[Rhodes22-list] Lightning mitigation

Sat Jul 14 21:36:51 EDT 2012

I agree with you chris.  I have read that people have had the plates blown off too.  If you are still alive you can bung a melted through hull.  Then of course if we were to use a close to waterline fitting like the starboard one that might get a short path to water, but wouldnt give us dissapation. Sure am glad we have a lot of floatation foam.

On Jul 14, 2012, at 6:15 PM, "Chris Geankoplis" <napoli68 at charter.net> wrote:

> Grounding a mast does not protect it from being hit, in fact there is a lot
> of evidence that there is a slight increase in incidents.  I think that the
> idea is that the flow of electrons can dissipate rather than build up, but
> the difference in potential when talking about hundreds of thousands of
> volts is very little.  The advantage for a grounded mast is when you are
> struck you will direct the path of the electrons and its exit point.  A word
> of caution, grounding to a single bronze through hull can have disastrous
> results as the fitting can heat almost to incandescence and any water
> trapped nearby is vaporized.  I have seen a through hull blown out of a
> boat, not good.  You will need something that has several square feet of
> surface area such as a copper plate.  Often when an ungrounded mast is hit
> the lightning travels to the base of the mast (if deck stepped) and then
> jumps to the water line right through the hull.  This can burn a hole in the
> fiberglass, but what do we care our boats are unsinkable.
> 
> Chris G
> 
> -----Original Message-----
> From: rhodes22-list-bounces at rhodes22.org
> [mailto:rhodes22-list-bounces at rhodes22.org] On Behalf Of Goodness
> Sent: Saturday, July 14, 2012 6:59 AM
> To: The Rhodes 22 Email List
> Subject: Re: [Rhodes22-list] Lightning mitigation
> 
> If your boat mast is grounded then a lightning strike to the mast is not
> really going to happen.  Many carry jumper cables and when a storm comes up
> clamps to a mast fitting and toss the other end overboard.  A more clever
> solution is an internal grounding wire to a metal underwater through
> hull......however that through hull needs to be protected with a zinc or it
> will corrode big time and sink you.  I have seen lightning switches that you
> flip in a storm too.  On a dock on a lift, it would be smart to ground the
> mast to the actual ground, very little corrosion risk there.
> 
> 
> 
> On Jul 14, 2012, at 12:51 AM, peter klappert <peterklappert at comcast.net>
> wrote:
> 
>> 
>> Just to bring you all up to date and ask a question (or two).
>> 
>> Did I mention that the day I discovered the damage the Tampa Bay Times
> reported that Tampa has lost its (completely unofficial) status as lightning
> capital of the world?
>> 
>> I may as well get to the important question right away, then rattle on for
> anyone interested in the patient's health. So here's the question: 
>> 
>> What kind of lightning mitigation does the R22 have? For example, it might
> be heavy guage wire or cable connecting the shrouds to centerboard or some
> other metal below the waterline.
>> 
>> Does anyone know? Or has anyone done or modified this sort of thing on
> their boat?
>> 
>> Here's the latest news. If I had more time I could make this shorter, but
> it's past midnight and the marine electrician is due at 8 A.M.
>> 
>> The damage to Aeolia is, of course, more extensive than I knew when I sent
> the list under the subject "Major Electrical Problems." But it's not much
> more extensive, just quirky and seemingly patternless.
>> 
>> There is no visible damage to hull cabin or rigging, but most electronics
> are fried, as are running and anchor lights; the VHF aerial apparently got
> melted out of its mast-top mounting. So far wiring seems to be ok, with some
> fuses blown and some not. The outboard's electric starter is gone, but the
> motor starts manually and runs like a purring cat. Both main & Genoa look to
> be like new--I was concerned because of their proximity to metal. 
>> 
>> I'll know a lot more after this weekend and hope to have Aeolia out on
> Tampa Bay sometime next week.
>> 
>> The concensus among those I've talked to is that having the boat elevated
> on the lift and the aluminun lift itself increased likelihood of my boat
> being either struck or damaged by a strike nearby. Still, the total height
> of Aeolia on the lift, including 2-foot VHF aerial, is only about 36-37 feet
> above mean high tide. 
>> 
>> One leg of dock wiring is shorted, but that may be unrelated. Aeolia was
> not on shorepower at the time and the hull made no direct contact with
> metal--it was on the carpet-covered PT lumber of the lift bunks. Odds are
> that was part of the problem.
>> 
>> Obviously I need to make sure the lift is grounded (never thot to wonder
> or doubt it until this happened) and the guy who built the dock is looking
> into what might be possible and legal by way of a lightning rod on a pole.
> His power boat has a 24' metal antenna and has never been struck. My next
> door neighbor docked his C & C 34 behind his house for many years without
> incident. Lightning strikes--or damage, at least--among the big sailboats on
> the other size of Apollo Beach (in Bal Harbor) are reputed to be rare.
>> 
>> G'night!
>> 
>> 
>> 
>> 
>> 
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