Anchor point failure?

[Pete Hart]

Had a conifer snap out on me 6 years ago but luckily the anchor point got well and truly hung up and I managed to get my side strop on pronto and detach the main line. Looking back it was a very wide tree and it would have been hard to get any where near the deck but i still needed heavily sugared tea and a sit down after that!

 

 

 

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[RTS1]

Good job we was all double anchored haha

 

 

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[Rich Rule]

Good job we was all double anchored haha

 

 

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Yeah mate it's all good, I anchored into fresh air on the way up. If I hadn't I would have hit the deck much quicker, eh?

[Rich Rule]

Ben,

 

Yeah it was SRT with a base tie off. The line went into the canopy and secured at the base. The line stuck on a piece of epi about 8-10 inches from the crotch I was aiming for. It also ran through other forks within the crown. I couldn't manage to flick it over the epi but as the limb was 6" plus diameter and Oak I presumed it would be ok.

 

The top snapped out due to side loading or the bounce effect of SRT ascending. The line fell into the next crotch which was about 10 foot below. Meaning about 20 foot of slack line. I was only 12 feet up and I hit the deck before the line caught in the nex crotch.

 

Then the top came down on me and the groundie but luckily missed us both.

[Rich Rule]

First two pics is the oak tree. If you look closely you may see the tear out.

 

Third is the limb.

 

[john p]

iwouldnt think twice about the strength of that! might have to start reconsidering whet i anchor into!

[IsaacRob]

It's amazing what can snap out given half a chance! I was always told to give your anchor point a good tug twice, and then one more for good luck (stropped in of course!)

[arbogrunt]

was rigging a Poplar (the usual suspects I hear you say! ) and I ended up having to share a pollard head for my anchor and the rigging anchor. I cut a lump out (which in hindsight was too big). The pollard head ripped in half, the lower block and anchor sailed over my right shoulder just missing my head. The lowered limb just missed the groundie using a Hobbs..as did the anchor point and block. The second groundie held on to the tagline for grim death and was dragged across a cemetery, between several headstones. My climbing anchor stayed intact...just. Under the tree were several headstones and a spiked iron railing fence. Nobody hurt, nothing broken...lesson (re)learned...

[Rich Rule]

It's amazing what can snap out given half a chance! I was always told to give your anchor point a good tug twice, and then one more for good luck (stropped in of course!)

 

I posted an answer to your theory a while back...

 

Consider this. It was going really well, throw line hit desired fork first go. Apart from being unsettled on a bit of epi. I tensioned up the line and a few bits of deadwood came out of the crown. I retentioned the line again and do the same, bit more dead wood. Took the last couple of feet out of the line and then had me and a groundie hang I the line.

 

All good so it seemed.

 

I started ascending and was about 12 foot up when the leader snapped out.

 

Did the process of bouncing on the line weaken the leader? Combine that with the effect of the increased force with a base anchor. SRT ascent is a bit of a bouncy affair. As I progressed up the single line you are taking the limb close to the point of elasticity. The next movement pushing a bit further and so on. An elastic band will only stretch so far before failure.

 

I think that largely contributed to the failure.

 

As a rough estimate, I probably weigh 14 stone with climbing kit and 020 on my arse. Base anchor would mean 14 stone required to suspend me. Therefore the anchor point, which seemed fine, had approx 28 stone to support.

 

A climber would have to think wisely, if he or she were that heavy, before choosing an anchor.

 

Put it this way, I am pretty wary of SRT anchoring these days from the base. Unless it looks double bombproof, I will try and re position it.

 

Just some food for thought as I thought the primary anchor point would have been fine, but was wrong.

 

My mate went up and finished the tree and he tied in about 4 foot about the leader I had that had snapped out. As you can see from the broken leader it was healthy sound wood.

 

Climb safe.

Edited February 14, 2013 by Rich Rule

[mistahbenn]

Wow you were lucky mate! Good post. It's guys like you that make this place a better one. Maybe go on a diet though? jk