This has been posted on the Derbyshire caving site
http://www.hnh.dircon.co.uk/cave0404.htm
On the P-bolted traverse at the end of the cave (coming back towards the entrance) there is a large (i.e. fridge size) piece of rock which has a big crack running all around it and looks like it doesn't want to be part of the wall much longer. There is tape and a warning sign.
Unfortunately it effectively prevents using the traverse and pitch back down.

Do you want to do our usual trick of you standing underneath it while I go psycho with a crowbar above you?

Yeah, that sounds like a great plan.

Or....maybe not. At least this time I won't be hanging off the bolt you are trying to remove :wink: