>>1742181Depends on a metric fuckton of things.
What's it pulling?
What does it weigh?
Locomotive size?
Number/size of cylinders?
Firebox design?
Crew competence?
Firing efficiency?
Grade/incline?
I'm sure there's a comprehensive equation that covers all of these variables in a single, neat arithmetic, but I'm nowhere near mathematically competent enough to gauge the right operations for it. Hell, I'm not sure I even covered all the bases.