What are the criteria for classifying heavy-duty vehicles?
1 Answers
Heavy-duty vehicles refer to M-class and N-class vehicles with a maximum gross mass exceeding 3500Kg. Such vehicles consist of a heavy-duty tractor and a heavy-duty trailer. Most of these vehicles employ axle-series hydraulic suspension systems and are primarily used for transporting large cargoes whose dimensions and weights exceed the limits stipulated by road traffic regulations. Heavy-duty tractor: A tractor designed for towing and pushing heavy-duty trailers. Equipped with high-power diesel engines, mechanical or hydraulic transmissions with high gear ratios, main reducers, and wheel reduction devices to lower speed and increase traction. Most heavy-duty tractors are 3-axle or 4-axle configurations, typically driven by the rear two axles, though some feature full front-and-rear axle drive. When towing full trailers, the tractor must carry additional ballast weight to increase the load on the driving wheels, ensuring sufficient adhesion between the tires and road surface. Heavy-duty trailer: Trailers designed for transporting oversized and overweight cargo. The basic configuration is a single flatbed trailer, most featuring the following structure. The axle frames typically employ two coaxial axles per unit (upper and lower axles on one assembly), also called twin-axle systems. Standard integrated flatbed trailers have 2-7 axles, with each axle carrying either 4 or 8 tires, allowing the overall vehicle width to exceed 3 meters.
