UKC

/ Large collapse in the slate quarries

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Brown - on 02 Jul 2018

Yesterday a huge buttress in the  The Lost World/Heaven Walls collapsed.

The routes North West Face of the Druid (E6 6a) and the The Coolidge Effect (E4 6a) are basically totally distroyed as everything above the tunnels has fallen down.

It has left a rather fine wall with a good looking crack though.

It was hard to tell but it appears the two tunnels running to Mordor are still clear.

ianstevens - on 02 Jul 2018
In reply to Brown:

Saw/heard the aftermath of this from afar. Was an impressive dust cloud to say the least!

Brown - on 02 Jul 2018
In reply to ianstevens:

We were climbing the Dinorwic Unconquerable at the time. It was impressive up close as well.

The wall had been dropping small rocks for an hour prior to it going and in the proceeding five minutes there was the sound of continual rock fall. It was all taking place in the chimney forming behind the buttress with clouds of dust appearing from the tunnel mouth and on the third pitch of the Coolidge Effect.

It gave loads of warnings. If you are in one of those holes and loads of small stuff comes down without an obvious culprit knocking it off I'd leave sharpish. 

Northern Star on 02 Jul 2018
In reply to Brown:

Any photos?

Brown - on 02 Jul 2018
In reply to Northern Star:

I think this link will work.......

https://www.flickr.com/photos/159287761@N07/?

and before....

https://www.aditnow.co.uk/SuperSize/Lost-World-Collapse-2014_95182/

Post edited at 12:50
In reply to Brown:

Thanks. Here is what I think has fallen. Curiously it actually looks like what is left could well be both stable and potentially good for climbing. I'd give it a while though!

https://www.ukclimbing.com/images/dbpage.php?id=313126

Routes gone A Small Rusty Nail on a Large Mantelpiece (E5 6a) (probably had already mostly fallen down), The Coolidge Effect (E4 6a)North West Face of the Druid (E6 6a) - pitch 4 of this might still be climbable although the ledge you start from is gone. It was a decent pitch at E2 5b. Lost Crack (E5 6b) might be okay too but has no starting ledge.

The Wall Within (7c) appears to be okay although I'd certainly give it a wide berth for a few months.

We are just trying to find out about the tunnel through to Mordor which is part of Snakes and Ladders and could be full of rubble.

Alan

Northern Star on 02 Jul 2018
In reply to Brown:

Wow, cheers for the photos, to think I and many others have fairly recently stood inside that tunnel entrance that's now completely gone from the face of the cliff on several occasions!

So that's the third big rockfall in Lost World in as many years!

Red Rover - on 02 Jul 2018
In reply to Northern Star:

This is very sad. The Lost world was amazing I spent a few happy weekends in the bothy down there.

Post edited at 13:18
Brown - on 02 Jul 2018
In reply to Alan James - UKC and UKH:

The section highlighted is what fell. The sight of it slowly tilting forwards was amazing. I'm glad we were as high on the other side as we were. If we had been on the level below I think it would have been scary!

I did not drop back down to have a look but from where I was it appeared that the tunnels through to Mordor were still clear.

The remaining wall or slab left behind appears to be very impressive. I'd have thought that an abseil approach might yield something of interest as it would avoid all the rubble strewn lower ledges.

ianstevens - on 02 Jul 2018
In reply to Alan James - UKC and UKH:

The "proper" version of snakes and ladders has been destroyed for ages now anyway

 

In reply to Brown:

The tunnel through from Lost Worlds to Mordor is fine. much was has been said has fallen down.

jezb1 - on 02 Jul 2018
In reply to Mark Reeves:

Give us a shout if you need a belay on any new routes Mark!

Northern Star on 02 Jul 2018
In reply to Brown:

So just to compare with how it was a few years back, before the large rockfalls, just uploaded some of my images of Lost World here (June 2014):

https://www.ukclimbing.com/images/dbpage.php?id=313143

and here (again June 2014 just days before the large collapse that buried the bothy):

https://www.ukclimbing.com/images/dbpage.php?id=313140

and again here, but much earlier photo from 2009:

https://www.ukclimbing.com/images/dbpage.php?id=313145

Hope this helps.  Have lots more too - PM me if anyone wants them

Post edited at 18:41
Red Rover - on 02 Jul 2018
In reply to Northern Star:

Thanks. It looks like there were some big rockfalls even before 2009, it must slowly have been going. Looks like the falls are getting bigger though.

SuperLee1985 - on 03 Jul 2018
In reply to Brown:

That's pretty scary! I tended to assume things only fell down in winter during bad weather (storms, freeze-thaw etc.). It's pretty unnerving to think that any piece of rock could collapse even in benign conditions.

Brown - on 03 Jul 2018
In reply to SuperLee1985:

I'd imagine from a position of no real geological knowledge that it was connected to the hot weather.

Yosemite experiences high rockfall during periods of hot weather. The solar gain on the slate was large. It was hot to touch anywhere it was in direct sunlight.

https://www.usgs.gov/news/hot-days-can-trigger-yosemite-rockfalls 

Toerag - on 03 Jul 2018
In reply to Brown:

Agreed. Anything that causes expansion or contraction is going to make things fall down. Once mobile debris starts filling a chimney it's only ever going to get wider as the debris slowly falls further into it with a wedging effect.

Michael Hood - on 03 Jul 2018
In reply to Toerag:

Maybe we should be watching Castle Rock in the hot weather

Simon Caldwell - on 03 Jul 2018
In reply to Michael Hood:

> Maybe we should be watching Castle Rock in the hot weather

Someone was watching it very closely when we drove past on Friday - they were half way up Overhanging Bastion. Rather them than me!

SuperLee1985 - on 03 Jul 2018
In reply to Brown:

Interesting, thanks.

Slightly alarming to read in that article that the crack grew by up to half an inch. That'd be enough to make your nuts pop out if you were hanging around for too long.

Brown - on 03 Jul 2018
In reply to SuperLee1985:

I think we underestimate the impact of temperature on cliffs.

I climbed Central Wall (E3 6a) one new year. It was a clear cold day and the waterfall at the base of the crag was frozen solid.

All of the belay pegs could be removed by hand! I left them all where they were and belayed on other gear. I returned the following summer and reclimbed the route. All of the pegs were solid.

I doubt that anyone had climbed that route with a hammer and reset them. Who carries a hammer. I think it was just a result of temperature changes.

Dave Cumberland - on 03 Jul 2018
In reply to Michael Hood:

Agree. It is very dry weather that will encourage rock fall in the lakes, largely due to soil shrinkage and related things.


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