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Are Bolted Anchors Safe at Long Dong Taiwan?


Original Post
Nick W · · Orford, NH · Joined Sep 2009 · Points: 40

Hi,

I have been thinking about heading to Taiwan for two weeks in late February to climb at Long Dong, and also experience other parts of what I have heard is a wonderful country. However, what I have read on this and other websites about the integrity of many of the bolts is both alarming and terrifying.

My question is in general, are enough of the bolts safe enough to make this trip worthwhile, or should I consider climbing elsewhere (i.e. in another country)? The one story of both anchor bolts failing makes me think that I might be playing a game of Russian roulette, where you never know if the next fall could be your last. And sticking to trad routes doesn't necessarily make things safer if you then have to lower off of two questionable bolts.

Am I being over-paranoid? Is there any system to figure out which bolts are new and therefore presumably safe? It sounds like even relatively new bolts may now be compromised.

Thanks!

Nick

Nate Ball · · Portland, OR · Joined Aug 2010 · Points: 9,512

Hi Nick. Lucky for you I am a creepily active member of Mountain Project, the administrator of all the SE Asian countries that use titanium bolts, and an active (excluded) member of the development team at LD... to which I am returning in a few days. And then leaving again. Three and a half years is enough... gotta take what I earned (a wife, no money) and get out.

To your question! So you've read my write-up on the main page of MP's Dragon Cave page? It really is a destination crag for those travelling east Asia. It's an incredible country, and incredibly convenient - English and 7-11's everywhere! And you can drink on the street!

Alright, side-tracked again. Here is the real answer to your question:
docs.google.com/spreadsheet…

I would say that, in general, "yellow" bolts are probably fine. But then again the bolts that failed on Big Drum (the double anchor failure you refer to) were actually forged 316L and thus should have lasted longer than any other - the TW bolts are all welded. The failure, in my educated though not professional estimation, was due more to the stress it received from constant top-roping and the micro-climate it was in (water seepage).

It all depends on your risk tolerance level. There is a lot of sport climbing to be done on "green" bolts at Golden Valley, First Cave interior, Music Hall left side, and Sky Wall. This is almost all in the range of 5.11-5.13 though, except for Dragonboat Wall (5.5-5.10). There are also a much higher percentage of "green" bolts on trad routes.

If you're not deterred, you should check out the Taiwan Climbing Calendar:
facebook.com/groups/4130189…

Let me know if you have any other questions.

EDIT: Oh, sorry! You'll obviously need the guidebook to interpret the chart. Otherwise, almost all routes 5.11 and under are on MP, and all the info is current, so you could download the app and use that as your guide too.

John Byrnes · · Fort Collins, CO · Joined Dec 2007 · Points: 582

Hi Nate,

After not hearing anything since our correspondence a year ago, I was put in contact with Matt R. in the last few days about the double anchor-bolt failure at Long Dong. Based on what he told me of the situation and attitudes over there, I'd say most folks are still in Denial about having "The Curse" of Stress Corrosion Cracking. In other words, not much has changed since we corresponded.

There's a theory that those SS316L anchor bolts broke due to galvanic corrosion because of quick-links hanging on them... very very unlikely. Has anyone got photos of the broken bolts?

We know from experience that 316L will last longer than 304, but that is only true if all other factors are equal! One bolt on a route may be in great shape but one 20' higher will be cracked through by SCC. The micro-environment is all-important.

We also know from Prosek's lab experiments that the same conditions that cause 304 to crack also cracks 316L. How old were the bolts on Big Drum?

As we discussed before, and agree, Ti is the only vetted solution at this time. Good to see you've been putting them in. BTW, great spreadsheet! Wish there were more turquoise on it! How do you like the Eternas?

Nick,

An Alpinist will go on a climbing vacation and dodge avalanches, falling rocks, hypothermia and other serious threats, and enjoy it. I'd say climbing at Long Dong is in the same category. Your call.

Nate Ball · · Portland, OR · Joined Aug 2010 · Points: 9,512
Big Drum broken anchors
As you can see from this image, the failure point was at the "fulcrum" rather than at the point of contact with the maillons. The maillons are 316 and the bolts are 316L, which does mean a slightly different composition but this would cause such negligible galvanic reaction as to be a non-issue. You can also clearly see the brittleness of the failure point, which is a clear indication of SCC. I believe Matt's concern was in relation to the galvanic corrosion of zinc-plated steel expansion bolts that failed in the early days of Thailand development.

corrosionist.com/Corros1.gif

As you can see on this chart, stainless steels are very close together whereas zinc is on the very "reactive" side of things, meaning it will corrode very quickly in contact with a more "noble" metal (steel) and will be accelerated by the highly corrosive environment in Thailand (sea spray, sunshine, water seepage, rock composition, etc).

The environment at LD is similar, with some differing factors: less stress from fewer climbers taking fewer lead falls (a majority of incidents have been caused by "foreigners") and different rock type. Micro-environments vary from bolt to bolt no matter where you are, and thus corrosion rates vary wildly. However, I don't think I would be making a rash conclusion to say that all steel bolts at LD have a 10-year expected lifespan. All yellow bolts are at or nearing that threshold.

As for my preference of Ti bolts, well... the Eternas make great lead bolts: really strong, low-profile, easy to install anywhere. But they're less ideal for anchors without some kind of lower-off setup. Martin makes these as well. The Tortugas make great anchors by themselves because of their size, and while they make not be as strong at 30kn, this is still 20 kn more than any anchor should ever take. The U-bolts are also ideal anchors for this reason, though the requirement of two perfect-distance-same-angle holes makes them more troublesome to use.

The upside of all this is that there are now OPTIONS! Whereas just three years ago, 316 steel was used even though it was known to have failed due to SCC, people now know that they have a limited life expectancy and thus are more trouble than they're worth. I've harping on this topic for years now, so it's nice to see that the Powers That Be have informed themselves (they certainly didn't want to hear it from me) and seem to be moving towards a massive rebolting and debolting effort using Martin's titanium bolts.

So, Nick, you may be just in time!
John Byrnes · · Fort Collins, CO · Joined Dec 2007 · Points: 582

I just this minute received a photo of the broken anchor bolts from Matt.

This is a classic case of SCC.

Nick, think about the fact that these bolts broke while top-roping, not from a leader fall. Think about the fact that, based on the photo, they have serious SCC in all bolts of this generation and in general, all stainless bolts there are somewhere along the path to failure.

These 316L Stainless anchor bolts, from from Long Dong Wall in Taiwan, a sandstone sea-cliff, have never held a lead fall and broke while toproping. This is a classic example of Stress Corrosion Cracking (SCC).

Nate Ball · · Portland, OR · Joined Aug 2010 · Points: 9,512

Hey John, while I agree with you that it's pretty scary that BOTH anchor bolts broke while the climber was being LOWERED, I don't think that it's fair to say that ALL bolts of this generation are in the process of failing. After all, the rate of corrosion will be determined by multiple environmental factors (sea spray, sun exposure, water seepage, etc) but it also requires STRESS. These anchors received a high concentration of it over the course of the nine years they were in as they were located at LD's most popular wall. This failure does warn us that all crux bolts and anchors on popular routes of this generation could be dangerous though.

Greg Barnes · · Unknown Hometown · Joined Apr 2006 · Points: 1,823

Classic SCC. We are now also seeing bolt failures due to SCC in California seaside crags that are in "cool" areas (north of San Francisco).

Actually, it is very fair to say that ALL bolts at that location are suspect, except titanium bolts. It really doesn't matter what grade of steel the old bolts are.

The "Stress" in Stress Corrosion Cracking has nothing to do with stressing the anchor by climbing, it's talking about the stress within the metal from the manufacturing process. The corrosion follows the lines of stress within the metal.

If you want to stay safe climbing there, only climb routes which have all titanium bolts.

John Byrnes · · Fort Collins, CO · Joined Dec 2007 · Points: 582
Greg Barnes wrote: Actually, it is very fair to say that ALL bolts at that location are suspect, except titanium bolts. It really doesn't matter what grade of steel the old bolts are. The "Stress" in Stress Corrosion Cracking has nothing to do with stressing the anchor by climbing, it's talking about the stress within the metal from the manufacturing process. The corrosion follows the lines of stress within the metal. If you want to stay safe climbing there, only climb routes which have all titanium bolts.
Truth.
Nate Ball · · Portland, OR · Joined Aug 2010 · Points: 9,512
Greg Barnes wrote:Actually, it is very fair to say that ALL bolts at that location are suspect, except titanium bolts. It really doesn't matter what grade of steel the old bolts are. The "Stress" in Stress Corrosion Cracking has nothing to do with stressing the anchor by climbing, it's talking about the stress within the metal from the manufacturing process.
This is simply not true. 316 bolts have proven themselves to have a minimum 10-year lifespan. I have removed dozens of mechanical bolts, specifically the Petzl P38 Long Life (304SS), which are usually older (closer to 15-20 years). As people who do this kind of work know, mechanical bolts have far more built-in stress from the manufacturing process than glue-ins. The bolts pictured above are forged and thus should have less internal stress than any other type of glue-in. Most of the mechanical bolts I removed show no outward signs of corrosion and those that do crack when whacked with a hammer often crack in different locations, if they crack at all. I have a plethora of pictures to prove this. My conclusion is that, at our crag, you either require a vastly more corrosive micro-climate (perhaps 1% of all bolts) or applied stress (or both) to have eventual bolt failure.

I am not saying this to try to dissuade anyone from "checking their safety" or from using titanium bolts. Martin and I regularly communicate and his bolts are the future of fixed protection at our crag. I am saying this so that others who may stumble upon this discussion will understand that it isn't as black-and-white as people make it out to be.

However, titanium is still the only long-term solution. We'll get there eventually. In the meantime, given the current rate of maintenance (40 titanium bolts in two years), it's important that we know where it is most needed. The discussion of whether to rebolt routes at all, given the possibility of supplemental (or entire) trad protection, is also a part of this whole debate, and certainly isn't helping to speed the process along.

Hopefully we will begin discussions in earnest in the next month. I'll keep y'all posted.
Nick W · · Orford, NH · Joined Sep 2009 · Points: 40

Thanks everyone for the useful and interesting comments.

Yes, I'm perfectly OK dealing with rockfall, avalanches, hypothermia, etc while climibng in the mountains. These are calculated or seemingly acceptable risks that are a given part of alpinism.

But dying or getting injured while sport climbing or trad cragging a few minutes from the road because a corroded bolt fails seems stupid and unacceptable to me. I go trad cragging and sport climbing with (maybe the foolish) assumption that I will have a certain margin of safety. And although I realize there is a continuum of bolt integrity that is likely a function of age and location on the cliffs, it seems like climbing here involves too much loss of control of risk for me. So sadly, we will probably pass on Taiwan. But hopefully will come back when more Ti bolts are in place.

On a somewhat unrelated note, does anyone know if it is warm enough to climb at Liming in Yunnan, China during this time (last two weeks of February)

Nick

John Byrnes · · Fort Collins, CO · Joined Dec 2007 · Points: 582
Nate Ball wrote: This is simply not true. 316 bolts have proven themselves to have a minimum 10-year lifespan. I have removed dozens of mechanical bolts, specifically the Petzl P38 Long Life (304SS), which are usually older (closer to 15-20 years). As people who do this kind of work know, mechanical bolts have far more built-in stress from the manufacturing process than glue-ins. The bolts pictured above are forged and thus should have less internal stress than any other type of glue-in. Most of the mechanical bolts I removed show no outward signs of corrosion and those that do crack when whacked with a hammer often crack in different locations, if they crack at all. I have a plethora of pictures to prove this. My conclusion is that, at our crag, you either require a vastly more corrosive micro-climate (perhaps 1% of all bolts) or applied stress (or both) to have eventual bolt failure.
I believe you, but were the 304 bolts in the SAME conditions as the corroding 316 bolts? We know that under the same corrosive conditions 304 and 316L both crack, 316L just takes longer. So it's surprising to hear that the 304 bolts were good if the 316 bolts were corroding.

It's rare, but it does happen, that there is no outward indications of SCC but the bolt is cracked internally. Usually there is obvious discoloration such as on the LD bolts in the photo. This bolt is apparently 304 with a 316 hanger.

Classic broken stainless bolt. Absolutely NO visible indication of cracking.
Nate Ball · · Portland, OR · Joined Aug 2010 · Points: 9,512

Here are all the documented failures at LD that I know of...

2003. Petzl P38 nail-drive. Age unknown, probably 10ish years. Area is prone to direct sea spray. Climber takes a fall from the crux, bolt breaks, climber decks, he eventually recovers from injuries.

2008. Ferno CT 304SS glue-in. Six years old. Area is prone to direct sea spray and seeps. Climber takes a fall from the crux, bolt breaks, next bolt catches him.

2012. Petzl P38 nail-drive. Age unknown, probably 10ish years. Back of a cave, no direct sea spray but lots of seepage. Climber takes a fall from the crux and breaks multiple bolts before he decks, he eventually recovers from injuries.

2012. Petzl P38 nail-drive. Age unknown, probably 10ish years. No direct sea spray or seepage. Climber TAKES at the crux, bolt breaks under body weight, next bolt catches him.

2015. Fixe glue-in, probably 304SS. Age unknown, probably 10ish years. Area is prone to direct sea spray, no seepage. Climber takes a fall at the crux, bolt breaks, next bolt catches him.

2015. Two Petzl Collinox anchor bolts. Nine years old. Below a roof that seeps, minor sea spray. Climber is being lowered when both bolts fail, he bruises his butt.

The one thing that the first five have in common is that they were crux bolts. Micro-climates varied. Falls were usually arrested by the next bolt.

People are falling on bolts all the time, but they don't break. I have whacked bolts in some areas and they were all fine, some areas where they all break, and others where some break and others are fine. The P38 hangers were always the part to fail - never the bolt itself. Not sure if this was the case for all of the falls, but it definitely was for the 2003 case.

So, we know that some P38 bolts have been in for at least 15 years but still don't break when hit with a hammer repeatedly. And then there is the incident of double anchor failure on lower of forged 316L bolts. What is different about this scenario? One, the micro-climate, specifically seepage. Two, regular stress from being weighted. These two factors can also be determined to be responsible for the previous failures.

In each case, the failure did happen at points in the metal that would hold internal stress from the manufacturing process: the bend in the hanger, the place where the bolt head meets the hanger, the weld in the glue-in bolt. However, this does not explain why some bolts of the same type didn't crack at all when hit with a hammer.

My conclusion, based on all this evidence, is that there is a degree of predictability in which bolts will fail. One of the more remarkable things is that the lifespan of mechanical bolts and glue-in bolts are relatively similar. Or, if we can accept that use-induced stress is a part of failure mechanism, that there are just more climbers stressing the bolts.

On a semi-related note, Martin has noticed visible corrosion of HCR and duplex steel on test bolts around Tonsai. Nothing on titanium, and still no failures of properly-placed titanium bolts.

We need titanium.

Nate Ball · · Portland, OR · Joined Aug 2010 · Points: 9,512
Maurice · · Taipei, Taiwan · Joined Nov 2011 · Points: 1

hum....

BrianWS · · Unknown Hometown · Joined Apr 2010 · Points: 790

Hi, just my 2 cents... which have depreciated in value since leaving the area 5 years ago. I was lucky enough to be climbing there before bolts began failing at the rate which they are currently. Nate B has certainly been passed the "Local Laowai Expert" torch from Matt R., in all of its glory and baggage... he is definitely your best source for information!

The climbing at LD is fantastic. If you are in the area, by all means check it out.

From what I know: Bring gear to supplement bolts (many sport routes can be supplemented or entirely led on gear). If the anchors look sketch, which clearly isn't always a solid indicator, be sure to bring some extra webbing and rings or some nuts to leave behind, etc. You may need to be creative and a bit more prudent than you would at any other sport crag, but its worth it. A truly beautiful setting with quality climbing!

Nate Ball · · Portland, OR · Joined Aug 2010 · Points: 9,512

Interesting development... so it turns out the Petzl Collinox bolts that failed were actually 304SS and not 316SS, which means that we have still yet to have a confirmed 316SS bolt failure at LD. This also means that all "yellow" still remain in the category of "no precedent of bolt breakage" at this point.

Spectrometer test on the broken Collinox bolts

John Byrnes · · Fort Collins, CO · Joined Dec 2007 · Points: 582
Nate Ball wrote:Here are all the documented failures at LD that I know of...
WOW! Excellent documentation. The best I've seen. Kudos!

Nate Ball wrote:The one thing that the first five have in common is that they were crux bolts. Micro-climates varied. Falls were usually arrested by the next bolt. People are falling on bolts all the time, but they don't break. I have whacked bolts in some areas and they were all fine, some areas where they all break, and others where some break and others are fine.
Yes, the unpredictability is very high; yours is similar to other areas that have SCC. There are many factors involved, however I think it's fair to say that if one bolt of a given type on a given wall cracks, they all will eventually crack. How long it takes can't be said. Is there a statistician in the house?

Nate Ball wrote:The P38 hangers were always the part to fail - never the bolt itself. Not sure if this was the case for all of the falls, but it definitely was for the 2003 case. So, we know that some P38 bolts have been in for at least 15 years but still don't break when hit with a hammer repeatedly. And then there is the incident of double anchor failure on lower of forged 316L bolts. What is different about this scenario? One, the micro-climate, specifically seepage. Two, regular stress from being weighted. These two factors can also be determined to be responsible for the previous failures. In each case, the failure did happen at points in the metal that would hold internal stress from the manufacturing process: the bend in the hanger, the place where the bolt head meets the hanger, the weld in the glue-in bolt. However, this does not explain why some bolts of the same type didn't crack at all when hit with a hammer. My conclusion, based on all this evidence, is that there is a degree of predictability in which bolts will fail. One of the more remarkable things is that the lifespan of mechanical bolts and glue-in bolts are relatively similar. Or, if we can accept that use-induced stress is a part of failure mechanism, that there are just more climbers stressing the bolts.
Everything I know says that climber induced stresses don't last long enough to make a difference. The cracking process takes months/years and climbers are loading the bolts for seconds/minutes.

However, if SCC cracking has started, even microscopically, a load from a fallen climber would likely exacerbate/accelerate the process. Perhaps that's what you're seeing.

Nate Ball wrote:On a semi-related note, Martin has noticed visible corrosion of HCR and duplex steel on test bolts around Tonsai. Nothing on titanium, and still no failures of properly-placed titanium bolts. We need titanium.
That's new news on the HCR and Duplex. Thanks.

Speaking of corrosion, I notice black discoloration of the bolts/hangers in the photos you posted. Is that color true? If so, it's quite different from what is normally seen in limestone. Perhaps there is some other salt involved besides Calcium or Magnesium Chlorides.
John Byrnes · · Fort Collins, CO · Joined Dec 2007 · Points: 582
Nate Ball wrote:Interesting development... so it turns out the Petzl Collinox bolts that failed were actually 304SS and not 316SS, which means that we have still yet to have a confirmed 316SS bolt failure at LD. This also means that all "yellow" still remain in the category of "no precedent of bolt breakage" at this point.
This is good, but not great. Since we know that the conditions that crack 304 also crack 316L; it just takes longer.

Do you have EDS data for the inside of the cracks, by any chance?
Appelkoos · · Unknown Hometown · Joined May 2014 · Points: 0

Nate,

In light of the spectrometer results on the broken Collinox (i.e. that it was 304) ...

... do you think that galvanic corrosion between the 304 bolt and the 316 mailon could be involved in the failure?

Interested in your opinion.

Nate Ball · · Portland, OR · Joined Aug 2010 · Points: 9,512
Appelkoos wrote:Nate, In light of the spectrometer results on the broken Collinox (i.e. that it was 304) ... ... do you think that galvanic corrosion between the 304 bolt and the 316 mailon could be involved in the failure? Interested in your opinion.
No. See my post above with the image of the bolts that begins "As you can see..."

Galvanic corrosion is a very obvious visible phenomenon and there is simply no visible evidence of it on those bolts. I have also observed titanium bolts that have had the same maillons on them for two years and there was also no visible sign of corrosion.
Guideline #1: Don't be a jerk.

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