Re: 464

Earl,

The notion that whether the loco is soak or super the T.E. stays the same depends upon holding to the 85% constant factor in the T.E. equation. I think it could be argued that the steam circuit in a soak engine might have a lower constant factor in real life. (or could a super loco have a higher factor?)

Steve


The normal formula used (for a 2 cylinder locomotive) is:

t = c x P x d² x s divided by D

where

t is tractive effort
c is a constant representing losses in pressure and friction; normally 0.85 is used
P is the boiler pressure
d is the piston diameter (bore)
s is the piston stroke
D is the driving wheel diameter