Reading about UP’s Gas Turbines got me to thinking about the UP’s Big Boys, as well. So much has been written about them. It also seems that everybody has an opinion of them.
Were they just an embellished "Challenger or an “Allegehany” on sterroids?
Quote from Wikipedia article on Big Boys:.
“During the war, after German agents filed reports that the Americans had giant steam engines that were moving huge trains full of vital war material over steep mountain grades at high speed, their reports were dismissed as “impossible”. Their performance in moving a huge volume of war material throughout WWII was repeatedly cited, and the Big Boys are generally acclaimed as having made a huge contribution to the war effort.[citation needed]”
I would imagine they had a real eyeful with the three-Mallet coal drags in Virginia and other places further north in the N&W, B&O, C&O, and in the DM&IR areas, and that they would dutifully have reported their findings about these as well.
I think you are certainly correct! Big Boys over Sherman with trains approaching 4,000 tons and toping the Hill at speeds between 40 and 60 MPH have got to be impressive and mind-boggeling to individuals only familiar with mid-Twentieth Century European railroading.
Long, heavy trains over a grade like Cranberry, and other steep Eastern grades at something between 5 and 15 MPH with three huge Mallets just pounding at the limits they were designed for; up grades with percentages anywhere from 1+ to around 4 or 5 give or take some would be impressive on their own scale…
Well, given that the Big Boy design evolved from the Challenger the “steroids” analogy may be apt…
The C&O(and Virginian) Allegheny was a very different design (basically Lima’s Superpower 2-10-4 was the starting point) and they were actually slightly larger than the Big Boys…
I have read Steam locomotive authors who make the argument that while the Big Boys operated in exactly the service they were designed for;fast freight (40-60 MPH) the Alleghenies may have been not as well suited to the coal drag service they were used in (i.e they would have been better suited for fast freight service but that d
NOPE, the Big Boys had a starting tractive effort of 135,000#, the Alleghenys had a starting tractive effort of 110,000#. The Big Boys could start a heavier train than the Alleghenies could. Horsepower=acceleration, torque (measured as tractive effort in railroading) measures the ability to overcome inertia.
The Allegheny would be able to out accelerate(greater Horsepower) a Big Boy with the same same train, within the Allegheny’s starting ability, but the Big Boy would would be able to start a heavier train than an Allegheny could.
I don’t recall what the Allegheny’s top speed was, but I do believe that you are right, the Big Boys were designed to run up to 80 MPH, and probably were faster than the Alleghenies.
It amazing how the passage of time inflates horsepower. The Allegheny was easily the most powerful steam locomotive ever created and had real world horsepower output of 6600-6700HP at the drawbar. The Big Boy, as a class of locomotives produced 5800 HP at the drawbar, with a few individual locomotives reaching 6000 HP.
However, this doesn’t tell the whole story. The Allegheny’s boiler was much more massive and powerful than the Big Boy’s. The Allegheny had well over 7200 sq.ft. evaporative surface, while the Big Boy had 5,800 sq.ft. At high speed, the Allegheny was in a class by itself in its ability to evaporate water into steam. The Big Boy reached maximum power around 35-40MPH, and above that, its horsepower curve dropped off. IIRC, the Allegheny was tested only up to 50MPH, and its horsepower curve was still rising. The dyno car’s reading was going crazy at that point and bouncing all over the place from the power output. Talking about speed, the Allegheny was just as capable of 80MPH o
As best as I can recall - which is subject to correction - LeMassena concluded that most of these big engines were mis-applied to heavy drag service at slow speeds way below their potential peak power output, and/ or handicapped by cheap / poor quality coal supplies - NP’s Yellowstones, for example - etc. But he viewed the Alleghenies as being well-matched to the service they were designed for.
I’d never heard the Wikipedia’s statement about the German agents applied to the Big Boys. Wouldn’t those guys have been kinda obvious watching trains at Sherman Hill back then ? But geez, if they were that impressed by the Big Boys, maybe they should have seen the GG1’s on the PRR during the war - such as at ZOO Tower in Phila. where 3 main lines join, or on the New York Division’s racetrack - if they’d been believed, perhaps the Germans would have given up sooner.
I have the impression that there was some controversy related to the amount of weight that the Allegheny locomotives carried on their drivers. Do you have any insight into that? Thank you.
(I THINK) THE STATEMENT AS TO THE INITIAL WORKING WEIGHT OF THE ALLEGHENY’S WAS IN A TRAINS ARTICLE ABOUT THEIR CONSTRUCTION, (I THINK THAT WAS THE SOURCE.)
The First Allegheny was suspected to be very much heavier than thought due to casting issues a the foundry. As was an apparent practice at the locomotive manufacturers facilities; the weighting of original locomotives was shrouded in mystery, the weighing process was only open to certain employees and management who were to be present during the process. The preparation for the initial weighing of a new product was very arcane and there was a lot of preperation, Water in the locomotive and tender was specified to be at a certain level, fuel was alos set to a specification, as well, and so it went.
The mystery and secrecy was due in some part to the facts that engineer’s pay was figured and factored with locomotive weight on drivers as part of the scale of pay. Plus the fact that if the locomotive was TOO Heavy, there was a chance that delivery could be refused as it would be out of the specification as ordered.
I thought, with reference to Kratville’s book, the calculated DBHP was 6000 and actual was 6100. A negligible difference, though, just courious were you got this data.
Sad, there are so few worthy test-data on that big locomotives. Still seeking to get test-results of the B&O and DM&IR Yellwstones, also.
In case of the BB test results, any speed above 40MPH was extrapolated. It was an uphill run with only 1mile level track where the train could accelerate to that speed. Who knows, maybe it could produce ongoing HP at higher speeds, but that was not the concern of the tests.
On note to the War-Efforts: How many percentage of military goods they really moved? I think to less to make a statement like “having made a huge contribution to the war effort”. They made a good contribution to their railroad, nothing more, nothing less.
I’m kinda amused at the bickering here attributed to a wartime spy for the losing side…No mention of the other articulated monsters roaming in the western mountains at that time on DRGW, ATSF (borrowed from N&W), GN and others…
RE: tonnage and people moved? … tonnage on most lines out here never got that high again until the advent of coal and the shift to offshore manufacture of goods. (Raton Pass never saw 60-80 trains a day over the hill after that…It only sees 2 a day now normally)
Here I thought we were just determining how observant, perceptive, and purposed a spy he/she must have been if his/her conclusion was that the Big Boy was the epitome of the grandest and most imposing of steam engines in N. America at the time. [:-,] Maybe, just maybe, he/she was so enthralled and full of admiration that he/she felt obliged to sabotage his/her nation’s efforts by reporting on the least capable.
Robert La Massena has first-rate credentials as an engineer. The article in question specifically mentions that the Alleghenies were designed for a higher speed range than the one in which they were used. La Massena basically states that Lima designed and built a Super-Power articulated that spent most of its time in low-speed mineral freight service.
They were designed for a speed range of … maybe -20 to +60 mph? and no doubt C&O mostly used them in that range. You probably meant to say they reached their peak horsepower at 40+ mph and C&O coal trains didn’t climb grades at 40+ mph, which is true.
and the bottom line is… a) there is no such thing as a ‘best’ locomotive. We all have our preferences, and so did the railroads. Particularly with steam, there were just too many variables to make any kind of realistic comparison possible. The best one can ever do is say that such and such a locomotive might have been the best at this service, or on that division. And even that will need qualification! b) as in sports, on any given day… the actual horsepower and tractive effort of a given class of steam locomotive is really kind of hard to pin down. No two were exactly alike, even within a very closely grouped class (ask anyone who ran them! They each had a personality, and while some were angels and did what you asked every time, others – even the very next one in a batch – were anything but angels, and seemed to be possessed of an evil spirit! On top of that, there were (and still are) good engineer and fireman pairings, who could make a 50 year old wreck of an engine perform like new or better, and bad engineer and fireman pairings, who could take the best example of a class on the line and manage to run out of steam or consume 30% more coal or otherwise carry on like the Three Stooges. That said, almost all of the late steam engines (Big Boys, Challengers, Allegheniys, Niagaras, FEF-4’s, you name it) were superb examples of the art of engineering and building steam locomotives, with few equals anywhere in the world (they did have equals, though – some of the late UK and German steam engines were pretty fantastic, too) and it would be hard to make a firmer statement than that. One can also say, though, that it wasn’t that uncommon for any of them to be used – particularly later in their lives – in services for which they were very unsuited, which distorts the picture.
Now Crandell, it all depends on how you define “Least Capable”. If you are measuring Pure Horsepower, the Allegheny does best the Big Boy. If you are Measuring Tractive Effort, which is more important in railroading, then the Big Boys have a very decided advantage over the Allegheny, but the Big Boys being the “Least Capable”? Not even close to being true.
Bottom line, regardless of which measurement you use to measure performance, the Union Pacific had arguably the Best PR department, that made “Big Boy” a household word. Even today, if you say “Big Boy”, many people will comment on them being the Biggest Steam Locomotives ever built. Mention “Allegheny”, and some will recognise there are Mountains by that name. Say “Yellowstone”, and you are likely to hear" Hey, I went there as a Kid, I should take my own kids some day"
Regardless of which is your favorite type, Big Boy, Allegheny, Yellowstone, Y Class, Class A, or J, Challenger(of any class) FEF, or GS class, and many others not mentioned, they were all impressive machines. It is a shame that so few of them are still operational today.