This builder's photo of Texas & Pacific 4-8-2 No. 902 was scanned from the 1951 edition of World Railways. These class M-1 Mountain types, oil-burners built in 1925 by the American Locomotive Company, were mainstays of the T&P's heavier passenger service along with the later M-2 class. They developed 57,300 pounds of tractive effort, with a booster adding 10,450 pounds, and weighed 360,000 pounds minus tender. With 73-inch drivers, they had 225 p.s.i. of boiler pressure and cylinder dimensions of 27x30 inches. Their grate area totaled 80.3 square feet, their evaporative heating surface 3769 square feet and their superheating surface 1,110 square feet. Late in the steam era some members of the M class were modernized with disc drivers and given a stylized paint treatment to match new streamlined passenger cars.