1. Trailer, a truck, is divided into semi-trailer and full trailer. The semi-trailer is the tractor in front and the trailer in the back. The trailer is placed on the tractor in front. The full trailer is the tractor in front and the carriage behind. The carriage is not placed on the tractor, but connected together.
2. A semi-trailer is a trailer whose axle is placed behind the center of gravity of the vehicle (when the vehicle is uniformly loaded) and is equipped with a coupling device that can transfer horizontal and vertical forces to the tractor. Semi trailers are generally three axle semi trailers, which are divided into 11 meter warehouse fence semi-trailer, 13 meter warehouse fence, low flat semi-trailer and so on. It is a heavy transport vehicle connected with the head of semi-trailer through traction pin.
3. The load of the full trailer is borne by itself, and it is only connected with the locomotive by hook. The locomotive does not need to bear the trailer load, but only provides power to help the trailer overcome the road friction resistance.
