Single flatbed trailers can be assembled vertically and horizontally to form a variety of variants to suit the shipment of large cargoes of different weights and dimensions. There are usually three variants:
①Combined flatbed trailer. It is composed of one or several monocoque flat trailers spliced according to the required length.
②Long cargo trailer. Two flatbed trailers, one in front and one back, are separated by an appropriate distance according to the requirements of the supporting position of the long cargo. Each of them is equipped with a rotatable bearing frame. The parts and the vehicle form a whole (Figure 3).
③Bridge trailer. Two flatbed trailers are separated by a certain distance, one in front and the other in the back, a hydraulic lifting platform is added to each, and a bearing bridge is installed between the two lifting platforms, so that the front and rear trailers, the lifting platform, and the bearing bridge are connected together. The load-bearing bridge is the loading position. Bridge trailers are used to transport large-scale cargoes with a large proportion. In addition, with a single flatbed trailer as the base, other variants can also be formed, such as a clamp-on trailer, a recessed low-flat bed trailer, a gooseneck semi-trailer, etc., to suit different usage requirements.
The development of heavy-duty vehicle trains In the mid-1970s, self-propelled heavy-duty vehicle trains appeared, that is, without tractors, high-power diesel engines and hydraulic pumps were installed on the flatbed vehicles, and hydraulic motors were installed in some of the wheels to drive the vehicles. . In this way, the length of the entire vehicle group is greatly reduced, and the requirements for the turning radius of the highway are also reduced, and the driver's operation is more convenient and safer. In the early 1980s, a self-propelled flatbed wagon that could be spliced vertically and horizontally, used electronically controlled steering, and had a load of several thousand tons, was able to carry heavy and large "modules" from pre-built factories.
