A roll film negative. On board the submarine Sealion (1959) towards the end of a long refit at Portsmouth. The photographer is in the motor room between 92 and 103 stations below the main flat looking to port from the starboard side at 93 station showing a row of batteries against the bulkhead at 92 station. On the left are two 225v 100 kw C.P. motor generator sets. A vertical format negative.