The kingpin of the trailer is attached to the underside of the step frame trailer’s upper deck, enabling the trailer to be coupled to the tractor unit’s fifth wheel. The upper deck is built sufficiently high to accommodate the tractor unit.

The lower deck of a machinery carrier trailer is built at a lower level than the upper deck, enabling high loads to be moved without the total height of the loaded trailer exceeding the legal limits for normal road transport. The lower deck height with hydraulic ramps is generally 0.95m. They often have a beaver tail at both the rear of the trailer and at the neck of the trailer.  Plant trailers with hydraulic ramps are also fitted with built in pop-up neck ramps or a set of loose neck ramps to enable the loading of wheeled vehicles up on to the top deck of the trailer. The lower deck height of a machinery trailer with hydraulic ramps is above the height of the trailer wheels, giving an uninterrupted flat lower deck. This makes the trailer useful for moving a wide range of loads ranging from tractor units and excavators, through to JCB’s, road planning equipment, crushers, access equipment, forklifts, military equipment, and vehicles.

Plant trailers are distinguished from low loaders by having a single lower deck height. In contrast, low loaders have three deck heights: the upper deck above the kingpin, the lower load-carrying deck, and a third deck height above the wheels. See low loader trailers.

We stock plant trailers from Broshuis, Dennison, Montracon, SDC and other manufacturers for hire, rental, or purchase.

We buy, sell, and rent extendable and non-extending flat, low loader, step frame and urban trailers plus plant, machinery, tractor, wing, and truss carriers. The majority of the 1000 plus modern trailers on our fleet are made by Broshuis, Dennison, Montracon, and SDC. We also offer repairs, re-furbishment, HGV / LGV / PCV testing, spares, service, test preparation, tachograph calibration and brake analysis. These services are suitable for most trucks, trailers, buses, tractor units, lorries, and PSVs.