What do YOU, anchor into? ;)

[tomtrees]

I wish I could remember the formula. Something like distance times weight times gravity (gravity being 1.5)

 

Any way take a climber 80 kg and a fall of 1m and he has a value of 1 ton on impact.

 

Thats a lot to ask a branch the size of my wrist.

 

May be someone can remind me of the formula.

[Bolt]

 

I was told that you shouldnt anchor into anything that is of smaller diameter than your wrist, are you all familiar with this and if so, do you abide by it?

 

 

In my opinion, the wrist thing is more to do with the minimum radius that the rope should pass through rather than the strength of wood.

 

 

If you are a tree climbing instructor (or a CS38 assessor come to that) you would be unwise to state that you should simply choose an anchor bigger than your wrist.

 

A gross simplification like that would have you heading towards either A + E or the local courts (or both).

 

The proof is in many of the previous posts, where this rule has led in some cases directly to a fall.

 

More important considerations are - the tree species - how close to the trunk the rope goes over the anchour branch - the health of the tree - whether the branch is epicormic - squirrel damage - where the climbers destination in the crown is.

 

Yet despite never actually giving this 'advice' you can pretty much guarantee this little gem is given as a golden-rule-to-serve-you-well-for-all-time by at least one candidate in every course.

 

Upon telling them that they are quite wrong (for the many reasons that many have given) they look at you as if you are a heretic. Why would any right thinking instructor even dare to dispute such a wonderful rule, they think.

 

Ask them where they picked up this fine myth, and the answer is generally along the lines of "the bloke who does our climbing at work told me when he let me have a little go the other day".

 

So, WHERE DOES IT SAY IT? Where in print (other than word-of-mouth chatrooms or forums) does it actually say it.

 

any ideas?

 

In the LANTRA guidance? - don't think so.

Maybe the NPTC assessment schedule? - wrong.

Afag guide? don't tell me that they missed it? - hmmmmm, well you won't find it there.

AA guide to good climbing practice? nope, not at home.

 

Now, the sharper and more questioning young minds on your climbing course will tend to ask that if its such a flawed and over simplified rule, - and it dosen't actually say it in print anywhere, - why is it so widely 'known'?

 

That’s a tricky one to answer, and I have given it more than a little thought.

 

This best answer I have come up with as to the origin of this rule is the one I gave the other day, and that is that its more to do with the 4:1 ratio of pulley to rope diameter (this is, after all, a figure widely in print from rope and pulley manufactures than anything to do with wood strength.

 

If you are not bothered about maintaining a 100% of a climbing ropes strength

 

(which I am not, because as had been stated, they have a MBS of several tons)

 

then you can ignore this

 

(which I often do by having my rope over little branches, through cambium savers, mailons and the like).

 

Anyway, it’s not a Gungho or manly post, so I won’t over-labour the point any longer.

[tomtrees]

Dose it have to be in print to be of value ?

[Bolt]

what? a bit of industry best practice?

 

well yes, its generally written down somewhere.

 

in our industry, you can generally rely on lantra, nptc, the aa or the hse to do the decent thing.

[Bolt]

if its a fine old Dartmoor legend (like the hairy hands for instance), probably word-of-mouth is better.

[tomtrees]

Well most of the things I have learned in my climbing life have been through working with other climbers and my own experiments.

 

 

I see that the people around me in the industry are not really readers or writers my self includid it is after all a practical skilled job. Learnnig to climb, weld, lay bricks or even be a doctor come from contact and experince.

 

I wouldnt rope into something the size of my wrist but I would be more likley to listen to someone with experince than what had been writen by some one with none.

Edited April 12, 2011 by tomtrees

[Bolt]

Well most of the things I have learned in my climbing life have been through working with other climbers and my own experiments.

 

 

I see that the people around me in the industry are not really readers or writers my self includid it is after all a practical skilled job. Learnnig to climb, weld, lay bricks or even be a doctor come from contact and experince.

 

I wouldnt rope into something the size of my wrist but I would be more likley to listen to someone with experince than what had been writen by some one with none.

 

 

You say that you are not a reader or writer, yet you have been a member of arbtalk since january, and a guess you visited arbtalk prior to this.

 

Arbtalk is exclusively a reading / writing community, so don't put youself, or your industry down

 

Anyway, the original poster bought up the 'wrist rule', and I don't think a single post on the thread has supported it. You either have the "I was anchored into a branch bigger than that and it failed" camp (which, unfortunately, I happen to be in) or you have the "often tie into smaller if I assess using my experiance that it is OK" camp (which I am also in), or you have the "as small as my wrist - no way ever) camp (which I am not in).

 

Not a single poster has said that they stand up for the "wrist rule".

 

why? 'cause it ain't no good, thats why (yet it still persists - strange, don't you think?).

[MOG]

what? a bit of industry best practice?

 

well yes, its generally written down somewhere.

 

in our industry, you can generally rely on lantra, nptc, the aa or the hse to do the decent thing.

 

is they anything saying what is apporiate in afga guides best pratice or other reading types? i dont think there is. So the best why is to dicuss and share knowledge. but in Trees there can be No Rule Of Thumb in any sistuation because they are all different.

[Bolt]

Exactly.

 

Long live discussion and alterative points of view on arbtalk

[liam1]

Hi all, I was yesterday anchored into a 50 foot conifer with a 4 inch thick anchor point. I weigh 7 and a half stone and am 5ft4. Having just reduced the hedge by half I went up to put a pull rope in, started to come down to fell my anchor to about 20ft. The wind half way down blew me out off the centre right out, so I swung out where the the whole 20ft length I was going to fell snapped and followed me to the floor. Where I landed on my back with the stem landing on me. On investigation it had snapped near to the main stem which was 6inch diameter luckily I escaped with badly bruised hand and arse after landing on the timber I had chogged off lol. Still carnt believe what happened