Allegheny Tractive Effort Table

[Anonymous]

The Y6b moved mountains in the east but could not keep up out west on a schedule with the Bigboys running 50 mph and a mile of Produce.

However the Bigboy would be most difficult to use in the east for a variety of reasons.

Horsepower = work availible in a unit of time. If there is additional horsepower availible near the top end then you can use it. If you used all of your horsepower to get to the top end and have nothing left over... well that all you got.

I am not exactly a horsepower man but more of a torque man. Once long ago my 300+ horse engine 3700 pound bomb of a car was defeated by a big block buick 4 door 6000 pound convertable off the light. If I had about a mile I could show him horses but doubt it. Not in that particular situation anyhow.

[Anonymous]

Quote:

"The western folks always had to go up hill or downgrade. They dont know any better. (Just teasing. lay off will ya?! LOL)"

No way, they knew better! But design concepts for the east, may not work as good for the west (and vice versa).

lars

[Anonymous]

Got the info, thank you so much!

Lars

[Anonymous]

The Y6b is king of the eastern hills. The TE of that engine will move earth backwards in it's orbit if permitted to do so.

The Alley was wasted on the ups, downs and sideways. Hardly it has room to get up and run.

The western folks always had to go up hill or downgrade. They dont know any better. (Just teasing. lay off will ya?! LOL)

[feltonhill]

So-called horsepower figures on the referenced site (and many others) are always suspect if they don't have consistent adjectives in front of the noun "horsepower."  The Q2 figure of 7,900+ is indicated horsepower, measured on the Altoona test plant at a relatively high evaporative and firing rate. The Allegheny figure of 7,489 is drawbar hp and was measured during over the road tests at a more normal firing rate, but under possible favorable grade conditions.  Therefore, the two "horsepower" figures aren't comparable.  Indicated HP is measured in the cylinders; drawbar HP is measured at the rear of the tender unless it's PRR.  Then it may be at the rear of the locomotive.  Big differences.  So unless you know what type of HP is being discussed, and under what conditions the HP figures were generated, you can't compare the numbers.  Admittedly it's not much fun, but this is the reality of trying to compare steam locomotive performance figures.  Detailed test data for the Q2, Allegheny, Niagara, N&W Class J, PRR T1, and many other locomotives exist in various archives, but those who try to use them in discussions are frequently considered didactic fuss-budgets.  Steam locomotives are dynamic creations, and their performance is audible, visible and measureable, but their secrets are still not easily discovered.  We  just have to keep trying to understand them as carefully as possible.

[J. Edgar]

 this site has some good info on various classes and survivors

 http://www.steamlocomotive.com/

[feltonhill]

Lars, 

Check your PM's.  I have some of the info you want.

[Anonymous]

Hello,

can somebody provide me with a Tractive Effort and Horsepower vs. Speed table for "Big Al"?

Any other big steamers are welcome!

Lets say for speeds

0-10, 10-20, ... up to 70mph?

Thanx in advance!

Lars