Throwline/electric protocol

SoftBankHawks

Well-Known Member
I wonder if someone could help me, I am thinking best choice of throwline material when working next to electrical lines? Is dyneema so non-conductive as to be able to pull it off a line or is this abject folly? Many thanks.
 

GregManning

Super Moderator
Staff member
Folly at best. Don't do it.

1. I used to work around big electricity (hundreds of volts, and hundreds of thousands of amps).
We always used dielectric boots & gloves that were tested daily.

2. Contamination, moisture, etc could soon change the resistance of any line.

3. Your boots & socks could be damp / wet and make you a very good ground.

4. Etc, etc

Several years ago I was at the Ontario, Canada TCC.
I warned them, when they were setting up the throwline event. There were high voltage wires just behind the throwing area.

Yep, a competitor let the throw ball fly backwards into the wires.
Hydro One (the Ontario Electrical Utility) had to retrieve it using dielectric boots & dielectric gloves.
 

RopeShield

Well-Known Member
Cordage Institute says elect. Conductivity resistance;nylon - poor
Polyester, polypropylene, polyethylene kevlar and spectra are all good. Sourced this in On Rope by Bruce Smith and Allen Padgette
during my research with the RopeKnight use near throwlines EUSA employee explained to me Clean and dry dyneema is safe.
Avoid it ZAP
 

BRT

Well-Known Member
I'm not a utility guy.

I've had throwline go over a single phase line--no issue IME. I was using Dyneema.

I did take the bag off to retrieve the line. If you leave the bag on, and it gets tangled up--you're left "not holding the bag" :D

Also, if you pull the bag over the line, the resistance from the bag itself can exert a lot of force on the line; that force is then released when the bag finally flops over the line. That can cause something the electrical guys are always on the lookout for (forget what it's called)--but it amounts to vibrations.

Or, when the line is released, it can be catapulted over into another phase line--NOT good!

I've never had throwline cross over 2 or 3 phase lines. I would expect that could potentially be very bad.

Other guys on here are utility tree workers--they can probably contribute much more.
 

classictruckman

Well-Known Member
I don't use throw lines around power if I can avoid it, even if it means pushing a rope up with 4 or 5 insulated pruner sections. if a throw line did go over a line no chance I would not touch it without insulated gloves or an insulated pruner
 
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mrtree

Well-Known Member
I have no idea what the rules are for working near conductors in Japan, but my training tells me that a throwline near a conductor is a no-no in the first place, trying to answer what is a dielectric throwline is the wrong. Don't work near hydro unless you are properly trained and equipped.
 

Jim Maloney

New Member
Let's take a look at what OSHA has to say.

• 1910.269(r)(7)(vii): A rope that is wet, that is contaminated to the extent that its insulating capacity is impaired, or that is otherwise not considered to be insulated for the voltage involved may not be used near exposed energized lines.

That kind of implies that rope is non-conductive. How about ANSI:

• 4.2.12 – A rope that is wet, that is contaminated to the extent that its insulating capacity is impaired, or that is otherwise not to be considered insulated for the voltages involved may not be used within the minimum approach distances shown in Table 1 or 2, as applicable. (Table 1 or 2 are MAD Tables)

Insulating capacity? And there's that distance comment again. So we get more lawyer-speak from an OSHA interpretation from '99 that was revisited in '07 (with the referenced company's name redacted).

• Interpretation of OSHA Standard 29 CFR 1910.269 on April 26, 1999 & February 28th, 2007:

We also note that (the company)’s employees will be asked to rope the energized conductors to keep them from "snapping back when the tension of a tree is released by its removal." Paragraph (r)(7) of Section 1910.269 lists certain requirements for ropes used by line-clearance tree-trimmers. These requirements include rope strength and size, rope inspection, and rope storage. We also refer (the company) to ASTM Standard F1701-96e1 Specification for Unused Polypropylene Rope with Special Electrical Properties which covers the requirements, sizes, construction tests, and procedures for unused polypropylene ropes for use by electrical utilities and related industries working on energized lines operating at voltages better than 1 kV.

Then ASTM Standard F1701-96e1 is 7 pages of some serious engineering but paraphrased it states:

• Test 1 foot of rope for 5 minutes @ 50,000 volts

• Any leak greater than 250 micro amps fails the rope

Keep in mind that as little as 100 micro amps can cause fibrillation.

Anyone dielectrically tests ropes? We don't either. And "clean and dry" means exactly that - no contaminants and no moisture. Hanging in your side box doesn't count.


So allowing a clean, dry rope to come into contact with an energized conductor simplified:

Are You Nuts?

Get an outage or choose another method to ascend the tree.
 

Stihlmadd

Well-Known Member
cool that has answered some questions I have personally had for some time.I avoid throwing towards the uninsulated cables like the plague but was working on the dyneema being non - conductive material more on guesstimate than real knowledge.
good topic.
 

treevet

Well-Known Member
Went to the all day EHAP seminar last week and ofcourse it is a no no. All a matter of acting reasonably re employees. But I have pulled dynaglide over primaries numerous times without the bag and am still here...sort of. Bzzzzt Bzzzzt
 
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LimbLoppa

Well-Known Member
I agree with treevet. I've thrown throw line over energized primary and lived to tell about it. Just make sure it's dry and if you do throw it over a line-Remove The Bag! You don't want to shake the phases together -that is.....unless you want an outage!
 

jimbo666

Member
A couple years ago my throwline bounce on a trunk over an uninsulated power line.. Nothing happened we manage to just pull it out... i had a conversation with some other treeworker and it seems that it dosent conduct electricity... Even if its not recomended we tried it again and again on mono and 3phases....for the advancement of science we also test an old and dirty 3 strand at the end of the throwline touching the 3 power line with the 3 strands...nothing happen. I know its dumb but is their some real study on the subject?
 

LimbLoppa

Well-Known Member
A couple years ago my throwline bounce on a trunk over an uninsulated power line.. Nothing happened we manage to just pull it out... i had a conversation with some other treeworker and it seems that it dosent conduct electricity... Even if its not recomended we tried it again and again on mono and 3phases....for the advancement of science we also test an old and dirty 3 strand at the end of the throwline touching the 3 power line with the 3 strands...nothing happen. I know its dumb but is their some real study on the subject?
Ever try it with a wet rope? WTF man? If you ran into traffic blindfolded and didn't get hit would you do it over and over? A dry rope (throwball or 3 strand) shouldn't conduct electricity......SHOULDN'T. That doesn't mean it won't. The danger in the situation arises if (1) a normally non-conductive rope becomes conductive (2) if you slap phases together or phase and ground together. If you happen to"accidentally" throw your line over the power line, just take the throwball off and pull the line off. Don't push your luck- electricity will F*CK you up!
 

jimbo666

Member
Ever try it with a wet rope? WTF man? If you ran into traffic blindfolded and didn't get hit would you do it over and over? A dry rope (throwball or 3 strand) shouldn't conduct electricity......SHOULDN'T. That doesn't mean it won't. The danger in the situation arises if (1) a normally non-conductive rope becomes conductive (2) if you slap phases together or phase and ground together. If you happen to"accidentally" throw your line over the power line, just take the throwball off and pull the line off. Don't push your luck- electricity will F*CK you up!
I dont want your opinion. I want to find real study on the subject. Rope on powerline. Thanks for caring
 

LimbLoppa

Well-Known Member
Not an opinion Bro-I've worked around electricity for almost 20 years and Im very familiar with what it can do if it's not respected. Judging by your words(not mine) you don't respect it. I understand your curiosity just not your concept of "for the sake of science". If you're curious about what is acceptable refer to OSHA for your minimum approach distance dependent on voltage. I do care....otherwise I would not answer and I'd wait to read about you in the awakenings thread.
 

jimbo666

Member
Not an opinion Bro-I've worked around electricity for almost 20 years and Im very familiar with what it can do if it's not respected. Judging by your words(not mine) you don't respect it. I understand your curiosity just not your concept of "for the sake of science". If you're curious about what is acceptable refer to OSHA for your minimum approach distance dependent on voltage. I do care....otherwise I would not answer and I'd wait to read about you in the awakenings thread.
I know about osha approach distance, im familiar with working around powerline too, im just asking why it doesn't ground when it should. I want to find people who tested it the right way . Some kind of studies or. something
 

LimbLoppa

Well-Known Member
I know about osha approach distance, im familiar with working around powerline too, im just asking why it doesn't ground when it should. I want to find people who tested it the right way . Some kind of studies or. something
I have been looking for one since the first post- it doesn't ground because of the conductivity ( or lack thereof) of the rope. There was a study done on this recently for rescue situations, but I cannot seem to find the results. I will post a link as soon as I do.
 

TimBr

Well-Known Member
Great post, @LimbLoppa. (Referring to post #14) Electricity is unforgiving. It is one thing to get your dyneema line over a high voltage line accidentally, and attempt to retrieve it after removing the throw bag. It is quite another to intentionally and repeatedly put throwlines over a utility company's power lines.

So here is my take on it. @jimbo666, Do not do that stuff, you are not qualified. I realize that maybe this is a done deal that happened a few years ago, but just in case you are considering continuing with the experiments. It is especially foolhardy to continue to try to push the limits to try to see just how crappy and dirty a rope you can get away with using.

The day you cross over the limit will be the worst day of your life, and almost certainly one of your last few remaining days. I have seen photographs of men's bodies who have been hit by high voltage. I nearly passed out just looking at them. Electricity burns a path through your body. The levels of voltage and current available with utility lines will cause horrific, life-ending damage to the body of a person hit by it. If one does survive it, one will most likely end up getting a large portion of the body amputated. It is absolutely nothing to play with. Do not push your luck.

Tim
 
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