A semi-trailer attaches to the tractor with a type of hitch called a fifth wheel.
(or semi, big rig, tractor-trailer, or eighteen-wheeler) is the combination of a tractor unit and one or more semi-trailers to carry freight. For other uses, see 18 wheeler (disambiguation) and Big Rig (disambiguation).Ĭonventional style cab tractor A cab over semi-trailer Tractor with an end-dump trailer A FAW semi-trailer truck in ChinaĪ semi-trailer truck, also known as a semi-truck, truck and trailer, For use of the expression in rugby union, see Glossary of rugby union terms § T. 'Big rig', 'Eighteen wheeler', and 'Truck and trailer' redirect here.
