I most certainly wouldn't use hydrogen, combined with the fact that its round trip efficiency is around 30% compared to a battery around 90% its safety and practical problems are far worse than any battery. In the short term, for towing, ICE is probably the best solution, in the future an EV built for the task will be my best bet. There are already EV locomotives with 7 and 10 MW batteries pulling iron ore trains in the Pilbara, you don't get more heavy duty towing than that.
