>>17785
You're thinking of "gas-electric transmission" rather than hybrid, these are widely used on diesel trains. "Hybrid" is when torque to wheels comes from an ICE as well as electric motor(s) and the transmission combines and/or balances the two sources. Neat little things from an engineering perspective and a fucking nightmare as far reliability and repairs go, as it tends to be with added complexity.
Back to tanks, gas-electric drive was literally the first thing US tried in WW1 era with the Holt tank. Germany, or Porche rather, developed an electric drive tank chassis that was to be Tiger 1 but it lost out to Henschel's design. Soviets built a few protypes (because of course they did) one based on IS and later T-80. So it's definitely been considered and works, not sure why it hasn't caught on, must have its own challenges. Heat dissipation around the electronics seemed to be a problem of its own, as well as balancing the load versus power available from the generator, like when a track is stuck and motor can't turn over you get voltage jumping and shit can catch on fire (I'm not an electrical guru, I don't understand this part as much). It's not really a problem for trains as loads are all slow and steady and predictable. I guess in a mechanical transmission you have the clutch eating shit to compensate for that. In WW2/Cold War era all the control circuits would have been analog, maybe modern electronics wo