A lowbed trailer is a heavy-haul trailer with a low deck, about 40–90 cm above the ground, designed to carry construction machinery and tall equipment. Thanks to the low deck, the combined height of cargo and vehicle can stay below the 4.00 m legal height limit. The more axles the trailer has, the more weight it can carry.
What sets a lowbed apart from other trailers?
The key difference of a lowbed is deck height. On a standard flatbed trailer, the cargo sits about 1.2–1.5 m above the ground. On a lowbed, the deck is designed as a "well" lowered between the axles or as a low middle section. This allows tall cargo to be carried without hitting the legal height limit.
| Trailer type | Deck height (approx.) | Typical use |
|---|---|---|
| Standard flatbed | 1.2–1.5 m | Palletised and general cargo |
| Semi-lowbed | 0.85–1.0 m | Medium-height machinery, steel structures |
| Lowbed | 0.4–0.9 m | Excavators, dozers, transformers |
| Modular hydraulic trailer | Hydraulically adjustable | Project cargo exceeding 100 tonnes |
Values vary by manufacturer and model. The choice between the two types is explained in detail in the entry when to choose a semi-lowbed.
Why is a low deck so important?
The legal height limit, including cargo, is 4.00 m. A 3.3 m tall crawler excavator reaches 4.7 m on a 1.4 m standard deck and requires a special permit. The same machine stays at 3.9 m on a 0.6 m lowbed deck. Even if excess height can be solved with a permit, every centimetre means a separate risk at overpasses, tunnels and power line crossings; a low deck reduces these risks from the outset.
What cargo is it used for?
- Tracked and wheeled construction machinery: excavators, dozers, rollers, graders.
- Mobile crane bodies and crane counterweights.
- Small and medium-sized power transformers, generators.
- Tanks, pressure vessels, industrial furnace parts.
- Prefabricated modules and container-type plant units.
Choosing the right trailer for each machine type is covered in the entry which trailer for construction machinery.
How do axle configurations and capacity vary?
Lowbeds are usually built with 2 to 6 axles; for heavier cargo, modular systems are used. The more axles there are, the more wheels the load is spread over, and the weight per axle can be brought closer to the legal limit. The regulation sets a limit of 10 tonnes for a single non-driven axle and 40 tonnes total weight for a combination with five or more axles; a lowbed loaded with a heavy machine often exceeds these limits, and a special permit is obtained from the General Directorate of Highways (KGM). For example, a 45-tonne excavator, together with a tractor of about 9 tonnes and a lowbed of 15 tonnes, forms a 69-tonne combination.
- Removable gooseneck (RGN): The front neck detaches and the machine drives onto the deck from the front under its own power.
- Rear ramp: The machine is loaded from the rear via ramps; this is the most common type.
- Extendable deck: The deck extends telescopically for long cargo.
- Steered axles: The rear axles turn, making manoeuvring easier on tight bends.
Common mistakes
- Not re-measuring the height after loading.
- Not placing the machine's centre of gravity in the middle of the well; axle loads become unbalanced.
- Not calculating chain and tensioner capacity according to the machine's weight when lashing (see chains or straps).
- Not checking the ramp angle for machines with low ground clearance.
How does Voltim Global support you?
For out-of-gauge and heavy cargo transport, Voltim Global selects a lowbed, semi-lowbed or modular trailer according to the cargo dimensions and permit requirements. Since the trailer choice determines the vehicle details in the permit application, the two tasks are handled together.