Tie-in fail

Treezybreez said:
It depends on the angle of the rope going through the tree as to whether the load is doubled. Also friction at the anchor point can effect the load as well. This article has been posted here before but it is so good I'll post it again. towards the end is where it talks about rope angles.
http://vtio.org.au/Content/wp-content/uploads/2010/07/Single-Rope-Technique-i.pdf
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Cheers TreezyBuzzy! I'm aware I posting a simplified summary of the basic loading principles - but that was because I perceived some confusion from previous posts.

I'm also aware that I was talking about the Total Climber Load (mass) as a static variable, which it is, but that by introducing movement we are really needing to consider the dynamic load.

The angle thing is interesting, but I ignored it for two reasons, first, we are generally here talking aboutthe initial access to a high tip (ie no redirects, and that here is not the TIP, but the tip of the climb, Top Of System = TOS) and so typically the load and anchor lines being close to parallel and second, 200% is the worse case (at least for the TOS!) so is a worthy consideration. (The caveat is situations where you can get the anchor line going above and beyond the TOS crotch in the direction of the supporting branch thereby bring the load vector closer to the branch itself, in which case a base anchor will put a much safer compression load on the TOS - but how difficult is that to achieve from the ground? which explains my point above.)

Friction makes life so much more complicated, but at the end of the day, in terms of TOS loading I suspect it is dwarfed by the shock loads of a climber ascending the rope, especially since no rope is anywhere near completely static, and again - the worst case scenario is that the anchor side holds the same load as the climbing/load side and so the effect on the TOS is doubled - and we always need to be considering the WCS.

I have no proof but I think there is a further effect that makes _certain points_ of a climb more risky than others. A shock (generated by movement - ie each climbing thrust or descent brake) travels along the line in waves. The transmission, duration and frequency will vary by the line construction, climber mass, movement aggression and timing, oh and by friction. Waves have a tendency to reflect off static points (ie the anchor and the TOS. At certain points the freqeency, wavelength and line length may collude to align fresh shock waves with reflections... either in the load or anchor side, amplifying their strength and the momentary loads on the TOS and harness and anchor.

But how to prove and/or quantify the effect... beyond me :)

Its certainly demonstrably very destructive to power lines, bridges and buildings with wind loading or earth movements... you dont have to trawl google very far for the evidence there.

EDIT:: I've replaced references to TIP above to TOS - meaning Top Of System. In DdRT and SRT with a top anchor the TOS will be the TIP also, unlike the base anchor system. SOrry for the confusion!
 
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glad your man didnt get it any worse than that. ive always thought ash was an untrustworthy bitch. i wont climb those ugly things on anything less than my thigh for an initial tie in. and if its all holey and ugly anything i cant get with a pole saw from there or knock out by shaking gets left for the next stiff breeze. or cut extra big.
 
its amazing how many injuries related to tree failure are related to ash trees. they will fall apart fast... my mentor once criticized me for having one man on a pull line , pulling over a 10' piece of wood, after taking out a 30-40' top on a dead ash. He said "what did I tell you about ash?"

seems like having 2-3 men shock loading a tie in point wuld be an easy and fairly trustworthy pre-caution...
 
Came back to this thread to talk about the mini but many shock load of the climb line / TIP while ascending and stopping descents. ( you guys where already all over it)
I'd love for someone with an enforcer to do extensive testing at the TIP and maybe the connection to harness demonstrating the fluctuation of force exerted on said points. (And post video)
Jared Aborjena said he was able to sheer the cover on kernmantle(?) with toothed ascenders with a 1' drop of 215# 100% of the time!
 
Tom Dunlap said:
...Something else I'm seeing in the butt of the broken branches is what looks like odd faces on the ends. They seem a bit too blocky rather than long angular fibers like I expect to see in a solid ash. When I've seen blocky ends like that it reminds me of what looks like early white rot. Might the tree be in decline? EAB stress is possible.
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Tom, that was my first reaction, doesn't matter if there are leaves on that top, that wood is getting punky and the cambium looks fried. Looking at the photo of the entire tree it looks like most ash in my area. Ash Yellows has made most ash in Massachusetts look like that long before EAB, It's very rare now to see a pristine ash in perfect shape.

Like most accidents in every industry it takes at least 3 fails for any accident to happen. If one of the 3 conditions below didn't exist unlikely there would be an accident.

1. Climber internalized pressure to get the job done within quote, accepted a sketchier TIP than he would have liked (this is a constant condition for majority of working climbers as far as I can tell)
2. Too much leverage on too low a diameter limb for the species
3. Limb compromised by fungus/rot process

Climbers would be dishonest if they said they never climb on TIPs that worry them. I'm probably more paranoid than many climbers so what worries me may not worry someone else ;-)

Sorry for the accident, wishing for a speedy and full recovery!
-AJ
 
Daniel said:
....seems like having 2-3 men shock loading a tie in point wuld be an easy and fairly trustworthy pre-caution...
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I believe in testing anchors but... put too much load on it and it might become weakened and fail as the climber ascends. Such a tough problem to solve. Looking at it another way, 99.99% of the time climber's access anchors don't fail during ascent. It is humbling for everyone when climbers fall and hopefully some of the safety measures mentioned in the thread will be taken to heart.
-AJ
 
Doing test pulls, I have broken a TIP out in a walnut full of bad branch unions. That was 2 guys bouncing on the rope... sure glad I did.. never have seen it go the other way.. so weakening by testing is more of a vague possibility that a reality to me.
 
Daniel said:
Doing test pulls, I have broken a TIP out in a walnut full of bad branch unions. That was 2 guys bouncing on the rope... sure glad I did.. never have seen it go the other way.. so weakening by testing is more of a vague possibility that a reality to me.
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Yer probably right. 2 people load testing makes sense, more than that seems like creating problems.
-AJ
 
Daniel said:
its amazing how many injuries related to tree failure are related to ash trees.
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I actually had my rigging point rip out of an alive ash 2 years ago. Hung the block maybe 8' out on a decent sized horizontal leader, just to rig the horizontal leader below it. I never even considered rigging point failure to be a possibility. The lead we were removing wasn't that big, and the guy on the Porti did a good job of letting it run, but as he slowed it, the branch with the block snapped off a foot or 2 out from the trunk. Thankfully the free falling leaders and rigging missed everyone and nearly everything, but several pairs of undies weren't quite the same after that! A real eye opener!
 
moss said:
I believe in testing anchors but... put too much load on it and it might become weakened and fail as the climber ascends. Such a tough problem to solve. Looking at it another way, 99.99% of the time climber's access anchors don't fail during ascent. It is humbling for everyone when climbers fall and hopefully some of the safety measures mentioned in the thread will be taken to heart.
-AJ
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Or you could think about it from the other side of the coin, why approach an anchor if the only logic of safety is vaguely increasing the mass to 'test' it. For me an anchor must be observably strong from the floor, eye sight only. There are of course times when 2 people pulling is helpful to clear the anchor leg off of deflected and unwanted branches but that is another matter. I think that Rich H is right, shoot lower and work in an efficient advancing system for finalising anchor point selection. Trunk anchor setting is complex but can be misconstrued as simple.
I'm so sorry to hear of the accident, wishing the climber and his family all the best.
 
SoftBankHawks said:
Or you could think about it from the other side of the coin, why approach an anchor if the only logic of safety is vaguely increasing the mass to 'test' it. For me an anchor must be observably strong from the floor, eye sight only. There are of course times when 2 people pulling is helpful to clear the anchor leg off of deflected and unwanted branches but that is another matter. I think that Rich H is right, shoot lower and work in an efficient advancing system for finalising anchor point selection. Trunk anchor setting is complex but can be misconstrued as simple.
I'm so sorry to hear of the accident, wishing the climber and his family all the best.
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sounds good but not always practical... so many variables to consider in this biz... best to have flexible strategies when you need to go with plan g
 
southsoundtree01 said:
If in doubt of a TIP, shoot a second line, and keep the slack out/ line taut as you rely on your high TIP. As you get closer, you can get a better visual on the high TIP.
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Part of the problem was he wasn't in doubt till he was 3/4th of the way up.

There is a bit more to the story...he posted it himself elsewhere so I'll put it here. About three quarters up, he started feeling uneasy about his tie in point. He was able to get his safety around another lead and get into the trunk. He then evaluated decending to the ground (and reset) or continue to ascend and reset. Worried about the jerking of decending, he decided to ascend.

Now for the part I truly don't understand, and I don't think he truly does either. Despite having a 20' double ended safety, he unclipped it and tried to minimize and his swing then ascend. That is when he heard the limb pop and then break.

Where he thinks he had his lanyard
ef41565cb34674a1eb3332ff368026cc.jpg


Never stop looking for different options to a pronlem, and don't settle for thinking it will be ok. If you don't know, it isn't good enough in my opinion. Since he had gotten lanyarded in he had other safer options.

"Kiss My Axe"
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Perhaps we are beginning to see the down side to SRT climbing, in that the working end becomes fixed and un-manageable. The choice of anchor lays with the climber or site foreman but system limitation is another thing.
 
SoftBankHawks said:
Perhaps we are beginning to see the down side to SRT climbing
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This downside has always been there but it is an extremely important consideration that isn't appreciated enough. Unfortunately injuries and accidents will put the spot light on the dynamics of SRT TIPs. This is good and bad...good, not enough attention seems to be paid but bad because the knee-jerk reaction is likely to be "No more SRT".

Would this TIP failed if the climber were footlocking the tail in DdRT?

Would this TIP failed if the climber were ascending with a doubled rope FL ascent that was traditional before SRT anchors/TIPs came in vogue?

Would this TIP failed if it weren't ash?
 
I was thinking more along the lines that he may have made a different decision at the point of lanyarding in, if he were able to simply pull out his anchor.
I disagree with you Tom, I don't see that SRT Work Positioning can have the finger wagged at it, more that it has begun to shine a light on a huge training gap within the current remit. Any floating anchor would load the same way. I truly believe that within the complexity of anchor setting lays a solid systematic approach, for which ever system you choose to apply.
 
"Training gap" is what I was grasping for.

Anchors are anchors...whether for SRT, DdRT, rigging or pulling the truck out of the mud. Each has some common characteristics...more than is understood. This is where the training gap comes in.
 
SoftBankHawks said:
Perhaps we are beginning to see the down side to SRT climbing, .... system limitation is another thing.
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Strange choice of words. Imprudent use of a system does not reveal a system limitation but a poor choice. This climber had many options that would have prevented his fall right up to the last time he unclipped his lanyard. A base tie can become a canopy tie at any point of the climb.

My best wishes for this climbers full recovery. There have been may others that have fallen less distance that are no longer with us.
 
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