The rule of thumb that I have used is 0.4 lb of diesel per bhp-hr. You then have to determine/guess at operating (brake) horsepower, availability/utilization factors for the equipment.
For example, in any given day, the scoop will operate 18 hours. During this period, it will use an average of 70% of full engine horsepower.
You can then convert pounds of fuel to volume (SG = 0.84 to 0.86 typically).
Alternatively, manufacturers have claimed that the fuel tank is sized for "one shift". The big mystery to me is how long of a shift (traditional 8 hours, or more common 10 to 11 to 12 hours)?
