2-10-10-2

ATSF 3000 class

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In 1911 and 1912, the Atchison, Topeka and Santa Fe Railway modified ten 2-10-2 Baldwin-built locomotives into a new 2-10-10-2 configuration dubbed the 3000 class. They were the largest locomotives in the world from their introduction until 1914. They performed well in helper service, but could only go 10 to 15 mph before losing steam. The ATSF reverted them to their 2-10-2 configurations between 1915 and 1918.

Virginian Railway class AE

Simple: 176600 lbf

These ten locomotives were built in 1918 by ALCO for the Virginian Railway. With a width of 12 ft, they were delivered without their cabs and front low-pressure cylinders and were assembled after delivery. The 48 in low-pressure cylinders (on 90 in centers) were the largest on any U.S. locomotive; these had to be inclined a few degrees to provide clearance. The boiler was also the widest of any locomotive; Railway Mechanical Engineer says "the outside diameter of the largest course is 112+7/8 in." but the drawing shows 118+1/2 in diameter at the rear tube sheet. Their accompanying fuel tenders were shorter than usual so the locomotive would fit on the Virginian's turntables.

This class were compound Mallet locomotives. The rear, high-pressure cylinders exhausted their steam into the huge front cylinders. They could also be operated in simple mode for starting; reduced-pressure steam could be sent straight from the boiler to the front cylinders at low speed, for maximum tractive effort.

The calculated tractive effort was 147,200 lb in compound, or 176,600 lb in simple for the Virginian locomotives.

The class remained in service until the 1940s. No examples have been preserved.

References

References

1. (1993). "Virginian Railway Locomotives". Walsworth Publishing Co..
2. Bruce, Alfred. "The Steam Locomotive in America: Its Development in the Twentieth Century". W.W. Norton.