Abstract: A trailer (50, 60) has a chassis (1) which is fabricated from sheet plastics material. The chassis (1) is hollow and substantially planar and has an upper sheet (6) and lower sheet (10) separated by a peripheral wall (12). The shape of the chassis is generally dart like being formed by a forward triangle 3 and a rear rectangle (4). The sheet plastics material is preferably high density polyethylene which is 16 mm thick.