Done that as a kid at upper haliford, the air try's to suck you off the ground and pull you up. There was also a bridge there that gave you about 1" spare if you stood against the wall.
We also used to lay on the top of trains going out of richmond station to kew bridge as there is a footpath and lowish wall right next to the station.
Also used to stand against the wall in the london underground, there was a couple of spots you could stand in the dark and wait for longer trains to stop so you could tag them.
Out of it all, the london underground was the scariest, the wind was real str