Jointly developed between Swiss tractor maker Rigitrac, Dresden’s technical university and a specialist electronic engineering firm, the EWD 120 diesel-electric tractor is a truly novel concept.

A 120hp Deutz four-cylinder engine provides power for an 85kW generator, which powers four hefty wheel motors built into the tractor’s hubs. The lack of mechanical drive means there is no need for true axles and so the team has employed an independent double wishbone arrangement at each corner.

Not only does this mean there is height-adjustable hydro-pneumatic suspension front and rear, but all four wheels can also be steered. In addition, there is a clever traction control system that senses when one wheel starts to spin faster than the others and slows it, applying more torque.

The key advantage of such a setup is said to be that the transmission runs at 85% efficiency, compared with the 65%-70% of the hydrostatic units used on Rigitrac’s standard machines.