Deker wrote:Ballast to be a 70kg inertia flywheel that is spun up to silly thousands of revs by means as a braking device,
which is then engaged to drive the vehicle when moving off from a stop, or when ascending a steep hill
It worked OK for flywheel powered buses (http://en.wikipedia.org/wiki/Gyrobus ). They had an electric motor and a big flywheel, but no engine or batteries. At the bus stop the electric motor was hooked up to power and span the flywheel up to speed, giving enough stored energy for the bus to drive to the next "charging point".
It's a pity they were scrapped, as it always seemed to me to be a neat and pollution free solution to urban public transport, with potentially low vehicle maintenance costs as well.