A multi-combination vehicle or road-train consisting of a powered prime mover, at least one powered trailer and which may include a number of non-powered trailers. The powered trailer includes a cooling system separated from the engine to provide improved cooling and enabling the road-train to be used in confined areas, such as in underground mines. Preferably, the cooling system is located at the rear of the powered trailer. The engines of the prime mover and powered trailer(s) are preferably controlled either by manual controls in the truck cab.