Lightning Strikes

[LeaseOnLife]

Copy of ABYC TE-4:

http://www.marinesurveyorschool.org/...Protection.pdf

[Tom Stormcrowe]

Originally Posted by Snowpetrel

Always wondered if that was what it was, I have never seen it since on any other boat. Somehow I thought it was more.. Well Like flickering orange streamers rather than just a greenish glow. Thanks

It's actually the same effect as the Northern Lights, emission of photons from the ionization of the component gases of the atmosphere.

[sabray]

Originally Posted by Tom Stormcrowe

It's actually the same effect as the Northern Lights, emission of photons from the ionization of the component gases of the atmosphere.

Say what. Okay I have no idea I thought northern lights were mass coronal ejection from the sun. St Elmo's fire was static charge. Both have something to do with ions but really not similar. Or at least I thought interesting so please expand.

[zeehag]

northern lights, aurora borealis, is awesome to watch--very very impressive show. so many colors when i saw in copenhagen----i have never seen st elmos fire.

[Celestialsailor]

Some great information here. I'm convinced that my next haul out there will be some lightning bonding. I'm still not a believer in bonding thru-hulls as some people do to the AC ground. But this makes sense when you're talking about lightning blowing holes in my little ship.

[Tom Stormcrowe]

Originally Posted by sabray

Say what. Okay I have no idea I thought northern lights were mass coronal ejection from the sun. St Elmo's fire was static charge. Both have something to do with ions but really not similar. Or at least I thought interesting so please expand.

Both are the result of emission of photons due to the exitation of the gases and associated with magnetic fields. The Aurora is associated with the planetary magnetic field and how the excited particles trravel along the ba==magnetic liness, creating energy discharge in form of photons, and SWt Elmo's Fire is photonic emission of gases fluorescing due to surface magnetic fields along the surface of the mast. Both are the result of the same weak force interactions, just different scale and different energizing source.

[goldiphlox]

I woke up this morning to what I'm thinking is some kind of scientific phenomenon...and now i have this question nagging at me and was hoping someone could help....
I looked in the mirror and my head looked bigger and im wondering if gathering too much information in a very short expanse of time could actually make your brain swell? Hmmm....i asked Arnold, beings we're old friends from my body building days and he assured me.....it's not a too-ma!

In any event i would like to say that i can appreciate everyones opinion and have learned alot about lightning! Now i think i'll go get an advil
I

[Tom Stormcrowe]

Sorry, goldi.....

Occupational hazard of being a science geek.

[westwinds]

Originally Posted by Snowpetrel

Thanks, sounds very nasty, there goes my smug "I don't need to worry 'bout lightnin' I've got a steel boat" look.

Maybe I need to investigate some better protection, I am more scared of lighning at sea than just about anything else.

I wonder what the worst is that could happen to a steel boat, and how bad it would effect anybody aboard?

From American Boat & Yacht Council, Inc, TE-4 "Boats with Metal Hulls. If there is electrical continuity between metal hulls and masts, or other metallic superstructures of adequate height in accordance with the Lightning Protective Mast of this document, then no further protection against lightning is necessary."

I cannot agree with the above from TE-4 because I think an effort should be made to protect electronics with Faraday cages and lightening protection devices such as Industrial Communication Engineers, LTD.
and Lightning Protection . I have to do more reading about Faraday cages. From what I have read so far, the energy from a lightning strike that forms an electromagnetic pulse is below the 1 megahertz frequency (the middle of the AM band, like in your car) and this is what kills the VHF, HF, autopilots, alternators, electronic Diesel engine injection controls, GPS, depth finders, lap top computers, radar any just about anything else with integrated circuits in them.

[Celestialsailor]

Originally Posted by goldiphlox

I woke up this morning to what I'm thinking is some kind of scientific phenomenon...and now i have this question nagging at me and was hoping someone could help....
I looked in the mirror and my head looked bigger and im wondering if gathering too much information in a very short expanse of time could actually make your brain swell? Hmmm....

No...actually, I think swelling of the head is due to persistent self focusing.

[sabray]

Originally Posted by Celestialsailor

No...actually, I think swelling of the head is due to persistent self focusing.

Wrong it's a known phenomena caused by micro polymer thermal expansion of fixed plate substrates. Not sure how I know that.

[goldiphlox]

Originally Posted by sabray

Wrong it's a known phenomena caused by micro polymer thermal expansion of fixed plate substrates. Not sure how I know that.

Lol

[conachair]

Originally Posted by westwinds

I cannot agree with the above from TE-4 because I think an effort should be made to protect electronics with Faraday cages

Isn´t a steel hull just a big faraday cage?


And I'm a bit concerned about faraday overcrowding. If we keep using all the cages then soon the all the faradys will have to be jammed into the last few cages

Poor things.

[westwinds]

Originally Posted by conachair

Isn´t a steel hull just a big faraday cage?
And I'm a bit concerned about faraday overcrowding. If we keep using all the cages then soon the all the faradys will have to be jammed into the last few cages
Poor things.

How long do Faradays live? Maybe they will die out and there will be plenty of room, or are they like Tribbles? Eating everything in the boat stores especially if there is no quadra triticale and born pregnant too. I just dated myself didn't I to 1967 when Captain Kirk delt with the Tribble problem.

As for the steel boat, it is a big Faraday cage, but still the electronics can take a huge hit in there. Could be a power surge comes in on the power supply line, or maybe the antenna and these power surges need be taken out before entry into the big Faraday cage, or maybe the electromagnetic pulse gets into the cage by way of the mast that penetrates the cage caused by the lightning strike, a huge current spike on its way to a grounding plate in seawater.

[Adelie]

Originally Posted by westwinds

How long do Faradays live? Maybe they will die out and there will be plenty of room, or are they like Tribbles? Eating everything in the boat stores especially if there is no quadra triticale and born pregnant too. I just dated myself didn't I to 1967 when Captain Kirk delt with the Tribble problem.

As for the steel boat, it is a big Faraday cage, but still the electronics can take a huge hit in there. Could be a power surge comes in on the power supply line, or maybe the antenna and these power surges need be taken out before entry into the big Faraday cage, or maybe the electromagnetic pulse gets into the cage by way of the mast that penetrates the cage caused by the lightning strike, a huge current spike on its way to a grounding plate in seawater.

A steel boat will not be a perfect faraday cage or even a very good one unless all the portholes are covered with steel plates and the hatches likewise.

Understand that an aluminum boat will not provide the same overall protection as a steel boat. While the aluminum boat will provide the same protection against direct electrical currents, there will be no protection from magnetic fields which can induce electrical currents in conductors already inside the faraday cage.