Comment Re:Might be a fit for EVs (Score 1) 103
The other reason is that an ICE can't generate force when at rest (unlike an electric motor), so getting going from stationary is impossible without a clutch. That's why, if you drive a manual, the engine has to be revved and the clutch gradually engaged, bleeding power into the axels while allowing the engine to run without stalling. Engage the clutch too fast and the engine will simply stall.
I believe External CEs like steam engines can generate force when at rest, so they don't need gearing.
It's one of the reasons by diesel trains (and some very large vehicals) are diesel-electric. A rail engineer I used to work with told me the gearbox and clutch needed to gear down a diesel engine to the point it could start a train would be enormous, bigger than a train car. Diesel electric trains are basically diesel generators that power electric motors, which is why they are sometimes used for emergency power.