billbedford wrote:yes, but...
The S&D's own 0-4-4T's had smaller tanks than any of the Midland classes, 750 gallons if I remember correctly. Assuming the trains were made up of four six wheelers instead of two bogie coaches, the duty cycles would have been much the same as in later LMS days.
Thinking further on this we should I think be including the weight of the loco into the calcs as well. The 1Ps varied between 40T and 50T empty and loaded so for an average perhaps 45T. The 1Fs were 34T to 42T so 38T average.
If I use Bill's capacity of 750 gallons
Train weight = 70T + 45T = 115T. Distance is 50 miles round trip. 80% water capacity = 600 g.
so 12 gpm for 115 tons = 0.1 gallons per ton per mile.
Extrapolating for a 1F with 12 wagons average weight 11T.
Train weight = 132T + 38T = 170T. Efficiency = 0.1 gallons per ton per mile. Available water = 592 gallons.
so effective range = 592gallons /17gpm = ±35 miles.
__________________
If I use John's capacity of 1150 Gallons
Train weight = 70T + 45T = 115T. Distance is 50 miles round trip. 80% water capacity = 920 g.
so 18.4 gpm for 115 tons = 0.16 gallons per ton per mile.
Extrapolating for a 1F with 12 wagons average weight 11T.
Train weight = 132T + 38T = 170T. Efficiency = 0.16 gallons per ton per mile. Available water = 592 gallons.
so effective range = 592gallons /27.2gpm = ±22 miles.
The 22 miles feels perhaps more likely?