[ebarker]

years ago the railroads used quantity four 3,600 hp locomotives to pull a large unit train.

today they use at most three. the way they did that is by automated traction control.

a doppler radar is under the locomotive measuring the actual speed. the traction computers optimize the power delivered to the wheels so that there is optimal slippage driving wheel, about 3%

they got rid of a whole locomotive, plus they get greatly improved fuel economy and operating performance.

anyone game for trying this ? we certainly have the computer to do the job !!

put a dedicated speed controller, drive motor combo on each wheel, figure out where you are actually going, versus where you want to go and off you go.