Anyone heard of a lightning strike on a sailboat supported with boat stands. Does anyone know how I can take precautions from this occurance. Advice appfeciated. M/C.
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Last winter...
...there was a beautiful ketch hit by lightning while on the land at the marina next door to mine in Warwick RI. It was bought over to our marina for a complete electrical/instrumentation refit and was in the water two slips down for a considerable time. I don't recall if there was any rigging/hull damage. I don't know if anything could have been done to prevent it. I can't see the yards providing grounding posts for all stored boats. It's a very rare occurrence - keep your insurance premium paid - and stop worrying
...there was a beautiful ketch hit by lightning while on the land at the marina next door to mine in Warwick RI. It was bought over to our marina for a complete electrical/instrumentation refit and was in the water two slips down for a considerable time. I don't recall if there was any rigging/hull damage. I don't know if anything could have been done to prevent it. I can't see the yards providing grounding posts for all stored boats. It's a very rare occurrence - keep your insurance premium paid - and stop worrying
Thanks Derek...
However, I failed to mention, my boat is in my yard, between my house and my neighbors. I want to step the mast on my new/used Hunter 25 so that I can check the rigging for deficiencies. My neighbor has the complete opposite personality from mine (blue vs white collar). When he saw my sailboat in the yard he went ballistic, went out and bought a new tractor/lawnmover and put it on the borderline of our yards. Who the heck knows why, but knowing him, he's about to buy a huge macho powerboat and put it on our border to keep up with the Jones's. When and if I step my mast, he'll have a fit and claim I'm endangering his home of lightning! Life in the middle class! Thanks again, M.C.
However, I failed to mention, my boat is in my yard, between my house and my neighbors. I want to step the mast on my new/used Hunter 25 so that I can check the rigging for deficiencies. My neighbor has the complete opposite personality from mine (blue vs white collar). When he saw my sailboat in the yard he went ballistic, went out and bought a new tractor/lawnmover and put it on the borderline of our yards. Who the heck knows why, but knowing him, he's about to buy a huge macho powerboat and put it on our border to keep up with the Jones's. When and if I step my mast, he'll have a fit and claim I'm endangering his home of lightning! Life in the middle class! Thanks again, M.C.
Grounding Boat on Stands
You could effectively ground your boat: ~ Drive/Bury two (2) 3/4" x 10' Ground Rods, ten feet (10') apart from each other, and near the boat cradle. ~ Using #4 AWG minimum copper cable, bond the 2 Gnd. Rods together (series), continuing up to the mast or lightning ground plate (if so equipped). Ground Rod /---- #4 Cu----/----#4 Cu---- [] Mast or Gnd. Plate or Engine Block Disconnect all electronics etc. (12V power and antennae).
You could effectively ground your boat: ~ Drive/Bury two (2) 3/4" x 10' Ground Rods, ten feet (10') apart from each other, and near the boat cradle. ~ Using #4 AWG minimum copper cable, bond the 2 Gnd. Rods together (series), continuing up to the mast or lightning ground plate (if so equipped). Ground Rod /---- #4 Cu----/----#4 Cu---- [] Mast or Gnd. Plate or Engine Block Disconnect all electronics etc. (12V power and antennae).
Gord's idea is right, but...
I'd have to say that #4 is VERY much the minimum guage. Far better, IMHO, would be something in the 2/0 range. The amount of energy that needs to be dissipated during a lightning strike is simply incredible, so if you're going to go to the trouble of grounding the boat, go with the biggest wire you can handle. You may also wish to do a 'triangle ground' wherein three ground rods are driven at 6'-8' intervals in a triangular pattern. The ground wire is attatched to the first rod, run to the second, then the third and then back to the first and then to the item being grounded. Remember, the ground conductor is one continuous piece of wire, do not use seperate conductors. You may also wish to consider the proximity of any flammable or other dangerous items near the boat, such as a propane or heating oil tank. Also, I'm not familiar with the type of soil conditions in your area, but if you have very dry, sandy or rocky soil, you may want to use ground rods longer than the standard 8 or 10 foot. You can get ground rods that are treaded on one end, this rod is driven first and then a second section is threaded onto the first section (with a special coupling nut) and driven in to finish height. If you have trouble driving the ground rods by hand with a sledge hammer, any good tool rental shop should be able to rent you a small electric jack-hammer (35-50 pound) with a ground rod driver attatchment. That's how we do it in my neck of the woods because of all the rocks. It's just too much work to put them in by hand (I've seen it take two guys an hour of hard hammering to put in one 8' GR, the jack-hammer can do it in about 4 minutes). Anyhow, hope this is helpful. Jeff
I'd have to say that #4 is VERY much the minimum guage. Far better, IMHO, would be something in the 2/0 range. The amount of energy that needs to be dissipated during a lightning strike is simply incredible, so if you're going to go to the trouble of grounding the boat, go with the biggest wire you can handle. You may also wish to do a 'triangle ground' wherein three ground rods are driven at 6'-8' intervals in a triangular pattern. The ground wire is attatched to the first rod, run to the second, then the third and then back to the first and then to the item being grounded. Remember, the ground conductor is one continuous piece of wire, do not use seperate conductors. You may also wish to consider the proximity of any flammable or other dangerous items near the boat, such as a propane or heating oil tank. Also, I'm not familiar with the type of soil conditions in your area, but if you have very dry, sandy or rocky soil, you may want to use ground rods longer than the standard 8 or 10 foot. You can get ground rods that are treaded on one end, this rod is driven first and then a second section is threaded onto the first section (with a special coupling nut) and driven in to finish height. If you have trouble driving the ground rods by hand with a sledge hammer, any good tool rental shop should be able to rent you a small electric jack-hammer (35-50 pound) with a ground rod driver attatchment. That's how we do it in my neck of the woods because of all the rocks. It's just too much work to put them in by hand (I've seen it take two guys an hour of hard hammering to put in one 8' GR, the jack-hammer can do it in about 4 minutes). Anyhow, hope this is helpful. Jeff
I've Done a Number of These
I worked with munitions in the Air Force many of them we must always keep grounded when stored outside. For the first one I was given a 10' rod a sledge hammer and the aid of an airman to install the rod. We looked at each other and wondered how to pound in the end of the rod if it is 10' in the air. We ended up standing on the tines of a forklift and lowered it as the rod was driven into the ground. Not an easy feat on an August afternoon into south Texas clay and caliche. When we got to about 2 or 3' we stood on the ground and were giving it full swings as sparks flew off the ends into the grass. Did I mention it was Texas and August? After a while the grass started to smoke and then flames shot up, pretty cool! Wait we are in the middle of the bomb dump and we just set the grass on fire, not so cool. We jumped on all of that grass and were stomping out that fire for what seemed like an hour it was probably a minute and a half. Not once did we consider if we were taking a chance on getting blown up we were more concerned with the ass chewing we were bound to get. We finished the driving the rod in and then parked the bomb trailer on top of the charred grass and neither of us said a word. I later learned (this will be the part that interests you, I just wanted to tell that story)) that a hunk of pipe with a cap on it does an excellent job of driving the rod in as a slide hammer. I was also told once it does not need to be driven straight into the ground that you can bury it sideways if I ever had to drive another one into the ground I was going to look up that little nugget of information. It would also be a very good idea to call your local utility company and make sure there are no underground utilities nearby that could be as bad as setting fire to the bomb dump. IYAAYAS Rick
I worked with munitions in the Air Force many of them we must always keep grounded when stored outside. For the first one I was given a 10' rod a sledge hammer and the aid of an airman to install the rod. We looked at each other and wondered how to pound in the end of the rod if it is 10' in the air. We ended up standing on the tines of a forklift and lowered it as the rod was driven into the ground. Not an easy feat on an August afternoon into south Texas clay and caliche. When we got to about 2 or 3' we stood on the ground and were giving it full swings as sparks flew off the ends into the grass. Did I mention it was Texas and August? After a while the grass started to smoke and then flames shot up, pretty cool! Wait we are in the middle of the bomb dump and we just set the grass on fire, not so cool. We jumped on all of that grass and were stomping out that fire for what seemed like an hour it was probably a minute and a half. Not once did we consider if we were taking a chance on getting blown up we were more concerned with the ass chewing we were bound to get. We finished the driving the rod in and then parked the bomb trailer on top of the charred grass and neither of us said a word. I later learned (this will be the part that interests you, I just wanted to tell that story)) that a hunk of pipe with a cap on it does an excellent job of driving the rod in as a slide hammer. I was also told once it does not need to be driven straight into the ground that you can bury it sideways if I ever had to drive another one into the ground I was going to look up that little nugget of information. It would also be a very good idea to call your local utility company and make sure there are no underground utilities nearby that could be as bad as setting fire to the bomb dump. IYAAYAS Rick
be a good nieghbor...he he he ;D
Extend sailor courtesy and buy your nieghbor a lightning ground set up for his house. Make it very tall (taller than your stepped mast)and well grounded (buried under his house). You, your boat, and your house are now safe from strikes.
Extend sailor courtesy and buy your nieghbor a lightning ground set up for his house. Make it very tall (taller than your stepped mast)and well grounded (buried under his house). You, your boat, and your house are now safe from strikes.
lightning myths
The only predictable thing about lightning is that it's behavior will be totally unpredictable. People tend to beleive that lightning will always hit the tallest object in an area. Not true. Or that grounding will protect something and make it "safe from a strike"--again, not true. TV, radio and cell towers are grounded and they get hit all the time. And that 50 foot tree next to a 500 foot tower can get hit when the tower doesn't. Some sailors believe in grounding and bonding their thru-hulls to dissapate the strike. Others believe that doing this directs the charge to the last place you want it--your thru-hulls. Whose right? Beats me. It's been my observation (emphasis on observation with no data or studies to support) that if lightning hits your boat, you will lose your electronics, and consider yourself lucky if it doesn't blow a hole in the hull, bonded or not. (Installing a lightning dissapator may help, but they don't garauntee that you won't get hit, they only garauntee that they will replace the equipment if it does, which is what you have insurance for anyway.) Some people claim that clamping jumper cables onto the boat and dangling in the water will protect you. Maybe, maybe not. I've never done it, and I've never been hit. So will driving a rod into the ground and attaching a cable prevent a strike? No, but it can't hurt, and if it makes you sleep better, why not?
The only predictable thing about lightning is that it's behavior will be totally unpredictable. People tend to beleive that lightning will always hit the tallest object in an area. Not true. Or that grounding will protect something and make it "safe from a strike"--again, not true. TV, radio and cell towers are grounded and they get hit all the time. And that 50 foot tree next to a 500 foot tower can get hit when the tower doesn't. Some sailors believe in grounding and bonding their thru-hulls to dissapate the strike. Others believe that doing this directs the charge to the last place you want it--your thru-hulls. Whose right? Beats me. It's been my observation (emphasis on observation with no data or studies to support) that if lightning hits your boat, you will lose your electronics, and consider yourself lucky if it doesn't blow a hole in the hull, bonded or not. (Installing a lightning dissapator may help, but they don't garauntee that you won't get hit, they only garauntee that they will replace the equipment if it does, which is what you have insurance for anyway.) Some people claim that clamping jumper cables onto the boat and dangling in the water will protect you. Maybe, maybe not. I've never done it, and I've never been hit. So will driving a rod into the ground and attaching a cable prevent a strike? No, but it can't hurt, and if it makes you sleep better, why not?
Another myth
is that doing something is always better than doing nothing. Many of us just can't feel at ease unless we have pur forth an effort. We are programmed to believe that doing something is necessary to a good outcome. Thats a myth. Man is sometimes his greatest enemy. A homeowner once had the foundation of his new house sag several inches in the middle before the house was even finished. He had put a sprinker on the dirt pad prior to the concrete and had watered it well. Turns out he simply expanded the clay layer deep under and in the middle and when it dried back out... it shrunk and the foundation drooped with the corners holding well where the sprinkler didn't saturate. When asked why he did it, he replied, "I heard it helped and I just couldn't not do it." Is there an application of this story to lightning? Perhaps. If the boat is sitting ungrounded on stands or cradle... grounding may invite a strike that otherwise wouldn't hit.
is that doing something is always better than doing nothing. Many of us just can't feel at ease unless we have pur forth an effort. We are programmed to believe that doing something is necessary to a good outcome. Thats a myth. Man is sometimes his greatest enemy. A homeowner once had the foundation of his new house sag several inches in the middle before the house was even finished. He had put a sprinker on the dirt pad prior to the concrete and had watered it well. Turns out he simply expanded the clay layer deep under and in the middle and when it dried back out... it shrunk and the foundation drooped with the corners holding well where the sprinkler didn't saturate. When asked why he did it, he replied, "I heard it helped and I just couldn't not do it." Is there an application of this story to lightning? Perhaps. If the boat is sitting ungrounded on stands or cradle... grounding may invite a strike that otherwise wouldn't hit.
Boat struck at Turner Marine last year
The boat was struck while on stands in the yard. Suffered some damage.
The boat was struck while on stands in the yard. Suffered some damage.
marina lightING
I just read the post and thought it said Marina lighting...lst year in the dark..in the winter a car backed out of a space and struck some jack stands and knocked a boat on its side.....the driver said there wasnt enough light in the marina lot....not sure whos insurance paid for the damage...car?? marina?? boat owner??? thoughts?
I just read the post and thought it said Marina lighting...lst year in the dark..in the winter a car backed out of a space and struck some jack stands and knocked a boat on its side.....the driver said there wasnt enough light in the marina lot....not sure whos insurance paid for the damage...car?? marina?? boat owner??? thoughts?
One more thought for ya....
In my original post, I was simply trying to answer Marks original question, with the best information I have from years as an electrician, without regard to the relevance of the question itself. Truth be told, I wouldn't go to the bother of lightning protection of any sort on a boat sitting in my yard. The chances of a strike are quite minimal, the chances that grounding the boat would help prevent damage are minimal, the chances that grounding the boat makes it a more likely target to a strike are reasonable, and it's gonna cost you $$ to implement. Honestly Mark, unless you're gonna be losing sleep over it, I wouldn't bother and I wouldn't worry. If your boat somehow DOES manage to get hit by lightning, it's quite likely that there will be pieces of fiberglass all over the neighborhood anyway, whether you ground it or not. So, what to do? Make sure your insurance is paid-up!
In my original post, I was simply trying to answer Marks original question, with the best information I have from years as an electrician, without regard to the relevance of the question itself. Truth be told, I wouldn't go to the bother of lightning protection of any sort on a boat sitting in my yard. The chances of a strike are quite minimal, the chances that grounding the boat would help prevent damage are minimal, the chances that grounding the boat makes it a more likely target to a strike are reasonable, and it's gonna cost you $$ to implement. Honestly Mark, unless you're gonna be losing sleep over it, I wouldn't bother and I wouldn't worry. If your boat somehow DOES manage to get hit by lightning, it's quite likely that there will be pieces of fiberglass all over the neighborhood anyway, whether you ground it or not. So, what to do? Make sure your insurance is paid-up!
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