Pendulum rigging

[rbtree]

Yo Shrek, didn't ya read Graeme's article? Their calculations were so precise that, after determining how much pretension to apply to each section, that each lifted off by about 1/4 inch!! And, due to the ever changing line angles, trig functions had to used to determine the tension needed.

[Stephen Blair]

Yo Shrek, didn't ya read Graeme's article? Their calculations were so precise that, after determining how much pretension to apply to each section, that each lifted off by about 1/4 inch!! And, due to the ever changing line angles, trig functions had to used to determine the tension needed.

 

i think i just dont get it mate lol:blushing:

[skyhuck]

how do you know what size of bit you are cutting off, and if its too big, then what do you do??sorry if i am missimg the point here, i think i know what you guys are talking about, but in my world, we just take less than what we thnik the equipement will take, if its too big, i just get a bit twitchy, cut a chunk off or hold my breath, holding your breath usually cancels out all weights and ratios to making a boo boo:001_smile:i havent and probably never will come across the tree situations you guys come across, but the bottom line is, someone has to get up there and cut off a bit.

 

I assume they will have a weight chart, giving approximate weight of timber by volume, so they can measure the diameter of the timber and calculate what length to cut in order to achieve the required weight.

[Stephen Blair]

I assume they will have a weight chart, giving approximate weight of timber by volume, so they can measure the diameter of the timber and calculate what length to cut in order to achieve the required weight.

 

up the tree with a measureing tape and calculator then, more like engineers with chain saws:thumbup1:

[rbtree]

Now you got it......and factoring in the added weight from increased water content--lower down the stem.....

[Mesterh]

Looks interesting and very precise.

 

Although there does seem to be quite a lot of different factors that you have to get right for it to work so well.

 

Would it not have been easier to pretension the ropes slightly, do a step cut, going through 95% ish(more or less right through in one) followed by the nick cut then tension the ropes until it popped off?

[Graeme McMahon]

Happy New Year

 

Angus said I should look up the thread and add. I'm not going to be fancy and quote previous comments (because I can't).

 

The setting we are working in is classified as a "Burra Charter"'. It is of historical, social, aesthetic, cultural and spiritual significance. The collection of about 100 clay sculptures at the base of the E. regnans trees is fragile and ageing. Mr. William Ricketts has passed away some time ago and his ashes are at the base of the tree he called the "Tree of Life".

 

We are to avoid damage to the moss on the rocks that line the sides of the narrow walking tracks and interference to the understory and groundcovers.

 

E. regnans produce much deadwood during the course of their short growth and following decline. The trees we used as high points were not part of the dead wooding program and had about 80' of dead limbs in a variety of decline.

 

The lowering lines had to work between these fragile appendages and thus minor shock loading would shower the 10 - 40' missiles onto the area and sculptures 100 - 200' below.

 

Understanding the client demands prior to devising the method speaks volumes. Guessing line tensions or "near enough" won't cut it either. Notwithstanding an up to 20' deflection of the crown of the support trees, at the point of severing the 1.25 ton blocks to be lowered, it needed to be static.

 

Hope this helps.

 

It’s been a while Rb, look forward to catching up. Pete thanks for the thread.

 

Graeme McMahon

[Mark Bolam]

Nice one Graeme.

 

Your vids keep us motivated when we are endlessly re-topping 20' conifers!

 

Happy New Year.

[rbtree]

Yo Graeme.....

 

I thought of you today while Brian and I were helping Cowboy Dave, my hotshot climber :thumbup1:wreck out a maple....It was about 18 feet tall ...heck, coulda been a whopping 22:001_rolleyes:......But it was on a steep bushy slope, with the house below and big low windows. So, we stood on the car deck, about 8 feet from the tree, and he handed the pollarded brush to us, but mostly tossed it onto a rope which we slid the mess to us, speed line style....big speed line style! Then, we did the same with a couple 100 pound limbs, swung em by pulling on the bight in the line, let em down so they wouldn't hit some other glass or the framework of the raised car deck, then pulled the pieces up. He chunked down the bottom 12 feet, and we carried it up to the alley, ducking under the canopy of a holly and rhody. Real hi tech stuff. Unfortunately, there will be no training video, as it was misting.......

 

Raining tomorrow, so we'll go back Thursday to prune (for the third time in 15 years) a gorgeous wide blue atlas cedar....view enhancement, and careful end weight reduction so it stay together. That will be the fourth day of mostly view pruning at two adjoining homes in an upscale part of Seattle.

 

Here's a vid of Dave, from "down under" Scary title, huh "Tandem ball riders, in the sky"

 

[ame]

[/ame] Edited January 6, 2010 by rbtree

[rbtree]

My comments in bold

Happy New Year And a prosperous one to all of us cretins

 

I'm not going to be fancy I dunno about that, your plaid shirts are way stylin'!!

 

 

Graeme McMahon