Haulage capacities w.r.t. different gradients and speeds have been mentioned (without acceleration reserve).
Very useful for determining balancing speed of the loco on various gradients.
For loads, consider 1 ICF coach = 55 tons.
Net load of 24 ICF coaches = 55x24 = 1320 tons.
Gross...
more... load of the rake = loco weight + net load = 78 tons (for WAP5 only) + 1320 tons =1398 tons.
Now, it'll be easy for you to find out.
Example : on a 1:100 up gradient, a WAP5 loco can haul 1460 tons at 70 km/h and 1325 tons at 80 km/h. This means the loco's balancing speed is between 70 and 80 km/h on a 1:100 gradient (~75 km/h to be precise).
Note : These aren't exact values but close enough. Also, acceleration reserve has not been taken into consideration