Published: July 28, 2025
By: Adam Burns
The 2-10-10-2 wheel arrangement represents a unique chapter in the evolution of steam engines. Their massive size and power were primarily designed to tackle the challenges of hauling heavy freight over mountainous terrain, where the need for tractive effort was paramount.
The first 2-10-10-2s emerged on the Atchison, Topeka and Santa Fe Railway, which ordered a group of ten in 1911. These engines, were not popular on the western road due to their very low speeds and could be used primarily in helper service only. The AT&SF utlimately converted them into 2-10-2s between 1915-1918.
The eastern coal hauler, Virginian Railway, saw much greater success with the design, in part due to their ideal nature in slow drag service. Their ten examples, sporting a relatively short wheel base given their numerous drivers (although at the time were considered massive), arrived in 1918 and remained in regular service until the early 1950s.
The Virginian Railway stands as one of the last monumental rail systems in the nation. Forged from the ambitions of oil baron Henry Rogers and the engineering prowess of William Page, its sole mission was to transport coal effectively.
Though its main line stretched under 500 miles, it was a constant thorn in the side of the larger Norfolk & Western due to its stringent construction standards.
Despite its modest size, the Virginian excelled in seamless operations, moving coal from the mines straight to the coast with clockwork precision.
Conceived at the dawn of the 20th century, the railway's inception was swift, propelled by Rogers' substantial financial backing. The 1920s witnessed part of its main line west of Roanoke, Virginia, transitioning to electrification, marking a golden era for the railway.
Initially, boxcabs were used, but they were later supplanted by more robust rectifiers from General Electric.
The constant rivalry drove the N&W to such frustration that they eventually offered top dollar to end the competition, absorbing the Virginian in the late 1950s. Nowadays, much of the Virginian's original main line remains operational, now under the Norfolk Southern banner.
The Virginian is well-known for its use of a large wheel arrangements, including the 2-8-8-2, 2-8-8-0, 2-8-4, 2-6-6-6, and even the gigantic 2-8-8-8-4 "Triplex." As Lloyd Lewis notes in his book, "West Virginia Railroads Volume 4: Virginian Railway," these big engines were acquired for two reasons; handling coal and tackling the 2.07% grades over Clarks Gap Mountain.
These engines were much better proportioned compared to the Erie's Triplexes or the 2-8-8-8-4s previuosly mentioned. Their boiler and grate demand factors were reasonable, allowing the crew to maintain consistent steam, largely thanks to the use of a Duplex or Standard mechanical stoker.
The firebox's heating surface was enhanced by a short combustion chamber. High-pressure cylinders received steam via 16-inch piston valves, while the massive low-pressure cylinders, with a volume of 33.51 cubic feet each, utilized double-ported slide valves. The simple starting tractive effort reached an impressive 176,000 pounds.
They were versatile enough to run in either single or double expansion modes. It's impressive that their giant boilers could maintain steam pressure even at a slow speed of around eight miles an hour.
In December 1921, Alco's Estimating Engineer, James Partington, highlighted the pulling power of these double decapods. One engine hauled a 15,725-ton train from Princeton to Roanoke, burning 26.9 pounds of coal per 1,000 ton-miles. Another 2-10-10-2 handled 110 cars, totaling 17,250 tons, over a tough grade of 0.2%.
The 2-10-10-2s may not have matched later articulated models in size, but with an almost 100-foot-long wheelbase, they were undeniably giants of their time.
However, many foreign railroads faced challenges handling these behemoths as the engines made their way to the Virginian due to more restrictive clearances—notably less generous than those of the Virginian, which was renowned for its accommodating space.
The low-pressure cylinders, measuring a massive 48 inches, were record-setting in size for any locomotive in the U.S. They were so large that they had to be installed at a slight upward angle for proper clearance. Interestingly, due to the constraints of the Virginian turntables, these locomotives had unusually small tenders.
Before these engines set off from American Locomotive's Schenectady Works, a few adjustments were necessary: the steam and sand domes, the spacious cab, and the massive front-end high-pressure steam cylinders were all removed, photographed, and packed onto a preceding gondola, ensuring a slow but steady journey southward.
Road Numbers | 800–809 |
Number Built | 10 |
Builder | Alco |
Year | 1918 |
Valve Gear | Walschaert |
Driver Wheelbase | 39' 8" |
Engine Wheelbase | 64' 3" |
Overall Wheelbase | 97' 0" |
Axle Loading | 61,712 Lbs |
Weight on Drivers | 617,000 Lbs |
Engine Weight | 684,000 Lbs |
Tender Loaded Weight | 214,300 Lbs |
Total Engine and Tender Weight | 898,300 Lbs |
Tender Water Capacity | 13,000 Gallons |
Tender Fuel Capacity (coal/tons) | 12 |
Minimum Rail Weight | 103 Lbs |
Driver Diameter | 56" |
Boiler Pressure (psi) | 215 |
High Pressure Cylinders | 30" x 32" |
Low Pressure Cylinders | 48" x 32" |
Tractive Effort | 135,170 Lbs |
Factor of Adhesion | 4.56 |
The AEs operated effectively for 30 years, initially as pushers until replaced by electric engines, and later as helpers on other grades. The engines remained largely unaltered, except for the addition of Worthington BL feedwater heaters. These workhorses served reliably for 34 years until their retirement in 1952, by which diesels and electrics had largely replaced Virginian's steam fleet.
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