Lowbed/Heavy-Haul trailers are similar to bridges and have a load-bearing space between two buttresses except that the buttresses in case of the trailers are mobile.
Their defining characteristic is a very low deck height, significantly closer to the ground than standard flatbed or platform trailers. lowbed trailers feature an extra strong frame with an open deck very low to the ground, and are designed for carrying extremely heavy, tall or bulky cargo. These trailers have a lower center of gravity when compared to standard platform trailers resulting in added stability for heavier and taller cargoes.
These trailers are considered the heaviest of all trailers and are used to carry extremely heavy equipment such as cranes, bulldozers and heavy machinery. A gooseneck connects the tractor to the lowbed trailer with the front end of the gooseneck attached to the tractor by means of a fifth wheel and its rear end attached to the trailer by means of a hook coupling.
Lowbed trailers/heavy-haul trailers can be single-drop, double-drop and/or extendable trailers and may feature fixed neck, detachable neck, or folding/scissor neck.
Lowbed trailers also include oilfield floats that look very similar to flatbed/platform trailers.
The capacity of these trailers vary widely but is designed for loads significantly above typical trailer capacities.
