tractor unit
characteristically heavy-duty towing engine that provides motive power for hauling a towed or trailered load
tug
airport service vehicle used to move aircraft
A-tractor
vehicle legally recogniced as a tractor (often a rebuilt car)
Scammell Pioneer
type of Tractor unit
ballast tractor
heavy haulage road vehicle designed to pull or push heavy or exceptionally large loads
semi-trailer tractor
tractor unit of a semi-trailer truck
Oshkosh Heavy Equipment Transporter
type of 8×8 heavy tractor