According to the programme information put out by virgin media it was first shown today, so new. Misread the year the first time - sorry for the misleading info.
I've now spotted the brief details that are on C5, and for next week it says "A heat wave causes a massive points failure near Didcot." Can anyone (with a working memory) remember when that was?
And when C5 list these two as S4 E1 and S1 E2, what does that mean? I guess it means "new series" either way.
It was a new program, old content
... first showing, but loads of
HSTs▸ ... from Spring 2018, I believe, when trains had slam doors and people were allowed to queue close to each other.