WARNING LOOSE BOLTS IN RHINO RIFT

[cap n chris]

Apparently they can be drilled out with a suitable bit or alternatively yanked out with a threaded & weighted extractor.

 

[Les W]

The other problem is that this cave has had so many SD spits installed over the decades that there's not a lot of clean rock left

This is a bit OT, but is it safe to remove a spit and put a P-anchor in it's place? OK, the rock has been stressed by the spit but P-anchors go much deeper in and don't stress the rock in the same way. Has this ever been tested before?

Just came to think of it as I read your post C'nC.

Francis

Not wishing to poo poo your idea, but how would you get the spit out?

It is perfectly acceptable to remove a spit and fit a "P" anchor in its place. The rock is no longer stressed once the spit is removed. What is not acceptable is to place on anchor within the stress cone of another so that they overlap.

Graham, there are propriety masonary hole cutters that will fit into an SDS drill and cut a hole around the spit allowing its removal. I'm not sure if this has been tried though.

 

[Cookie]

The other problem is that this cave has had so many SD spits installed over the decades that there's not a lot of clean rock left

This is a bit OT, but is it safe to remove a spit and put a P-anchor in it's place? OK, the rock has been stressed by the spit but P-anchors go much deeper in and don't stress the rock in the same way. Has this ever been tested before?

Just came to think of it as I read your post C'nC.

Francis

Its perfectly safe to do as you suggest. But it's generally so much grief to extract the old spit that it isn't done.

 

[cap n chris]

Please can we not end up suggesting that the entire cave gets rebolted and all SD spits are removed and red carpets are installed and there's hot showers plumbed in to the top grotto?...

The plan will be to test these supposedly "VERY LOOSE" (Hammy's words) bolts and if they don't pop out scarily quickly then obviously they are not as loose as people are claiming them to be; laterally mildly wobbly, perhaps, but not loose and certainly not very loose. The words "loose" and "very" are arbitrary and subjective.

We shall see.

 

[damian]

I'm sure somebody who knows what they're talking about will answer this in a minute but in the meantime you'll have to make do with me!

I am sure the original idea of P-bolts was just what Francis has suggested. In places where there is not much usable rock they can be put where the spits used to be. I have always assumed this is done by drilling small holes around the spit and then finally enlarging the new hole to P-bolt size.

Going off-topic slightly this is undoubtedly much more effort and probably explains why so many p-bolts have been placed much nearer existing spits than is supposed to be safe.

 

[francis]

Not wishing to poo poo your idea, but how would you get the spit out?

My idea. would be to use a 12mm metal drill bit and drill it out. Then drill the hole for the P-anchor which has a larger diameter. There might be a tiny bit left of the spit after drilling but I would have thought that it would be so thin that the masonry drill bit would manage to chew through it.

I have never tried removing a spit so I might be talking out of my @rse, just an idea.

Francis

 

[damian]

red carpets are installed and there's hot showers in the top grotto.

No there's an idea. I'll drink to that!

 

[cap n chris]

Also see:

http://ukcaving.com/board/index.php/topic,2899.0.html
http://ukcaving.com/board/index.php/topic,1682.0.html
http://www.cscc.org.uk/AccessFrameset.htm (news, Loose hanger etc.)
http://www.cscc.org.uk/Documents/CSCC_2006.02.04_Minutes.pdf (item 12.eight)
http://www.cscc.org.uk/Documents/CSCC_2006.05.06_Minutes.pdf (item 13)
http://www.cscc.org.uk/Documents/CSCC_2006.09.09_Minutes.pdf (item 10.9)
http://www.cscc.org.uk/Documents/CSCC_2004.12.04_Minutes.pdf (item 12 - !NOTE! the Swildon's Bolt replacement report)

 

[chriscastle46]

  The problem for most people is working out how to rig the three consecutive Y hangs in a user-friendly way. 




[/quote]
Why are there now three consecutive Y-hangs? It used to be fine with two.

 

[cap n chris]

It is two.

 

[Hughie]

Not wishing to poo poo your idea, but how would you get the spit out?

My idea. would be to use a 12mm metal drill bit and drill it out. Then drill the hole for the P-anchor which has a larger diameter. There might be a tiny bit left of the spit after drilling but I would have thought that it would be so thin that the masonry drill bit would manage to chew through it.

I have never tried removing a spit so I might be talking out of my @rse, just an idea.

Francis

That's the approach that I'd use. Very simple, and no reason not to be effective.

 

[Cookie]

http://www.cscc.org.uk/AccessFrameset.htm

For testing dates of Mendip Anchors.

The current info is a little out of date and shows some of the bolts out of test.

So far as I know this is not the case and all the bolts are actually in test.

Sorry for the misleading info. I've asked the Bolting Coordinator for an up to date list so that I can update the site.

The Anchor list on the CSCC website is now up to date.

The newly placed bolts have been added and the test dates have been updated.

See http://cscc.org.uk/anchors.htm

 

[Bob Mehew]

Could I ask people who read this thread also go and read the thread at http://ukcaving.com/board/index.php/topic,3120.0.html which is on BCA's discussion document on anchors and perhaps more importantly, the document itself at http://british-caving.org.uk/?page=129 . You will find that we are proposing to shift the view on what movement constitutes looseness by some amount. 

I would also add that looseness of 1 mm is very difficult to show as the reference point which you should be using needs to be very stable.  CNCC's original work on movement used a micrometer bolted to the rock face some distance away from the anchor in question.

I got an E Mail last night from the Mendip anchor coordinator part of which states "We have had another report of all the hangers been loose in Rhino rift I am going to take the tester down and test them all"

I can also confirm that the Swildon's 20 anchors were tested two years ago and were found OK, despite previous reports of looseness.

 

[graham]

apropos of this thread & comments in another thread about what goes on behind the scenes; please note that thanks to this report several cavers will have an unscheduled trip down Rhino lugging some heavy kit when they probably wanted to be somewhere else.

I also know of others who will be investigating other reports of potentially dangerous installations & many others who have been dragged round caves & mines after (spurious) reports of rockfalls. I could go on.

I hope all those who read this and are not involved in assisting in any of our multifarious organisations will feel just a little bit guilty and will volunteer themselves at the next meeting of their nearest regional council/access body/whatever.

 

[whitelackington]

Just a thought but perhaps worth a try out.
If it is acceptable to remove a spit and replace with a "P" bolt,
is it possible to do the operation in one go.


Ie; use an 18mm hole cutter. :idea:

 

[graham]

Why don't you volunteer to try it out, get the kit & do the experiment on a spare lump of limestone somewhere?

Then you can come back and tell us the answer.

 

[whitelackington]

Good idea :idea:

 

[Andy Sparrow]

  The problem for most people is working out how to rig the three consecutive Y hangs in a user-friendly way. 

Why are there now three consecutive Y-hangs? It used to be fine with two.
[/quote]

It's not changed - it's three Y hangs including the rebelay - or least it is when I rig it.

 

[caverbabe]

apropos of this thread & comments in another thread about what goes on behind the scenes; please note that thanks to this report several cavers will have an unscheduled trip down Rhino lugging some heavy kit when they probably wanted to be somewhere else.

I also know of others who will be investigating other reports of potentially dangerous installations & many others who have been dragged round caves & mines after (spurious) reports of rockfalls. I could go on.

I hope all those who read this and are not involved in assisting in any of our multifarious organisations will feel just a little bit guilty and will volunteer themselves at the next meeting of their nearest regional council/access body/whatever.

This sounds as if you are assuming that others don't volunteer!  Perhaps you should see the very helpful post from Bob Mehew a few up from yours.  Bob has been working tirelessly in MANY capacities for NCA/BCA, and actually provided some useful information!  I don't know of a single caver who would maliciously or intentionally make a "spurious" report - especially not just so good volunteers like yourself have to make unscheduled and undesired trips down holes in the ground...People have different judgement, different opinions, different time constraints, different priorities and different motivations.  

At the end of the day, the important thing is these suspect bolts will be investigated.  Sorry that might inconvenience someone who volunteered to do it, but isn't that the very essence of being a volunteer "someone who willingly undertakes tasks or enters service of their own free will, not constrained, compulsory or mandatory service".

 

[graham]

apropos of this thread & comments in another thread about what goes on behind the scenes; please note that thanks to this report several cavers will have an unscheduled trip down Rhino lugging some heavy kit when they probably wanted to be somewhere else.

I also know of others who will be investigating other reports of potentially dangerous installations & many others who have been dragged round caves & mines after (spurious) reports of rockfalls. I could go on.

I hope all those who read this and are not involved in assisting in any of our multifarious organisations will feel just a little bit guilty and will volunteer themselves at the next meeting of their nearest regional council/access body/whatever.

This sounds as if you are assuming that others don't volunteer!  Perhaps you should see the very helpful post from Bob Mehew a few up from yours.  Bob has been working tirelessly in MANY capacities for NCA/BCA, and actually provided some useful information!  I don't know of a single caver who would maliciously or intentionally make a "spurious" report - especially not just so good volunteers like yourself have to make unscheduled and undesired trips down holes in the ground...People have different judgement, different opinions, different time constraints, different priorities and different motivations.  

At the end of the day, the important thing is these suspect bolts will be investigated.  Sorry that might inconvenience someone who volunteered to do it, but isn't that the very essence of being a volunteer "someone who willingly undertakes tasks or enters service of their own free will, not constrained, compulsory or mandatory service".

I've known Bob for many years, we have had our differences, but I am well aware of all he has done for UK caving in that time. Without him we would not have much that we now take for granted. All I am trying to do is raise awareness of how much goes on behind the scenes & hopefully prod a few more in to volunteering to assist their fellow cavers in such ways.