U.P bigboys/challengers


N&W like many other RR's in the steam era tweaked their engines as any problems arose. The N&W NOT like all railroads had daily discussions with the track folks to optimize the performance of their railroad. They designed their engines for their system. N&W didn't have tons of management levels like some other roads so these discussions and teamwork in solving the problems was almost unique. Very few railroads used compound articulated engines after about 1924. The N&W liked the efficiency of their Y class and Z class (2-6-6-2) so stuck with them. Their shops were among the very best, and they designed all their Y class engines after the Y4's and built them at Roanoke Shops. N&W's profile was mostly in the hills of southwest VA and into West VA. Their flatland was from Norfolk up to Desputana or so in the east and Cincinatti eastward. That is where most of the "A" class engines worked. I will check all my books and articles to find the TE power curves and report back.
 
From the N&W Historical Society discussion, comments from Ed King.

Here are some interesting stats:

H8 on C&O’s .57% Allegheny Mountain: 5750 tons per, total of 11,500 per train, 18 MPH lugging speed (according to Dr. Huddleston).

Y-6 on N&W’s 1% Alleghany Mountain: 5150 tons per, total of 10,300 per train, 15 MPH lugging speed (according to everybody I ever talked to who worked on them). And FWIW, I’ve seen them do it in the rain (under bad rail conditions).

So the 2-6-6-6 was good for 600 tons more on a grade just a little more than half as steep. Big Whoop! And how much more profit did C&O get out of the extra 3 MPH?

Of course, just before the Y-6 got to that grade, it had dragged its 10,300 tons up New River at around 31 MPH. Get your train resistance formula out and turn the crank and tell us what DBHP at the end of the auxiliary tender was necessary for it to do that. Oh, Wait! Dave Stephenson has already done that for you!

55-5600 is all. Just about the same as the H8 put out at that speed. But Wait, again. How many H8s would it have taken to lift that train up to Christiansburg?

On a tractive effort basis, valid at that speed, probably about three. A Big Boy could probably have brought that train up the river at that speed, but two of them would have had to have more help getting up the Mountain with it. (Using Big Boy’s horsepower curve published in Kratville’s book – same DBHP as the Allegheny and the Y-6 at that speed).

But here’s the rub. The Y-6 did it, as Bud Jeffries has so capably pointed out, with a boiler about the size of the J’s.

So you comparison guys can chew on these facts for a while, while I go back to sitting in the corner.

EdKing
 
They gave me an i-phone at work last week. I didn't want it at first, but once I got used to it I actually like it.
Anyway I was browsing around in the app store and typed in "union pacific" and found a UP steam app!
It's pretty cool, you can track the big steamers and see pics, video, and stats!
I recommend it to any railfan, check it out!
 
From the N&W Historical Society discussion, comments from Ed King.

Here are some interesting stats:

H8 on C&O’s .57% Allegheny Mountain: 5750 tons per, total of 11,500 per train, 18 MPH lugging speed (according to Dr. Huddleston).

Y-6 on N&W’s 1% Alleghany Mountain: 5150 tons per, total of 10,300 per train, 15 MPH lugging speed (according to everybody I ever talked to who worked on them). And FWIW, I’ve seen them do it in the rain (under bad rail conditions).

So the 2-6-6-6 was good for 600 tons more on a grade just a little more than half as steep. Big Whoop! And how much more profit did C&O get out of the extra 3 MPH?

Of course, just before the Y-6 got to that grade, it had dragged its 10,300 tons up New River at around 31 MPH. Get your train resistance formula out and turn the crank and tell us what DBHP at the end of the auxiliary tender was necessary for it to do that. Oh, Wait! Dave Stephenson has already done that for you!

55-5600 is all. Just about the same as the H8 put out at that speed. But Wait, again. How many H8s would it have taken to lift that train up to Christiansburg?

On a tractive effort basis, valid at that speed, probably about three. A Big Boy could probably have brought that train up the river at that speed, but two of them would have had to have more help getting up the Mountain with it. (Using Big Boy’s horsepower curve published in Kratville’s book – same DBHP as the Allegheny and the Y-6 at that speed).

But here’s the rub. The Y-6 did it, as Bud Jeffries has so capably pointed out, with a boiler about the size of the J’s.

So you comparison guys can chew on these facts for a while, while I go back to sitting in the corner.

EdKing

I'm chewing (with an open mouth). :) Anyways, I do not discredit the effectiveness of the other big articulated loco's. I am no where near an expert on any other them. However, my Y6b pulled 175 cars at club and it takes 2 PCM Big Boy's to do that. Hehehe. I truly like them all. I just don't have deep enough pockets to model them all. Nor do I have the storage capacity in my brain to keep all of this awesome info stored. I love this forum. When I go to work there is a couple of guys who play "mine is bigger than yours ". I can get on here and read about the RR's doin the same. My $.02 is the big boys and h8's were probably close to each other in ability for what they were designed for. C&O used the H8's poorly from what I have read. The Y's sound like they were a whole other breed designed and refined by the N&W to be an awesome machine more than capable on doing what they needed to do. With all that being said, I spit your info out and proclaim that the Big Boy's were #1! (Stirring pot)
 
Btw, N&W must of had traction tires on their Y6's because my BLI had em. I bet if U.P. had put traction tires on the Big Boy's my PCM would've pulled the train too! ( my attempt at humor ) you may or may not get it....
 



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