Using figure 8 to rig?

[DDM]

i recently took down a bunch of small trees on the side of a house. each one would land on the insulated line/cable and nothing happened. these were the cable/electric lines that ran from the poles to the house panel.

what's the deal with those. as long as they remain insulated their ok right?

Guess if you had of ripped there mast off the house you could have drummed up some great value to the customer electrical repair.

 

[Ekka]

Oh, I got away pretty light with that, Clearance didn't even get up me but dobbed his mate in for a 25KV burn.

Guys, around these parts you'd be pretty hard pressed getting an energy company to do that task if the "parts" are outside the exclusion zone.

And frankly, that was basic rigging.

Also, you guys assumed he didn't have the experience or skill, but I knew from his diagrams and ideas (inc figure 8) that he wasn't stupid, and here's some supporting evidence.

and i have taken down many trees before

What he needed was coaching and confidence.

And yes, I'm certified to work around power so I'm not blowing it outta my backside.

If he tip tied it, butt tied it and even cut completely through the hinge he was safe. There was the other rigging options, an "A-Frame" balance with a tag line for a slew or direct vertical lift (bulletproof). He could have cut the notch, put in the backcut and got well away, no worries. Heck, he could've even put the pulley way up the trunk and just pulled that sucker straight up and cut it at the trunk.


Bykerkyle did give us some numbers so I'll work with the worst case scenario, we also dont know the species so I'll pick the heaviest wood for worst case scenario. Also, we wont consider that there is taper on the branch but that may balance out the foliage factor.

4" dia x 10' long has to be converted to cu ft.

3.1416 x (0.1666 x 0.1666) x 10 = 0.872 cu ft and if you dont believe my math you can use this http://www.online-calculators.co.uk/volumetric/cylindervolume.php

Live oak is the heaviest @ 76lbs per cu ft (source:The Art & Science of Practical Rigging p158/159)

So, 0.872 x 76lbs = 66.3lbs ... that's all that branch weighs.

So we got a 66lb branch that's 10' long 10' above the wires ... big deal! And that's worst case scenario. Now I assume that's to his green cutting line on the diagram. With some of the above options he could've taken the whole branch (tip tied)in one hit straight up with a pulley on the trunk up high ... it is a removal and he could have removed the branches above that one for room to do a full lift.

Now put all of this into perspective and you can see that there was no reason for the big flashing lights and sirens.opcorn:

 

[DDM]

Oh, I got away pretty light with that, Clearance didn't even get up me but dobbed his mate in for a 25KV burn.

Guys, around these parts you'd be pretty hard pressed getting an energy company to do that task if the "parts" are outside the exclusion zone.

And frankly, that was basic rigging.

Also, you guys assumed he didn't have the experience or skill, but I knew from his diagrams and ideas (inc figure 8) that he wasn't stupid, and here's some supporting evidence.



What he needed was coaching and confidence.

And yes, I'm certified to work around power so I'm not blowing it outta my backside.

If he tip tied it, butt tied it and even cut completely through the hinge he was safe. There was the other rigging options, an "A-Frame" balance with a tag line for a slew or direct vertical lift (bulletproof). He could have cut the notch, put in the backcut and got well away, no worries. Heck, he could've even put the pulley way up the trunk and just pulled that sucker straight up and cut it at the trunk.


Bykerkyle did give us some numbers so I'll work with the worst case scenario, we also dont know the species so I'll pick the heaviest wood for worst case scenario. Also, we wont consider that there is taper on the branch but that may balance out the foliage factor.

4" dia x 10' long has to be converted to cu ft.

3.1416 x (0.1666 x 0.1666) x 10 = 0.872 cu ft and if you dont believe my math you can use this http://www.online-calculators.co.uk/volumetric/cylindervolume.php

Live oak is the heaviest @ 76lbs per cu ft (source:The Art & Science of Practical Rigging p158/159)

So, 0.872 x 76lbs = 66.3lbs ... that's all that branch weighs.

So we got a 66lb branch that's 10' long 10' above the wires ... big deal! And that's worst case scenario. Now I assume that's to his green cutting line on the diagram. With some of the above options he could've taken the whole branch (tip tied)in one hit straight up with a pulley on the trunk up high ... it is a removal and he could have removed the branches above that one for room to do a full lift.

Now put all of this into perspective and you can see that there was no reason for the big flashing lights and sirens.opcorn:

Why dont you tie off to the tip of the branch run it higher into the tree tie off the end off the branch? Cut from the bottom have the groundie pull the branch tip up thru the 8 to lift it away from the ZAP ZAPline.
of course I'm probably missing something in the description.

Thats what i was trying to describe.

 

[Ekka]

Poor guy, he's all beat up now, I's just trying to help the bloke out. If he's climbed trees and lowered before .....

I remember a lady had this big limb of a rubber tree going over her roof. There was no high point or rigging point so even to lower it off itself was pretty much impossible but I suppose if you were desperate and crazy you'd give it a go.

Anyway, I bid for a tower and to reach over the roof and cut small blocks off, slew the tower back and chuck the blocks. Well the price was way to much for her and she got the lawnmower man.

Now fig limbs are big and HEAVY and fairly horizontal like a dirty great 18" dia pipe over the two story roof.

The lawn guys managed to get a rope over the end, tied it to their ride on mower. A guy cut a sideways notch and then he did the back cut yelling at the guy on the ride to take off.

Well, the limb turned about 5 degrees and came down on the roof busting it up really bad, damage was $7000

And the lawnmower men weren't insured for treework above 5m in height.

Now that is what you call dumb.

 

[rbtree]

Good one, Eric. note the second post in this thread..


rb, the chest thumper....

 

[DDM]

tied it to their ride on mower.

See there was the problem lawnmowers just arent fast enough!You need to tie it to a fast car! :hmm3grin2orange:

 

[xtremetrees]

tthere should be no rigging around powerlines, no matter insulated or not.
I always cut powerline trees small. If I cant cut it small and keep a 10 feet lcearance. I Dont Do It. I leave powerlines to the pros who do it all day.\

 

[Ekka]

One, a branch that size sounds more like 50-100 lb. Two, though an 8 will work, it is a bit hard to take up slack with it, as your drawing shows you pulling the branch up and sideways away from the line. Suggest adding a pulley on your overhead anchor, then it'll be easy to lift the limb.

Three, what kind of power line is this? Top of the pole is where the primaries are, don't mess with them. A service line to a house is less of a problem.

Four, are you a working arborist? Doesn't sound like it from the questions, unless you are just inexperienced.

regardless, be extra careful.

Nice RB, you big chest thumping hero. Does be extra careful mean he can attempt the job?

Certainly not illegal to do so or the authorities would have a rule which states no-body, other than a suitably qualified line clearance worker is allowed to work above lines or where there is the possibility of cut pieces contacting the line.

The only reg over here like that is the one that says no bucket truck is allowed to have the bucket above the line ... to either side is OK but never above. The reasoning being is if there was a hydraulic failure and uncontrolled bleeddown you would go straight into it.

We have used cranes with the boom extended over and below wires, a certified operator is allowed within 3' (low voltage) of the wires providing there is an observer with a loud whistle or horn constantly watching. No parts of the machine or load can enter the 3' exclusion zone.

Hey Bykerkyle, do us all a favour and tell us how many insulator discs are on the wires where they meet the pole. It can be quite common for the centre wire that meets the pole to have an extra disc, from this we can tell what voltage you got up there, a pic would be even better.

Around here the top wires are 90% of the time 11kv (3 cables).

The 11kv lines run above the 240/415v (4 cables), they drop down to pole transformers which is another indicator, you wont see the 33kv lines etc drop down to pole transformers for consumer supply.

Also, air is an insulator, the distance between wires, the distance between the insulator and the pole also works on air space so the energy cant arc or jump the gap. So when you look at wires look at the pole end, look at the surface area the from the wire past the insulator to the pole. That is a good indication of absolute minimum distance uninsulated ... but no-one will teach you that.


Why don’t birds get electrocuted when they sit on power lines?

The insulators that hold conductors in position combined with the excellent insulating properties of dry air mean that electricity does not flow between ‘live’ components and the earth. Moist air and rain may cause unstable irregularities in the electrical field around the conductors and insulators, which can generate a crackling noise and under some conditions can produce a dull glow called corona. Under damp conditions, a small current may leak along the insulator string, between the conductor and the ‘earthed’ structure, as the live components attempt to go to earth potential. This current is very small and trickles harmlessly to earth through the tower. These conditions are normal and not dangerous.

Animals are damaged by electricity only when it flows through them. A bird sitting on a power line is surrounded by air, which is a good insulator. No current flows through the bird, and there is no harm done. For the same reason, maintenance workers can sit on live transmission lines as long as they get there using insulated ladders and ropes, and keep a good air gap between themselves and the tower steel.

source:http://www.transpower.co.nz/?id=171&currentsec=2

 

[xtremetrees]

Here is the way TM riggs with a 8.