Patent ID: 7635038

Claim:
A heavy vehicle of a mass greater than 500 metric tons configured to carry heavy loads over a terrain and operable to generate a motive power, the vehicle comprising: tires of radial structure having a diameter greater than 3.5 meters and an axial width greater than 37 inches; a front steering axle coupled to at least two of the tires; at least one rear axle coupled to at least two of the tires and by which is transmitted at least part of the motive power; and a third, intermediate axle coupled to at least two of the tires; wherein said intermediate axle is a steering axle and is moveable to a raised position, and when the intermediate axle is in the raised position, the tires coupled to said intermediate axle are not in contact with the ground, and a longitudinal position of the intermediate axle is a function of at least one of the load and the slope of the terrain.