What is the difference between a trailer and a semi-trailer?

Semi-trailer is one of the commonly used models in domestic logistics and transportation. With its high convenience, mobility, adaptability, and flexibility, it occupies the main position in the freight arena.

Many car owners are used to referring to semi-trailers as "trailers" for short. In fact, the models referred to by the two are not exactly the same. To put it simply, the category of trailers is wider than that of semi-trailers, and semi-trailers are just one type of trailers trailer axle.

What is a trailer?

A trailer refers to a vehicle that is driven by a tractor and does not have its own drive. It is composed of a tractor (truck, car, forklift) and one or more trailers. It can be divided into semi-trailer, Full trailers and center axle trailers.

(1) Semi-trailer

A semi-trailer is a trailer whose axle is mounted behind the vehicle's center of gravity and is equipped with a hitch that transmits horizontal and vertical forces to the tractor. In layman's terms, the wheels of a semi-trailer are generally installed at the rear end of the carriage. When driving, the front end of the carriage needs to be placed on the saddle of the tractor. The tractor not only provides the forward force of the carriage, but also needs to bear part of the weight of the carriage. When detached from the tractor, the semi-trailer compartment cannot be balanced alone, and needs to be supported by outriggers.

(2) full trailer

The full trailer means that the load of the carriage is completely borne by itself, and it is connected with the tractor through a hook. The tractor only needs to provide a forward driving force for the trailer, and does not need to bear the weight of the carriage. A trailer is generally equipped with axles at the front and rear of the car, so it can maintain its balance independently even if it is separated from the tractor.

(3) Central axle trailer

The axle of the central axle trailer is often installed in the middle of the car, so it cannot maintain balance independently when it is separated from the tractor, and it also needs the strength of the trailer's outriggers. Some car owners think that the central axle looks very similar to a trailer, but in fact the difference is quite big. In addition to the fact that the balance cannot be maintained independently just mentioned, there are also differences trailer axle in the way and position of the connection between the carriage and the tractor. It is slightly less difficult than a full trailer.

Whether it is a semi-trailer, full-trailer or center-axle trailer, you need to get an A2 driver's license to drive on the road. Although the B2 driver's license can drive a freight car, it cannot drive a trailer. The permitted types of A2 driver's license 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 mechanical vehicles.

By the way, the registration requirements for A2 driver's license:

1. Age: 24 to 50 years old;

2. Requirements for additional driving: 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 records in the last 3 consecutive scoring periods before the application.

It is worth noting that the A2 driver's license for trailers trailer axle can only be obtained by applying for additional driving through B1, B2 or A1. Transmission vehicles, low-speed trucks, three-wheeled automobiles, small automatic transmission passenger vehicles for the disabled, ordinary three-wheeled motorcycles, ordinary two-wheeled motorcycles, mopeds, special wheeled mechanical vehicles, trolleybuses, trams ; The scope of application for an increased driver's license is large passenger vehicles, heavy-duty tractor trailers, city buses, medium-sized passenger vehicles, large trucks, small cars, small automatic transmission vehicles, low-speed trucks, three-wheel vehicles, light traction trailers, and ordinary three-wheeled motorcycles Cars, ordinary two-wheeled motorcycles, mopeds, special wheeled mechanical vehicles, trolleybuses, trams) There is no semi-trailer type. If the owner wants to switch to semi-trailer transportation, he needs to plan ahead.