What is a Semi-trailer? Distinguishing Between Trailers and Semi-trailers

In today’s context of booming trade, semi-trailers have become an indispensable link in the freight transport system. With the capacity to carry large volumes over long distances, this type of vehicle plays a vital role in meeting the transportation needs of the economy. From domestic routes to international ones, the image of semi-trailers is always present, contributing to the development of the transport industry.

What is a Semi-trailer?

A semi-trailer is a special type of transport vehicle. A semi-trailer does not have its own engine but connects to a tractor unit to form a complete transport system. The trailer section is responsible for carrying the cargo, while the tractor provides the power to pull the system.

See more: What is a trailer? Detailed component structure of trailers

What is the structure of a container semi-trailer?

A semi-trailer is an integral part of the road transport system, specifically designed for transporting goods in large volumes. The structure of a semi-trailer is quite complex, consisting of many different parts, each with its own distinct function.

Main parts of a semi-trailer:

Chassis frame

This is the main load-bearing part of the semi-trailer, made from high-strength steel. The chassis frame is responsible for evenly distributing the load across the axles of the semi-trailer.

Kingpin

Connects the semi-trailer to the tractor unit, ensuring a tight link and transmitting the pulling force.

Drivetrain

The drivetrain of the semi-trailer unit is 6×4 or 6×2. This means the vehicle has 6 wheels with 4 or 2 driven wheels. The drivetrain transmits motion from the engine to the wheels to create traction and move the vehicle.

Suspension system

The suspension system helps reduce vibration during travel, protecting the cargo and increasing the lifespan of the semi-trailer. There are many different types of suspension, such as leaf spring suspension and air suspension.

Braking system

The braking system ensures safety during operation, helping the vehicle stop quickly and safely.

Cabin

The cabin is comfortably designed to help the driver perform driving operations. The cabin features amenities such as: seats, air conditioning, a smart control panel, and safety systems.

Cargo box

The cargo box is where goods are contained. There are many different types of cargo boxes depending on the type of goods transported, such as closed boxes, stake trailers, and dump trailers.

Other parts

Wheels, signal lights, landing gear (for dump semi-trailers),…

>>> What is a Doosung dump trailer? Where should you buy one?

Distinguishing between a Trailer and a Semi-trailer

This type of tractor unit is used consisting of two parts: a semi-trailer and a full trailer.

A trailer (full trailer) is an independent transport vehicle capable of standing on its own. Trailers are often used for short-term transport tasks. Short-term transport can be carried out at factories or seaports. Common types of trailers include:

• Freight trailer: Used for transporting large volumes of goods.
• Passenger trailer: Designed for carrying passengers, often seen in tourist areas.
• Caravan trailer: A type of trailer designed for living, usually pulled by a car.

A semi-trailer cannot operate independently and must be connected to a tractor unit. Semi-trailers are typically used for long trips and transporting goods in large volumes. Common types of semi-trailers include:

• Freight semi-trailer: Used for transporting industrial goods, agricultural products, consumer goods…
• Container semi-trailer: Used for transporting standard containers.
• Dump semi-trailer: Used for transporting bulk cargo with the ability to lift and lower the cargo box.
• Car carrier semi-trailer: Used for transporting cars and motorcycles.

Features	Trailer	Semi-trailer
Operational capability	Independent	Dependent on tractor
Weight	Supported mainly on the trailer body	Supported mainly on the tractor unit
Connection	Connected to tractor by a drawbar hook	Connected to tractor by a kingpin
Usage	Short-term, specialized transport	Long-distance, large volume freight

Conclusion

The semi-trailer is an integral part of the modern transport system. Trailers play a crucial role in efficient and flexible freight transport. We hope that with the information above, Naltako has helped you clearly understand the structure and function of semi-trailers. From there, you can evaluate and choose the suitable type of semi-trailer for each type of goods and transport condition.