The Mallet Locomotive is a type of articulated steam railway locomotive, invented by the Swiss engineer Anatole Mallet (1837 - 1919).
The essence of his idea combines articulation of the locomotive and compound steam use. The articulation was achieved by supporting the front of the locomotive on a bogie frame (called a Bissell truck); the compound steam system fed steam at boiler pressure to high pressure cylinders for the main driving wheels. As the steam was exhausted from those cylinders, it was passed into a low pressure receiver and was then sent to low pressure cylinders to power the driving wheels on the Bissell truck.
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