BOARDING STAIRS

PROPEL MACHINERY

The propel machinery is driven by two AC motors, each horizontally mounted to a shelf, cantilevered off the truck frame. The motors are coupled to twin planetary gearcases high up off the pit floor for protection from water and rock damage. The planetary gearcases bolt to the crawler frames. One low-inertia, spring-set, air-released, disc-type air brake is mounted to each of the two motors. The dual planetary configuration with separate drive motors permits straight ahead or reverse propel as well as counter rotation steering.