http://i.imgur.com/J7Bvx1e.png
A huge vehicle who can be controlled by a character, but is automatic and don't need to be controlled. The legs make it possible to dig tunnels in mountains and ground. In case of emergency it can be armed with a gun.
Stong at the upside, but weak at the underside.
Works on atomic energy, when the upside part is destroyed it can stay moving (uncontrolled) for a few days.
(Low storage room, so ores must be picked up by other vehicles, persons... but this info isn't needed)
Maybe a little bit too detailed, but why not... :p
Spoiler: Show More
(Right hand side is front.)