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Old 07-10-2009, 16:12   #61
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I can't imagine a fuse would be any help in a lightning strike, with that kind of current it would just arc over the blown fuse.

That's why fuses have a max voltage rating that they are effective at - beyond that voltage, arcing occurs.
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Old 07-10-2009, 17:42   #62
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yeah...what he said!!
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Old 07-10-2009, 18:30   #63
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Similar experience to Tropic Cat

Rick,

My recent experience was similar to yours. Hull and mechanical systems fine, but pretty much everything connected to the 12V system was shot. I did have a few cabin lights that survived, but that's it. Our cat was all alone, tied up to the dock behind our house. The water is shallow there, don't know if any of that has anything to do with the strike or not. I think I've come to the same conclusion as you, which is to pretty much take my chances on another strike. It seems to me that leaving a ground wire hanging over the side of the boat is just asking for trouble. I'm pretty sure your electronics would end up fried anyway even if the most of the charge did go down the ground line.

I may change my mind if we end up getting struck again. Replacing your electronics and electrical panel gets to be an expensive proposition.

Chris
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Old 07-10-2009, 18:47   #64
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Cats are twice as likely to be stuck with the ugly stick too! Awe, SNAP!
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Old 08-10-2009, 03:15   #65
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Did he say that out loud? Its a perfect reason mono guys should stay out of the multihull area.
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Old 08-10-2009, 03:40   #66
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So Rick it is entirely yours and Chris's fault that the multihull statistics are so high.

I am sure it has nothing to do with cats normally being at sea more often, or at anchor on their own rather than bunched around lightning conductors like a lot of half boats
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Old 08-10-2009, 03:41   #67
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Strangest hit I've seen was a mono that ended up with hundreds of holes throughout the hull. The strike also went through the fridge and bonded a 6 pack of beer cans together and vaporized al the beer out of all the cans.
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Old 08-10-2009, 03:53   #68
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Strangest hit I've seen was a mono that ended up with hundreds of holes throughout the hull. The strike also went through the fridge and bonded a 6 pack of beer cans together and vaporized al the beer out of all the cans.
I've seen this as well with monos. Only with Smaller boats with raised outboards. The charge entered the boat and had no natural path to the water. So it made a bunch.
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Old 08-10-2009, 03:59   #69
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So Rick it is entirely yours and Chris's fault that the multihull statistics are so high.

I am sure it has nothing to do with cats normally being at sea more often, or at anchor on their own rather than bunched around lightning conductors like a lot of half boats
I now believe that shallow water is a big factor in lighting striking boats. Sea water of itself isn't a great conductor, but combine it with shallow water and it's a more attractive current path. Upon reflection, I do believe it was a factor in my case as I purposely, and now believe mistakenly, headed for shallow water when I was caught in a storm cell.

I will graciously accept the blame for the multihull statistics...
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Old 08-10-2009, 05:47   #70
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I will graciously accept the blame for the multihull statistics...
Damned decent of you!!

Actually the statistics as presented are meaningless, without some reference to the actual numbers, and looking at the locations of the hits, it is impossible to analyse and come up with anything worth the sweat.
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Old 08-10-2009, 12:32   #71
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Damned decent of you!!

Actually the statistics as presented are meaningless, without some reference to the actual numbers, and looking at the locations of the hits, it is impossible to analyse and come up with anything worth the sweat.
Yep.
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Old 08-10-2009, 19:50   #72
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The insurance surveyor that looked over our boat said that he had just done a monohull that had been struck 3 weeks before us. That boat was a total loss due to fire damage. I feel like we were very lucky in comparison. I'm not saying that it didn't handle the strike as well as our boat just because it was a monohull, but hey, if they can make dodgy assertions, I guess we can too.
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Old 09-10-2009, 08:33   #73
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Cats are twice as likely to be stuck with the ugly stick too! Awe, SNAP!
A pox on you Chris, but that's actually pretty funny . My one word retort would be "Benehuntalina".

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Old 09-10-2009, 18:04   #74
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A pox on you Chris, but that's actually pretty funny . My one word retort would be "Benehuntalina".

Mike
Funny you should mention that! I am currently epoxying my pox ridden bottom! As for BeneHuntalina...it sounds like a Japanese Italian restaurant!
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Old 12-10-2009, 17:50   #75
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Lightning is one of the most deadly natural phenomena known to man, with bolt temperatures hotter than the surface of the sun and shockwaves beaming out in all directions.

In an electrical storm, the storm clouds are charged like giant capacitors in the sky. The upper portion of the cloud is positive and the lower portion is negative.
The electric field becomes more and more intense, so intense, in fact, that the electrons at the oceans’ surface are repelled deeper into the ocean by the strong negative charge at the lower portion of the cloud. This repulsion of electrons causes the earth's surface to acquire a strong positive charge.
All that is needed now is a conductive path for the negative cloud bottom to contact the positive earth surface. The strong electric field, being somewhat self-sufficient, creates this path.
When the electric field becomes very strong, conditions are ripe for the air to begin breaking down. The electric field causes the surrounding air to become separated into positive ions and electrons

The importance of this separation is that the electrons are now free to move much more easily. The ionization of air or gas creates plasma with conductive properties similar to that of metals. We can view the ionization process as "burning a path" through the air for the lightning to follow.

A path is not created instantaneously. In fact, there are usually many separate paths of ionized air stemming from the cloud. These paths are typically referred to as step leaders, objects reach out to the cloud by "growing" positive streamers. These streamers also have a purplish color and appear to be more prominent on sharp edges

After the step leader and the streamer meet, the ionized air (plasma) has completed its journey to the earth, leaving a conductive path from the cloud to the earth. With this path complete, current flows between the earth and the cloud. This discharge of current is nature's way of trying to neutralize the charge separation. The flash we see when this discharge occurs is not the strike, it is the local effects of the strike. Any time there is an electrical current, there is also heat associated with the current. Since there is an enormous amount of current in a lightning strike, there is also an enormous amount of heat. This heat is the actual cause of the brilliant white-blue flash that we see.

After the original strike occurs, it is usually followed by 30 to 40 secondary strikes. These strikes follow the path of the main strike, the secondary strike can occur while the flash from the main stroke is still visible or after the flash from the main strike ends, making it appear that the main strike is flickering.



The purpose of lightning rods is often misunderstood. Many people believe that lightning rods "attract" lightning. It is better stated to say that lightning rods provide a low-resistance path to ground that can be used to conduct the enormous electrical currents when lightning strikes occur. If lightning strikes, the system attempts to carry the harmful electrical current away from the structure and safely to ground.

The lightning can strike and then "seek" a path of least resistance by jumping around to nearby objects that provide a better path to ground. If the strike occurs near the lightning-rod system, the system will have a very low-resistance path and can then receive a "jump," diverting the strike current to ground before it can do any more damage.
Lightning rods only become relevant when a strike occurs or immediately after a strike occurs.

Regardless of whether or not a lightning-rod system is present, the strike will still occur.

After lightning strikes the ocean, there is an electric potential that radiates outward from the point of contact which can also cause damage and death

Surge protectors won't save your electronics if lightning strikes you need a lightning arrester on the circuit. The arrester uses a gas-filled gap that acts as an open circuit to low potentials, but becomes ionized and conducts at very high potentials. If the lightning hits the line you are protecting, the gas gap will conduct the current safely to ground.

However a Faraday cage is much better protection, the metal cage will shield objects within the cage when a high potential discharge hits. The metal, being a good conductor, would direct the current around the objects and discharge it safely to the ground.

An oven does this nicely if it is connected to ground (remember to make sure the door is electrically connected to the body). And in conjunction with a quality lightning rod set up, may help to protect your boat, your electronics and you.

“This information is edited from other sources and does not constitute electrical advice”.
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