RE: (erielack) C-424/GP-35 use

["Tupaczewski, Paul R (Paul)" <paultup_@_lucent.com>]

> > GP-7 units. A GP-7 would pull about two loads less up the 
> hill out of
> Portland 
> > than a C-424.
> 
> They went from 2400 HP to 1750 and wondered why they could 
> only handle 2/3 as much train...

It ain't the horsepower, my friend. HP is only good for SPEED. It's tractive effort that counts here:

C424 starting/continuous tractive effort: 62750/53000 lbs
GP7 starting/continuous tractive effort: 60325/40000

The Alco blows away the Geep!


 
> > In 1975 a move was made to replace two GP-7 units with one GP-35.
> 
> Another brilliant move, replacing 3500 HP with 2500.  The 
> GP35 might have been a suitable replacement for the 2400 HP 
> ALCo, but they probably had been loading the train up to the 
> capacity of the two GP7's.

See above:

GP35 tractive effort (starting/continuous): 62250/51400

Still not as good as the C424!


> If the train is overloaded, slippage is one symptom...

"Tractive effort." (am I making this point clear? ;)


 
> > The GP-35 was replaced with two GP-7 units.
> 
> At least they admitted failure and went back to what had worked.  

A pair of GP7s have far greater tractive effort than a single GP35. No question about it!

	- Paul

------------------------------