>>13320519The trains are wider than they are tall, as depicted.
While we don't know the depth of the curve, one may immediately assume that A is more efficient, because the bottom is essentially a flat drop off, but with B both sides have to taper evenly.
However, A would have an amount of "lift" acting against gravity, that may actually influence the amount of force available for forward propulsion.
These are all of the immediate considerations.
Without actual measurements and numerical information, one can only base a fast assumption on the design themselves. So I will postulate the answer as train A.
With measurements and data, it may still be possible to argue for train B.
