Have you ever heard of "train spotting"? It's one of the most unusual (hobby) in Britain. It's usually men over the age of 40. but not always. You'll see men (stand) around at railway stations and other places where trains pass by, and you'll see (they) taking photos and exchanging notes with each other. So, what are they doing? They're collecting information trains — the number on the front of the trains, or the make and model of the locomotive(火车头). These men collect and exchange all kinds of details about trains and railways.
The idea goes back as far as 1942. That year a young man (name) Allan was working at Waterloo railway station in London. It was his job (answer) letters about trains, and quite a lot of the questions he received were very similar. He found himself getting a little annoyed at replying to same questions. So he started to write a booklet (小册子) giving the answers to (common) questions of all. And by the 1950s, a million copies of 'British Railways Locomotives' were selling every year. He died in 2015, his train spotting hobby lives on.