Built by the Baldwin Locomotive Works in 1906 for the Union Pacific subsidiary, the Oregon Short Line, this Consolidation type (2-8-0) locomotive was originally numbered #1101. It is one of three hundred and fifty-eight of what became known as "Harriman Common Standard" Consolidations built for the UP and its subsidiaries by Baldwin, Brooks and Schenectady from 1904 to 1910. It was renumbered #561 in 1915 and was leased to the Union Pacific in 1936.
As built, #1101 weighed 208,000 lbs, 187,000 lbs on its 57” drivers. It has a 15’ 9” driver wheelbase and engine wheelbase of 24’ 4”. With Stephenson valve gear and 22” x 30” cylinders, it had a 49.5 sq ft grate, 177 sq ft firebox and total heating surface of 3,403 sq ft. Operating at a boiler pressure of 200 psi, it delivered 43,035 lbs tractive effort.
From 1936, superheaters were fitted to all in-service C-2s. The engine weight went up to 212,800 lbs, 191,110 on the drivers. The firebox grew to 191 sq ft and total heating surface to 3,471 sq ft including 574 sq ft superheating. Tractive effort remained unchanged.
