Utah Railway 2-8-8-0 "Consolidation Mallet" Locomotives in the USA

Class 200 (Locobase 9496)

Data from "Mallet Locomotives for the Utah Railway," Railway and Locomotive Engineering, February 1919, p.39. See also DeGolyer, Volume 56, pp. 249+. (Thanks to Steve Low for his 18 March 2018 email underscoring the UR trio's design origins.) Works numbers were 48221-48222 in April 1918 and 48901 in June.

Virtually identical to the B&O ELs shown in Locobase 439, this trio went to the United States Smelting company for them to operate on the UR. Steve Low noted that the UR asked for the Union Pacific's help in selecting the best design for their particular requirements. It was the UP that spotlighted the EL-series as the best fit. Low adds that the 200 class strongly resembled the later MC class (e.g. Locobase 7466) procured by the Union Pacific.

One small difference was the UR engines' use of 1" (25.4 mm) smaller diameter drivers to conquer grades of up to 2.4%. The Mallet layout contributed to an ability to negotiate 20-deg curves in sidings and 9-deg curves on the main line.

All four cylinders were supplied through 15" (381 mm) piston valves. Firebox heating surface area included 43 sq ft (4.0 sq m) in four arch tubes and 118 sq ft (10.96 sq m) from the combustion chamber.

The article noted another feature of use in the Utah Railway's winding surroundings: "The Baldwin design of flexible articulated frame connection is used. With this construction, the front and rear frames can move relatively to each other in a vertical plane, without causing binding at the hinge pin. The value of this feature is specially noticeable in a Mallet locomotive with long wheelbase, when passing over uneven tracks or sudden changes in grade."

The design proved successful enough to endure into the 1950s with two of the engines leaving service in 1954 and the third (201) as late as March 1957.