> That's actually quite difficult for this suggestion. The amount of Volts on these lines differ greatly across countries. [...] Tracks can differ in size and lots of trains only handle one electrical system.

Implementing an international standard for rail gauges and electrification voltages/frequencies is still currently much more feasible than electrifying cargo ships (unless nuclear-powered cargo ships become more widespread, which would be great, but that doesn't seem to be happening). Worst case scenario, you start from scratch (which is what we'd have to do here in the US, since electrified freight rail is basically nonexistent here).