What are the main components of a semi-trailer truck?
A semi-trailer truck consists of two separable units — the tractor unit and the semi-trailer — joined by a fifth-wheel coupling on the rear of the tractor chassis.
The tractor unit is the powered front section. It houses the engine, driver's cab, transmission, and drive axles — but carries no cargo of its own.
The semi-trailer is the rear unit that carries the load. Its defining mechanical characteristic is the absence of a front axle — the front of the trailer rests on the tractor's fifth-wheel plate.
The fifth-wheel coupling connects both units. The trailer's kingpin locks into the coupling plate while allowing the trailer to pivot horizontally.
What is the difference between a semi-trailer truck and a rigid truck?
A semi-trailer truck separates the power unit from the cargo unit — a rigid truck integrates both on a single chassis that cannot be detached.
A rigid truck engine and load area share one permanent frame. A semi-trailer truck allows the tractor to drop one loaded trailer and collect another, reducing waiting time during loading operations.
A full trailer is not the same as a semi-trailer. A full trailer has its own front axle and can stand independently, while a semi-trailer requires either the tractor's fifth-wheel plate or landing gear.
What are the EU dimensions and weight limits for a semi-trailer truck?
EU Directive 96/53/EC sets the maximum dimensions for semi-trailer trucks operating across EU member states — 16.5 metres total length, 2.55 metres width, and 40 tonnes gross vehicle weight.
The 16.5 metre total length covers the complete combination — tractor and semi-trailer together. For intermodal or combined road-rail transport, the GVW ceiling rises to 44 tonnes.
After deducting tractor and trailer tare weight, the net cargo payload of a standard loaded semi-trailer truck runs to approximately 24,000–25,000 kg.
What types of semi-trailers are used in European road freight?
The most common semi-trailer in European road freight is the curtainsider — a flatbed frame with a fixed roof and sliding tarpaulin side curtains that open fully for forklift side-loading.
Box body trailers have rigid fixed sides and a sealed cargo area, suited to high-value goods, pharmaceuticals, and electronics. Flatbed trailers carry no sides or roof and suit construction materials, steel coils, and oversized machinery.
Refrigerated trailers maintain controlled temperatures for food, pharmaceutical, and perishable cargo. Mega trailers provide additional internal height for high-volume light goods.
How does Go Trans use semi-trailer trucks in European freight?
Go Trans arranges full truckload freight across Europe using semi-trailer trucks through carrier partners DSV and DHL Freight.
A full truckload consignment occupies one complete semi-trailer — one customer, one truck, one direct linehaul from the Belgian collection point to the European delivery address without intermediate consolidation.
For consignments sharing trailer space with other customers, Go Trans arranges LTL freight through the same road networks. Additional vehicle types, trailer specifications, and freight terminology are covered across the logistics glossary.