"Clive" wrote in message
...
In message m, Martin
Underwood writes

I know about diesel-electric and diesel-hydraulic transmission on
locomotives, but I imagine that the size and weight of these types of
transmission make them rather impractical for use in a car.
If you know these things then you'll know that a car auto transmission
is just a cut down locomotive hydraulic transmission.

I thought car auto transmission used epicyclic gears ie a mechanical
connection between engine and prop shafts, though via a hydraulic clutch
rather than a true hydraulic transmission in locomotive where the engine
drives a hydraulic pump which sends high pressure oil to turbines attached
to wheels - ie with no mechnical connection between engine and wheels.