Hydrogen trains: Are these the eco-friendly trains of the future?
Hydrogen-powered trains are said to be the greenest trains out there.
“Mini power stations on wheels”, is how a University of Birmingham researcher describes them, as they give off zero emissions and their only by-product is water.
Two hydrogen trains are already in service in Germany but that design is not compatible with the UK's rail network.
BBC's Tom Burridge went on a test run for the UK's version.