In the recent, superb anime Girls und Panzer
one of Ooarai's tanks is a Renault Char B1 bis
. When, several times, we see shots of the girl who is driving it, she has a steering wheel and during Operation Biker Gang (in episode 11) she's swerving it back and forth.
I can't understand how that would work. Most tanks in the show are steered using two levers, each of which brakes the tracks on that side of the tank. Wikipedia says that the steering system is "double differential", which tells me nothing.
What would a steering wheel connect to, and what would it control, on a tracked vehicle? What are the drawbacks? Why did no one else use such a system, if it could be made to work?