With all the excitement with the upcoming release of Lionel's Big Boy, I thought I would throw this in for discussion. I was not aware of such a steam locomotive until I saw it in my book. Are any of you familiar with the Virginian's 2-10-10-2? I don't have any specifications on this beast but it would be fun to see how it stacks up to the "Big Boy" 4-8-8-4. Anybody in Forumland have that information?
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There's a fair bit of information on that locomotive on this wikipedia page. 
The Virginian 2-10-10-2 is a Compound articulated locomotive, and not nearly as big, nor as heavy, nor as powerful, as the Union Pacific 4000 class Simple articulated 4-8-8-4 locomotives.
Looks somewhat like this.
I'd like to have one. Not as "big" as the Big Boy but big and brawny in its own way. Very desirable. I think maybe 3rd Rail has/is/will do one.
3rd Rail made the Virginian 2-10-10-2 recently. They have one left in stock, according to the website. It can be yours for a mere $2,000. And, as Marty's link points out, Lionel made a Vision Line version of Santa Fe's 2-10-10-2. That pretty much exhausts the universe of locomotives in that wheel arrangement. The Santa Fe did not consider theirs a success and cut them down into 2-10-2's. The Virginian, on the other hand, kept theirs in service until the 1940's.
Paul: You, being a big-time Milwaukee Road fan, should start campaigning for someone to do the Milwaukee Road "N" class articulated. of course these engines can't hold a candle to the 4000's on the U.P. but they were fairly large for the "road" and would make a nice model. They were 2-6-6-2's and were built as compound but a number of them were rebuilt to simple articulateds. One of these would b e the only artic' on my layout.
By the bye, my understanding is that Lionel will be coming out with an engine that was very popular on the Milwaukee. The L3 class were USRA Heavy Mikados, and the Milwaukee had 100 of them. They were actually the largest power on the road until the S-2 Northerns were built starting in 1938. you're gonna hafta save up for one of these authentic Milwaukee Road engines.
Will you be going to York next month?
Paul Fischer
This BEHEMOTH is a BIG'GA BOY in it's own right, though smaller, lighter and not as powerful, by comparison to the BIG BOY, as pointed out by HOT WATER.
Ralph
Paul, I would love to go to York. Unfortunately, cancer ate my right hip and I am confined to a wheelchair. I suppose I could make it happen, but I don't think the hassle is worth it. I always liked the Mikado, it has nice clean lines.
The Virginian 2-10-10-2 is a Compound articulated locomotive, and not nearly as big, nor as heavy, nor as powerful, as the Union Pacific 4000 class Simple articulated 4-8-8-4 locomotives.
not nearly as big?? I question on that...Big boy at 132 feet long and virginian 3000 class at 144 feet long..Big boy was heaviest loco ever made.. but it wasnt as long as the virginian class.
The (only?) true Bigger Boy was the C&O/VGN 2-6-6-6. It was heavier so far as
I know (that was a whole different can of worms back in the day - seemed that Lima
fudged on the weight figures by understating them, or so the story goes) than
the UP 4-8-8-4.
Also, I read a comment - in a major model RR mag - a few years ago by someone who had drawn scale plans of both the BB and Allegheny, and the substance
of his remarks were that he "realized that, dimensionally, the BB's boiler
would fit inside the boiler of the Allegheny" (rough quote).
So, there's my Bigger Boy candidate.
The Virginian 2-10-10-2 is a Compound articulated locomotive, and not nearly as big, nor as heavy, nor as powerful, as the Union Pacific 4000 class Simple articulated 4-8-8-4 locomotives.
not nearly as big?? I question on that...Big boy at 132 feet long and virginian 3000 class at 144 feet long..Big boy was heaviest loco ever made.. but it wasnt as long as the virginian class.
Just because a steam locomotive is "longer" than another locomotive, that really does NOT equate to horsepower and/or tractive effort. For example, those Erie and Virginia "Triplex" locomotives were really long, but neither was remotely close to the horsepower of a C&O H-8 or a UP 4000 class.
The Virginian 2-10-10-2 is a Compound articulated locomotive, and not nearly as big, nor as heavy, nor as powerful, as the Union Pacific 4000 class Simple articulated 4-8-8-4 locomotives.
not nearly as big?? I question on that...Big boy at 132 feet long and virginian 3000 class at 144 feet long..Big boy was heaviest loco ever made.. but it wasnt as long as the virginian class.
Just because a steam locomotive is "longer" than another locomotive, that really does NOT equate to horsepower and/or tractive effort. For example, those Erie and Virginia "Triplex" locomotives were really long, but neither was remotely close to the horsepower of a C&O H-8 or a UP 4000 class.
I think the OP was using the term "bigger" in relation to overall size. The word bigger usually refers to size anyway.
When it comes to comparing horsepower and tractive effort, I usually hear that referred to as higher or lower, not bigger.
I think the OP was using the term "bigger" in relation to overall size. The word bigger usually refers to size anyway.
When it comes to comparing horsepower and tractive effort, I usually hear that referred to as higher or lower, not bigger.
OK, sounds logical. The OP may have assumed that just because the Virginian locomotive had two more powered axles that it was "bigger" than the UP 4000.
It was actually a close race between the Allegheny and the Big Boy as far as horsepower is concerned, and I believe at least one published report placed the Allegheny #1. Of course, that doesn't always equate to tractive force, but it was a brute. 
Of course, that doesn't always equate to tractive force
Actually it does.
Drawbar horsepower is determined by
Drawbar Pull (pound feet) x Speed (MPH)
375
Starting drawbar pull may be very high but drawbar pull drops off as locomotives accelerate. Some locomotives experience a very rapid drop off in drawbar pull. Mallet compounds tended to loose drawbar pull quickly as they went faster due to their complex steam passages and because most of them had small drivers and relatively small boilers for their cylinder size. Super Power locomotives like Berkshires, Northerns and simple articulateds including Challengers, Alleghenys and the Big Boy experience less drop in drawbar pull with increasing speed than just about any type of locomotive.
A Virginian 2-10-10-2 running in compound at low speed has about the same tractive effort as a Big Boy and they would produce about the same drawbar horsepower at 5-10 MPH. By 15 MPH the Big Boy would have an advantage. By 20 MPH a the Big Boy would have a significant horsepower advantage. At 40 MPH a Virginian 2-10-10-2 would be starving for steam and beating itself to death while a Big Boy would just be coming into the peak of its horsepower curve.
I question on that...Big boy at 132 feet long and virginian 3000 class at 144 feet long..Big boy was heaviest loco ever made.. but it wasnt as long as the virginian class.
The Virginian 2-10-10-2s had boilers 144 inches wide and they had short 8 wheel tenders to fit on 100 foot turntables. The Big Boys have much longer 14 wheel tenders and a much greater overall length.
The Virginian 2-10-10-2s were probably the most successful of the early attempts at a really huge compound articulated. They could work all day producing high tractive effort at a slow speed in heavy haul service, something that the earliest road diesels had a hard time doing with their relatively fragile traction motors.
The best heavy simple articulateds could slog it out a slow speed with high tractive effort and then run fast and make high horsepower. It really took until the arrival of the F9 and GP9 for a four unit set of diesels to substantially exceed the performance of a big boy all across the horsepower curve.
Of course, that doesn't always equate to tractive force
Actually it does.
Drawbar horsepower is determined by
Drawbar Pull (pound feet) x Speed (MPH)
375
Which, of course, is the standard horsepower equation.
http://www.physlink.com/education/askexperts/ae66.cfm
Using the physical definition of a horsepower is can be seen that horsepower is product of force and velocity. Using the equation, this leads to:
1.) Traveling at a velocity of 550 feet per second against a force of 1 pound is 1 horsepower.
2.) Traveling at 1 foot per second against a force of 550 pounds is 1 horsepower.
The definition is work done at the rate of 550 foot-pounds per second.
In case (1) the velocity is high against a low force.
In case (2) the velocity is low against a high force.
Thus, horsepower does not equal velocity. It is just the ability to do work.
Thus, this statement:
The best heavy simple articulateds could slog it out a slow speed with high tractive effort and then run fast and make high horsepower.
Is incorrect.
Both running fast and slogging it out require high horsepower. The power is being used for different purposes.
By the bye, my understanding is that Lionel will be coming out with an engine that was very popular on the Milwaukee. The L3 class were USRA Heavy Mikados, and the Milwaukee had 100 of them. They were actually the largest power on the road until the S-2 Northerns were built starting in 1938. you're gonna hafta save up for one of these authentic Milwaukee Road engines.
I'm also a Milwaukee Road guy and was wondering where you heard about a USRA Heavy Mikado from Lionel. I don't keep a good handle on planned production from any of the manufacturers. If Lionel does a L-3 version of the USRA Mike I wanna be sure to get one when they first come out. I almost missed out on the S-3 Northern and ended up paying more for the one I finally got.
Discussions like this will never get settled: between the very real grays areas in the interpretation of what words like power, etc. can mean (At what speed? Under what conditions?) and the fact that you always hear someone bring up that "the weight was deliberately under-reported" or the firebox grate was actually larger than listed for whatever reasons, or . . . something . . . there will always be that un-resolvable element in these discussions.
What I do know is that the Big Boy and Allegheny were designed for very different purposes, railroads, and regions of the country, and that each could do its particular job much better than the other could have done it. That's sort of the key thing in my mind. They shared some common characteristics - both were really big, both had gobs of wheels, both were the biggest boy in their own neighborhood, both represented the top of the pyramid for their particular evolutionary branch of steam, and both are iconic locos in some sense as a result. But they were different enough that its apples and oranges - at least enough - that you can't ever settle the issue
Quite right, 2 engines built for very different roads and operating conditions.
Which is why I own at least one of each.
Just to muddy the waters further, where does the Yellowstone fit into all this?
---PCJ
Years ago I had an old copy of that now mainly HO magazine......the Model of the Month was a scratch built O scale 6-12-12-6 that had the look of a Bog Boy but was a fictitious 'what if' build......just produce a model like that and no more arguments!!!
Great link
UP Big Boy Heaviest 772,250
C&O H8 Highest Hp 7,498
N&W Y6b Most Pulling Force 170,000 (@5600 hp)
This is an argument that can never be settled. The UP 4012 is being restored, the N&W 2156 and C&O Allegheny are sitting in museums. Even if the N&W and C&O engines were restored, what could be proven? All three were built for different railroads, with different design criteria.
I think we can reasonably agree that these were all fine examples of the state of the art at the end of the steam era.
Gilly
Thus, this statement:
The best heavy simple articulateds could slog it out a slow speed with high tractive effort and then run fast and make high horsepower.
Is incorrect.
Both running fast and slogging it out require high horsepower. The power is being used for different purposes.
WBC
Perhaps you haven't done the math or seen a dynamometer chart from a locomotive test. Steam locomotives are reciprocating engines. And as external combustion reciprocating engines they produce their peak torque at slow speed. As speed increases torque is lost to increasing friction in the machinery and the flowing steam. But the number of power impulses per minute increases with speed so horsepower increases even as torque (drawbar pull) decreases.
If our Virginian 2-10-10-2 and a Big Boy can produce 130,000 pounds of drawbar pull at 8 mph (and that is a real possibility for both of them) they are producing 2773 drawbar horsepower. If the Big Boy is making 50,000 pounds of drawbar pull at 45 mph it is producing 6000 HP. That is a remarkable figure, and possible for the remarkable Big Boy but not for a slow speed machine like a 2-10-10-2.
50,000 pounds of drawbar pull at 45 mph is one heck of a lot of work. An Allegheny could do it. Four GP9s could do it. Two SD45s could do it. The only single unit diesel that might be able to perform that much work is a DD40.
What I do know is that the Big Boy and Allegheny were designed for very different purposes, railroads, and regions of the country, and that each could do its particular job much better than the other could have done it.
Lee
The Allegheny was not a good design for hauling coal drags. It could not use its horsepower potential in that service and it did not have the slow speed tractive effort of a Y6, Yellowstone or Big Boy. The Big Boy had better low end power than the Allegheny and also performed very well on fast freights. The Big Boy was the more versatile machine.
Just to muddy the waters further, where does the Yellowstone fit into all this?
Rail Ride
The NP Z-5 Yellowstones were built a decade before the fist Big Boys and were the worlds largest locomotive until the creation of the UP 4000s. The Z-5 were built to replace double headed heavy 2-8-2s on 4000 ton trains on the sawtooth 1% grades of the NP Yellowstone division. The were really pushing locomotive technology in their day put could do the work of two mikes as intended. They were rebuilt the cast steel front frames in 1941 and received roller bearings. They could slightly out pull a Big Boy at slow speed but could not match a Big Boys horsepower in the 40-50 mph range.
C&O H8 Highest Hp 7,498
Gilly
Only in questionable momentary readings. However it did sustain readings between 6700 and 6900 drawbar horsepower at 45 mph.
N&W Y6b Most Pulling Force 170,000 (@5600 hp)
Only by sending high pressure steam to the low pressure engine and lowering the factor of adhesion and only at very low speed and lower horsepower. The 5600 drawbar horsepower figure is at 25 mph which corresponds to 84000 pounds of drawbar pull at that speed, a very respectable figure.
The points you make are all good Ted Hikel - very good. I agree with all of them, including your comment about my noting they were different locos designed for different service - that the Big Boy was likely more capable of doing the Allegheny's job well than the other way around. But this comparison (not just your, everything we have been discussing here) neglects one big area that was important to the railroads: cost.
I'm opening up a can of worms here, because without offense to anyone, I think most people, including me, have few hard facts to go on here and so this can make for a unproductive discussion. I don't have a lot of cost data on the Big Boy or Allegheny or Yellowstone or H8s, etc., for that matter. And I would not trust it to be comparable if I did without a lot of detail not available and a lot more effort at studying it than I can put into the analysis: given how different companies account for costs differently, etc. a straight up comparison if cost data if it were available would not necessarily be useful.
So I'm going on fundamental engineering principles here and what I do know about the Big Boy and Allegheny.
From what I read, the Allegheny as a "simple" design concept, just one that was done much better than most previous executions of that same idea: build a really big brute of a locomotive with well-engineered firebox,boiler-steam plumbing aimed at creating massive tractive effort at low speed. Don't compound anything or make that much of the machinery adjustable/variable as speed increases, etc., etc., and you will save both initial cost and operating and maintenance costs down the road because its a simple basic design built to do its one thing dependably and well, etc. The thing will be able to start and drag massive coal and similar trains up mountains at low speeds, but you will just have to accept the inevitable consequences whenever you want/try to run it fast.
By contrast, everything I have read and seen about the Big Boy says it was designed for the Wasatch Front route, by people quite experienced with designing and running locos up and down Sherman Hill and the entire Wasatch front run, etc. As such, low speed tractive effort was critical: the Big boy had to start and drag a big train and crawl up slopes with a heavy (around 3500 ton) load. I know that UP and Baldwin engineers considered carefully the engineering of massive tractive effort at low speeds - that much is covered in books I have.
All I can find about higher speeds leads me to doubt UP and Baldwin engineers were thinking 70 mph when they laid the Big Boy's design out, but its clear they they were thinking 50-60 mph. And what I have to read, etc., seems to imply that efficiency, rather than outright max HP, was more on their mind for those speeds. Regardless, the Big Boy was engineered as a compound, a somewhat more complicated and expensive steam plumbing which, among other things, could give pull at low speeds and via variation of this and that in the valve gear and plumbing, more efficiency and HP at higher RPMS. It also has lots of variable what-nots here and there throughout so that operators could have their cake (low speed pull) and eat it too (high speed HP and efficiency).
So in this regard, again, the Big Boy and Allegheny were very different locos, each designed for its job, both ending up roughly the same size and capability at low speeds. The Allegheny was perhaps more of a one-trick pony - a very powerful Clydesdale at low speeds. The Big Boy was capable of roughly that same low speed pull and operating efficiently at higher speeds, but I'm fairly certain it cost more - it was certainly much more complicated. That combination of size and complexity is, frankly, why I have such an interest in the Big Boy and consider it the ultimate big steamer, but I admire and have the Allegheny and Yellowstone, too, and H8 (the only big loco I have two of).
I know that UP and Baldwin engineers considered carefully the engineering of massive tractive effort at low speeds - that much is covered in books I have.
Sorry Mr. Willis, but ""Baldwin engineers" had nothing to do with the design of the UP 4000 class locomotives (nor the C&O Allegheny locomotives for that matter). In fact, the UP stopped purchasing any new big steam locomotives from Baldwin Locomotive Works in the late 1920s.
ALCO was the designer & builder of choice for the Union Pacific RR.
Also, many of your "assumptions" are not quite correct concerning the UP 3900 and 4000 class locomotives, as they were BOTH designed to handle tonnage trains at speeds faster than "drag speeds", i.e. NOT coal trains on the C&O, N&W, B&O, Western Maryland, or PRR.
The biggest difference between the designs of the UP 3900s and 4000s versus the C&O Allegheny class was the fuel! The C&O had massive supplies of HIGH BTU coal, while the UP was forced to burn Wyoming coal, with much lower BTU content. Thus, the furnace systems of the UP locomotives had to be designed differently than the C&O locomotives.
Regardless, the Big Boy was engineered as a compound, a somewhat more complicated and expensive steam plumbing which, among other things, could give pull at low speeds and via variation of this and that in the valve gear and plumbing, more efficiency and HP at higher RPMS.
??
Regardless, the Big Boy was engineered as a compound, a somewhat more complicated and expensive steam plumbing which, among other things, could give pull at low speeds and via variation of this and that in the valve gear and plumbing, more efficiency and HP at higher RPMS.
??
???????? My sentiments exactly!
Another post by a person who has limited, or no, knowledge of modern steam locomotives.
When I first posted this topic, I had no idea it would cause such a ruckus and heated discussion. I figured that a comparison in weight, length, HP, pulling power and top speed would be sufficient. When I post topics, excluding for sale or help me, it is just for the fun of learning new things in the world of real and model railroading. I believe all of us can learn from these posts. Also, when someone has posted incorrect info in these posts, there is a polite way and a sob way of correcting the response.
I know that UP and Baldwin engineers considered carefully the engineering of massive tractive effort at low speeds - that much is covered in books I have.
Sorry Mr. Willis, but ""Baldwin engineers" had nothing to do with the design of the UP 4000 class locomotives (nor the C&O Allegheny locomotives for that matter). In fact, the UP stopped purchasing any new big steam locomotives from Baldwin Locomotive Works in the late 1920s.
ALCO was the designer & builder of choice for the Union Pacific RR.
Also, many of your "assumptions" are not quite correct concerning the UP 3900 and 4000 class locomotives, as they were BOTH designed to handle tonnage trains at speeds faster than "drag speeds", i.e. NOT coal trains on the C&O, N&W, B&O, Western Maryland, or PRR.
The biggest difference between the designs of the UP 3900s and 4000s versus the C&O Allegheny class was the fuel! The C&O had massive supplies of HIGH BTU coal, while the UP was forced to burn Wyoming coal, with much lower BTU content. Thus, the furnace systems of the UP locomotives had to be designed differently than the C&O locomotives.
Yeah, I knew that Alco did it, too, just didn't think about it, and didn't want to bring up the coal issue because that is sort of another issue - not as I see it, really relevant to the simple-versus-compound issue I think led to the difference in character of the two locos.
The coal is an interesting and important issue. UP had such crud to work with: I have always wondered if the UP Coal Turbine would have been deemed a success had it run on that good-quality eastern coal rather than that crud that caused all the turbine blade wear, etc.
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When I first posted this topic, I had no idea it would cause such a ruckus and heated discussion. I figured that a comparison in weight, length, HP, pulling power and top speed would be sufficient. When I post topics, excluding for sale or help me, it is just for the fun of learning new things in the world of real and model railroading. I believe all of us can learn from these posts. Also, when someone has posted incorrect info in these posts, there is a polite way and a sob way of correcting the response.
MilWRdOPaul: This is a very good discussion and I appreciate your bringing it up. If people keep things reasonably civil, the disagreements are not going to hurt anybody. In one sense it is quite amazing that anyone can get so enthusiastic and sensitive about opinions/facts/disagreements over stuff that was over 50 years ago, but its a sign of how much people care about their toy trains, etc. I learn a lot from threads like this and enjoy listening to and thinking aobut other opinions. I must admit that I am going to shut down this computer now that lunch is done and go work on the layout this afternoon, but threads like this a part of why I love this forum!
Yeah, I knew that Alco did it, too, just didn't think about it, and didn't want to bring up the coal issue because that is sort of another issue - not as I see it, really relevant to the simple-versus-compound issue I think led to the difference in character of the two locos.
I still don't understand your references to "simple-versus-compound issue", when neither of the UP "big articulated steam locomotives" (4-6-6-4 and 4-8-8-4) were EVER even remotely considered to be compound types, nor were the C&O 2-6-6-6 H-8s!
Speaking pf horsepower - not TF - I note above that the Allegheny was rated at 7,498
cylinder hp. That sounds about right - I'm not going to get out my "Lima's Finest" book to check. Huge loco, simple, 4 high-pressure cylinders.
Funny thing, the NYC Niagara, 2 cylinders, medium-sized 4-8-4 was rated at 6,600 cylinder hp (more than the ATSF 2900's). Nearly as much; more per cylinder. (Best boiler ever.) Horsepower was very important in the world of modern steam.
But an Allegheny could not have done the Niagara's job, and a Niagara could not have
done the Allegheny's.
Nevertheless these apples-and-oranges debates can be entertaining.
Lee
I think you are confusing the UP Big Boy with the N&W Y series including the Y6.
The UP Big Boys and Challengers along with the Alleghenys, Yellowstones, SP 4-8-8-2 cab forwards and N&W A Class 2-6-6-4 were all simple articulateds. All were intended to be capable of moving fast freights at 40-50 mph or more.
The N&W Y6s were unusual in being compound locomotives built late in the steam era. They had very good low end pulling power and were capable of more speed than any other Mallet type that I am aware of. They hit their peak horsepower at about 25 mph. They were very versatile for Mallet compounds, many of which would do damage to track at the speeds the Y6s ran at regularly.
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