In 1930, Baldwin Locomotive Works began delivery of 25 4-8-2s to the Wabash Railroad with dimensions almost identical to the 25 4-8-4s ordered at the same time, for the same type of freight service; to this day it remains a mystery why the railroad did not order 50 locomotives of the same type. Like the class O-1 Northerns, the M-1 Mountains had 70-inch drivers and 27x32-inch cylinders. Their boiler pressure, as delivered, was 235 p.s.i. but was later raised to 245 p.s.i., raising the tractive effort to 69,400 pounds. These engines of the M-1 class weighed 406,400 pounds minus tender. They had 4620 square feet of evaporative heating surface, 2004 square feet of superheater surface, and a grate area of 84 square feet. All were removed from service and scrapped in the mid-1950s. No. 2815 poses here in a photo acquired through an eBay seller; note the Walschaerts valve gear in reverse position. There is no information about the original photographer, location, or date.