How to calculate the horse power required to haul railway coaches?

Question

How to calculate the horse power required to haul railway coaches?

Answer 1

Rolling train resistance formula.

Determine tonnage of coaches.  Divide by horse power to reach horsepower per ton, or HPT.

Multiply HPT by 12.

Divide by percentage of grade.

This will tell you your speed with this particular tonnage.  Determine the speed you want to travel and add horsepower as needed.  Of course there are draft gear limitations play with freight cars, and the tonnage of coaches is far more moderate.

But the math remains the same.

Good question.