Abstract: A vehicle having a main chassis (3) and a power source (4) for driving the vehicle, a drivable steer carriage (1) pivotally supporting the main chassis (3) about an at least substantially upright pivotal axis (2), the carriage including a plurality of opposed pairs of carriage wheels (5a, 7a, 9a), at least one said pair of carriage wheels being driven by a drive transmission including an input shaft (17a) at least substantially aligned with said upright pivotal axis (2) such that the power source (4) can transfer power through the input shaft (17a) to at least one carriage wheel pair.

Abstract: A command steer assembly (15) for an articulated vehicle having a prime mover, and at least one trailer body (1) having a sub-chassis (3) rotatable about a main axis (5), the sub-chassis (3) being supported by a plurality of wheel axles, at least one of the wheel axles being steerage, the command steer assembly including: a steer plate (17) supported for rotation about said main axis and interconnectable by a linkage arrangement (13) to the at least one steerable wheel axle; and a drive arrangement (33) for selectively driving the steer plate for rotation, wherein rotation of the steer plate results in pivotal movement of the at least one steerable wheel axle relative to the sub-chassis.

Abstract: The invention provides a trailer for use as part of an articulated vehicle (15) with improved cornering characteristics. The trailer includes: a main chassis (18) connectable to a wheeled section (16) of the vehicle immediately ahead of the trailer so that the trailer is rotatable relative to the wheeled section (16) about a substantially upright first axis (19) in the main chassis (18); a sub-chassis (20) having ground-engaging wheels (21) mounted thereto, the sub-chassis (20) being connected to the main chassis (18) and pivotable about a substantially upright second axis (23) in the main chassis (18); and stop means arranged for limiting rotation of the sub-chassis (20) about the second axis (23) and away from a position of a longitudinal alignment with the main chassis (18). The stop means is movable responsively to relative rotation of the wheeled section (16) and the main chassis (18) about the first axis (19).

Abstract: A vehicle having a main chassis (3) and a power source (4) for driving the vehicle, a drivable steer carriage (1) pivotally supporting the main chassis (3) about an at least substantially upright pivotal axis (2), the carriage including a plurality of opposed pairs of carriage wheels (5a, 7a, 9a), at least one said pair of carriage wheels being driven by a drive transmission including an input shaft (17a) at least substantially aligned with said upright pivotal axis (2) such that the power source (4) can transfer power through the input shaft (17a) to at least one carriage wheel pair.