Does anyone have any eral information on what happens when lighting hits a water ballasted boat? I have sailed one for over 10 years in lots of lightning and never have been hit but have always wondered what will happen to all that water in the ballast tank. Would like real stories. Maybe we don't want to talk about it either. Thanks Corky
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Water Ballast Lightning Strike
I just recently purchased a 99 H240 that had been struck by lightning while sitting on its mooring. The bolt knocked a couple of holes just above the water line on each side of the hull, blew out the sink drain through-hull, perforated several small holes of pin hole size up to about 1/8 inch in the bottom of the hull, burned a 12 inch hole in the folded bimini and fried all the electricals. The insurance company totaled the boat and the then current owner got a new boat. Upon inspection, no holes were found in the top of the ballast tank between the cabin sole and the ballast tank and all the hull penetrations were repaired with standard fiberglass construction techniques. The electrical components were replaced, the boat was very, very thoroughly tested for water tightness and I'm now very happy with it. Karl
I just recently purchased a 99 H240 that had been struck by lightning while sitting on its mooring. The bolt knocked a couple of holes just above the water line on each side of the hull, blew out the sink drain through-hull, perforated several small holes of pin hole size up to about 1/8 inch in the bottom of the hull, burned a 12 inch hole in the folded bimini and fried all the electricals. The insurance company totaled the boat and the then current owner got a new boat. Upon inspection, no holes were found in the top of the ballast tank between the cabin sole and the ballast tank and all the hull penetrations were repaired with standard fiberglass construction techniques. The electrical components were replaced, the boat was very, very thoroughly tested for water tightness and I'm now very happy with it. Karl
Depends on where it exits.
Corky: No one can tell you what will happen to YOUR boat. So much of this is dependent on the stike. We had a house in our neighborhood that was stuck by lightning. It his the chimney and blew all the sheet rock off the wall in the room where the fireplace was located.
Corky: No one can tell you what will happen to YOUR boat. So much of this is dependent on the stike. We had a house in our neighborhood that was stuck by lightning. It his the chimney and blew all the sheet rock off the wall in the room where the fireplace was located.
What about me?
The question to my mind is what would happen to me if I were on the boat if it were hit. It is apparent from a previous reply that lightening has the potential to sink the boat by blowing holes in the bottom but what about people on board?
The question to my mind is what would happen to me if I were on the boat if it were hit. It is apparent from a previous reply that lightening has the potential to sink the boat by blowing holes in the bottom but what about people on board?
Give Lightning a path...
Give lightning a path to follow, and it will protect the rest of the boat. That's the idea behind lightning rods. Just make sure you stay away from the path you've given it (or anything else connected to that path). Some people have fastened jumper cables to the shrouds and dropped the other end in the water. I think it works best if the cable is not covered (insulated), because lightning is static electricity, and static electricity prefers to run along the surface of a conductor, not through it. On the other hand, I recently heard that the experts don't think lightning rods are so wonderful.
Give lightning a path to follow, and it will protect the rest of the boat. That's the idea behind lightning rods. Just make sure you stay away from the path you've given it (or anything else connected to that path). Some people have fastened jumper cables to the shrouds and dropped the other end in the water. I think it works best if the cable is not covered (insulated), because lightning is static electricity, and static electricity prefers to run along the surface of a conductor, not through it. On the other hand, I recently heard that the experts don't think lightning rods are so wonderful.
Hold on guys...
I would strongly agree with Steve; since lightning discharges are not constant in magnitude in terms of current and voltage, it depends on factors that are different on every boat, tree, house, human, flagpole, etc. Russ, lightning is only static charge while current is not flowing (i.e. as long as there is no discharge). Once charge flow occurs (a strike), it's the same old garden variety "electricity" generated by your power company albeit raised several magnitudes. Due to physics, charge flow occurs primarily on the surface of a conductor, insulated or not. Insulation may help contain the charge flow on its path to ground (water). An uninsulated conductor would have many opportunities to "leak" charge to paths of lesser resistance. Steve describes another nasty side effect of lightning; the concussive shockwave. As lightning strikes, it literally burns the air in the leader channel. This creates a partial vacuum that is immediately filled in by the surrounding air and causes quite a bang (thunder). That concussive shockwave can deflect steel plates, knock siding off of houses, and blow chunks out of concrete. Calvin, the only thing I can tell you is that numerous boats have been hit with no injury to the occupants. If you're not touching the metal parts energized by the strike, you will probably fare okay. If you are, then we might not have this discussion afterwards. Mark Kissel Kittiwake/98H240
I would strongly agree with Steve; since lightning discharges are not constant in magnitude in terms of current and voltage, it depends on factors that are different on every boat, tree, house, human, flagpole, etc. Russ, lightning is only static charge while current is not flowing (i.e. as long as there is no discharge). Once charge flow occurs (a strike), it's the same old garden variety "electricity" generated by your power company albeit raised several magnitudes. Due to physics, charge flow occurs primarily on the surface of a conductor, insulated or not. Insulation may help contain the charge flow on its path to ground (water). An uninsulated conductor would have many opportunities to "leak" charge to paths of lesser resistance. Steve describes another nasty side effect of lightning; the concussive shockwave. As lightning strikes, it literally burns the air in the leader channel. This creates a partial vacuum that is immediately filled in by the surrounding air and causes quite a bang (thunder). That concussive shockwave can deflect steel plates, knock siding off of houses, and blow chunks out of concrete. Calvin, the only thing I can tell you is that numerous boats have been hit with no injury to the occupants. If you're not touching the metal parts energized by the strike, you will probably fare okay. If you are, then we might not have this discussion afterwards. Mark Kissel Kittiwake/98H240
What you really want to know about lightning
If you really want to know how to prepare your boat to deal with lighting, and avoid it; get a small book called Lightning and Boats: A Manual of Safety and Prevention. It discusses avoidance through use of Ion Dissipators, proper grounding etc. I just received it from bn.com and it was about $10 well-spent. (I have no connection with the author or Barnes and Noble).
If you really want to know how to prepare your boat to deal with lighting, and avoid it; get a small book called Lightning and Boats: A Manual of Safety and Prevention. It discusses avoidance through use of Ion Dissipators, proper grounding etc. I just received it from bn.com and it was about $10 well-spent. (I have no connection with the author or Barnes and Noble).
more lightning
I don't have the numbers at my fingertips, but statistically, deaths from lightning strikes at sea are rare. But you cannot predict what lightning will do because there are so many variables. If I got hit and lost only my electronics, I would consider myself lucky.
I don't have the numbers at my fingertips, but statistically, deaths from lightning strikes at sea are rare. But you cannot predict what lightning will do because there are so many variables. If I got hit and lost only my electronics, I would consider myself lucky.
Mark: question about lightning
I recall reading (a lot of years ago) that lightning is static electricity, similar/identical to the electrical discharge you get from a Tesla coil or Van de Graff generator. Just with a lot higher amps (it's the amps that kill, not the voltage, as you know). I also read more recently that insulation on wires impedes the flow in a lightning strike, and the lightning can explode the insulation (and anything else in the way). I assumed bare wires might be "safer" (after all, why are ground wires uninsulated?). But you have a very pertinent point about stray paths. The best advice, as always, is to be elsewhere when the lightning strikes. I would love to update my knowledge about lightning. Where can I learn more? Thanks! Russ
I recall reading (a lot of years ago) that lightning is static electricity, similar/identical to the electrical discharge you get from a Tesla coil or Van de Graff generator. Just with a lot higher amps (it's the amps that kill, not the voltage, as you know). I also read more recently that insulation on wires impedes the flow in a lightning strike, and the lightning can explode the insulation (and anything else in the way). I assumed bare wires might be "safer" (after all, why are ground wires uninsulated?). But you have a very pertinent point about stray paths. The best advice, as always, is to be elsewhere when the lightning strikes. I would love to update my knowledge about lightning. Where can I learn more? Thanks! Russ
Insulation / static
Some miscellaneous ramblings: Lightning charges build as static electricity, but once they discharg (the bolt) I think by definition they are no longer static since there is a current involved. I don't think insulation inhibits current flow, but lightning is an extreme case and regular rules may not apply. However, insulation probably has no value in terms of containing the current in the conductor. The voltage of a lightning bolt is well beyond the ratings of any wire insulation. Also, most lightning grounding wires are probably bare because they are not energized conductors (except of course during an actual strike and then see the previous statement).
Some miscellaneous ramblings: Lightning charges build as static electricity, but once they discharg (the bolt) I think by definition they are no longer static since there is a current involved. I don't think insulation inhibits current flow, but lightning is an extreme case and regular rules may not apply. However, insulation probably has no value in terms of containing the current in the conductor. The voltage of a lightning bolt is well beyond the ratings of any wire insulation. Also, most lightning grounding wires are probably bare because they are not energized conductors (except of course during an actual strike and then see the previous statement).
Russ, sorry for the delayed response.
Due to a cable cut, I've had no telephone service since Friday.
You ask an excellent question! Ron is pretty much on target regarding insulation on wires. If you are referring to NM (Non-Metallic sheathed) wiring (often called "Romex"), the ground conductor IS insulated. It's covered by the sheathing. Think about it for a moment, if you have three wires, how many need to have their own thermoplastic insulation to isolate one from another? -- only two. This is the most cost-effective method of producing commercial wiring. But the ground wire is still covered (insulated) by the sheathing. So, all three wires are insulated. Ground wires for meter bases and lightning rods are typically not insulated since it would serve no purpose. What would we be insulating it from? No current is intended to normally flow on these wires. Additionally, thermoplastic insulation can be a fire hazard if the wire overheats due to excessive current flow. By not insulating the wire, it can dissipate heat as rapidly as possible. Insulation will not impede the flow of current through the conductor inside. Insulation is used primarily as a "people protector" or deterrent to potential fire hazards. Where neither of these pose a problem, wires are typically not insulated. Look at transmission and distribution lines on utility poles and you will see that they are largely non-insulated conductors. Covering a wire with insulation increases the cost. So, if you were going to be near a wire on your boat that has been energized by a lightning discharge, which would you rather touch (accidentally, of course), an insulated one or bare one? With millions of volts of potential, it likely will not make a great deal of difference. However, I would hope that the insulation and my body's natural impedance would represent a much less likely path for lightning to follow. To learn more about lightning, try: www.globalatmospherics.com
Due to a cable cut, I've had no telephone service since Friday.
You ask an excellent question! Ron is pretty much on target regarding insulation on wires. If you are referring to NM (Non-Metallic sheathed) wiring (often called "Romex"), the ground conductor IS insulated. It's covered by the sheathing. Think about it for a moment, if you have three wires, how many need to have their own thermoplastic insulation to isolate one from another? -- only two. This is the most cost-effective method of producing commercial wiring. But the ground wire is still covered (insulated) by the sheathing. So, all three wires are insulated. Ground wires for meter bases and lightning rods are typically not insulated since it would serve no purpose. What would we be insulating it from? No current is intended to normally flow on these wires. Additionally, thermoplastic insulation can be a fire hazard if the wire overheats due to excessive current flow. By not insulating the wire, it can dissipate heat as rapidly as possible. Insulation will not impede the flow of current through the conductor inside. Insulation is used primarily as a "people protector" or deterrent to potential fire hazards. Where neither of these pose a problem, wires are typically not insulated. Look at transmission and distribution lines on utility poles and you will see that they are largely non-insulated conductors. Covering a wire with insulation increases the cost. So, if you were going to be near a wire on your boat that has been energized by a lightning discharge, which would you rather touch (accidentally, of course), an insulated one or bare one? With millions of volts of potential, it likely will not make a great deal of difference. However, I would hope that the insulation and my body's natural impedance would represent a much less likely path for lightning to follow. To learn more about lightning, try: www.globalatmospherics.comThanks, Mark!
I'll check out that web site. When I was a kid, the TV antenna on the roof had a heavy bare copper ground wire, as did the ground wires my older brother had rigged up for his ham radio antenna and gear. You don't see many TV antennas any more....
I'll check out that web site. When I was a kid, the TV antenna on the roof had a heavy bare copper ground wire, as did the ground wires my older brother had rigged up for his ham radio antenna and gear. You don't see many TV antennas any more....
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