English: Bogie (truck) on a South Australian Railways Bluebird railcar at the National Railway Museum, Port Adelaide. This design of bogie (with a pair of coil springs nested at the middle) and its variant that has a single nested coil spring were manufactured from 1954 onwards by Bradford Kendall, Sydney, Australia under licence from the Commonwealth Steel Company, of Granite City, Illinois. Variants of the Commonwealth bogie design have been fitted to many passenger rail vehicles throughout the world since it has exceptional riding qualities. The springs have an inner and an outer coil. Other components are, from left: an axlebox with roller bearing, a large equalizing beam that spans the distance between the axleboxes; a vertical swing link, a hydraulic motion damper, another swing link, a stabilising tube, another axlebox with roller bearing, and an air-brake cylinder.