Bending Moments

[Carburetorless]

From the Sherrilltree website.

"Bending moments -

To be avoided! These are created when a load or force is put on a rigging or redirect point at an extreme angle. This force can cause the stem or spar to bend with extreme forces present at its base, which may lead to partial or complete failure".

Does this apply to the rope it's self or only mechanical parts of the system such as a pulley?

Also; How much of an angle is considered extreme?

 

[sgreanbeans]

Get "The Art and Science of Practical Rigging" by Arbor Master, will teach you many things. Advanced rigging is not something to guess at. Stay safe

 

[tree md]

All they're saying is to avoid stressing the spar while aloft. Read up on some of the zip line threads and you'll see what they mean. Spar failure is absolutely the worst thing that can go wrong while working aloft. Not many walk away from that.

 

[Carburetorless]

All they're saying is to avoid stressing the spar while aloft. Read up on some of the zip line threads and you'll see what they mean. Spar failure is absolutely the worst thing that can go wrong while working aloft. Not many walk away from that.

I guess most of this stuff only comes into play when you're lowering really heavy loads that are difficult to judge the weight of.

So the "If you don't know, let someone who does do it" rule is the best rule to follow.

 

[tree md]

Either that or take it in smaller pieces, which is always prudent when your not sure.

 

[lone wolf]

Either that or take it in smaller pieces, which is always prudent when your not sure.

Yup dont Murph it down!

 

[Bomber]

I guess most of this stuff only comes into play when you're lowering really heavy loads that are difficult to judge the weight of.

So the "If you don't know, let someone who does do it" rule is the best rule to follow.

You got it. Learn from others and start practicing by rigging small limbs on you own even if you don't have too rig them. Try speedlines to judge angles, weight, and speed.

You can learn a lot on this sight when you don't have a piss poor attitude!

 

[ddhlakebound]

I guess most of this stuff only comes into play when you're lowering really heavy loads that are difficult to judge the weight of.

So the "If you don't know, let someone who does do it" rule is the best rule to follow.

Moreso with heavy loads, but even medium loads can cause problems IF the rigging system allows too much shock loading. There's only one part of the rigging system which isn't rated.

A rigging rope with a fair bit of stretch, and a groundman who can let it run and stop it smoothly/slowly can mean the difference between failure and success. But if the limits are being pushed that much, a smaller piece probably would have been a good idea.

 

[ROPECLIMBER]

got me reading, here are a couple good articles the third one is from UK so some terms are diferent and I mostly skimmed it and read the pictures but if you are a mechanical engeneer then it might make sense on the formulas, etc,
I like smaller and going home,

http://www.#############/pdf/speedline_variations_1.pdf

http://www.#############/pdf/speedline_variations2.pdf

http://www.treevolution.co.uk/images/pdf/rr668.pdf this one is long I skiped to page 21 then skimmed a lot of it. a lot of it is common sense, if you leave the math out, math with letters dont add up in my pea brain,
Paul

 

[NCTREE]

"bending moments" have more to do with rigging points and angles. The position of your blocks in the tree and the forces that are put on the trees. The forces put on the tree can be manipulatated by the number and angles of your rigging points. Not the best at explaining it just know. Here's a little article I found by a well known climber that explains some of the forces.

Training & Educatin: Forces and Factors in Rigging Operations | Articles & Archives | Arbor Age

 

[Carburetorless]

"bending moments" have more to do with rigging points and angles. The position of your blocks in the tree and the forces that are put on the trees. The forces put on the tree can be manipulatated by the number and angles of your rigging points. Not the best at explaining it just know. Here's a little article I found by a well known climber that explains some of the forces.

Training & Educatin: Forces and Factors in Rigging Operations | Articles & Archives | Arbor Age

That one I've read before, but the more I read it the more sense it makes.

 

[Carburetorless]

got me reading, here are a couple good articles the third one is from UK so some terms are diferent and I mostly skimmed it and read the pictures but if you are a mechanical engeneer then it might make sense on the formulas, etc,
I like smaller and going home,

http://www.#############/pdf/speedline_variations_1.pdf

http://www.#############/pdf/speedline_variations2.pdf

http://www.treevolution.co.uk/images/pdf/rr668.pdf this one is long I skiped to page 21 then skimmed a lot of it. a lot of it is common sense, if you leave the math out, math with letters dont add up in my pea brain,
Paul

First off; www.#############/ isn't a website anywhere.

And the last never finishes loading.

Algebra and Trig I get, but when you start throwing linear and empirical equations at me my head starts hurting.

 

[ROPECLIMBER]

First off; www.#############/ isn't a website anywhere.

And the last never finishes loading.

Algebra and Trig I get, but when you start throwing linear and empirical equations at me my head starts hurting.

Carb, try this site the other 2 were blocked because they came from competetive site, google speed line variations a photo essay by Mark Adams sept and oct arborist news 06 there is 2 PDF's from tree Buz, then the forestry studie down loads slow because it is big will take a while on dial up,


http://www.treemagineers.com/downloads/Detter_Kinematics_Arborist_News.pdf

Paul