[Iris7]

Been wondering just exactly that. I think the front wheel was used with both tracks running on the output of a differential and free to run at different speeds. At slow speeds the right and left track (differential) brakes were used.

Hints were: taking front wheel off for rough ground and going slowly.

3rd pic from top shows maybe a brake disc on the left.

#20 post shows the top of the differential brake covers with ventilation holes.

#26 shows differential brake operation pedals. Just like an old tractor.

The whole thing is set up like an old tractor.

[colorado tanker]

Thanks, Iris. Very astute. I think you're right.