Crane/powerline survivor

Re: Crane/powerline survivor

I agee. I don't see why the discussion is focused on the legitimacy of the picture. As a conscientiously aware and pro-active group of arborist's- it seems it would be the duty of all who bear wittness to such an anomoly-cropped or not-to take it as a lesson learned and treat it as fact. The climber could be holding a charge and not feel the effect of the arc, or perhaps just having been extremly lucky in having the charge by-pass his body and make its way down the tree instead. Electricity goes in the path of least resistence. If the tree already held a charge, why would it decide to change coarse?

Also if I see a climber with out a helmet up in a tree I question his ability to make sound decisions. Especially on a crane job! What kind of logic is going on here? If he is nieve enough to forgo the most basic PPE, its seems resonable to conclude he was nieve enough to fogo any sort of safety prune by his local powerline company, or atleast try to attempt a safety prune himself(NOT RECCOMENDED!)

Thirdly- Hard as it may seem-the camera lense can capture sights that would otherwise be blind to the normal naked human eye. Im buying what their selling. I look at the picture as fact to the highest level of degree, if not for the lives possibly saved from it in times to come, but perhaps for the lives our industry has lost in simular situations in times past.

Im not sure the picture should be confined. I say spread it, get a buzz going....You can't create an awarness of an obvious current arborcultural industrial delema and negative statisical impact it has on the trade by keeping this in the closet.
 
Re: Crane/powerline survivor

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The sapwood sliver sticking up, (the barbar chair shard); would have been in contact with the raising log the longest amount of time, and this would be the easiest path for the electricity.

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I thought that too. We would think that physical/natural laws cannot contradict themselves (as we know it). So, logically speaking, we can see a conflict.

However. I guess my observation of water flowing through a tree aggressively (as with Cottonwood or Elm) would be in the center of the tree. So, yes the path of least resistance would be at the barber chair tear, however, perhaps the most conductive portion of the spar and log were more towards the middle.

In other words, what if I said that electricity takes the path of least resistance through conductive material.

Therefore, the outer edges of the wood is not a conductive.

Just speculation. Because I don't have the answers.
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Re: Crane/powerline survivor

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He asked, "how much do you think electric can jump? Even on our most powerful distribution line, how far?" No one really answered.

He said the most powerful lines can only jump something like 1/8" or something like that. 1/8" or 3/16", I don't think it was as much as 1/4".

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Hmm... I wonder where he got that information?
 
Re: Crane/powerline survivor

When we don't want to face the truth of things we challenge the validity of the sources. Electricity is a strange and powerful force. Did it arc over? No, it was pulled so the pic we see is later in the chain of events starting with the initial contact The "path of least resistance" isn't a straight line to the closest point. It can change as the variables influencing that path change. Look at the path lightning takes and one should not be surprised by this instant captured.

You would be amazed at the sheer number of events we miss that happen just out of our direct line of sight...
 
Re: Crane/powerline survivor

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Did it arc over? No, it was pulled so the pic we see is later in the chain of events starting with the initial contact The "path of least resistance" isn't a straight line to the closest point.


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Great observation & clarification Rob.
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Re: Crane/powerline survivor

Thanks,

My first choice of career was electrical engineering technology. The education has served me well in this field.
 
Re: Crane/powerline survivor

[ QUOTE ]
[ QUOTE ]

He asked, "how much do you think electric can jump? Even on our most powerful distribution line, how far?" No one really answered.

He said the most powerful lines can only jump something like 1/8" or something like that. 1/8" or 3/16", I don't think it was as much as 1/4".

[/ QUOTE ]

Hmm... I wonder where he got that information?

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This is a great vid, but this too is an arc being pulled as the switch is opened...not jumping
 
Re: Crane/powerline survivor

An arc can "jump" a gap (think about spark plugs) when the potential difference (voltage) is sufficient to overcome the resistance of the insulator (air). As the two pieces are pulled apart the ionized air allows for an increased distance until once again the insulation value exceeds the voltages ability to create current flow.

It may have started with the wood contacting the conductor at the point where there was still some attachment or a split second after. Current will continue to flow through an ever changing path of least resistance until the the air gap was of "infinite resistance" to the voltage.
 
Re: Crane/powerline survivor

Thats a crazy video allmark has. Even though the shortest path is a straight line the electric arc swoops up ten feet. Compared to the guys below that thing was huge!
 
Re: Crane/powerline survivor

That is true, even though it was a longer path for me to sneak back in my house through the garage door when I was young, it was less resistence than dealing with my Mom.
 
Re: Crane/powerline survivor

Tom, is there a way you can get me a copy of the picture. It looks like the paper took it off their site. We had a tree limb that "swallowed" the wire (cable line), needless to say that piece is still hanging on the wire, the city administrator asked if someone - me - could go down and knock it off the line with a pole or cut it off. Thought this picture might give him an idea of what could happen when he wants us to get close to power lines or any line for that matter. Thanks!
 
Re: Crane/powerline survivor

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Tom, is there a way you can get me a copy of the picture.

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Go back up to the first post in the thread. I attached the picture there.
 
Re: Crane/powerline survivor

Going into this discussion I had the impression that there should be a blue arc. I was wrong. Here is something fun to have.

Click on the guy above
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