How to rate your power in locomotives?

[Beattie]

What I have been looking for but not able to is to find out how much pulling power a engine has. Like for example a train has 60,000 pounds starting and 42,000 pounds continuous with 1,500 horsepower the unit I am looking at is a alco c415 unit. So far all I came up with is it only has 20 ton based on 2,000pounds=1ton but that can't be right sense trains pull alot more than that. Is there some sort of formula for this?

 

[jjanmarine3]

If you google the subject there are so many .
This might help though.

P=TS/375 Where P is power in horsepower at the rails, T is tractive effort in pounds and S is speed in miles per hour. The engine horsepower at the flywheel is reduced by the auxiliaries such as air compressor, cooling fan, charging alternator, traction generator and motor losses, drive losses, and gearing losses. The net effect of these losses is to reduce power to the rail by 20% to 30%. About 80% of the rated engine power is available at the rail for a modern AC traction locomotive versus about 70% for the older DC units. Most yard switching applications seldom exceed about 30,000 pounds of tractive effort and speeds of 5 to 7 miles per hour. Therefore the industrial locomotive will perform well with 500 to 600 horsepower. A short line railroad or branch line with the same tractive effort requirements might require up to 2000 horsepower to move the train because of the higher speeds involved. Main line locomotives may need over 4000 horsepower each with multiple units because of both high tractive effort and speeds.