Winterthur universal drive

It was characterised by double gearbox, which enabled the transmission ratio to be selected freely within a wide range.

[1] Two coaxially opposed motors were arranged in the frame above each drive axle.

[2] The Winterthur universal drive was extensively used by SLM in locomotive designs from 1928 to 1948.

However, it was difficult to access for maintenance and repair work, a particular problem as the gears were prone to wear.

The drive was unpopular amongst drivers due to loud noise that it made, and production was discontinued when the design was rendered obsolete with the advent of lighter motors which enabled the modern axle-hung (also known as nose-suspended due to the "nose" that transfers weight and torque to the frame), direct-drive designs.