Yes putting things on rail tracks. When I was a young kid in primary school and later into high school. We didn't have a train line near us but we did have a tram line. flattening pennies, and other objects was the fun thing to do on the way home from school. On one particular day we were joined by a kid from another school that was known to be quite rough.
This rough kid really showed us up by putting a .22 bullet on the track which went of with a nice bang. satisfied with the result he then produced what I think was a 303 bullet, and put on the line for the next tram, they were about ten minutes apart. This went off with a very loud bank and the driver bought the tram to a screeching stop He and the conductor got out and chased us off, yelling at us all.
The next day there was an item in the daily news paper which mum and dad discussed at the dinner table, lecturing me and my younger brothers that we stay well clear of these ruffians., Little did they know I wa sthere, but I was too scared to admit it.