Books

Since you don't want a story, I suggest a train-specific travel book rather than a novel.

you'll get the highest concentration of train lore with travel books. Any novel will be focused on a story, with the train as a set piece rather than the focal point.

Amazing Train Journeys, Ticket to Ride, around the world in 80 trains, The Big Book of Trains, there are lots of train travel books to choose from.

Check out “The Great Railway Bazaar: By Train Through Asia” by Paul Theroux. It might fit the bill. If that appeals to you, then definitely look into his other books too.

Mrs Bradshaw's Handbook, by Terry Pratchett comes to mind, although I suspect you aren't looking for a book about a train journey through an imaginary landscape.

Hmm, that is tricky, isn't it? Of course there are many travelogues about train journeys and many novels where the train journey is incidental. I can even think of a radio show on the BBC, Alexei Sayle's Strangers on a Train, where the presenter takes train journeys and talks to people he meets about their journeys and their lives:

https://www.bbc.co.uk/sounds/brand/m0013zmp?partner=uk.co.bbc&origin=share-mobile

However, novels like the one you are looking for are elusive and nothing comes to mind. For what it's worth, here's a list of train-related books from Goodreads, which might give you some ideas:

https://www.goodreads.com/list/show/89742.Tales_on_Track_Trains_in_Fiction

The closest media I know would be: https://en.wikipedia.org/wiki/Train_to_the_End_of_the_World It's an anime not a book and it's not great. After the first episode it has its charm.

Maybe you can write one based on a YouTube channel. There are many train videos there from people who love train travel like yourself.

That sounds like literally the most boring book I could imagine.