Southern Pacific’s first 4-10-2 was reason for celebration at the railroad’s Sacramento Shops. Locomotive No. 5000 was the first Alco three-cylinder engine built for SP. The 4-10-2 wheel arrangement became known as the Southern Pacific type and the railroad acquired a total of 49 of this type. As it turned out, only Southern Pacific and Union Pacific bought Alco’s 4-10-2s and all were built as three-cylinder simple locomotives. Unlike the three-cylinder compounds popular in Europe and built for greater thermal efficiency to save fuel, Alco’s three-cylinder designs directed steam from the boiler to all cylinders to provide greater power. This view is looking east; both ends of the Sacramento Roundhouse are visible. A similar view was reproduced on the cover of the company magazine, the Southern Pacific Bulletin, for July 1925. All of SP’s 4-10-2s were scrapped in the mid-1950s, except No. 5021, preserved at Pomona, California.