 The Cannonball was a plastic shell that was originally built for the  film _Ticket to Tomahawk, A (1950)_ (qv). It was modeled after a  real train in Sonora, California. For action shots of the train the  film crew went to Sonora to film the real train. There was only one  set of wheels. They would be moved from locomotive to baggage cart  to passenger car as scenes required.