A yard truck is a single-person cab offset to the side of the engine intended to move semi-trailers within a cargo yard, warehouse facility, or intermodal facility. It is built to accommodate a hydraulic lifting fifth wheel allowing the operator to move trailers without exiting the cab or cranking the landing gear. Once a trailer has been moved the operator can lower the trailer back to the ground and uncouple the fifth wheel without leaving the cab.
Sometimes referred to as a terminal tractor, it's known in the United States as a trailer jockey, shunt truck, spotter tractor, yard truck, yard dog, yard goat, yard horse, yard bird, yard jockey, or mule..