lightning strikes

Some boaters attach an outside line of copper wire to the rigging and let it hang to the water in stormy weather avoiding kinks or twists. You're not necessarily dead if you're not holding onto the metal or conductive things in your boat. A commercial fishing vessel coming into Santa Cruz harbor a long time ago took a hit and it fried all his electronics. It was probably wooden. A concern for fiberglass is any moisture in the laminates such as blisters could react as they are salty and acidic. Has anyone here ever seen a boat after it has been struck? HH

If the top of your mast is 100 million volts and the water is 0, you have something like 100 thousand volts per inch across your boat. You better be standing on one foot when it strikes. The one time I was near lightening, I stood with one foot on top of the other but the tiller would probably have killed me so maybe it would not have mattered. Also, the lightening is likely to turn your boat into conductive carbon so I don't think the fiberglass is going to save you. Think of it this way, you are struck by lightening and you are sitting on a boat made out of oil. Best to stay away from lightening. However, I have never seen a boat struck by lightening. I am assuming few people have ;-) Allen On Tue, Apr 13, 2010 at 6:37 PM, Helen Horn <he… [at] sbcglobal.net> wrote: > > > Some boaters attach an outside line of copper wire to the rigging and let > it hang to the water in stormy weather avoiding kinks or twists. You're not > necessarily dead if you're not holding onto the metal or conductive things > in your boat. A commercial fishing vessel coming into Santa Cruz harbor a > long time ago took a hit and it fried all his electronics. It was probably > wooden. A concern for fiberglass is any moisture in the laminates such as > blisters could react as they are salty and acidic. Has anyone here ever seen > a boat after it has been struck? HH > > >

/Celtic Naut/, our Cal-40, was struck a year and a half ago in Bayou Chico, Florida. The strike hit our masthead antenna turning it into pretzel shaped molten goo that left a nice charcoal brand on our newly painted deck. It then proceeded down the cable into our electronics cabinet and fried our new refrigeration system, battery charger and one bank of batteries. It then followed the ground wire through shore power, up to the dock breaker, tripped it, then up to the house, tripped that one too, over to the neighbors on the next dock over and tripped their shore power breakers as well. She has been hauled out, mast removed and there is no other damage aside from the expensive stuff. It really set us back on our cruising dream, but in hindsight, maybe it was an omen that we needed to do some more work on her before setting out. And we're paying heed as well as getting our ducks in a row. Mike Cal-40 #44, /Celtic Naut/ On 4/13/2010 9:49 PM, Allen Edwards wrote: > > > If the top of your mast is 100 million volts and the water is 0, you > have something like 100 thousand volts per inch across your boat. You > better be standing on one foot when it strikes. The one time I was > near lightening, I stood with one foot on top of the other but the > tiller would probably have killed me so maybe it would not have > mattered. > > > Also, the lightening is likely to turn your boat into conductive > carbon so I don't think the fiberglass is going to save you. Think of > it this way, you are struck by lightening and you are sitting on a > boat made out of oil. Best to stay away from lightening. > > However, I have never seen a boat struck by lightening. I am assuming > few people have ;-) > > Allen > > > On Tue, Apr 13, 2010 at 6:37 PM, Helen Horn <he… [at] sbcglobal.net > <mailto:he… [at] sbcglobal.net>> wrote: > > > Some boaters attach an outside line of copper wire to the rigging > and let it hang to the water in stormy weather avoiding kinks or > twists. You're not necessarily dead if you're not holding onto the > metal or conductive things in your boat. A commercial fishing > vessel coming into Santa Cruz harbor a long time ago took a hit > and it fried all his electronics. It was probably wooden. A > concern for fiberglass is any moisture in the laminates such as > blisters could react as they are salty and acidic. Has anyone here > ever seen a boat after it has been struck? HH > >

a Catalina 36 in our yacht club was struck b y lightning. arced a hole in the mast about the size of a nickle, took out all electrical and blew 110 power on that dock. The only oats i know of which have been hit by lightning were plugged into shore power. Reggie To: Ca… [at] yahoogroups.com From: al… [at] PaloAltoPhoto.com Date: Tue, 13 Apr 2010 18:49:16 -0700 Subject: Re: [Cal_Boats] lightning strikes If the top of your mast is 100 million volts and the water is 0, you have something like 100 thousand volts per inch across your boat. You better be standing on one foot when it strikes. The one time I was near lightening, I stood with one foot on top of the other but the tiller would probably have killed me so maybe it would not have mattered. Also, the lightening is likely to turn your boat into conductive carbon so I don't think the fiberglass is going to save you. Think of it this way, you are struck by lightening and you are sitting on a boat made out of oil. Best to stay away from lightening. However, I have never seen a boat struck by lightening. I am assuming few people have ;-) Allen On Tue, Apr 13, 2010 at 6:37 PM, Helen Horn <he… [at] sbcglobal.net> wrote: Some boaters attach an outside line of copper wire to the rigging and let it hang to the water in stormy weather avoiding kinks or twists. You're not necessarily dead if you're not holding onto the metal or conductive things in your boat. A commercial fishing vessel coming into Santa Cruz harbor a long time ago took a hit and it fried all his electronics. It was probably wooden. A concern for fiberglass is any moisture in the laminates such as blisters could react as they are salty and acidic. Has anyone here ever seen a boat after it has been struck? HH

Because we don't sail enough! :-( Mike On 4/13/2010 11:57 PM, r good wrote: > > > a Catalina 36 in our yacht club was struck b y lightning. arced a > hole in the mast about the size of a nickle, took out all electrical > and blew 110 power on that dock. > The only oats i know of which have been hit by lightning were plugged > into shore power. > Reggie >

My 25 was not struck by lightning, but was run into some high voltage power lines by the PO. Headstay burned in two, rig came down, current exited the port cockpit drain through hull and, in the process, removed over a 1/4" of the bronze fitting. Burned the outboard ground cable in two at the crimp fitting in the engine, killed all the electronics. Hull was damaged, some say due to steam from moisture in the laminate. I think it was EMF in the wires in the rigging. Large currents in a wire react with the earth's magnetic field and try to form the wire into a circle. The resultant force torqued the hull to the breaking point in several places. Watch a car battery cable sometime when it is being started. Secure it somewhere so the engine motion doesn't move it and look for motion when the starter first engages. In my case, there were probably thousands of amps flowing for a second or two until the rig fell away. Two friends' boats were struck, one at the dock behind his house, with resultant loss of all electronics and pinholes in the hull near the ground wires. The other was struck at Crab Cay in the Bahamas while at anchor. All electronics were lost, but no structural damage. Unfortunately there does not seem to be a consensus on how to protect a boat. But I can understand how wires clipped to the stays and dropped overboard could seem attractive to reduce the currents on anything inside the hull. Remember that the lightning has jumped 8 miles or so of air, one of the best dielectrics short of a vacuum. Less than an inch of plastic resin with glass fiber is essentially invisible to it. Al 1974 Cal25 #1693, Sweet Mary 1985 Cal33-2 #0026, Short Wave

Allen Edwards wrote: > > > > However, I have never seen a boat struck by lightening. I am assuming > few people have ;-) Problem is, it's hard to establish recommendations when you can't experiment. Lightning is random and sporadic. I have read and heard about lightning that hits fiberglass boats and exits through the FRP laminate, leaving a mass of tiny pinholes over a wide area (big mess). I have also heard about the blown-out through-hull problem. The guy whose boat was struck in my marina had the pinhole effect. His ego is far larger than his talent, if you know what I mean, and I always wondered if the lightning strike weren't some sort of message from the gods. There are two principal schools of thought. One says that grounding simply attracts lightning, so those folks choose to go ungrounded. The other says that a proper lightning grounding system tends to discharge the potential difference that sets you up for a strike, and then if you get one anyway, it adds protection to vessel and crew by guiding the discharge in a preferred route. I have followed the second school of thought. I have a sharp-pointed spike at masthead (a piece of old surgical pin stainless, ground to a point). The conductors from there are the bronze strap under the sail track straight down the wooden mast (it covers a routed groove for masthead wires) and the sail track itself, plus the upper shrouds and the fore/back stays. All of those (except backstay) are grounded to the iron keel via heavy copper conductors. Those conductors are routed to the keel without sharp bends, which tend to "derail" a lightning charge. It has been my hope that if the boat were struck, the lightning would choose the "easy route" via copper and iron instead of the higher-resistance route through my fiberglass hull, and further, that the multiple conductors would further encourage that route. They also would have the effect of reducing side flashes. My Cal 20 has copper conductors running from the mast step to the keel, but they have fairly small-radius bends installed by a prior owner. My real hope, of course, is that I never have to subject this theory to experimental test. Chris Campbell >

I have seen three boats that have been struck by lightning. The first time was nearly 40 years ago. The boat was hit while in it's slip, it removed the masthead antenna, blew off teak trim on the transom, fried the electronics (tube radio), blew 4 holes about six inches above the waterline and tripped one leg of the 220V dock feed and made a mess of everything loose in the cabin. Within two weeks they were back sailing. The second wasn't an actual hit but the rigging started glowing while they were aboard. In this case there was no damage except for some soiled undies for the family that was sleeping on the boat. The third was sailing back to their dock when they got hit, fried the electronics and blew some holes in the bottom causing them to miss a few races. An article in BOAT/US last year said that death or even injury was rare in lightning strikes on boats. John Boyce _____ From: Ca… [at] yahoogroups.com [mailto:Ca… [at] yahoogroups.com] On Behalf Of Helen Horn Sent: Tuesday, April 13, 2010 8:38 PM To: Ca… [at] yahoogroups.com Subject: [Cal_Boats] lightning strikes Some boaters attach an outside line of copper wire to the rigging and let it hang to the water in stormy weather avoiding kinks or twists. You're not necessarily dead if you're not holding onto the metal or conductive things in your boat. A commercial fishing vessel coming into Santa Cruz harbor a long time ago took a hit and it fried all his electronics. It was probably wooden. A concern for fiberglass is any moisture in the laminates such as blisters could react as they are salty and acidic. Has anyone here ever seen a boat after it has been struck? HH

Our boat was struck while in the slip. The Captain of a nearby mega-yacht witnessed it. He said that you could see electrical arcs travel down the entire mast. We were unable to find any damage. The second experience was on the flybridge of a gulfstar trawler trying to get into a slip. There was lightning activity all around the boat and I was naturally anxious, there was a huge boom and I found myself sitting dazed on the flybridge deck. We were unable to detect any damage to the boat. I wonder how many strikes occur that involve no damage? Just call me Sparky. From: Ca… [at] yahoogroups.com [mailto:Ca… [at] yahoogroups.com] On Behalf Of Allen Edwards Sent: Tuesday, April 13, 2010 9:49 PM To: Ca… [at] yahoogroups.com Subject: Re: [Cal_Boats] lightning strikes If the top of your mast is 100 million volts and the water is 0, you have something like 100 thousand volts per inch across your boat. You better be standing on one foot when it strikes. The one time I was near lightening, I stood with one foot on top of the other but the tiller would probably have killed me so maybe it would not have mattered. Also, the lightening is likely to turn your boat into conductive carbon so I don't think the fiberglass is going to save you. Think of it this way, you are struck by lightening and you are sitting on a boat made out of oil. Best to stay away from lightening. However, I have never seen a boat struck by lightening. I am assuming few people have ;-) Allen On Tue, Apr 13, 2010 at 6:37 PM, Helen Horn <he… [at] sbcglobal.net <mailto:he… [at] sbcglobal.net> > wrote: Some boaters attach an outside line of copper wire to the rigging and let it hang to the water in stormy weather avoiding kinks or twists. You're not necessarily dead if you're not holding onto the metal or conductive things in your boat. A commercial fishing vessel coming into Santa Cruz harbor a long time ago took a hit and it fried all his electronics. It was probably wooden. A concern for fiberglass is any moisture in the laminates such as blisters could react as they are salty and acidic. Has anyone here ever seen a boat after it has been struck? HH

My 1987 Catalina 27 was hit last year at a mooring and all electronics (that is all including all wiring, instruments, instrument panels etc.) were wiped out including the engine harnesses. The furled jib was burned in places. To net, the insurance company totaled the boat and I then bought a 1988 CAL 28-2. ----- Original Message ----- From: Wyatt Hendricks To: Ca… [at] yahoogroups.com Sent: Monday, April 26, 2010 3:13 PM Subject: RE: [Cal_Boats] lightning strikes Our boat was struck while in the slip. The Captain of a nearby mega-yacht witnessed it. He said that you could see electrical arcs travel down the entire mast. We were unable to find any damage. The second experience was on the flybridge of a gulfstar trawler trying to get into a slip. There was lightning activity all around the boat and I was naturally anxious, there was a huge boom and I found myself sitting dazed on the flybridge deck. We were unable to detect any damage to the boat. I wonder how many strikes occur that involve no damage? Just call me Sparky. ------------------------------------------------------------------------------ From: Ca… [at] yahoogroups.com [mailto:Ca… [at] yahoogroups.com] On Behalf Of Allen Edwards Sent: Tuesday, April 13, 2010 9:49 PM To: Ca… [at] yahoogroups.com Subject: Re: [Cal_Boats] lightning strikes If the top of your mast is 100 million volts and the water is 0, you have something like 100 thousand volts per inch across your boat. You better be standing on one foot when it strikes. The one time I was near lightening, I stood with one foot on top of the other but the tiller would probably have killed me so maybe it would not have mattered. Also, the lightening is likely to turn your boat into conductive carbon so I don't think the fiberglass is going to save you. Think of it this way, you are struck by lightening and you are sitting on a boat made out of oil. Best to stay away from lightening. However, I have never seen a boat struck by lightening. I am assuming few people have ;-) Allen On Tue, Apr 13, 2010 at 6:37 PM, Helen Horn <he… [at] sbcglobal.net> wrote: Some boaters attach an outside line of copper wire to the rigging and let it hang to the water in stormy weather avoiding kinks or twists. You're not necessarily dead if you're not holding onto the metal or conductive things in your boat. A commercial fishing vessel coming into Santa Cruz harbor a long time ago took a hit and it fried all his electronics. It was probably wooden. A concern for fiberglass is any moisture in the laminates such as blisters could react as they are salty and acidic. Has anyone here ever seen a boat after it has been struck? HH