How do you move such a heavy machine? Crawlers, just like in a tank! Seen in this video is the movement of a single crawler track as the bucket wheel excavator is moved backward. You can’t really hear the 700V, 500A electric motors unfortunately, but the rubbing of metal parts can be clearly heard. The whole machine sits on three ‘ball and cup’ type mechanisms, above each of the three crawlers. This creates enormous friction whenever the crawlers rotate, even though it is well lubricated.