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Lightning

Discussion in 'General Yachting Discussion' started by CaptEvan, Apr 17, 2009.

  1. CaptEvan

    CaptEvan Senior Member

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    Was coming out of Anna Maria Island Tuesday for a quick seatrial when lightning cracked right on top of us and ripped horizontally across the harbor and Galati's marina and yard. Looks like the damge could approach $500K. Ignitions turned on without keys, spotlights rotated, battery chargers ran up to 29 volts, navigation systems fried, like the "Langoliers" in reverse. Obviously, the big Vikings with the tuna towers got the worst of it.

    What are the thoughts on protection? Does a "lightning rod" system like some sailboats install offer any? Or is the static electricity simply enveloping and unaffected by grounding? With so many computers on board these days the issue becomes ever more important. (we had 21 of them but no damage due to my stupidity/luck for having left the dock)
  2. Capt J

    Capt J Senior Member

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    From what I have seen the energy and quickness of a boat getting hit by lightning cannot be dissappated by anything fast enough to stop a lot of damage. Also what usually gets hit are your vhf antannae's and such due to their height and it then feeds directly to the electronics and down from there.
  3. Natalie

    Natalie New Member

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    Precisely what happened to a head boat out of Huntington, NY when hit by lightning last summer during hail/water spout storm. Hit the antenna, blasted through the cockpit. Captain's hearing was gone for a while. Thankfully, no personal injury with clients - only costly electronics & minor structural damage.
  4. Capt Bill11

    Capt Bill11 Senior Member

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    About the only thing that might give you a "cone of protection" would be a heavy rod placed as high up as you can get it, connected to a heavy cable going to a large grounding plate mounted on the hull.

    But I guess if it failed, it could blow a hole in the bottom of your boat.

    A good friend of mine's father did some research into lighting protection for boats years ago. And he set up a antenna like rod that he could but up in bad weather that was high enough to form a "cone of protection" over the whole boat. It had a large cable that terminated with a plate of some kind that went right into the water overboard, as I recall, so the charge would, in theory, never entered the boat.

    You have 21 computers on board!?
  5. goplay

    goplay Senior Member

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    I've done a little reading on lightning protection. Lightning strikes have been found to generate strays that jump sideways inside a boat and put holes through everything in their path... including you!

    A single lightning rod grounded to the bottom of the hull may give you peace of mind, but may be totally insufficient in a direct hit.

    If I can find a particular article I will post the link. In this particular research, a cone of protection was created with multiple lightning rods placed around the boat. These were connected with a heavy gauge cable (0 or 00?) terminated at through hulls as close to the water line as possible. This has something to do with allowing the current to get to ground potential as soon and as quickly as possible.

    Clearly, not an easy retro-fit!
  6. K1W1

    K1W1 Senior Member

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    Hi,

    What do you call a bolt of Lightning that strikes a Ferro Cement Yacht?


    A Plaster Blaster:D
  7. Codger

    Codger YF Wisdom Dept.

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    Ouch! Even well sealed concrete will hold some moisture. If the lightning charge accessed the wire mesh there would be substantial heat generated. Or am I just imagining a ridiculously remote worst case?
  8. Capt J

    Capt J Senior Member

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    Maybe we can get a hold of that ferro cement sailboat that was docked across from Norseman's house and get it over to Mythbusters so they can test it out. It make for a very very good tv show!
  9. K1W1

    K1W1 Senior Member

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    Maybe it is a subject that could be suggested to the shows producers?

    Edit: I just signed up to the Discovery Channel and posted that question in the Mythbusters section.
  10. CaptTom

    CaptTom Senior Member

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    I wrote a piece on lightining protection for one of my publications. Let's see if I can sway the YF powers that be to let me repost it here.
    Until then, watch out for that lightning. Mother Nature can be very fickle.
  11. C4ENG

    C4ENG Senior Member

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    Just incase you do not get your article posted here, I will recap it..

    CaptTom wrote a great article on the subject in the Triton paper after doing research with some very well known ship builders trying to find out what sort of lightening protection is used on some of these 30+ million dollar yachts. Bottom line.. the technology that is out there has not been proven and basically lightening protection for yachts is myths for Mythbusters (as that just happens be on now as I write this) Pausible?
  12. YachtForums

    YachtForums Publisher/Admin

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    Tom,

    If it's OK with Lucy, it's OK with me.
  13. CaptTom

    CaptTom Senior Member

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    Thanks C4.

    Surprising is the fact that we can put a man on the moon and harness the power of the atom, we still cannot figure out this lightning thing.

    With permission from and thanks to Yachtforums and The Triton, here's the story.

  14. K1W1

    K1W1 Senior Member

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    Hi,

    Whilst I have great respect for John Dale- The brains behind ATLAS I find the Ft Lauderdale sales office statements a little bold given the huge currents that the units would be subject to given a strike.
  15. CaptEvan

    CaptEvan Senior Member

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    Thanks Tom, not only for the well done piece but going through the effort to share it.
  16. CaptTom

    CaptTom Senior Member

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    You're welcome. Hope the info helps out.
  17. Steve in SoCal

    Steve in SoCal New Member

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    Storm scope or Strike finder use?

    Do boats use Storm scopes ie lightning sensing systems? Reading the tales of lightning strikes got me wondering if anybody uses or has used these devices to minimize exposure?

    Steve
  18. Norseman

    Norseman Senior Member

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    Not sure about Storm scopes on boats.

    On airplanes yes, because you are fast enough to fly away from a thunderstorm if you see one on the scope while IFR.

    On a boat you will see it visually in day-time and see the lightening at night and can try to run.
    If you get caught in a squall on the water, the storm scope may not help anyway..(Too late)

    Perhaps the more experienced Captains on this here board have a different opinion on the Storm Scope..?
  19. captdjohn

    captdjohn New Member

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    We were hit last fall while at the dock in our home port of Fort Lauderdale. Our boat has a sophisticated lightning arrestor at the high point of our antenna mast with a heavy cable leading to a massive ground plate in the hull.

    Most systems were shut down at the time, including the MTU controls. It is the engineer's practice to shut down the breakers to the MTU's as well when in port. I had one of the flat screen monitors, the gyro, one depth sounder, and the AIS running. Also running was one of two SeaTel TV antennas.

    All of the items that were swicthed on were damaged and had to repaired or replaced. Also, all three VHFs, which were off, had to be replaced. Most of the other systems seem to be OK, including the MTU controls.

    In the future when I find myself caught out in an active lightning storm, I think that I will switch off my secondary and back up systems ie; one radar, second GPS and screens etc in order to preserve some use of the systems if we get hit again.

    Capt Dave - M/Y KIPANY
  20. CaptEvan

    CaptEvan Senior Member

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    Sirius Weather shows lightning strikes, but in a bad storm, a Raymarine G-Series' whole screen is peppered over with bolt symbols. So putting the weather system in motion, you can rest assured the sky welder is coming. Whether you can get out of it's way is a question of your max planing speed and the girth of your cajones.;)

    On Furuno's latest system, you can see when/where a strike occurred, and it will delete itself after a predetermined time frame. So as it approaches, you can watch the electrical activity increase/decrease.

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