A rail transport bogie configured to operate on a track having track surfaces (3, 4) on opposite sides thereof and a slot through the track extending along substantially the centre of the track, the bogie comprising: a load-bearing wheel to run on a first of the two track surfaces, a load support shaft extending from the load-bearing wheel operatively through the slot in the track and terminating in load support means, a pinch wheel bracket secured to the load support shaft, with the bracket extending to two opposing ends, a first end to a forward position in respect of the load support shaft and second end to a rearward position in respect of the load support shaft, characterised in that: a forward pinch wheel is rotatably secured to the first end of the pinch wheel bracket and a rearward pinch wheel is rotatably secured to the second end of the pinch wheel bracket, with both the forward and rearward pinch wheels (12, 13) located between the load-bearing wheel and load support means to run on the second of the two track surfaces, at least one of the load-bearing wheel and either or both of the pinch wheels (12, 13) is connected to a motor operatively to be driven thereby to comprise a driven wheel for the bogie, the load-bearing wheel and either the forward pinch wheel or rearward pinch wheel clamping between them the bogie to the opposing track surfaces (3, 4), with the ratio of: the distance between the axis of the rearward pinch wheel and the attachment of the pinch wheel bracket to the load support shaft, to the distance between the attachment of the pinch wheel bracket to the load support shaft and the load support means, being variable depending upon how much friction is required between the driven wheel and the track surfaces (3, 4) to create the optimum amount of traction that is required for any specific set of circumstances. a load-bearing wheel to run on a first of the two track surfaces, a load support shaft extending from the load-bearing wheel operatively through the slot in the track and terminating in load support means, a pinch wheel bracket secured to the load support shaft, with the bracket extending to two opposing ends, a first end to a forward position in respect of the load support shaft and second end to a rearward position in respect of the load support shaft, characterised in that: a forward pinch wheel is rotatably secured to the first end of the pinch wheel bracket and a rearward pinch wheel is rotatably secured to the second end of the pinch wheel bracket, with both the forward and rearward pinch wheels (12, 13) located between the load-bearing wheel and load support means to run on the second of the two track surfaces, at least one of the load-bearing wheel and either or both of the pinch wheels (12, 13) is connected to a motor operatively to be driven thereby to comprise a driven wheel for the bogie, the load-bearing wheel and either the forward pinch wheel or rearward pinch wheel clamping between them the bogie to the opposing track surfaces (3, 4), with the ratio of: the distance between the axis of the rearward pinch wheel and the attachment of the pinch wheel bracket to the load support shaft, to the distance between the attachment of the pinch wheel bracket to the load support shaft and the load support means, being variable depending upon how much friction is required between the driven wheel and the track surfaces (3, 4) to create the optimum amount of traction that is required for any specific set of circumstances. a forward pinch wheel is rotatably secured to the first end of the pinch wheel bracket and a rearward pinch wheel is rotatably secured to the second end of the pinch wheel bracket, with both the forward and rearward pinch wheels (12, 13) located between the load-bearing wheel and load support means to run on the second of the two track surfaces, at least one of the load-bearing wheel and either or both of the pinch wheels (12, 13) is connected to a motor operatively to be driven thereby to comprise a driven wheel for the bogie, the load-bearing wheel and either the forward pinch wheel or rearward pinch wheel clamping between them the bogie to the opposing track surfaces (3, 4), with the ratio of: the distance between the axis of the rearward pinch wheel and the attachment of the pinch wheel bracket to the load support shaft, to the distance between the attachment of the pinch wheel bracket to the load support shaft and the load support means, the distance between the axis of the rearward pinch wheel and the attachment of the pinch wheel bracket to the load support shaft, to the distance between the attachment of the pinch wheel bracket to the load support shaft and the load support means, being variable depending upon how much friction is required between the driven wheel and the track surfaces (3, 4) to create the optimum amount of traction that is required for any specific set of circumstances.