In article , Recliner
writes
- You still need to book in advance, but only a few days. You must
book tickets for a particular, timed train, and turn up 10 mins
before.

When I went my plans had changed, so I turned up about 3 hours before my
booked trip. I explained to the staff both at the surface and in the
depot that I was early. They got me to wait around near the boarding
queue in case someone didn't turn up; I got to ride about 40 minutes
after arriving, taking the last very-cramped place on the train.

(I didn't have to stand there the whole time; I was able to look at the
other exhibits between trains.)

--
Clive D.W. Feather