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 Post subject: A Shocking Portage
PostPosted: July 30th, 2020, 10:59 am 
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Joined: July 30th, 2006, 1:31 pm
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Location: Hamilton ON
We had a strange (shocking) experience last week while portaging between Wolf Lake and Nine Mile Lake north of Parry Sound.

We were camped at the north end of Nine Mile and had made a day trip to Wolf, Marsh and Round Lakes. The portage from Nine Mile to Wolf had been buggy and swampy, so we decided to portage along an ATV trail on the return trip. My son was carrying a Swift 16’ Kevlar Prospector with wooden yoke and carbon Kevlar gunnels. I had a similar boat but with a carbon fusion hull. I use a leather tumpline tied from the bow seat to the yoke, looped along the yoke and back to the bow seat. I hold the tumpline rather than the gunnels. I occasionally pass the tump over my head to lift the canoe off my shoulders.

The trail left Wolf Lake and climbed a hill to an open area under a high voltage transmission line. My son was about 100 metres ahead of me. He shouted that he was being stung by wasps, but actually, he was getting electrical shocks every time he let go of the gunnels. He felt like throwing his canoe on to the rocky ground but didn’t.

By the time I caught up to him, he had the canoe on the ground. He told me about the shocks. I wasn’t getting any. I took my hand off the tump and reached for the gunnel and sparks jumped between the gunnel and my hand. I quickly decided that the canoe was going to stay on my head. If I moved my arm over closer to the gunnel, all the hair on my arm stood on end.

My son and daughter-in-law were able to carry their canoe by the wooden carrying handles as long as the canoe didn’t get close to their legs.

After I got out from under the transmission line, I put the canoe down, getting a shock in the process even though I wasn’t under the line. A few minutes later, my granddaughter got a shock while trying to lift the canoe.

Has anyone else experienced this with a canoe? I haven’t found any other reports. You can find stories of cyclists having the same trouble. If they are holding the metal handlebar, the sparks come up through the bike seat to a more sensitive area.


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 Post subject: Re: A Shocking Portage
PostPosted: July 30th, 2020, 12:00 pm 
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Joined: September 21st, 2006, 8:41 pm
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Location: Southern Ontario
Wow, that is crazy. I have never heard of such a thing in all my years. So do you think it was a static in the air situation or improper grounding of the transmission tower poles and the electricity was travelling through the ground?

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 Post subject: Re: A Shocking Portage
PostPosted: July 30th, 2020, 12:14 pm 
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Joined: March 26th, 2013, 9:27 pm
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Location: Winnipeg, MB
Lots of induction when there's a lot of current on the line. We see hundreds of volts on fibre optic cable sheaths run long transmission corridors. Possibly the gunwales are long enough for a little induction but I would think that short of a strip wouldn't induce much. Possibly static electricity. If it was any sort of ground potential rise, you'd feel it as you step, with or without a boat.

Tall metal structure towers? Three conductors per side?


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 Post subject: Re: A Shocking Portage
PostPosted: July 30th, 2020, 12:15 pm 
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Location: Toronto,ON
It must have been about 10 years ago in that same portage, I got a few electrical shocks and the aluminum gunnels on the boat gave an audible buzz.


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 Post subject: Re: A Shocking Portage
PostPosted: July 30th, 2020, 12:21 pm 
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Location: Hamilton ON
Neil Fitzpatrick wrote:
Tall metal structure towers? Three conductors per side?

Yes, tall metal towers with 3 conductors per side.
I have asked my son to do some more experiments. Different canoes, different clothing, weather etc. he refuses, :-)


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 Post subject: Re: A Shocking Portage
PostPosted: July 30th, 2020, 2:03 pm 
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Location: Hamilton ON
The lines are at very high voltage and maybe 25 metres above the ground. There is an electric field in the region between the lines and the ground. (thousands of volts/m near the ground). If you are hiking below the lines your head is at a higher voltage than your feet and a small AC current must flow up and down through you. No problem.
Don't stick a metal pole up in the air.
I am assuming that the carbon kevlar gunnels are conducting. The wooden yoke is insulating. I don't know about the hull. I was insulated from the canoe as long as I didn't reach out to the gunnel. The canoe was higher than me and therefore at a higher voltage. How much higher? I don't know but high enough for AC sparks to jump from the gunnel to my hand continuously. No wonder my son felt he was being stung.
It may be that the canoe acts like a large capacitor resulting in larger currents.


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 Post subject: Re: A Shocking Portage
PostPosted: July 30th, 2020, 3:16 pm 
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Joined: March 26th, 2013, 9:27 pm
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Location: Winnipeg, MB
I wonder if it's an unbalanced load. More current on one phase than the other. Even with a balanced load, you would still have an electric field. Not sure why it's so intense on this line, or if the canoe has anythign to do with it.

https://www.bchydro.com/news/press_cent ... facts.html


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 Post subject: Re: A Shocking Portage
PostPosted: July 30th, 2020, 4:09 pm 
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I didn't notice anything in that area last year when I portaged along the ATV trail north out of Wolf to the next lake, but maybe it depends on the day, humidity, weather conditions, etc. I was carrying a Kevlar Shearwater Swift canoe with aluminum gunnels. The way the ATV trail goes on that part you pass under the transmission wires twice.


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 Post subject: Re: A Shocking Portage
PostPosted: July 30th, 2020, 5:59 pm 
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Joined: June 21st, 2009, 3:15 pm
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Location: Winnipeg, Manitoba
Faradays' Law in action. I'm not an electrical engineer and it's been a few years since my university physics courses; but I think that is the reason. I think these articles can explain it much better than I ever could:

https://electrical-engineering-portal.c ... -and-poles

https://home.howstuffworks.com/induction-cooktops2.htm

https://www.youtube.com/watch?v=hvQ9H9K7XeM


Last edited by crowmaster on July 30th, 2020, 6:12 pm, edited 1 time in total.

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 Post subject: Re: A Shocking Portage
PostPosted: July 30th, 2020, 6:07 pm 
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Joined: June 28th, 2008, 2:06 pm
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Location: GTA
Here's a photo of the transmission lines that run along Nine Mile Lake & the general area for anyone who might be interested. Part of the ATV/access trail that runs along below these wires can be seen. (The giant puddle is part of the trail.)


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 Post subject: Re: A Shocking Portage
PostPosted: July 30th, 2020, 7:07 pm 
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Location: Hamilton ON
crowmaster wrote:
Faradays' Law in action. I'm not an electrical engineer and it's been a few years since my university physics courses; but I think that is the reason. I think these articles can explain it much better than I ever could:

https://electrical-engineering-portal.c ... -and-poles

https://home.howstuffworks.com/induction-cooktops2.htm

https://www.youtube.com/watch?v=hvQ9H9K7XeM


I don't believe that it is induction (faraday's Law). I might be wrong but my rough calculations say it is simply the electric field, magnetic effects are much smaller.


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 Post subject: Re: A Shocking Portage
PostPosted: July 30th, 2020, 7:17 pm 
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Joined: July 30th, 2006, 1:31 pm
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Location: Hamilton ON
I received a private message with some very relevant info.

"Carbon fiber is an electrical conductor. Kevlar is not. Innegra is not. Both of those, including the
resin used to bond them, should be insulators. Fiberglass is an insulator also.

You mentioned "a metal pole." A carbon fiber paddle is a conductor and shaped like a pole. Don't
replace the metal pole with a carbon fiber one. Be careful setting a carbon canoe (gunnels or
entire hull) down. Don't stand it on end or you get your electrical gradient. There are instances
of paddlers using carbon fiber equipment getting killed in electrical (lightning) storms."

Wow.


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