beam of the torpedo reload racks are a notice related to shutting down the fore-end above a notice headed 'Modification record equipment - P.L.C. Mk. I Mod. 10'. On the aft bulkhead are two torpedo battery alarm units above a televalve block holding rows of handwheels marked 'Return' and 'Pressure'. A vertical format negative.