Yes I said lightning

sinnettc · Feb 15, 2012

Fresh or salt water? I read somewhere that the plate has to be really big, and even bigger in fresh water. Add to that the fact that the lightning will want to jump off at any curves/corners and you need a straight run from your mast to the bottom of your hull so you'll need to drill holes. I don't think it will work though, otherwise it would be for sale somewhere.

Chris Patterson · Feb 16, 2012

I've read quite a lot about the lightening phenomenon, and I'm under the opinion that speculation still rules. The literature goes into great detail about this, grounding everything, with plates underside, etc. Yucch.
Bearing in mind, I know little about this personally, for the exception that lightening hit my house once. It dodged a thousand feet of steel fence, went past several trees 50 feet tall, past a hugh C-band satellite dish, to strike a nail holding down some landscape timbers around the flower beds. From there it proceeded through a vent to the crawlspace, into the electrical system, and destroyed EVERYTHING electrical in the house. If it was plugged in, or wired in, it was toast. Tremendous explosion.
So, lightening is odd. It ignored the obvious suspects. A nail. Go figure.
If I had it to do, I guess I like the Lightening Master, manufactured by Forespar. No experience with it, but their literature is compelling.
As Archie Bunker used to say to Edith, "nobody knows"...

Merlin Clark · Feb 16, 2012

sinnettc said:
Fresh or salt water? I read somewhere that the plate has to be really big, and even bigger in fresh water. Add to that the fact that the lightning will want to jump off at any curves/corners and you need a straight run from your mast to the bottom of your hull so you'll need to drill holes. I don't think it will work though, otherwise it would be for sale somewhere.

Like this? http://www.marinco.com/product/standard-dynaplate
I'd be afraid the "path" wasn't enough and I'd end up with a big hole in the bottom of my boat.

toddco · Feb 16, 2012

I work on weighing equipment like truck scales and railroad scales. These kinds of systems hate lightning. In the past, the conventional wisdom was to drive ground rods everywhere and create a ground mesh. The problem with that was that lightning after it hits the ground travels out like a wave, the difference in potential between the ground points could be as high as 50,000 V. The new way of thinking has all parts of the system tied to one point for an exit path. I'm afraid you would need to ground or isolate every chain plate to give a dedicated path. I was also taught the four types of lighting. ( Air to Air, Air to Ground, Ground to Air and "White").

Chris Patterson · Feb 16, 2012

Just an idea. If I did this web address right.

Got rid of it, thought that didn't look right.
computer moron..

Bilbo · Feb 16, 2012

That's not a web address Chris...Unless your computer is a web server.

Chris Patterson · Feb 17, 2012

Ok, try this:

www.catalina22experiment.com

go to lightening protection.

If you manually enter the addy, it should come up.

Maybe that'll work..

Thanks Bilbo.

Bilbo · Feb 17, 2012

Yes Chris. This is a good site. The lightning protector experiment is here:
http://sites.google.com/site/catalina22experiment/home/projects/lightning-protection

These may also be informative:
http://www.marinelightning.com/science.htm
http://www.marinelightning.com/ECE/SGEB17.html

If we see a T-storm coming up.....we just get off the water and out of the boat.

AtlanticAl · Feb 21, 2012

I was sailing in a lightning storm once, and we took a chain, put it round the foot of the mast, and dropped the other end into the sea, one of the guys that was with us, was a very experienced delivery skipper, and he said that was a standard thing, but, he believed if we did get hit, it would still do quite a lof of damage, especially to electronics, so we put the VHF and a handheld GPS into the oven, which was effectively a faraday cage.

AtlanticAl · Feb 21, 2012

I was told by a later date though, by someone who works with radio equipment, and goes up towers, and services all that sort of stuff, that lightning can hit a tower, go into all the equipment at the bottom of the tower, and not do any damage, he said, a component in a radio, such as a resistor, capacitor, or any other component, can take thousands and thousands of volts without any damage, provided, the voltage goes up in all the components at the one time, and goes down at the one time, he said, but, when the voltage, drops in one component, faster, than it drops in others, you get amps, which blow things, in the base of a tower, their are lots of different system connected to the tower, the lightning raises the voltage in them all at the one time, then it lowers at the one time, by going to ground, but, if one system is not properly grounded, that creates difference in voltage, which creates amps, and it blows things.

Bilbo · Feb 22, 2012

Bog13 said:
See this is good stuff, Yes we get off the water too. But if one ever gets stuck out there (I have) and or has had a boat hit even when not on, Its still a bugger,
I just dont know if it gets so complicated that we over look the simple plan of a house system like I have at home

I was told that lightning rods attract lightning but that the lightning misses the rod. I'm not sure if this is true and am not game to intentionally test it. Generally with sailboat there is a lightning rod attached atop the mast and then a connection to the water via metal ground. One could connect the aluminum mast to the swing keel lockdown bolt with a good grounding wire -assuming that the bolt is tight with the keel it may be the ticket. Maybe run chains from a few of the shrouds into the water.