The lowly 0-6-0 switcher, of which the Canadian National listed 317 in a 1937 roster, is represented here by No. 7439 posing for an unknown photographer at Chatham, Ontario. No. 7439 belonged to class O-18-a, built by the Grand Trunk Railway in 1919. These switchers weighed 174,000 pounds and mustered a tractive effort of 36,700 pounds. The rolled on low drivers 51 inches in diameter, their cylinder dimensions were 22x26 inches, and their boiler pressure was 175 pounds per square inch. Tom Rock of T.D.R. Productions supplied this image, date unknown, for our Random Steam Collection. Two members of this class remain, including one that is operational; No. 7470 serves tourist operations on the Conway Scenic Railroad in New Hampshire.