Semitrailer is one of the commonly used models in domestic logistics transportation, and with its high convenience, mobility, adaptability, and flexibility, it occupies a major position in the freight market.

Many car owners usually refer to semi trailers as "trailers" for short, but in fact, the two types of vehicles they refer to are not exactly the same. In short, the scope of trailers is broader than that of semi trailers, which are just one type of trailer.

What is a trailer?

Trailer refers to a vehicle that is provided with driving force by a tractor and does not have driving force by itself. It is composed of a tractor (truck, truck, forklift) and one or more trailers, and can be divided into semi trailers, full trailers, and center axle trailers.

(1) Semitrailer

Semitrailer means a trailer with an axle mounted behind the center of gravity of the vehicle and equipped with a coupling device that transmits horizontal and vertical forces to the towing vehicle. Generally speaking, the wheels of a semi trailer are generally installed at the rear end of the carriage. When driving, it is necessary to attach the front end of the carriage to the saddle of the tractor. The tractor not only provides the forward force of the carriage, but also bears a portion of the weight of the carriage. When disengaging from the tractor, the semi trailer cannot be balanced alone, and requires support such as legs.

(2) Full trailer

Full trailer refers to a vehicle whose load is entirely borne by itself and connected to the tractor through a hook. The tractor only needs to provide a forward driving force to the trailer without bearing the weight of the vehicle. Full trailers are generally equipped with axles at the front and rear of the carriage, so they can maintain balance independently even if they are separated from the tractor.

(3) Center axle trailer

The axle of a center axle trailer is often installed in the middle of the carriage, so it is not possible to maintain balance independently when separating from the tractor, and it also requires the strength of the trailer legs. Some car owners feel that the center axle looks very similar to a full trailer, but the difference is quite significant. In addition to the inability to maintain balance independently mentioned earlier, there are also differences in the way and position of coupling between the carriage and the tractor, making driving slightly less difficult than a full trailer.

Whether it's a semi trailer, full trailer, or center axle trailer, you need to obtain an A2 class driver's license to drive on the road. Although a Class B2 driver's license can drive a freight car, it cannot drive a trailer vehicle. The approved driving models for A2 driver's licenses mainly include tractors (including semi trailers and full trailers), medium-sized buses, large trucks, small manual transmission vehicles, small automatic transmission vehicles, low speed trucks, three-wheeled vehicles, and wheeled self-propelled vehicles.

Incidentally, the registration conditions for A2 driver's license are:

1. Age: 24-50 years old;

2. Additional driving requirements: Hold a B1 or B2 driver's license for 3 years or more, or an A1 driver's license for 1 year or more, and have no full score record in the latest three consecutive scoring cycles before applying.

It is worth noting that Class A2 driver's licenses for trailers can only be obtained by applying for additional driving through B1, B2, or A1, Within the scope of initial application (The initial application for a driver's license covers urban buses, large trucks, small cars, small automatic transmission vehicles, low-speed trucks, three-wheeled vehicles, small automatic transmission passenger vehicles for the disabled, ordinary three-wheeled motorcycles, ordinary two-wheeled motorcycles, mopeds, wheeled special mechanical vehicles, trolleybuses, and trams; the application for an additional driver's license covers large buses, heavy traction trailers, urban buses, and medium-sized passengers Vehicles, large trucks, small cars, small automatic transmission vehicles, low-speed trucks, three-wheeled vehicles, light traction trailers, ordinary three-wheeled motorcycles, ordinary two-wheeled motorcycles, mopeds, wheeled special mechanical vehicles, trolleybuses, and trams) do not have semi trailer models. If car owners want to switch to semi trailer transportation, they also need to plan in advance.