The Union Pacific's first group of class 4-8-2s came from the American Locomotive Company's Brooks Works in 1922 with the Young valve gear, as shown here on No. 7038 in a photo purchased from an eBay seller, location and photographer unspecified. These class MT-1 4-8-2s were the only UP engines to feature this type of valve gear, promoted by the Pyle-National Corporation. In the mid-1930s their valve gears were changed to the Walschaerts configuration, dating this image probably to that time, and they were given one-piece cast-steel frames. Before the advent of the 4-8-4s in 1937 they were the UP's premier passenger power, one (No. 7002) even being streamlined. Members of the MT-1 class rolled on 73-inch drivers; they sustained 200 p.s.i. of boiler pressure and had cylinder dimensions of 29x28 inches. With a grate area of 84 square feet, they had 4974 square feet of evaporative heating surface and 1241 square feet of superheating surface. They weighed 350,250 pounds and developed a tractive effort of 54,838 pounds.