Not traditional motor bogies as such, QuadDrivers sit on the loco's axles and drive the wheels, with the weight of the engine supported by the sideframes or superstructure. Although they have been developed for specific proptypes, they should be suitable for other applications which share the same wheelbase.
The design allows one of the driven axles to rock, so 3-point compensation can be used. The inter-linking geartrain runs as high as possible, keeping the visible space between the wheels free with the motor ideally situated to fit under a small loco bonnet.
Reduction ratio is either 97 or 108:1 - ideal for a small shunters - with wheelbases from 20 to 24mm.
and the units are small and very compact
- Simple design
- Can be easily compensated
- High Ratios for super-slow running