Forage harvester trailers, unlike standard forage harvesters, are not self-propelled machines, but tools which are pulled by tractors or attached to the three-point linkage. Forage harvester trailers are used for the mowing, crushing and loading of crops and are optionally and depending on the manufacturer available with a mower disc or drum. In addition, the harvesters are also equipped with an ejection tower, by means of which the harvested corn or grass is transferred onto a trailer.
Forage harvester trailers were very popular on the agricultural market from their invention in 1942 until the development of self-propelled harvesters in the 1970s. At that time, the devices had an approximate working width of two meters, nowadays there are some which are ten meters wide. For driving on roads, the crop-picking head of the forage harvester trailer can be flipped up on its side. Manufacturers of forage harvester trailers include Kemper, Pöttinger and Vicon.