UP 2-10-2 steam locomotive

Twenty-five locomotives of this type have recently been built for the Union Pacific Railroad and two for the Utah Railway. With but few exceptions, these
are duplicates of the engines built in 1917. The main frames are of open hearth vanadium steel. Walschaerts valve motion is used and the setting is the same
as that on the Pacific type locomotives, except the lead is reduced to 1/8 in. This amount is more suitable for heavy freight service.

(from a 1921 magazine, in the public domain)

The boiler has a straight top and the tubes are of the same length as those used in the Pacific type. As the total length of the boiler is considerably greater,
however, a combustion chamber is installed. A Duplex type of stoker is also applied.

The tenders have a capacity of 12,000 gallons of water and 20 tons of coal. The total weight of tender is 217,000 lbs The wheels are of rolled steel and the axles have journals 6 1/2 ins. x 12 ins.