Flat-racks consist of a floor structure with a high loading capacity composed of a steel frame and a softwood floor and two end walls, which may either be fixed or collapsible. The end walls are stable enough to allow cargo securing means to be attached and several flat-racks to be stacked on top of one another. Flat-racks are available in 20' and 40' sizes.
A number of lashing rings, to which the cargo may be secured, are installed in the side rails, the corner posts and the floor. The lashing rings may take loads of up to 2000 kg in the case of 20' flat-racks or up to 4000 kg in the case of 40' flat-racks.
Some types of 20' flat-racks have forklift pockets.
40' flat-racks have gooseneck tunnels at each end. In addition, they are sometimes equipped with lashing winches with 2 metric ton lashing belts.
For transport of certain cargoes, flat-racks may be provided with stanchions.
Flat-racks are mainly used to transport heavy-lifts and overheight or overwidth cargoes.