Lightning protection for you boat

[btrayfors]

Originally Posted by rwidman

I have a trawler. I try to stay around sailboats when there's a chance of lightning!

Might make you feel better, but totally ineffective.

Some years ago while at my favorite bar adjacent to Bahia Mar in Ft. Lauderdale I watched a direct hit on a small powerboat which was slipped in between two large sailboats. The sailboats were not damaged, but the powerboat was destroyed.

....which led me to the conviction that:

Nothing, absolutely nothing is going to prevent a strike. The voltages are incredibly high and will ensure that lightning not only takes the shortest path to ground, but in addition TAKES ALL PATHS TO GROUND.

Chocolate on the cabin sole sounds like as good a solution as I've heard, particularly when accompanied by a full measure of rum :-)

Bill

[Nightcrawler]

I posed this question to the local Coast Guard commander up on Lake Huron years ago. Figured they should have some ideas. My question was, anchor, drift, or keep moving if caught in a lightning storm. Answer "I'd rather be a moving target as it takes a second or so for the charge to map it's way. That's the hair raising on your head right before the strike." If you've been there you know the feeling. Of course at the dock or on our slow mover now. . . probably won't make any difference. So as noted above, I love it when a 50' sailboat pulls in next to us.

[Mark Johnson]

Originally Posted by thomm225

That's an excellent question if you are a multihull owner since those boats get struck twice as much as monohulls

http://www.boatus.com/seaworthy/maga...ning-facts.asp

This is not true of properly grounded trimarans...

[GTom]

Copper lightning rod, longer than the VHF aerial + a 25mm2 copper* wire running along the forestay? Instead of hull-trough, the end/grounding part (3-4m) stored normally in the anchor locker and thrown in the water?

This way most of the energy would be channeled as far from the galley/instruments as possible, thus the EMP is somewhat weaker.

*Copper has ~ half the resistivity of the mast material Aluminum, this way more current will run down along the copper wire than the mast.

[thomm225]

Originally Posted by Mark Johnson

This is not true of properly grounded trimarans...Attachment 158614

Actually there's some debate as to which boats get struck more often, those with so called lightning protection or those without.

I believe at this time those without lightning protection get struck less often than boats with lightning protection.

https://www.yachtingmagazine.com/fire-sky

“The idea behind the ground plate has been that it somehow conducts current into the water and then down to China — that’s been the concept,” Thomson says, launching into an analogy. “On a battery you have a plus terminal and a negative terminal. Hook a wire up to the positive and a wire to the negative and put something like a light in the middle. Charges flow from the battery through the light, give it energy and then go back to the battery again. That’s an electric circuit. Lightning, when it hits the boat, is effectively a wire to the charge in the clouds, through the boat to the water. But what’s the return path from the water to the cloud to make a complete electric circuit? It makes a huge difference when you realize that this circuit is not going to China; it’s not even going into the ground. The current goes back into the sky, but the way it gets there is from a charge on the surface of the water.”
Trying to force this massive charge out through a ground plate at the bottom of the vessel is a bad idea because water is a medium that impedes the process, like impedance in an electrical circuit.

This is a basic concept that surprises many boaters: A lightning-protection system is not designed to prevent a lightning strike, but rather to provide a safe discharge path for the lightning. This is the only viable solution for lightning protection (short of going back to wooden ships, kerosene lamps, and sextants). The technology to prevent lightning strikes does not yet exist.

[wgoodbye]

Its very easy to throw around the "snake oil" term when you haven't done your homework. As I mentioned, I've done extensive research on the underlying technology. You can Google DDCE-100 and find many references to the earlier generation of the device (many in Spanish) that's been deployed over 5000 times with a perfect safety record. That's empirical data, not snake oil.

Take a look at this case study of the DDCE-100 device installed on Las Pardinas telecom tower. Hit every year from 1997 to 2002 including one lightning strike that destroyed the tower. After installing the device in 2003 no strikes on the tower.

http://www.rj.my/2017/03/01/analysis-of-effectiveness-of-ddce-at-las-pardinas/

"Over the 12 years of the analysis (June 21, 2003 to December 31, 2014) 930 lightning

strikes were recorded within a radius of 2 km from the LAS PARDINAS TOWER, with the

following results.: ZERO DIRECT STRIKES"

There are many more case studies like this on the DDCE-technology.

Google it. Call and talk to engineers and operators who have purchased and deployed the devices!

EMP Solutions is now distributing devices that have been improved over the original patent and have a greater streamer dissipation capacity including a smaller lighter weight device that I previously mentioned designed for recreational boats.

Chris

Originally Posted by hellosailor

I was going to say that EMP Solutions appears to be snake oil. They say nothing beyond 'Tesla found a problem in 1916' and if you click the "know more" or product pages on their web site, they only say that same thing again, with no difference between the three products.

But it appears that they DO say more, they just say it in a pop-up window that requires active technology (why oh why?!) instead of a regular web page, so my browser was declining to show it. Note to EMI: Hire a real web site designer who is aware of these things.

Their magic saucer "balances" charges, but somehow needs no power source to do that. Hmmm. And it comes with a ten year warranty (against failing perhaps?) but despite a 100% performance history in all those thousands of non-US locations, there's no warranty against damages to the vessel it is installed on.

Kinda like when the bottle brushes first came out, and then magically the maker simply refused to make any warranty payments (they did warranty against damages) to the damaged vessels.

There's more objective research that was published last year, indicating that the "ground charge" actually flows in the moist air above the water surface, so that "grounding plates" several inches above the waterline combined with a conventional protection system will actually dissipate charges effectively, minimizing strikes. A work still in progress, but a scientific one.

EMP's masthead gizmo sure LOOKS pretty though.

[thomm225]

Originally Posted by wgoodbye

Its very easy to throw around the "snake oil" term when you haven't done your homework. As I mentioned, I've done extensive research on the underlying technology. You can Google DDCE-100 and find many references to the earlier generation of the device (many in Spanish) that's been deployed over a 5000 times with a perfect safety record. That's empirical data, not snake oil.

Take a look at this case study of the DDCE-100 device installed on Las Pardinas telecom tower. Hit every year from 1997 to 2002 including one lighting strike that destroyed the tower. After installing the device in 2003 no strikes on the tower.

Chris

Oops, looks like the tower isn't mounted on a boat in the middle of a bay or ocean!

From Boats US:

http://www.boatus.com/seaworthy/maga...protection.asp

This is a basic concept that surprises many boaters: A lightning-protection system is not designed to prevent a lightning strike, but rather to provide a safe discharge path for the lightning. This is the only viable solution for lightning protection (short of going back to wooden ships, kerosene lamps, and sextants). The technology to prevent lightning strikes does not yet exist.

[Mark Johnson]

Originally Posted by thomm225

Actually there's some debate as to which boats get struck more often, those with so called lightning protection or those without.

I believe at this time those without lightning protection get struck less often than boats with lightning protection.

This is a basic concept that surprises many boaters: A lightning-protection system is not designed to prevent a lightning strike, but rather to provide a safe discharge path for the lightning. This is the only viable solution for lightning protection (short of going back to wooden ships, kerosene lamps, and sextants). The technology to prevent lightning strikes does not yet exist.

Actually... not so simple. (I have 50 years as a boatwright/cruisr)... I have cruised extensively on all of the three of the boats I have built, with 15 years having been as full time liveaboard.

When we launched our current tri, 21 years ago, I installed a complete system, with a bottle brush/lightning rod, and grounded shrouds/stays, all running to a 2 sq ft copper plate, directly below and 2’ from the base of the mast.

I researched my installation extensively, read hundreds of books, and over 5,000 monthly periodicals, over the 21 years I was building my boats.

At the time, the “bottle brush”, (dissipator), was assumed to repel lightning, because it was 100% proven to do so to an extent, on cell towers all around the world.

The proof of this on boats, is weak, but it IS proven, that it does not hurt, as long as one also has the rest of the system, including the lightning rod with a point, which we do.

The 2’ long wire that grounds my mast is as big as my thumb!

The odds of being hit over say... 30 years of cruising/liveaboard, are very high, like 50/50.

We have never been hit, but boats next to us at marinas or anchored out have, several times.

Their hit was 100’ away from us, but was close enough to fry our battery charger.

More often, it will come in through the dock cable, if the marina is hit!

The goal is not to prevent all damage to electronics or to necessarily prevent the strike, (jury is out on that on boats). The goal in making an immediate path to a ground plate, is to keep the mast from being driven through the bottom of the hull, and/or kill everyone onboard.
Without this ground, it can do exactly that!

We have also been underway in storms so violent that lightning was hitting the water all around us, (within 200’), and I was very glad to be in a properly grounded boat.

[wgoodbye]

You are still thinking in terms of Franklin lightning rod technology. Everything out there, including the fuzzy bottle brush devices are based on Franklin lightning rod technology (200 years old). The DDCE device is not based on Franklin lightning rod technology. Its a game changer, that's why they have a patent on it.

I understand your bias based on 200 years of Franklin lightning rod technology in various forms that does in fact ATTRACT lightning with the thought that you can control where it hits and dissipate with less damage. Hard to do reliably with a lightning bolt. Better to prevent the strike. Nobody has been able to do that in a statiscally significant way, until now.

The DDCE technology works on a boat the same as on a tower as long as the down conductor to ground (sea water) is less than 10 ohms resistance.

Originally Posted by thomm225

Oops, looks like the tower isn't mounted on a boat in the middle of a bay or ocean!

From Boats US:

Modern Lightning Protection On Recreational Watercraft - Seaworthy Magazine - BoatUS

This is a basic concept that surprises many boaters: A lightning-protection system is not designed to prevent a lightning strike, but rather to provide a safe discharge path for the lightning. This is the only viable solution for lightning protection (short of going back to wooden ships, kerosene lamps, and sextants). The technology to prevent lightning strikes does not yet exist.

[thomm225]

Originally Posted by wgoodbye

You are still thinking in terms of Franklin lightning rod technology. Everything out there, including the fuzzy bottle brush devices are based on Franklin lightning rod technology (200 years old). The DDCE device is not based on Franklin lightning rod technology. Its a game changer, that's why they have a patent on it.

I understand your bias based on 200 years of Franklin lightning rod technology in various forms that does in fact ATTRACT lightning with the thought that you can control where it hits and dissipate with less damage. Hard to do reliably with a lightning bolt. Better to prevent the strike. Nobody has been able to do that in a statiscally significant way, until now.

The DDCE technology works on a boat the same as on a tower as long as the down conductor to ground (sea water) is less than 10 ohms resistance.

Well, I'm no expert but I guess the folks at Boat US have yet to hear of this. The article below was published in 2016.

From the article:

The technology to prevent lightning strikes does not yet exist.

Modern Lightning Protection On Recreational Watercraft - Seaworthy Magazine - BoatUS

[GTom]

Originally Posted by wgoodbye

You are still thinking in terms of Franklin lightning rod technology. Everything out there, including the fuzzy bottle brush devices are based on Franklin lightning rod technology (200 years old). The DDCE device is not based on Franklin lightning rod technology. Its a game changer, that's why they have a patent on it.

I understand your bias based on 200 years of Franklin lightning rod technology in various forms that does in fact ATTRACT lightning with the thought that you can control where it hits and dissipate with less damage. Hard to do reliably with a lightning bolt. Better to prevent the strike. Nobody has been able to do that in a statiscally significant way, until now.

The DDCE technology works on a boat the same as on a tower as long as the down conductor to ground (sea water) is less than 10 ohms resistance.

You can patent whatever you want, I'll put one of these on my boat if I see it used and working all around. Are these government approved devices for those building owners who are obliged by law to install lightning protection?

True, the Franklin rod is a 200 years concept. Is that a problem? The wheel is a 5000+years concept, yet I bet the coming 5 Tesla generations will all have 4 each...

[Mark Johnson]

Originally Posted by wgoodbye

You are still thinking in terms of Franklin lightning rod technology. Everything out there, including the fuzzy bottle brush devices are based on Franklin lightning rod technology (200 years old). The DDCE device is not based on Franklin lightning rod technology. Its a game changer, that's why they have a patent on it.

I understand your bias based on 200 years of Franklin lightning rod technology in various forms that does in fact ATTRACT lightning with the thought that you can control where it hits and dissipate with less damage. Hard to do reliably with a lightning bolt. Better to prevent the strike. Nobody has been able to do that in a statiscally significant way, until now.

The DDCE technology works on a boat the same as on a tower as long as the down conductor to ground (sea water) is less than 10 ohms resistance.

As I said... the differences in a boat (vs a land based tower), is the perpetual supply of ions under the boat, where as under a cell tower, not so. What works on land is a different scenario...

21 years ago, I installed a bottle brush with the pointed rod going down the middle, and always was a bit skeptical as to “prevention”, but not as to directing a hit, safely to ground. One would still loose some electronics, but not nearly as badly.

The jury is out as to a bottle brush technology dissipating enough ions to prevent a strike, but it is clear that it does not make it worse!

If one also has a proper grounding system, as I described, that is about all one can do. With lightning, as fickle as it is, improving your odds of not being blown to bits, is the goal.

I have written about my system with ample photos, in the “Trimarans/Searunners” forum, for those who want to look up my past posts on the subject.

[wgoodbye]

You are absolutely correct!

The first boat in North America to deploy this technology is a Catamaran down in Florida that installed the device 4 years ago. My boat will be the 2nd. I called and spoke with the owner. He did the same research and came to the conclusion that nothing of the Franklin lightning rod category was statiscally significant in mitigating a lightning strike, until he came across EMP Solutions. Its very tough to get past 200 years of bias based on Franklin lightning rod technology, but the DDCE technology has proven itself out over a decade with over 5K devices and I believe this is a watershed moment for lightning prevention.

Originally Posted by thomm225

Well, I'm no expert but I guess the folks at Boat US have yet to hear of this. The article below was published in 2016.

From the article:

The technology to prevent lightning strikes does not yet exist.

Modern Lightning Protection On Recreational Watercraft - Seaworthy Magazine - BoatUS

[TreblePlink]

Originally Posted by thomm225

That's an excellent question if you are a multihull owner since those boats get struck twice as much as monohulls

Striking Lightning Facts - Seaworthy Magazine - BoatUS

I'm not convinced this is true - for the same mast height. The cited data is based upon insurance claims - boats that are damaged.

Mono hulls typically have submerged grounding electrodes - lead keels. Cats do not typically have much metal in the water except props - a bunch of strike current must flow through the engine.

I would offer up a theory that multi-hulls do not cope with strikes as well as a mono.

[GTom]

Originally Posted by TreblePlink

I would offer up a theory that multi-hulls do not cope with strikes as well as a mono.

Add classic encapsulated keel designs too. Anyway, a decent grounding is of paramount importance.