Bolt failure at The Mine

[chrisb]

DO NOT climb Pink Harmonica in Ashes 19 at The Mine until it has been fixed!

My friend was back-climbing the route to clean it. When she reached the top she left the last quick draw before the chains in place and back-clipped the belayer's end of the rope into it. This is a standard "extra" precaution that I highly recommend when back-climbing a route to clean it. She began to clean at the chains when one of the two bolts snapped off This would have left her on only one (dodgy) point of safety if she had not left the last in place and back-clipped it. I lowered her down and climbed the route to the side to retrieve our quickdraws. No one was hurt!

We wrote a warning message with chalk on the base of the route to stop people from climbing it. On closer inspection, most of the bolts look to be in a similar state to the one that broke at the top. This route is unsafe to climb until is has been rebolted.

Is this something ARF can do soon?

Cheers!

Chris

[Justin]

Thanks for letting us know. Glad nobody got hurt (that is why we have 2x bolts at the top).

Assuming the bolter(s) used the same hardware on the other routes that were opened at the Mine. I would advise staying off all the other routes until the bolts on the other routes can be checked.

http://www.climbing.co.za/wiki/The_Mine

[Brussel]

in so far as I recall there where several routes (of which pink harmonica is one) that were bolted by Scott Millar at about the same time and probably use the same hardware

[mokganjetsi]

yikes!!

kudos for the practice to be on the chains and the bolt below that.

i would suggest staying off the routes at the Mine that have expansion bolts. or at least check when they were bolted.....

maybe it is a good time to start a flag system based on the type of bolt, age of bolts and the area - i.e. each route has a rating based on bolt safety as well. i think such a system is in use in thailand (?)

[NatureBoi]

Hi Chris,
Would you know if there is a stamped letter on the end of the shaft?

Cheers
Cormac

[NatureBoi]

yikes!!

kudos for the practice to be on the chains and the bolt below that.

i would suggest staying off the routes at the Mine that have expansion bolts. or at least check when they were bolted.....

maybe it is a good time to start a flag system based on the type of bolt, age of bolts and the area - i.e. each route has a rating based on bolt safety as well. i think such a system is in use in thailand (?)

Route was bolted in 2003, so only 13 years old.
I'm not certain but I think this was one of the last routes not to be ARFed.
Trying to find out what type of bolt was used.
Most (90%) routes in Cape Peninsula are ARFed with Glue-ins, barring a few at Peers Cave and some routes 26+ elsewhere.

Cheers
Cormac

[chrisb]

Hi Chris,
Would you know if there is a stamped letter on the end of the shaft?

Cheers
Cormac

Hi Cormac,
I'll check the make of the bolts when I go back there this Thursday.
Chris

[Old Smelly]

Just an observation -

Funny that none of us actually like ending up on one bolt BUT very few people protest when the anchors are deliberately set up to load one bolt

YES I know this was argued back and forth and some contend that one bolt is plenty strong - they never fail right!

BUT see how when it comes down to it all two equalised anchors do give more confidence and have the added value that if one fails there is very little shockload! With no real downside.

I rest my case.

[hendriks]

I would strongly recommend that people only back climb when they need to, i.e. Only when it is not safe to top rope. Then you always have a long line of bolts. Back climbing is in my opinion a very dangerous thing to do as often you hear about someone completely unclipping themselves.

[mokganjetsi]

Most (90%) routes in Cape Peninsula are ARFed with Glue-ins, barring a few at Peers Cave and some routes 26+ elsewhere.

i have some concerns re some routes at montagu, hellfire etc. a lot of them bolted in the early & mid-90's. it would be useful to develop a safety benchmark for bolt type, age & area. e.g. for expansion bolts: the Mine 15-years; Montagu 20-years etc. not sure what those numbers should be though.

i have been supplementing some older bolts (where i can) with trad placements

[Wes]

Hey Guys,

Just got confirmation from Chris that it was actually the bolt the sheared off. Leaving about 3mm protruding from the rock.

Imaging showing the hanger:

Image curtsey of Chris:

646c44e7-a067-47ef-be31-009ad64fdea9.jpg (138.19 KiB) Viewed 3459 times

[chrisb]

Hey Guys,

Just got confirmation from Chris that it was actually the bolt the sheared off. Leaving about 3mm protruding from the rock.

Imaging showing the hanger:

Image curtsey of Jayson:
646c44e7-a067-47ef-be31-009ad64fdea9.jpg

Hi Wes,

That's the pic I took of the hangar/oval. The bolt snapped off with the nut still on leaving about 3 millimetres of jagged, rusty metal protruding from the rock.

[NatureBoi]

The bolts which have been failing are the ones with-out a letter designated on the head.
Not sure if that is the case with this route .
Attached is an example of a correct Hilti/ Fisher bolt.
FYI: Each letter corresponds to the length of the bolt.

Cheers
Cormac

[Keith]

Totally disagree old smelly

Look up "common mode failure"

(and "American death triangle")

[Nic Le Maitre]

Here's a thought:

We have no idea what configuration the bolts at the top of this route were in. Until we do, any speculation is pointless as the facts as they stand can be argued either way.

What we do know is that SCC is bad, some of the routes at the Mine may have suffered from it. Make sure you only climb routes on the new ARF bolts.

[Old Smelly]

Keith it would be idiotic to imply that equalised anchors and the American Death Triangle have any real context to each other!

American Death Triangle.gif (14.55 KiB) Viewed 3187 times

How an anchor is rigged is up to the person who attaches to it and has nothing to do with the position of the anchor points - in fact by just making it impossible to equalise with 2 similar length quickdraws, you are probably more likely to have people who create an ADC - so I do not know if you have a point at all or whether you grasp that an ADC can happen wherever there are two anchors.

Lets looks back at the three legged cow and point out that shared load will extend the life of each anchor way more then if you load one until it fails and then load the next one. That is logical. Shared loads are logical, which is why my four legged table (or cow) is able to cope better than your one legged table or 3 legged cow. Let's just say that most people prefer to be on two anchors than one.

How about you try this- climb really high up a big wall and then place one piece of pro and suspend all your gear and yourself off it. Then go to sleep for the night - and tell yourself it's only a static load and go to sleep (after reading a long and tedious explanation on common mode failures - and if that can't get you to go to sleep then not much will) Surely by that distorted logic and your implicit faith in it you will sleep soundly...

[hendriks]

How about we take this "How should we bolt top anchors debate" here: viewtopic.php?f=13&t=13271

Then we can keep this thread on track

[Nic Le Maitre]

Fact: We don't know which configuration the bolts were in

Fact: SCC is not caused by climbers hanging on the bolts or falling on them either. It is caused by chemical weathering of the steel structure along weak points in the grain structure of the metal.

Pointless speculation in the absence of ANY evidence is just that, pointless.

[Marshall1]

Donald Trump = importance of fact checking.

Stress is an element of Stress Corrosion Cracking. Falling on to a bolt would be a stress factor.

https://en.wikipedia.org/wiki/Stress_corrosion_cracking

[Nic Le Maitre]

The SCC in the Cape is as a result of using a bad batch of expansion bolts and the constant tension on the bolt produced by the nut. This is why the ARF are rebolting with P-bolts that glue in.

[henkg]

Donald Trump = importance of fact checking.

Stress is an element of Stress Corrosion Cracking. Falling on to a bolt would be a stress factor.

https://en.wikipedia.org/wiki/Stress_corrosion_cracking

Can you prove that climber induced "stress" is of sufficient duration and magnitude to meaningfully contribute to SCC? It should only be a factor to an already weakened anchor.

[Scott]

Glad No one was hurt. All bolts placed then were whatever the MCSA was recommending. Purchased from Dave Davies at MMO. All bolts Ive ever placed in RSA have been whatever the MCSA was recommending at the time purchased either at MMO, City Rock or Fischer/UPat.

Most of those routes were put up in the same time frame so whatever hasn't been ARF'ed should be avoided I would assume.

Cheers
Scott

[NatureBoi]

Route has now been ARF'd

Thanks, Mary, Ryan and Brian

Cheers
Cormac

[KaiPF]

Great stuff ARFers! Appreciate the hard work!

[bad]

So, the re bolting was done February last year and I have been meaning to return to remove the old hangers, and break off the old studs
This is my report on the condition of the 7 old clips on Pink Harmonica.
On Tuesday 5th June in the afternoon I went with our nice long ARF power bar & socket to snap off all the old hanger bolts.

Bolt 1 took immense effort of between 25-30 cranks
Bolt 2 probably 15-20
Bolt 3 snapped off after 1 crank, yes 1 crank ( a pretty important clip IMO nay crucial clip )
Bolt 4 I hammered into the hole and only a small bit protrudes and is under an overlap, quite safe
Bolts 5 & 6 took about 15-20 cranks to shear off
Bolt 7 too 1 crank like bolt 3 (also a seriously critical clip as it is usual to back up the cleaning from this clip )
Remaining lower off took about 20-25 cranks to shear off so appeared to be strong still

These bolts were not rated bolts and they had no letter on the protruding end of the bolt

[Old Smelly]

Interesting Feedback - thanks for that...

I think it may also hint that statistics and reality can diverge quite rapidly - it being that if a critical bolt fails easily then the person doing the falling will not care how safe the rest were. Maybe over simplistic but certainly in my view calls the lie to all that "common failure mode" crap that was cited earlier in this thread - bolts never fail until it happens to be a critical one...and its not important until it happens to you..

You guys who are making sure bolts are safer deserve all of our thanks.

[Nic Le Maitre]

I think it may also hint that statistics and reality can diverge quite rapidly - it being that if a critical bolt fails easily then the person doing the falling will not care how safe the rest were. Maybe over simplistic but certainly in my view calls the lie to all that "common failure mode" crap that was cited earlier in this thread - bolts never fail until it happens to be a critical one...and its not important until it happens to you..

I think the phrase that applies to this is "confirmation bias"

Just because a bolt is a critical bolt (i.e. one relied upon to prevent a ground fall) doesn't mean that it is a bolt often fallen on/subject to loading (and hence more likely to break according to your theory). The 3rd bolt on pretty much every sport route is a critical bolt, but that doesn't mean that the crux is at that bolt. Likewise the last bolt below the chains is a critical bolt as it is the back up while cleaning, again that doesn't mean that the hardest section of the climb is there.

Statistics and reality don't diverge, that's the entire point of statistics to reveal the signal in amongst the noise or show that it is just noise. Human beings are evolved to spot patterns, so much so that we find them where they don't exist, because from an evolutionary point of view false positives (seeing a tiger when there isn't one) aren't bad where as false negatives (not seeing the tiger and getting eaten) don't help you propagate the next generation. Statistics are there to show up real patterns rather than ones we think are there.

[emile]

That's some deep stuff Nic

[Gustav]

The UIAA Safety Commission is looking for samples of failed climbing anchors to assist in several related matters with the UIAA Climbing Anchor Standard UIAA 123. The Anchor Corrosion project is part of the UIAA’s commitment to continually researching and innovating in order to further develop its international standards for climbing equipment. The UIAA SafeCom team dedicated to the project are studying factors ranging from the impact of temperature and humidity, pollution and chlorides on climbing anchors.

https://www.theuiaa.org/home/submit-exa ... corrosion/

[Old Smelly]

What Nic said...

Apart from the bit where the bolt fails and you fall... then as I said the stats don't help you squat!

I guess I like it when all the bolts are strong enough or stronger and that does rely on statistics - to make sure the manufacturer makes the bolt strong enough or stronger - then its all up to the bolter...

I like the look of those UIAA Standards though - particularly if they are looking into top anchors (as you will recall I believe load sharing Top Anchors are better than loading a single anchor and having a back up bolt)

As far as I am concerned a clear, well Engineered, simple easily applied solution would be ideal, something that doesn't involve a whole lot of obfuscation and deliberate complexity - lets hope the UIAA can do it!