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Old 07-25-2012, 10:36 AM   #21
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Lightning

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Originally Posted by Moonstruck View Post
I did a search of the site, and did not find any specific threads on the subject of lightning. Is anyone doing anything to protect against lightning or the effects of a lightning strike? We have had many severe thunderstorms this season. Some have been extremely violent. Just wondered if I am missing something that I should do.
Moonstruck.

You have asked.

"Is anyone doing anything to protect against lightning or the effects of a lightning strike? ".

Here is my take on your question for home and boat.

Verify that you insurance policy covers lightning damage.

Insurance companies will not support claims by people who make no effort to reduce liability, however there are a few exceptions.

All electrical storms start somewhere , they don't all come from the parking lot at Wall-mart , some storms can have there beginnings mat be just across the street from you ,this is also depending on where you live on the planet.

To avoid the loss of, or damage to, our electronic equipment and prior to an electrical storm we systematically un - plug all incoming electrical supply cables and also including incoming transmission lines to items such as Cable TV ; Stereo systems ; Telephones ; Micro waves; Computers and so on !

Don't be lulled into a of false sense security by thinking that a 15 Amp electrical power bar having voltage surge protection will save you equipment because it will not.................. Pull the Plug.

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Old 07-25-2012, 10:55 AM   #22
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Originally Posted by psneeld View Post

Thinking lightning always hits the tallest object has been disproven many a time...it's all about the potential and where it's the greatest and the best path. While never being next to the tallest object is a great idea...being near it doesn't mean you are safe either...
Now, you've done it! I thought I was safe here. Now, I'm paranoid again.

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Old 07-25-2012, 11:48 AM   #23
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Good info in Chapman's on how to construct a Faraday cage for your boat.
A cone from the highest point to the water.
It needs a separate ground from mast to keel and a path to follow.

In 30 years of boating in the Prince William Sound I have yet to see lightening or even a thunder storm.
They get them in the interior of Alaska just not on the coast.

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Old 07-25-2012, 05:02 PM   #24
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Lightning

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Originally Posted by Moonstruck View Post
Now, you've done it! I thought I was safe here. Now, I'm paranoid again.

The night before last we had an all night lightning and thunder storm the light show was nearly comparable all to the 4 th july events for the last 99 years.

We had one hit but not where you would normally expect.

Here is a list of potential targets.


4 Police 100 ft steel radio towers
4 commercial radio station steel towers
2 Power station 80 ft exhaust chimneys
1 waste disposal incinerator chimney up 120 ft
1 Cast steel 245 ft Lighthouse. big target
A big bunch of city steel buildings , 2 all glass and steel.
A big bunch of cell phone towers
The Governors mansion with two towers
The house of Parliament house with two towers
1. 40 ft steel to ham radio grounded steel tower 280 ft above sea level , had two recent hits >>>>> its mine.
Miles of Airport and Prison chain link fences
6 super large steel fuel storage tanks.

You may say that lightning does not strike twice, don't you believe that one
our 245 ft Lighthouse takes lots of hits ,but not this time.

Where did it hit ?

The lightning took out a utility pole transformer located next to a steel water way swing bridge.

Why did the bridge not take the hit ?

Step right up Ladies, pay your money and take your pick.

Question : If lightning takes the path of least resist then why is fork lightning jagged and random.
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Old 07-25-2012, 05:37 PM   #25
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That does it. I will just move the wheel down to the lower cabin level. Maybe Northern Spy will let me know where he gets his periscopes and hats.
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Old 07-25-2012, 05:55 PM   #26
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Quote:
Originally Posted by SOMERS View Post
The night before last we had an all night lightning and thunder storm the light show was nearly comparable all to the 4 th july events for the last 99 years.

We had one hit but not where you would normally expect.

Here is a list of potential targets.


4 Police 100 ft steel radio towers
4 commercial radio station steel towers
2 Power station 80 ft exhaust chimneys
1 waste disposal incinerator chimney up 120 ft
1 Cast steel 245 ft Lighthouse. big target
A big bunch of city steel buildings , 2 all glass and steel.
A big bunch of cell phone towers
The Governors mansion with two towers
The house of Parliament house with two towers
1. 40 ft steel to ham radio grounded steel tower 280 ft above sea level , had two recent hits >>>>> its mine.
Miles of Airport and Prison chain link fences
6 super large steel fuel storage tanks.

You may say that lightning does not strike twice, don't you believe that one
our 245 ft Lighthouse takes lots of hits ,but not this time.

Where did it hit ?

The lightning took out a utility pole transformer located next to a steel water way swing bridge.

Why did the bridge not take the hit ?

Step right up Ladies, pay your money and take your pick.

Question : If lightning takes the path of least resist then why is fork lightning jagged and random.
It only takes the path of least resistance where a strike is going to occur
due to the electrical potential difference between atmosphere and ground...otherwise every town on the planet coule just erect one tall tower and lightning would never be an issue.

No potential great enough...no strike. Ligtning rods are there to "bleed off" potential...not take the strike.
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Old 05-14-2013, 02:47 PM   #27
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The summer storm season is here. Last week we were anchored in front of Clarence Town, Southern Bahamas. The catamaran on the right went dark during one of the strikes. I don't know what else they lost but the storm sure got our attention.
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Old 05-14-2013, 09:01 PM   #28
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I've taken a couple of courses on lightning taught by recognized "experts". The one thing they agree on is that lightning does not take the "path of least resistance" it takes all "paths" and can jump significant distances to find another path as someone already mentioned.

One thing that struck me in these courses was the constant references to "theory" in that the "experts" acknowledge that much of our thinking on lightning is just that, "theory" and there is little that is accepted as absolute.

Having investigated a few strikes (i'm no expert), some that made sense and some that defied all the rules. I have come to the conclusion that 60,000,000 volts discharging 60,000amps, hotter than the surface of the sun and travelling near the speed of light .... pretty much goes where it wants despite the efforts of mere mortals with their grounding cables, sintered bronze ground plates, ion disipators and all the other snake oil sold.
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Old 05-14-2013, 09:34 PM   #29
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47 foot catamaran sailboat get struck here 2 weeks ago it had a 70 foot tall mast. Tow boat was towing the boat from Key West to Fort Lauderdale for repairs I think it's good not to be the tallest boat in the harbor
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Old 05-14-2013, 09:36 PM   #30
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Is a lightning rod worth it?

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Old 05-14-2013, 09:59 PM   #31
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Best lightning rod you can have is a No.1 Wood tied to the top of your mast............................not even god can hit a one wood.
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Old 05-14-2013, 11:11 PM   #32
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LOL!!

I understand that lightning is often much less than an inch in diameter! Pretty amazing amount of power in such a small 'package'.

Mark, I think your lightning rod is a tremendous help to those of us boating with you at a safe distance. At least we have a pretty good idea where the lightning will strike.

Last week, I was helping my friend Gene clean his boat when lightning started to move in. I figured I better get home while the getting was still good. I had a 2 mile boat ride home. I made it half-way there (between light 45 and Korth's Pirate's lair) when my radar lit up with rain all around me, but none was hitting the water...yet About 30 seconds later, it was like someone turned in a faucet. The cell was directly overhead me and my canvas was getting a great wash down! Visibility was down to about a mile in heavy rain, but it was no problem as I was just a few turns from home and the winds were still relatively light. There was lightning all around for a short time. Sure wish you were there!!
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Old 05-14-2013, 11:27 PM   #33
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Lightning last week?? This ain't Florida!

Don't know what the Coot's maker was thinking. Boat and mast are metal, so what's with the lightning rod? (Electricity is one of my worst subjects.)
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Old 05-14-2013, 11:31 PM   #34
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I think the idea is to provide a SAFE path for the energy to take instead of energizing the entire boat with the electrical jolt. I bet there's a beefy insulator at the masthead and a stout cable to a safe exit point preventing the electrical charge from passing through the mast and hull.
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Old 05-15-2013, 06:07 AM   #35
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In 30 years of boating in the Prince William Sound I have yet to see lightening or even a thunder storm.

Come to the Florida I-4 area , 1000 strikes a DAY are common.
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Old 05-15-2013, 11:37 AM   #36
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Quote:
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I think the idea is to provide a SAFE path for the energy to take instead of energizing the entire boat with the electrical jolt. I bet there's a beefy insulator at the masthead and a stout cable to a safe exit point preventing the electrical charge from passing through the mast and hull.
Per the builder, the lightning rod's purpose is to bleed off electrical energy to reduce the likelihood of a lightning strike, not to attract or absorb a strike. There is no insulator: the rod is screwed directly into the metal mast.
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Old 05-15-2013, 11:56 AM   #37
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That sort of fixture is usually installed to provide a point where corona discharge can occurr and like you wrote "bleed off" energy that might otherwise build up to more destructive levels and damage or interfere with radio frequency devices.

Your spike is the equivalent of the "static wicks" used on aircraft and serves the same purpose.

Your mast is the lightning rod, you are standing in the path to ground.
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Old 05-15-2013, 01:51 PM   #38
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Makes perfect sense.
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Old 05-16-2013, 06:20 AM   #39
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There is no insulator: the rod is screwed directly into the metal mast.

Your mast is the lightning rod, you are standing in the path to ground.

Be prepaired for the lightning to come straight down the mast , and exit the boat directly UNDER the mast.

Most L rod setups prefer a copper wire on any shrouds leading overboard to a ground .

Any connections are made with copper nuts and bolts .
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