Some MORE Comparisons In The ENDLESS Argument Over America’s “Mightiest” Steam Locomotive
by Emmett Smith
THE Following figures are from the pp of LeMassena, Robert A, Articulated Steam Locomotives Of North America — Sundance Books, Silverton, CO (1979), ISBN: 0913582263. My purpose in drawing them together here is to enable railfen to make a more direct comparison as between the Union Pacific ALCO-built “Big Boy” 4000-series 4-8-8-4 single-expansion articulated steam locomotives, and the Chesapeake & Ohio H-8 “Allegheny” 2-6-6-6 single-expansion engines, built by Lima (OH) Locomotive Works.
As the locomotives were erected over a period of time in different lots there are at least two sets of figures in each case.
UP RR “Big Boy” 4000-series 4-8-8-4
1941 #4000-4019 & 1944 #4020-4024:
[copyright Richard Leonard’s Rail Archive http://www.railarchive.net/index.html]
300 psi… boiler
150 sq ft fire grate
24 & 24×32 inch cylinder bore & stroke
135,000 lbs TE, or tractive effort
762,000 lbs locomotive weight
428,000 lbs 4+10 wheel round-bottomed tender weight
437,000 lbs 4+10 wheel round-bottomed tender weight
28 T tender-capacity, coal
24,000 gal tender-capacity, water
25,000 gal tender-capacity, water *
The differences in the five 1944 locomotives and their nineteen predecessors of four years earlier were minor and centered on changes in tender-capacity, given in italics below the 1941 figures. A thousand gallons of water added perhaps only an additional ten miles range, at approximately 100 gallons per mile at speed. It seems curious to me to have made a big investment in tenders for so small a return, not least because the UP “Big Boys” remit in the end was to range all over the West, although designed mainly for heavy drag-duties between Ogden, UT, and Cheyenne, WY. However, it may have been a matter of the economies of scale, as UP was investing in the larger tenders also for its large purchases of late-model 4-6-6-4 “Challenger” locomotives. (The round-bottom tender configuration further suggests that the tenders were thus the more adaptable as tank platforms for the 1942-conversion oil-fired UP “Challenger” 4-6-6-4s, that could then go the 500 miles from Cheyenne to Council Bluffs without a re-fueling stop.)
All of this, anyhow, stands in marked contrast to the specific design of the “Allegheny” locomotive (see below) for a particular, and shorter, run on laden coal drags between Hinton, W VA, and Clifton Forge, VA. If anyone reading this has a truer idea of the UP 4000-series “Big Boy” mileage (and that of the H-8 “Alleghenies”) on coal and water, please let me know in your comment!
C&O Railway “Allegheny” H-8 series 2-6-6-6
1941-4 #1600-1644 & 1948 #1645-1659:
[copyright C&O Historical Society http://www.cohs.org/ ]
260 psi boiler
135 sq ft fire grate
22-1/2 & 22-1/2×33 inch cylinder bore & stroke
110,000 lbs TE, or tractive effort
771,000 lbs locomotive weight
758,000 lbs locomotive weight
426,000 lbs 6-8 wheel rectangular tender weight
432,000 lbs 6-8 wheel rectangular tender weight
25 T tender-capacity, coal
25,000 gal tender-capacity, water **
Arguably, these minor changes — again in the realm of engine- and tender-weight, but with no change in tender-capacity — may have had to do with the fact the “Allegheny” locomotives in their last years of service went down onto the (comparatively) “flatlands” for higher-speed freight-service. Weight re-distribution may have been the key to offset any possible “phasing” in and out of synchronisation, of the two cylinder-sets. (Sometimes, in compound- and single-expansion articulated locomotives, the two — or three in some cases! — cylinder-pairs are referred to technically as separate engines.) I have read mainly that this phasing, or surging, was most problematical on certain rigid-frame locomotives such as the PRR Q1, with its pairs of opposed cylinders. However, since such problems as phasing and slippage are at least a statistical fact with cylinders driving any arrangement of independent wheel-sets under a common load, it is possible that such a consideration as the damping benefit of weight re-distribution were a factor in the calculations also of UP design engineers, as they made their engines the readier to work at road-speeds.
After all, the “Big Boys” were equipped to supply steam heat to passenger cars and Pullman troop-sleepers, and they did do their duty as troop-train locomotives.
The whole point of course of all of the foregoing is yet another exercise in the haggle over which was the “most powerful” and “The Greatest” and “BIGGEST” of the late-modern American articulated steam locomotives, at the end of the last World steam age. This is a topic endlessly fascinating to boys of all ages (and every gender, all tomboys welcome!) and it is probably pretty harmless….
Right now, as an amateur historian of some salience and insight, I do perceive that the economic side of the argument has to be taken into account:
The “Big Boys” may have been the more diverse haulers of every sort of freight and consist — and I certainly fell in love with them as a small boy one Summer in the 1950s as we ran West beside a pair of them doubleheaded along the highway in Nebraska through the broiling Platte Valley! But, just perhaps in terms of “value added” to America’s mighty WW II effort, the “Allegheny” engines hauled in their careers more sheer industrial power for warfare in the fuel they carried for the American war-time production struggle.
So…does anyone have an idea of the total tonnage hauled by the UP “Big Boys” in their careers? And that dragged by the C&O “Allegheny” steam locomotives?
* — op cit, p 116
** — ibid, p 165
[Emmett R Smith all text-rights reserved & all other rights revert to holders 4 August 2009]