We had a fantastic trip down Trapdoor Pot yesterday, but there were a couple of issues on Megatron pitch:

On our way back up, the bolt holding the deviation came out of the wall so now there's no anchor in place to put one in. I think I'm right in saying that this was one of the 8mm exploration studs rather than the more recently installed Long Lifes though. The people coming up after this happened reckoned it wasn't necessary in terms of rope rub but could be useful to avoid any of the loose rocks at the top if they were accidentally knocked, which brings me on to my next point...

Coming off the top Y hang of Megatron pitch there was a crash below as a sizeable (0.5m x 0.5m) rock landed on the ledge a few metres below. It had come out of the right wall (looking down) at the very top of the pitch with virtually no contact and from what appeared to be a solid section of wall. When we derigged we checked to see if any more pieces around here were in imminent danger of falling and several more smaller pieces were very easily dislodged, again from a seemingly solid wall.

Obviously Trapdoor isn't the most stable of caves and loose rocks are fairly common throughout, but it was a bit concerning that such large pieces were so loose in what appeared to be sound walls.

Thanks Mark.

If you haven't already, it would be useful to others if you could send the below to Mike Cooper for display on the NFTFH website.  There's a few bits on there about Trapdoor Pot already!

Email feedback@notforthefaint-hearted.co.uk
See http://www.notforthefaint-hearted.co.uk/Caves/trapdoor.html

I thought the Megatron deviation was a new anchor?  I may be wrong.  Did the anchor drop away or was it still attached to your rope?  Could this have been rock failure too?  I think we decided it wasn't strictly necessary either.

Ian.

Thanks for the links, I've emailed them to let them know.

As for the deviation anchor, the hanger itself was stainless steel but it seemed to be bolted on to an exploration stud. I imagine it didn't help that it was being loaded perpendicular to the wall apart from anything. It may have been rock failure that caused it to come out but it was difficult to tell at the time - certainly nothing large came off with the bolt. There was a sling in-situ which we clipped in at the top of the pitch (with the bolt attached) so hopefully people will realise not to expect it further down!

Having thought about it a bit more, I think the deviation would be useful to avoid any falling bits & pieces, as the ledges from the top of Electron down to the bottom of Megatron are all littered with various size loose rocks.