Locomotive frames run the length of the engine and carry the weight of the firebox and boiler, as well as offering convenient places to attach the running gear and other equipment. The entire locomotive is supported by a series of bars fastened together like a bridge—rigid enough to support the engine boiler and firebox, yet flexible enough to respond to rough track without breaking or causing a derailment. Frames can be one-piece castings or riveted composites.
Quick facts
Space-saving feature
First use in England
First use in United States