Lightning...

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R

Roger

A lot of thunder and flashes in my area. So, i rigged a thingy of heavy (1/2") copper cable that can be attached to a shroud by a strong battery clamp. Of course the cable hangs in the water about 4 feet... Will it work--effectively enough to prevent disaster??? Any experiences with hot-flashes? Remedial suggestions?? Roger
 
Jun 6, 2006
6,990
currently boatless wishing Harrington Harbor North, MD
Acts of God

Well it certainly will not hurt. There are two schools of thought on lightning, ground and no ground. The ground school will say that you can direct the lightning "over the side" and safely away keeping it out of the boat. This is the method buildings us and it works fine unless you have a big metal rod that goes from the top of the structure to the keel which most of us have. There is also the VHF antenna lead that goes from the top and directly into the boat. And all the electrical wiring that goes right back to the breaker panel. The no-ground school will say that if you insulate the mast electrically then lightning will not be interested in your mast as it will not provide a "path to ground". But you still have the wiring to contend with. In either case you should have some way of disconnecting the mast wiring so that it plugs into the grounding circuit if you want to use either method. I personally use your method Roger with one ground on each stay (fore, aft, port and starboard) Unfortunately when a bazillion amps of electricity goes anywhere near you boat it is going to induce currents in anything metal. So even if the lightning strikes the water near your boat you could still have damage.
 

GuyT

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May 8, 2007
406
Hunter 34 South Amboy, NJ
I'm the "no ground" school

Once lightning finds a path, it's all over. It may take your path that you've made for it - or maybe not. Those little battery clamps will blow up in a milli-second - then where will it go?
 
Jun 7, 2007
875
Pearson- 323- Mobile,Al
I used to do That

I had heavy wire and aluminum plates atttached. I'd wrap the bare wire around the mast at the boom and lead the wire overboard. I had a separate one for the rear stay kinda making a cage around the cockpit. After a year or so I stopped using it. Just hanging a wire might not be enough there are requirements for a grounding plate to be effective and you need a larger plate in freshwater as it doesn't conduct electricity as well as saltwater. As the electricicty has enough volts to overcome the resistence of several thousand feet of air fiberglass' resistence should slow down lightening. But maybe if your rig just gives some of the electricity a path to ground it might lessen the severity of a strike. My boat is 27 years old and been sitting in the water almost all of that time and has never been struck...pretty good odds. There is an old oak probably over 150 years old across the street from my house that has never been struck. Lightening is kinda like a shark attack. Extremely horrible if it happens to you but also extremely unlikely to happen. I once just happened to be looking at a churches chimmney when it was struck by lightening. The chimney exploded throwing bricks 100'. Pretty impressive. You feel Lucky???
 
Jun 6, 2006
6,990
currently boatless wishing Harrington Harbor North, MD
Directing lightning

The civil engineering handbook has some "Key safety tips". Always avoid sharp bends in your lightning ground path. Start up high on the stay and gently curve the cable over the side. Always have good physical connections. a battery clamp if probably the minimum "good" connection. Better is a pair of hose clamps. While at port you can be assured there will be one "ground" person in the harbor so if you can convince the lightning to hit his boat by un-grounding yours........ While at sea your are really at the mercy of the elements (read God) so a strong faith and reading your bible every day may be just as effective as any other means. You can begin to see how sailors of old became superstitious
 

higgs

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Aug 24, 2005
3,736
Nassau 34 Olcott, NY
Been hit

No predicting lightning and that is the bottom line. You can be the shortest mast around and get hit, you can be grounded and get hit you can be ungrounded and get hit, etc, etc, etc. My phycisist friend told me that out on the water an ungrounded boat is less likely to get hit, but more likely to suffer damage. I have found the best defense against lightening strikes, particularily if you are on board, is prayer.
 
Jun 12, 2004
1,181
Allied Mistress 39 Ketch Kemah,Tx.
No way to predict

A lightning arrestor may help, but to what degree is up for debate. Lightning is the discharge of electricity from ground to clouds caused by a large difference in electrical potential( the + and - thing). What makes it difficult if not impossible to predict is that these electrical potentials ( +'s and -'s) keep moving. We are taught that the highest objects get hit thats why you are not supposed to stand in an open field or get under a tree. (That always puzzled me because if you are outdoors, usually those are the ONLY two choices). Anyway, that generalization is not a good one. Sometimes lightning will travel 20 miles through the air, which incidentally is a great electrical insulator, and pass over many high steel structures and hit a spot in an open field on the grass. I work offshore and the Platforms are all steel structures, the legs go down hundreds , sometimes thousands of feet into the salt water Gulf of Mexico. The legs are then anchored down in various ways, but usually at least 200 more feet into the bottom of the Gulf. The Oil and gas wells are also all steel and they go down into the ground under the Gulf several thousand more feet. You cant get a better ground that that. And yet most of the time, the lightning will travel all of these miles through the air and hit the open water a 100 yards or less from a platform that stands an average of 100 feet above the water. As for sailboats, some get hit with little to no damage and others get completely fried. It does however seem that Higgs's friend is correct in the statement "that out on the water an ungrounded boat is less likely to get hit, but more likely to suffer damage". Tony B
 

jimq26

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Jun 5, 2004
860
- - -
Thank you Tony!

I am sure that the majority of people are not aware of that. Alway a lot of perplexed faces when that statement is made eh? In his posting Tony explains - "Lightning is the discharge of electricity from ground to clouds caused by a large difference in electrical potential( the + and - thing). What makes it difficult if not impossible to predict is that these electrical potentials ( +'s and -'s) keep moving".
 
Jun 4, 2004
125
Hunter 333 Elk Rapids, MI
Will it work?

You're asking us to predict the unpredictable. You'll just have to try it. Let us know what happens. If you get hit and your boat doesn't sink, consider it a success!
 
Jun 7, 2007
875
Pearson- 323- Mobile,Al
Infrequency is the problem

If something happens regularly in a predictable manner it's easy to separate fact from fiction. lightening is so infrequent that we can't sort out what to do. Another varible is that all lightening is not of the same strength. Protection that may work well with a small strike can't handle the mega strike. Grounding, prayer or whatever makes you feel safe is what you should do. Ther was an interesting lightening strike about 20 years ago near Houston TX I read about it in the San Antonio paper. A guy saw an approaching storm and said "lord take me I'm ready". Almost immediately he was struck by lightening and fell overboard dead. This of course terrified and made believers out of the other unharmed people on the boat. Neptune will not be taken lightly.
 
Jun 12, 2004
1,181
Allied Mistress 39 Ketch Kemah,Tx.
lightning Arrestor

What makes a lightning arrestor (lightning Rod) work......only some of the time.....is that it doesnt attract lightning and bring it to a ground. What it does do in theory and in practice (only some of the time) is that the prongs or fork looking thing at the top, or the little wire things sticking up, slowly dissipate the charge from the ground and become electrically neutral for an instant, then slowly take on the same charge as the clouds passing over. Same charge (Neg to Neg or Pos to Pos) and nothing happens. When Ben Franklin did the famous kite and key trick, he didnt actually attract lightning. What happened was that when he pulled in the kite and went for the key, there was a small spark (electrical discharge). This he concluded was that lightning was an electrical event. If I'm wrong, at least it dounds good. I think Tony B
 
R

Roger

Ground to cloud...

...not cloud to gound??? IF i'm understanding youse-guys :)correctly??? So, electrical +s and/or -s in the 'ground', are looking for 'mates' in the 'sky'? "WOW!" Glad i asked the question! Roger, over...
 

jimq26

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Jun 5, 2004
860
- - -
Yes Roger - even in Bobcaygeon!!!!

Hope you have your hydro back on after the big storm last Friday.
 

Ross

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Jun 15, 2004
14,693
Islander/Wayfairer 30 sail number 25 Perryville,Md.
I know of buildings well past one hundred years

old that have never been struck by lightning. Some of these buildings have lightning rods and some don't. I know of trees that have been hit several times and are still standing and I have seen others that were blown apart by a single strike. I love thunder storms but I don't stand outside with a long metal rod seeing if I can attract a strike.
 

Jim

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May 21, 2007
775
Catalina 36 MK II NJ
My dad used to

attach chains to the shrouds and drag them in the water, Can it help? Well it can hurt. Lighting will take the shortest path to ground as long as it can handle the load. I think it would help.
 
Jun 12, 2004
1,181
Allied Mistress 39 Ketch Kemah,Tx.
Jim

attaching chains to shrouds and dragging them in the water may not help, but it certainly wont hurt. As for lightning taking the shortest path to ground, well we will never be able to predict what that path will be. lightning is a strange phenomenon. The molecules moving rapidly inside a storm cloud creates a static electricity charge same as a new carpet does. With the cloud moving, the molecules inside the cloud moving and also the static charge of the clouds moving across the ground all keep the charge moving. What would normally be the shortest route, or more properly, the path of least electrical resistance would be the way it will travel. if we didnt account for all this movement, then lightning would always travel in perfectly straight lines whether it be cloud to cloud or cloud to ground. BTW, you cannot see lightning on the move. It happens way too fast. Its the shape of lightning that makes it appear to go from cloud to ground as opposed to ground to cloud. This ground to cloud discharge is far more common than the cloud to ground discharge. But it still does happen. I'm not sure but I think cloud to cloud is the common discharge. This makes it even more unpredictable. Lightning has been known to hit cars. Cars are on 4 very well insulated rubber tires. This means that a lightning discharge might travel 10 miles in the air which is a great electrical insulator, then hit a car which is also electrically insulated, the jump the last few inches to the ground, and yet, that discharging cloud may be only 1000 feet directly above a steel tower that is well grounded. Go figure. Tony B
 
R

Roger

Bronte Harbor eh?

No "outage" for me with my solar panels :)But the sky sure was black!! Thanks everyone for the information and counsel. Wiser, if not smarter... Roger, over...
 
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