The production Deltics had a fuel capacity of 900 gallons. A trip from Kings Cross to Edinburgh should use between 400 & 500 gallons ruling out a round trip without refueling. In theory round trips to/from Newcastle or York were possible. Did this happen in reality or was refueling a matter of course. Also the water held 640 gallons. Post eth stock would the water tanks be kept full in readiness for the sleeper services?