Lightning Strikes

PDQ issues applicable across all PDQ Yachts (or if you can't find a place for something, it probably belongs here for now)
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Page 83
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Re: Lightning Strikes

Post by Page 83 »

No rush! The new sales pitch is that bottle brushes divert lightning strikes safely away from crew members. Is it better to sink than glow?
Sandy Daugherty "Page 83" PDQ 36026
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thinwater
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Sorry - can't agree.

Post by thinwater »

ATTITUDE wrote:"... at the electronic repair shops recommendation, we disconnect the radio antenna when not need and during thunderstorms."

I believe this to be very good advise.

Best to all.
Being able to monitor the aproach of a storm and the location of the worst cells has helped me plan around the worst weather too many times. It also allows one to monitor for distress calls for others. I actually responded to a dismasting of a small cruiser once and towed him in. I would hope we all keep our ears on when it is most important. The call might not wait until after the storm.
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Re: Lightning Strikes

Post by Page 83 »

I'm still cleaning up after all the installation work, but I got to watch individual cells march over the Potomac and hit all around me on the South River on my XM Weather. Cool.
Sandy Daugherty "Page 83" PDQ 36026
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Re: Lightning Strikes

Post by PDQ-Dave »

We got caught out in one heck of a scary squall on Lake Okeechobee here in Florida last week. I was tracking the storm on my radar and at 24 miles in consumed half the screen! Tons of lightning and winds to at least 47 knots at which point I ducked inside. We dropped the anchor when we spotted a water spout approaching. Since I'd been watching the black wall interlaced with lightning for some time I did a little prep. I wrapped a 10' length of 5/16" chain around my Stbd backstay and hung it in the water #4 cable clamped to my upper stbd stay was already rigged so I just dropped it in the water. Then I added two extension cords that I wrapped on the mast and then dropped over the side. Luckily we did not get a hit. The high winds persisted for 40 minuets plus.

I have to say this was the most severe squall I've ever experienced in 25,000++nm of offshore sailing. Who would have thought the inland Lake Okeechobee would dish out such fierce winds and lightning. I think we got lucky to not be hit.
Dave Kane
Previous owner of Pacifica #36068
http://www.DKsail.com
http://www.PDQ36.blogspot.com
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Re: Lightning Strikes

Post by ATTITUDE »

Dear Thin Water:

I think the operative words in the suggestion posted by Root on April 29th

"... at the electronic repair shops recommendation, we disconnect the radio antenna when not need and during thunderstorms."

are - "when not need" (ed. should be not needed).
ATTITUDE
Captain Doug
Admiral Jeannie
Sea Dog 1st Class Paca

ATTITUDE - the last of human freedoms (Viktor Frankl)
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Re: Lightning Strikes

Post by SecondWind »

We have a "bottle brush", which was on the boat when bought it. Two years on the Chesapeake and six in Florida, and we have had no lightning strikes. My conclusion: Pure coincidence. None of my neighbors without the brush have had a strike either. Their advertising is just selling an insurance policy. Grounding the vessel in case of a strike is still a good idea, since most of the current will take the path of least resistance, but I have been warned that any turns in the path could be jumped. My take is to save your money for other toys aboard and keep your insurance up.
Terry Green
s/v Second Wind
36040
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Re: Lightning Strikes

Post by MagicDragon »

Magic Dragon experienced a direct lightning strike Thursday, June 25, 2009 when a freak thunderstorm blew threw Cleveland with 60-70 knot winds during Race Week at EYC. http://www.youtube.com/watch?v=_9Nu0zm6lm0
The lightning blew off the newly installed vinyl striping at the waterline when it exited the boat. Still in the middle of diagnosing - lift the boat, step the mast, etc. etc. UGH! And we thought we were finally going sailing, SIGH!

Will edit this post rather than develop a new one: we met with insurance appointed marine surveyor 7/7/09 at the boat, now out of the water with mast unstepped. Here's what we found:

Circumstances appear to indicate direct mast head strike and we were docked in the marina with power cord hooked up.
We did not have any lightning protection system installed. We believe lightning came down the mast, and then flashed out through the forestay (all joints on aluminum roller furler track had flash smoke), the power cord, and through the hull at the water line.

Resulting damage includes several small holes (not bigger than an inch) blown through the hull, some fiberglass tabbing in the bilges was loosened, and the new 3" vinyl striping at the water line was blown right off the hull. Equipment losses include almost everything that was electrical - batteries, Xantrax inverter charger, refrigerator compressor, both radios (VHF and SSB) and the stereo system, the starter on port engine, all NAV instrumentation (wind, depth, GPS), all wiring through the mast for antenna and lights was fried. And that's just the short list - we are still waiting for full damage report and will repost here when we get it.
Last edited by MagicDragon on Wed Jul 08, 2009 8:16 am, edited 1 time in total.
http://www.MagicDragonPDQ.com
Angela Barbati
S/V Magic Dragon 36054
near Cleveland, OH
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Page 83
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Re: Lightning Strikes

Post by Page 83 »

My sincere condolences! I have been through that and know it can pretty much kill the whole season getting everything in order. My advice: chalk it up to "life experiences" and keep your sense of humor!
Sandy Daugherty "Page 83" PDQ 36026
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Re: Lightning Strikes

Post by jak430 »

We are the new owners of 'Dream Catcher' PDQ 32017.
The survey that was just done stated:
"Suggest lighting protection by ground chain plate to water since vessel traveling south to tropical areas. See ABYC E-4.8"
Anybody know what he is referring to? When he was on the boat he said to attach a ground wire from the shroud chain plate to the water.
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Page 83
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Re: Lightning Strikes

Post by Page 83 »

That is not gospel. There is an on-going debate among scientists about the effectiveness of lightning grounds, and no one has the final word. Your surveyor let his opinion (of his opinions) get in the way of objectivity. Ask your insurer if you need to challenge this to avoid having to make provisions for a questionable suggestion.
Sandy Daugherty "Page 83" PDQ 36026
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Re: Lightning Strikes

Post by MagicDragon »

We experienced a direct hit three weeks ago, and have been doing lots of research as a result. Here's what Boat US, one of the largest insurers of marine vessels, has to say about this issue:
Lightning Strikes On Boats By BoatUS Tue, Aug 09, 2005

There may not be much a boater can do to prevent lightning from striking their vessel, but there is an important step to take immediately after a jolt hits, according to the July 2005 issue of Seaworthy magazine, the quarterly BoatU.S. Marine Insurance and damage avoidance report. In "Lightning! Flash, BANG! Your Boat's Been Hit- Now What?", Associate Editor Chuck Fort reviewed five years of lightning strike claims data from the BoatU.S. Marine Insurance claims files. What he found might surprise or confirm your suspicions about lightning strikes.

The feature reports that in any one year the odds of your boat being struck by lightning is about 1.2 in 1,000, with 33% of all lightning claims coming from the sunshine state, Florida. The second most struck area in the country was the Chesapeake Bay region (29%), while on the opposite side, 13 states had no lightning-related claims, including states such as Idaho and Nebraska.

The rate of lightning strikes for sailboats was about four boats per 1,000, while motorboats averaged 0.5 per 1,000. A surprise finding was that multi-hulled sailboats were struck more than twice as often as monohulls.

Interestingly, the files also showed that many boats equipped with lightning dissipaters were also hit, questioning their effectiveness. Most electronics aboard a boat were found not damaged by a direct hit but rather from surging electrical current created in the wiring by the strike.

While the story explains that some vessels can have little or no damage after a strike, an immediate short-haul is a must. The reason is that when lightning exits your boat, it can go through the hull itself or via a through-hull fitting. This may cause a gradual leak that could go unnoticed.

Oftentimes boaters don't know their unattended vessel has been struck or suffered collateral damage as the result of a nearby strike. The article reviews a claim in which lightning damage was found only after an amber LED light lit up on a battery charger - a light the owner had never seen before - and his depth sounder quit. Sometimes a damaged or missing VHF antenna is the only clue that an unattended boat has been struck.

Fort also mentions that most vessels are not electrically bonded according to American Boat & Yacht Council lightning protection standards. Boats built to these construction standards offer a more direct pathway for lightning to exit a vessel.
http://www.MagicDragonPDQ.com
Angela Barbati
S/V Magic Dragon 36054
near Cleveland, OH
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