One big honking vehicle, the TC-497 Overland Train, Obsolete the day it was finished

Above image from Big Lorry Blog, where there are a couple more photos and the info that one is restored and at Ft Yuma Arizona
In the 1950s the LeTourneau company developed several overland trains, essentially oversized semi-trailer trucks that could travel over almost any terrain. Their intention was to be able to handle logistics needs without being dependent on local road or rail systems, allowing them to operate in back-country areas.

six-wheeled TC-497 Overland Train MkII used four Solar gas-turbine engines (at 1,170hp each, that’s 4,680hp total) to spin generators that delivered juice to 54 total motors – one for each of its wheels. Of its 12 trailers, two were dedicated just to carrying the turbines and generators. The Overland Train stretched 572 feet long, easily making it the world’s longest vehicle. Funny enough, it could only carry 150 tons of freight – as much as the Sno-Freighter – though it carried such developments as steerable trailer wheels that allowed the entire train more maneuverability.

Read about it here: because Dan at Hemmings wrote a cool long post about the land trains

For other crazy polar exploring vehicles: