The Canadian National's U-4-a 4-8-4s had 77-inch drivers, 24x30-inch cylinders, and 275 p.s.i. of boiler pressure. Weighing 379,800 pounds without tender, they developed a tractive effort of 52,500 pounds. Their evaporative heating surface totaled 3861 square feet, and they had a superheating surface of 1530 square feet and an 84-square-foot grate area. This photo from Elwin K. Heath shows No. 6403 near the famed Turcot roundhouse at Montréal, being readied for her first run under steam when new.