I just shelled out $85.00 for a lightning disipator because in 3 years, 2 of my boats have been struck by lightning. I also just read Don Casey's 12 volt bible. In it he states that a disipator will not make my boat any less likly to be stuck by lightning with it or with out it. He says that the disipator "will" decrease the static build up but he also states and I quote " there is plenty more where that came from" Question, do you think that the disipator is a waste of time and money? or well it do me some good installing the disipator? Don Casey says that if your going to get hit, your going to get hit! He also states that a boat in fresh water is more likely to hit by lightning than a boat in salt water. I sail in fresh water! Boat/US (my insurance co.) has told be that the odds of getting struck by lighnting once is 1 in 6 billion and the odds of getting struck twice are 1 in 11 billion. hmmm......... makes me start to think about it? Thanks for your replys. Steve, s/v The Odyssey (H310)
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lightning
I don't buy the part about boats in fresh water being more likely to get hit than boats in salt water. I think you are more likely to get hit where there is more lightning. Florida is notorious for electrical storms, for instance, and I have heard of a lot of boats hit down there, but in 20 years only one strike in my freshwater marina. The only way to tell if your dissapator works is to put it up and see if you get hit again. If you don't, then it was worth the $85.00!
I don't buy the part about boats in fresh water being more likely to get hit than boats in salt water. I think you are more likely to get hit where there is more lightning. Florida is notorious for electrical storms, for instance, and I have heard of a lot of boats hit down there, but in 20 years only one strike in my freshwater marina. The only way to tell if your dissapator works is to put it up and see if you get hit again. If you don't, then it was worth the $85.00!
Let's think about this!
Now if there is a lightn' bolt with however many thousand volts of electricity that is going to strike something. What is the chance that anything in the world is going to prevent it? There is nothing that is going to prevent it! I think that proper grounding may help prevent some damage but if you get hit you should expect damage even with proper grounding. My idea is to try to get to port and be in the middle of the harbor, hoping that the lighting gets the other guy. <no offense other guys> Fresh water/Salt water? When I lighting bolt strikes its going to hit anything in its path.
Now if there is a lightn' bolt with however many thousand volts of electricity that is going to strike something. What is the chance that anything in the world is going to prevent it? There is nothing that is going to prevent it! I think that proper grounding may help prevent some damage but if you get hit you should expect damage even with proper grounding. My idea is to try to get to port and be in the middle of the harbor, hoping that the lighting gets the other guy. <no offense other guys> Fresh water/Salt water? When I lighting bolt strikes its going to hit anything in its path.
I alway thought of Don as the 12 volt God!
He says what he says and I go along with it. Now Wisconsin has a lot of lightning storms and both strikes I was in the marina docked at my slip. My H310 has the second tallest mast in the marina by the way. Steve..
He says what he says and I go along with it. Now Wisconsin has a lot of lightning storms and both strikes I was in the marina docked at my slip. My H310 has the second tallest mast in the marina by the way. Steve..
Charge Disipator
Hi, Steve (Cook, that is). I agree with Steve (Dion, that is). Once a lightning bolt decides to happen there is NOTHING that is going to disipate the gazillions of volts driving that bolt fast enough to prevent consequences. But it MAY be possible to try to prevent the bolt from being attracted to your boat in the first place. Lightning bolts are caused by strong separation of positive and negative charges that can occur in the atmosphere during storms. If your mast happens to be a local collector of charge, your mast becomes one pole of a gigantic battery, and the charge is going to FLOW. I have seen beautiful ultra-high speed photographs of electical discharges leaping UP OFF a tower just milli-seconds before a lightning bolt struck the tower. St. Elmo's Fire is a visible form of local charge buildup. What these "disipators" might actually be doing is acting as a collecting and channeling point to attract and drain off a building local charge zone; prevent the local charge from building up in strength until a strike becomes inevitable. Our approach is to get into a harbor and moor right next to a boat with a taller mast! Carl and Jule s/v 'Syzygy'
Hi, Steve (Cook, that is). I agree with Steve (Dion, that is). Once a lightning bolt decides to happen there is NOTHING that is going to disipate the gazillions of volts driving that bolt fast enough to prevent consequences. But it MAY be possible to try to prevent the bolt from being attracted to your boat in the first place. Lightning bolts are caused by strong separation of positive and negative charges that can occur in the atmosphere during storms. If your mast happens to be a local collector of charge, your mast becomes one pole of a gigantic battery, and the charge is going to FLOW. I have seen beautiful ultra-high speed photographs of electical discharges leaping UP OFF a tower just milli-seconds before a lightning bolt struck the tower. St. Elmo's Fire is a visible form of local charge buildup. What these "disipators" might actually be doing is acting as a collecting and channeling point to attract and drain off a building local charge zone; prevent the local charge from building up in strength until a strike becomes inevitable. Our approach is to get into a harbor and moor right next to a boat with a taller mast! Carl and Jule s/v 'Syzygy'
Against the odds
Static electrical charge buildup occurs on any surface over which air is flowing. Being hit twice by lightning would make me think that you have an electrical bonding issue. You didn't mention the initial point of the lightning strike but my guess is an antenna at the mast head since that has a small cross-sectional area and is very exposed to air flow. A very large charge can build on the antenna if it is not bonded to ground correctly. The antenna shield should be bonded to ground at the antenna not at the radio to minimize the charge buildup and the resulting ground current. My 2 cents worth on lightning strike prevention which is as much art as science.
Static electrical charge buildup occurs on any surface over which air is flowing. Being hit twice by lightning would make me think that you have an electrical bonding issue. You didn't mention the initial point of the lightning strike but my guess is an antenna at the mast head since that has a small cross-sectional area and is very exposed to air flow. A very large charge can build on the antenna if it is not bonded to ground correctly. The antenna shield should be bonded to ground at the antenna not at the radio to minimize the charge buildup and the resulting ground current. My 2 cents worth on lightning strike prevention which is as much art as science.
1 in 11 billion
Steve: Have you considered buying a lottery ticket? Good Luck, John Finch, S/V/ Doxology
Steve: Have you considered buying a lottery ticket? Good Luck, John Finch, S/V/ Doxology
Grounding Wires in Corners
Being on a boat with a tall rig and lightning all around is nothing to laugh at. If I could wire my boat to resist lightning damage I'd have your fuzzy gadget at the masthead and copper wire clamped to the stays (fore, aft, and side) with heavy copper wire (say, about #8) on each stay that then goes into the water. When hit the charge and current should stay on the outside of the stays and wires and hopefully not cause harm to the inside of the boat. The copper wires attached to the stays should not have any sharp bends or they might not carry the charge down to "earth". A boat without a backstay or a boat with a mast mounted radar on the stern would need special consideration. Objects that extend outside the triangle of protection, or components connected by wires to same, would be subject to being fried and this might be a VHF or wind speed and direction indicator. I only see a couple storms a year and I'm not prepared. Maybe this year....
Being on a boat with a tall rig and lightning all around is nothing to laugh at. If I could wire my boat to resist lightning damage I'd have your fuzzy gadget at the masthead and copper wire clamped to the stays (fore, aft, and side) with heavy copper wire (say, about #8) on each stay that then goes into the water. When hit the charge and current should stay on the outside of the stays and wires and hopefully not cause harm to the inside of the boat. The copper wires attached to the stays should not have any sharp bends or they might not carry the charge down to "earth". A boat without a backstay or a boat with a mast mounted radar on the stern would need special consideration. Objects that extend outside the triangle of protection, or components connected by wires to same, would be subject to being fried and this might be a VHF or wind speed and direction indicator. I only see a couple storms a year and I'm not prepared. Maybe this year....
Jerry...
Both strikes that I had were on 2 different boats, my old H27 and my new H310. Both took hits to the antenna. Now how do I ground the antenna? Ony one person has said to install the disipator, what do you think? I like the idea with the copper wire to the stays. I feel that Hunter grounds their boats well however, the electronics are not bonded to the ground. Both strikes took out all of the electronics and both antennas exploded! I was on the boats both times during the strikes and let me tell you, it scared the hell out of me!!! The last strike blew off my bow nav light and I never found it. I really don't want to ever go through another lightning strike again and would like to protect my boat and myself as best as I can. Thanks Steve...
Both strikes that I had were on 2 different boats, my old H27 and my new H310. Both took hits to the antenna. Now how do I ground the antenna? Ony one person has said to install the disipator, what do you think? I like the idea with the copper wire to the stays. I feel that Hunter grounds their boats well however, the electronics are not bonded to the ground. Both strikes took out all of the electronics and both antennas exploded! I was on the boats both times during the strikes and let me tell you, it scared the hell out of me!!! The last strike blew off my bow nav light and I never found it. I really don't want to ever go through another lightning strike again and would like to protect my boat and myself as best as I can. Thanks Steve...
Study
Install your lightning protection system exactly as per the attached website to minimise lightning damage. http://www.cdc.gov/niosh/nasd/docs/as04800.html
Install your lightning protection system exactly as per the attached website to minimise lightning damage. http://www.cdc.gov/niosh/nasd/docs/as04800.html
Another Opinion
The following is the lighting protection system on my Hunter 30. As a point of reference I am an electrical engineer with 35 years experience and part of that 35 years was spent designing lightning protection systems for buildings. I also live and practice engineering in Florida. 1. A # 6 AWG conductor which run from the mast to the keel bolts. 2. A second #6 AWG conductor which runs from the mast to a copper ground plate directly under the mast step. 3. Copper straping which runs from the base of the mast step to the copper ground plate. Four stainless bolts from the top of the mast step through the coach roof and into the mast base casting. 4. Connections to the copper ground plate are via 3- 1/2" silicon bronze flat head bolts which were soldered to the ground plate before it was epoxied to the bottom of the boat. 5. #6 AWG conductors from the ends of the shroud anchor rods to the keel bolts. 6. #6 AWG conductors from the back stays to the keel bolts with a jumper to the stainless steel pushpit frame on both port and stbd sides. This connection also picks up the aluminum rub rail. 7. #6 AWG conductor from my bimini frame and steering pedestal to the keel bolts. 8. A Forespar lightning dissipator on the mast top. All the ground wiring is to ensure that if the boat is hit that the current will be conducted safely to the water. The Forespar dissipator is to reduce the probability of a hit. Anyone who has studied electric field theory will tell you that the dissipator reduces the probability of a hit. The operative word is reduces not eliminates. The boat has not yet suffered a hit, if it were I would expect the following: That the boat and crew would come through shaken but not hurt, new radio, radar, autopilot, and GPS. That is about as good as it gets. No gurantees in this business you just pays your money and takes your chances. I don't go looking for lightning, but it is just a fact of life in Florida and elsewhere. Boats and electronics are replacable lives are not. Frank Walker
The following is the lighting protection system on my Hunter 30. As a point of reference I am an electrical engineer with 35 years experience and part of that 35 years was spent designing lightning protection systems for buildings. I also live and practice engineering in Florida. 1. A # 6 AWG conductor which run from the mast to the keel bolts. 2. A second #6 AWG conductor which runs from the mast to a copper ground plate directly under the mast step. 3. Copper straping which runs from the base of the mast step to the copper ground plate. Four stainless bolts from the top of the mast step through the coach roof and into the mast base casting. 4. Connections to the copper ground plate are via 3- 1/2" silicon bronze flat head bolts which were soldered to the ground plate before it was epoxied to the bottom of the boat. 5. #6 AWG conductors from the ends of the shroud anchor rods to the keel bolts. 6. #6 AWG conductors from the back stays to the keel bolts with a jumper to the stainless steel pushpit frame on both port and stbd sides. This connection also picks up the aluminum rub rail. 7. #6 AWG conductor from my bimini frame and steering pedestal to the keel bolts. 8. A Forespar lightning dissipator on the mast top. All the ground wiring is to ensure that if the boat is hit that the current will be conducted safely to the water. The Forespar dissipator is to reduce the probability of a hit. Anyone who has studied electric field theory will tell you that the dissipator reduces the probability of a hit. The operative word is reduces not eliminates. The boat has not yet suffered a hit, if it were I would expect the following: That the boat and crew would come through shaken but not hurt, new radio, radar, autopilot, and GPS. That is about as good as it gets. No gurantees in this business you just pays your money and takes your chances. I don't go looking for lightning, but it is just a fact of life in Florida and elsewhere. Boats and electronics are replacable lives are not. Frank Walker
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