What's so special about Big Boys?

[BaltACD]

Educuate yourselves

http://www.steamlocomotive.com/bigboy/

[feltonhill]

GP40-2 probably won’t believe this but I’m going to agree with his appraisal of the Allegheny. As far as test results are concerned, it posted the highest sustainable drawbar HP known (about 6,500 to 6,700 at 47 mph). And this was done using achievable firing and evaporation rates. C&O did not typically flog their locomotives during tests to obtain unrealistic results. Sure, sure, everybody knows it produced a maximum DBHP of 7,498 at 47 mph, but that was a maximum point on the scatter plot of data, not a sustained reading (see page 204, The Allegheny, Lima’s Finest by Gene Huddleston). Under the same over the road conditions (normal firing and evaporation rates), Big Boy posted about 6,100 DBHP at 36 mph (see Big Boy, pg20 by William Kratville). And this was using UP’s not-so-good grade of coal.

The PRR Q2's oft-quoted maximum HP of 7,987 at 57.4 mph is actually indicated HP, measured in the cylinders. It is not drawbar HP by any stretch of the word. This figure was achieved at extremely high firing rates on the Altoona test plant and could not be considered reasonable over the road. In comparative tests with N&W’s A 2-6-6-4, the Q2 could not match the speed or operating economy of the A with the same load.

So why do people say Big Boy is the biggest, most powerful, etc, etc, when in fact it wasn’t? Easy!! Myths and legends are a lot more fun than dry old statistics and reality any day. Take something that’s physically imposing, stir in some impressive operation, spice it up with a little exaggeration, and there you are - a recipe for legend.

This sort of thing happens in a lot of different fields, but it seems to be epidemic in railroad history. A bit of healthy skepticism can be useful to evaluate how horsepower readings were obtained..

[GP40-2]

QUOTE: Originally posted by jockellis

G'day, Y'all,
Size matters but so does speed. The Y-6bs and the C&O and Virginian locomotives (I cannot spell Alleg something) were designed for lower speed coal field to port operations. While they could have pulled bigger trains up Sherman Hill, it would have taken them longer to get to the top. Also, 4000s worked alone. Y-6bs were almost always joined by several other Y-6bs in pushing and pulling staggering amounts of tonnage.
Jock Ellis
Cumming, GA US of A
Georgia Association of Railroad Passengers

Wrong! Wrong! Wrong! concerning the H8 Allegheny. It WAS NOT designed for pulling low speed coal drags. That is however, how the C&O ended it's career after diesels came on line.

Everything about the H8's design, from its driver diameters, to its huge firebox/boiler (the most powerful ever put on a steamer) was designed for high speed horsepower.

The only advantage the Big Boy had over the Allegheny was it's higher starting tractive effort. Once they both got a train moving, the Allegheny would simply run away and hide from a Big Boy.

[coborn35]

Actually, the largest locomotives (steam) the D.M.I.R used had more tractive effort than Big Boy. They were called Yellowstones, and classified 2-8-8-4's.

[jockellis]

G'day, Y'all,
Size matters but so does speed. The Y-6bs and the C&O and Virginian locomotives (I cannot spell Alleg something) were designed for lower speed coal field to port operations. While they could have pulled bigger trains up Sherman Hill, it would have taken them longer to get to the top. Also, 4000s worked alone. Y-6bs were almost always joined by several other Y-6bs in pushing and pulling staggering amounts of tonnage.
Jock Ellis
Cumming, GA US of A
Georgia Association of Railroad Passengers

[Modelcar]

....Somehow the phrasing of "biggest" got tagged to it true or not...Even it's name was tagged to it by a worker and it stuck...."Big Boy"....
It was built to pull tonnage up Sherman Hill...{if I remember correctly}, and in so doing would replace several smaller units and of course reducing number of crew to do the job.
It is a locomotive that really looks like super power and most fans and probably railroaders liked it too...
It was kinda rare...{believe 25 was the total built}....so it was unique in a way....
It is arguable if it really is the "biggest"...Personally from what I've studied on it, it's not.
But for many reasons....the masses believe it's the greatest and most powerful...when most likely it wasn't quite up to that billing. Pennsy's Q2 {again, I hope I'm remembering correctly}, was mighter in some ways.

[balearic]

But if higher horsepower was all that mattered, why not just copy the Pennsy's Q2's and have done with it?

[samfp1943]

The Big Boy locomotives developed a certain mistique about them, whether it was size, raw ability to pull heavy trains up steep grades or to see something moving freight with the speeds they were able to achieve,[ moving perishaibles and merchandise over the system with a lot of panache]. It was truly the last of the really big articulated steam engines and as eolafan stated "ON THE UP, BIGGER WAS BETTER" and that too was part of character of the Big Boys. I guess that where this class of locomotives was concerned it was truly a case of 'size matters'.

[Anonymous]

It was advertised as the biggest by UP. The big boys were built to help keep 'em rolling in World War II. It also higher speed than for example the Y6-b which had more tractive effort.

[eolafan]

OK, how about this...the Big Boy could move the same amount of tonnage (or perhaps even more on some grades) than several smaller steamers just as the DDA40X, the turbines, etc. could displace several or more smaller locomotives with one single unit...this was a U.P. tradition for many years...ON U.P. BIGGER WAS BETTER.

[Anonymous]

QUOTE: Originally posted by eolafan

What makes it great? The same thing that impressed people with the DDA40X, the G.E. turbines, the SD45 in its time, and recently the SD90 units from EMD...RAW POWER!

I'm not asking why people are impressed by it. I'm asking why do they say it was the most powerfull steamer, when it it was actually quite weak in tractive effort compared to some other steamers of the time.

[Anonymous]

QUOTE: Originally posted by ndbprr

What makes some people like certain women and others aren't impressed? Or how about the color or brand of car you drive? Value judgements are always arguable and wise people just smile and listen. It isn't a good idea to tell someone his wife is ugly or his engine choice is illogical.

well it's not subjective when someone says that this engine could pull more cars up the grades than any other locomotive. That is eithe true or false.

[eolafan]

What makes it great? The same thing that impressed people with the DDA40X, the G.E. turbines, the SD45 in its time, and recently the SD90 units from EMD...RAW POWER!

[Anonymous]

It's one of the last true Steamers, and people always flock to to it as a reminder of what steam was capable of.

[ndbprr]

What makes some people like certain women and others aren't impressed? Or how about the color or brand of car you drive? Value judgements are always arguable and wise people just smile and listen. It isn't a good idea to tell someone his wife is ugly or his engine choice is illogical.

[spbed]

Bigness real big! [:o)]

Originally posted by electro-ortcele
[

Living nearby to MP 186 of the UPRR  Austin TX Sub

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