<p>A freight system comprising a conveyor adapted to be driven along a monorail track (18). A frictional drive wheel (28) of the conveyor engages the upper side of the track (18) and various embodiments of reactive force creating means are positioned to engage the underside of the track (12) to create improved frictional forces during ascendancy. All of these embodiments employ the weight of the unit to create the reactional force and in all embodiments there are positioned a pair of spaced apart guide rollers (79) that engage the underside of the track. In some embodiments, these guide rollers are resiliently biased by either separate springs (81) or by making the guide rollers themselves resilient. In some embodiments there is provided an intermediate fixed guide roller (78) to limit the degree of relative movement between the conveyor and the track. In one embodiment, the guide rollers are suspended by a Y shaped lever (134) that itself carries the load transmitted by the conveyor.</p>
