Ooh, I’d love to do the ones in the Greenwich Foot Tunnel. Big spiral staircase. A full-susser might be preferable, to preserve the spine, and of course you’d have to ensure no-one was coming up the other way…
I’m going to try and do that, and film the bastard.
http://www.unicyclist.com/index.php?page=gallery&g2_itemId=125951
They are a bit slippy slidy though and steep and tight, and yes, like you say, have someone at the bottom to check no-one is coming, you can see bugger all from the top.
I think we may have waited till the lift was going up from the bottom to run it*, cos then you don’t get noticed. We didn’t get any hassle for doing it anyway.
Joe
*When I say ‘we’ I took the sensible option of taking photos for this one. I’m a big fan of not being dead.