Click for Mulder Click for Perko Click for Ocean Alexander Click for Burger Click for JetForums

Lightning

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

You need to be registered and signed in to view this content.
  1. CaptEvan

    CaptEvan Senior Member

    Joined:
    Aug 15, 2006
    Messages:
    172
    Location:
    Great Lakes
    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

    Joined:
    Jul 11, 2005
    Messages:
    14,432
    Location:
    Fort Lauderdale
    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

    Joined:
    Mar 26, 2007
    Messages:
    51
    Location:
    North Shore Long Island
    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

    Joined:
    Feb 27, 2006
    Messages:
    1,458
    Location:
    Sarasota/Ft. Lauderdale FL
    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

    Joined:
    Mar 16, 2006
    Messages:
    169
    Location:
    Sausalito, CA
    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

    Joined:
    Sep 30, 2005
    Messages:
    7,388
    Location:
    My Office
    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.

    Joined:
    May 29, 2005
    Messages:
    923
    Location:
    Western Canada

    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

    Joined:
    Jul 11, 2005
    Messages:
    14,432
    Location:
    Fort Lauderdale
    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

    Joined:
    Sep 30, 2005
    Messages:
    7,388
    Location:
    My Office
    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

    Joined:
    Jan 26, 2006
    Messages:
    1,949
    Location:
    Palm Beach to Ft Lauderdale
    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

    Joined:
    May 19, 2006
    Messages:
    581
    Location:
    Ft Lauderdale
    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 Administrator

    Joined:
    Dec 22, 2002
    Messages:
    20,353
    Location:
    South Florida
    Tom,

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

    CaptTom Senior Member

    Joined:
    Jan 26, 2006
    Messages:
    1,949
    Location:
    Palm Beach to Ft Lauderdale
    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

    Joined:
    Sep 30, 2005
    Messages:
    7,388
    Location:
    My Office
    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

    Joined:
    Aug 15, 2006
    Messages:
    172
    Location:
    Great Lakes
    Thanks Tom, not only for the well done piece but going through the effort to share it.
  16. CaptTom

    CaptTom Senior Member

    Joined:
    Jan 26, 2006
    Messages:
    1,949
    Location:
    Palm Beach to Ft Lauderdale
    You're welcome. Hope the info helps out.
  17. Steve in SoCal

    Steve in SoCal Member

    Joined:
    May 6, 2007
    Messages:
    75
    Location:
    Land locked in woodland Hills
    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

    Joined:
    Feb 24, 2005
    Messages:
    2,904
    Location:
    Ft. Lauderdale
    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

    Joined:
    Aug 8, 2008
    Messages:
    1
    Location:
    Ft Lauderdale, FL
    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

    Joined:
    Aug 15, 2006
    Messages:
    172
    Location:
    Great Lakes
    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.