The Mallet Locomotive

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.