> Just keeping the lights on uses more gas than that.
Can you elaborate on this?
One gallon of diesel = ~41kWh. Assuming 30% conversion efficiency that gives us 14kWh. Assuming a 50mph speed to traverse 500 miles means we need to keep the lights on for 10 hours, giving us a power budget of 1.4kW. I don't know what kind of lights locomotives carry but that seems like an awful lot.
locomotives have two headlamps around 200W, and two ditch lamps (the ones at the bottom near the rails) of 350 watts each. That's 1.1KW already, plus any interior lighting and conversion losses from the diesel genset.
Also average freight train speed is tracked and its consistently less than 25mph:
Note however that fuel efficiency is almost always given in mpg per freight ton, in which case the power usage of the lights would be amortized over the considerable mass of the train. >400 mpg per ton is not uncommon on a train.
It occurred to me that elevation change could have huge impact on those calculations. More back of the envelope stuff: a 5k ton train requires 13.6kWh to ascend 1m. If such elevation changes are common that would quickly dwarf small values like the power consumption of lights.
Can you elaborate on this?
One gallon of diesel = ~41kWh. Assuming 30% conversion efficiency that gives us 14kWh. Assuming a 50mph speed to traverse 500 miles means we need to keep the lights on for 10 hours, giving us a power budget of 1.4kW. I don't know what kind of lights locomotives carry but that seems like an awful lot.