The volume of fuel fluctuates with temperature, hence mass is often a more consistent and reliable measure. Modern-day road transport tanker companies often have a disclaimer about gross or net volume at transfer from tanker to a receiving station tanks, so clients understand they might receive more fuel per load in winter than in summer.
Also, for the RN with their tankers (like any other navy!), with the pumping/measuring tech at the time, a tanker might simply receive fuel from shore supplies until their engineering team was satisfied it was at (or about!) 100% capacity. Likewise, when refuelling ships, often there was some conservatism in accepting fuel - far better to fill to only 95% on a destroyer than try to go to 100% and risk not stopping in time, and spilling fuel everywhere. I recall reading something about fuelling (in harbour) in the D.A. Rayner book 'Escort' - might have to try to see if that has more info on this...
Simon
Responses