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the distance between the front and rear axles of a two-axle motor vehicle, tractor, or trailer or between the front axle and the center of the two-axle undercarriage of a three-axle motor vehicle (trailer).
Increasing the wheelbase improves the stability of transport vehicles but reduces their maneuverability. For example, in the case of dump trucks, which usually operate within the crowded conditions of a construction site or a quarry, the wheelbase is shorter than it is in the case of conventional trucks of the same type. (The wheelbase of the ZIL-130 panel truck is 3,800 mm, whereas the ZIL-MMZ-555 dump truck has a wheelbase of 3,300 mm.)
The wheelbase of a railroad car or locomotive is the distance between the centers of the terminal axles. In the case of a truck-type railroad car or locomotive, the wheelbase is measured as the distance between the centers of the pivot journals of the terminal trucks. In the case of nontruck-type locomotives, a distinction is made between the total wheel-base and the base of the driving (movable) wheels. The dimensions of the wheelbase are determined to a great extent by the conditions under which rolling stock passes over curved sections of track.