i ran into two problems when considering something like this as a cart....
1) This point, brought up by a visit to a sponser (Anorad Inc.) who uses large hovercraft-like devices to move large machinary around, had to have a custom built factory, with a perfectly level floor. They had a "spider-bot" that went across the still-wet concrete andusing lasers and crazy stuff like that made the entire factory floor perfectly level. Reason? The hovercrafts have no friction. Hit a slope, it's gone, and you'll have one hurting robot, and many hurting people.
2) You'll need lots of clearance. I'm talking like minimum of 2 inches. More than most robots. There's so many wires / tools / feet in the pits, anything less and you'll get stuck. You could put wheels under the skirt, just in case, but it kind of defeats the purpose of a hovercraft...
Oh, and one more thing. I don't believe gas motors will be allowed, so you'll need lots of batteries.
Get around those and build a robot carrier, and, well, you'll have the coolest robot carrier to date
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