Not so off topic, just imo to happen a bit later.
Hydrogen fuel replacing diesel powered trains is very likely to happen. I can not see it for the Ring this early. Because diesel power is not a fore front issue at this time for the north. People would be glad to get any transportation to their communities at first. However, unless some better alternative arrives soon, it will happen.
Mind you at the cost of clean energy, producing hydrogen probably through electrical power in much more expensive than diesel so hydrogen would have to be subsidized in some manner. Countries with densly populated regions ( meaning more polluted) are most likely to first use that mode of transportation. Hence I say not quickly for our RofF, my bet is still on diesel.
Thanks for providing this info about our future, Ed.