While looking through one of the railway auction house catalogues, I was intrigued when I came across this sign from the old Nine Elms locomotive depot in South London. We had to have it. For a museum devoted to railways, we have surprisingly few objects which directly refer to trainspotting and trainspotters. Trainspotting was a mass participation activity, especially among teenage boys, reaching its height in the 1950s with the publication of the popular Ian Allan ABC Locospotters guides. By and large, British Railways did try to accommodate trainspotters visiting loco sheds and depots, by prior arrangement. But, as the sign flags up, railway managers and police took a dim view of youths sneaking onto railway property unannounced. The sign has already provoked a rash of reminiscences amongst the National Railway Museum staff and volunteers. I’m hoping that I can use the sign to get more discussion going.