After photographing 66537 leaving Long Marston on 19 June 2026 with the 4Z37 08:39 Long Marston to Doncaster Europort working, I thought it was worth taking a picture of the miniscule payload. The train consists of a couple of pressurised hydrogen containers (note the Hazchem label). These had been exhibited at the Rail Live event, which took place at Long Marston over the previous two days.