I remember as a kid watching a random sci-fi film of which the title illudes me. All I remember is one of the first action sequences involving a pirate ship on rails, rolling through a desert that gets ambushed. The heel of the flick is a bald guy attached to a crane of sorts with big mechanical claws instead of hands. I know its not much to go on but I'm sure it existed yet no one I know has ever heard of it. Help! :-)

Sounds like,.

Spacehunter:
Adventures in the Forbidden Zone (http://www.badmovies.org/movies/spacehunter/)