Two R. & H. Green & Silley Weir mechanical engineers at work in the engine room on board an unknown ship. They are inside the crankcase of a diesel motor and are working on the removal of an item marked No. 1. One of them is undoing a nut by hand and the other is using a stainless steel ring spanner. The photographer is standing on the floor plates looking at the men inside the manhole which is in a dirty white painted panel. The location may be any of the docks in the Port of London or in Falmouth.