pedrails

Noun

pedrail (plural pedrails)

1. A device intended to replace the wheel of a self-propelled vehicle, allowing traversal of rough roads and the ability to climb over obstacles. The tread consists of a number of rubber-shod feet connected by ball-and-socket joints to the ends of sliding spokes attached to rollers and springs.
2. A vehicle, such as a traction engine, fitted with these devices.