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Old 29-10-2017, 15:35   #1
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Lightning protection for you boat

I am wondering what methods members are using to protect their craft from possible lightning strike.
Whilst the chance of being struck are slim it is a possibility.
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Old 29-10-2017, 15:38   #2
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Re: Lightning protection for you boat

That's an excellent question if you are a multihull owner since those boats get struck twice as much as monohulls

http://www.boatus.com/seaworthy/maga...ning-facts.asp
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Old 29-10-2017, 16:21   #3
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Re: Lightning protection for you boat

Quote:
Originally Posted by Stilllooking View Post
I am wondering what methods members are using to protect their craft from possible lightning strike.
Whilst the chance of being struck are slim it is a possibility.
There are some snake oil products that claim to reduce the probability of a lightning strike. But as far as I know there is no proven method to do that. The reality is there is nothing you can do to prevent a lightning strike. It's just a matter of being in the wrong place at the wrong time. (Somebody will chime in here and say I am wrong.)

But there are things you can do to reduce the probability of serious damage. You can look at how the mast is electrically connected to a submerged metal part such as the keel. A short but large diameter wire can help with that. The shroud chain plates can also be bonded to the keel with short large diameter wires.

There are other things you can do such as installing transient protection on radio RF connectors and DC power connections. When away from the boat disconnect every wire from sensitive electronics such as radios, multi-function displays and the like. But not very many cruisers are willing to go to that much trouble.

No matter what you do there is no possible way to guarantee no damage from a lightning strike. Lightning can damage electronics no matter what you do and even the hull can be damaged by creating holes at the water line.
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Old 29-10-2017, 16:29   #4
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Re: Lightning protection for you boat

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Originally Posted by transmitterdan View Post
There are some snake oil products that claim to reduce the probability of a lightning strike. But as far as I know there is no proven method to do that. The reality is there is nothing you can do to prevent a lightning strike. It's just a matter of being in the wrong place at the wrong time. (Somebody will chime in here and say I am wrong.)

But there are things you can do to reduce the probability of serious damage. You can look at how the mast is electrically connected to a submerged metal part such as the keel. A short but large diameter wire can help with that. The shroud chain plates can also be bonded to the keel with short large diameter wires.

There are other things you can do such as installing transient protection on radio RF connectors and DC power connections. When away from the boat disconnect every wire from sensitive electronics such as radios, multi-function displays and the like. But not very many cruisers are willing to go to that much trouble.

No matter what you do there is no possible way to guarantee no damage from a lightning strike. Lightning can damage electronics no matter what you do and even the hull can be damaged by creating holes at the water line.
The above is totally correct but there is also data that says lightning protection systems can actually increase the probability of being struck due to the path to ground.......but with the protection your damage will be less.

I got sort of interested in this after my Spring Sailing Vacation on the Chesapeake Bay. I sailed 30 miles North and when I anchored it looked like the attached pictures. 30-45 minutes later while arguing on CF about my anchoring technique this squall rolled in.





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Old 29-10-2017, 16:34   #5
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Re: Lightning protection for you boat

There's absolutely nothing you can do other than stay out of areas where there are electrical storms. I've been hit twice. Bonded, not bonded, bottle washer on the top of the mast. Nothing works.
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Old 29-10-2017, 16:51   #6
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Re: Lightning protection for you boat

I suggest you have a look at Marine Lightning Protection Inc.
The man behind this company is regarded by many as the world leader on lightning protection systems. The site has a lot of interesting and informative information on the topic.
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Old 29-10-2017, 20:19   #7
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Re: Lightning protection for you boat

I second Savagebee's suggestion of contacting Dr. Ewen Thomson at Marinelightning.com

He has designed a system for our new cat that mitigates the personal risk and the equipment damage. Very clever stuff by someone who knows what they are talking about.

I have worked on the bridgedeck electrode to take the bulk of the earthing directly from mast to sea surface using the right sort of mast compression post. If your mast is on the forward bulkhead, you'll need a way to deploy/retrieve the electrode directly under the mast.



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Old 29-10-2017, 20:34   #8
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Re: Lightning protection for you boat

These guys seem to offer an unbiased perspective, and advice.

Protecting your boat from lightning.
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Old 29-10-2017, 20:36   #9
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Re: Lightning protection for you boat

There are things you can protect, and things you can not.

First, nothing can prevent a lightening strike.

If you get struck, you CAN, with a properly designed system of grounding, prevent the lightening from blowing a hole in your boat and sinking it. I have seen this happen in San Francisco Bay, not exactly a hit spot for lightening! Some people just would have no luck at all if not for bad luck!

If you get struck by lightening, nothing will protect your electrical and electronic systems. They are almost certainly total toast. A current flux of millions of amps per second generates a powerful, and rapidly changing, magnetic field which induces large voltages and currents in every conductor around. Including on all the circuit boards in every piece of electronic gear--enough to fry all those IC chips. No matter if they are turned on or not, no matter if they are plugged in or not.

When somebody tells you that paper charts are obsolete, you might want to remind them that every boat is just one lightening strike away from the 19th century.
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Old 29-10-2017, 20:37   #10
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Re: Lightning protection for you boat

I would never suggest the cost of a carbon mast and dyneema rigging to mitigate a lightning strike, but does anyone know if they are less of a target than aluminum masts and steel if you already had these installed?
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Old 29-10-2017, 21:54   #11
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Re: Lightning protection for you boat

Carbon fiber mast may blow apart. They are strictly for racers. Stay metal for mast and stays. The general theory is that the stays, lifelines, grounding well placed throughout the hull constitute a crude Faraday cage. We have four inch wide copper straps fore and aft, port to starboard. All are connected to large ground planes and to the rigging.

We have a fuzzy on top of the main mast. It has survived three strikes, having protected itself well but not apparently anything else.

There are different types of strikes. Many are nearby and you may only be touched by a leader or indived charges. These are still damaging. A direct hit will light up everything. Our last hit was one of these, observed by a neighboring boat. Our mast was hit, jumped to two other boats. Our cabin glowed for considerable time. We lost: AIS, VHS, stereo, 18 glass buss fuses, main 60 amp shore breaker, all wires in the bow fused, three LED deck lights, all nav lights, windex vaporized, two VHS antennas gone, all diodes in one alternator blown, several LED cabin lights, Xantrex working but unreliable, Simrad autopilot dodgy.

NOT lost was the Simrad NSE, backbone, radar and graphing sonar and electronic barometer. These were protected as noted below. I reinstalled all new electronics this way as well.

Observations following our three hits are that electronic items that survived were all installed with a main breaker on the + "off". They also had a two pole manual mechanical air gap switch also "off". The two pole switch is as close to the device as possible, inches, and interrupts both plus and negative leads. Note that all modern stuff has a software power switch and continuous connection to the boat common ground. This means off is not disconnected from boat wiring. I also disconnect all antenna cables. My mast wiring passes through an industrial monster 64 pin connector. I use this to disconnect the mast entirely.

When we are away or if a storm approaches my electronics is nearly as separate from the boar as if it was in a box on the table.

Prior to this extra disconnect, all devices were destroyed every time. As the others have stated, there is nothing you can do to prevent a strike, especially in the open. I am convinced that what we do on ROXY reduces probability of damage.
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Old 30-10-2017, 08:47   #12
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Re: Lightning protection for you boat

There is some new technology distributed by EMP Solutions.

First boat in North America used on a Catamaran in Florida for over 4 years successfully after being struck by lighting two years consecutively before installing the device.

Halo System | Paradise Adventures

I called and spoke to Donnie personally about the system as I was researching what system to install myself. I've done extensive investigation before I purchased the device myself and am currently in the process of installing the device on our 50' sailboat. This is not a Franklin lightning rod.

The devices have been in use for over 10 years outside the US with over 5000 devices installed on everything from telecom towers, buildings, research vessels, airport towers, deep sea drilling rigs etc. with an impressive safety record.

I purchased the device myself and am currently in the process of installing the device. The device is fairly heavy and weighs about 16lbs. That's pretty heavy to go on the top of some masts. I have been talking with EMP Solutions for about a year about producing a smaller device better suited for recreational sailboats and they are about to release a smaller device that weighs around 6lbs and also costs much less but maintains a 50 meter radius of coverage as opposed to the heavier device's 100 meter coverage.



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Old 30-10-2017, 09:02   #13
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Re: Lightning protection for you boat

Quote:
Originally Posted by Thalas View Post
I would never suggest the cost of a carbon mast and dyneema rigging to mitigate a lightning strike, but does anyone know if they are less of a target than aluminum masts and steel if you already had these installed?
friends of mine were in cartegena for a lightning storm and were struck. their mast was a beautiful pricey rotating carbon fiber mast that after they left
cartagena disintigrated when under sail off nicaragua. i saw them in zihuatenejo with no mast on their trimaran.
there was a beneteau 50 0r 55 in slidel hit twice by lightning while sitting i n same place for 4-5 yrs.. the strikes were 4 yrs apart. first time damaged boat nicely the second time boat was sunk, totally destroyed and the cables to his home were also affected. he was well protected from lightning as a nasa scientist. oopsy. before second strike he re-protected even better .
i think i will continue to abstain from protection scams. they donot work.
friends of mine in la cruz, mx, were hit via wifi antenna with a burn spot on their electrical panel at the breaker used for hte antenna. oopsy. they were at anchor.
watched a well protected catamaran in la cruz also get hit by lightning..something about that greeen glow was fascinating, boat was damaged. was in a marina.
these were all allegedly lightning protected boats.
lightinig is random. protection makes no difference. seems to me protection is a magnet for lightning to hit your boat. attractor as it were. no thankyou.
i have yet to buy a protection for my boat. if there is a close storm i turn all electrics and attractors off and watch the show. i have sailed since age 7 without protection from lightning and without a strike to my boat. i am actively knocking wood. yes i have sailed thru many lightning storms and sat thru as many or more than i have sailed thru.
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Old 30-10-2017, 09:03   #14
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Re: Lightning protection for you boat

There is nothing that you can do for lightening strikes
Sailing in the Far East where lightening storms are a regular every day thing, I have seen boats anchored amounts 10 others get struck for no reason , other than they were there.
We have a very high rate of strikes up here, An nothing seems to work, talked to a yachtie who had a special anti lightening fixture at the top of his mast an it took the full hit.
The voltage is such that even disconnecting gear does not save it due to the electrical charge in the air.
I was some 500 meters away from a yacht struck an I suffered some electrical damage.


I have heard that eating chocolate on the cabin sole does help, but I tend to just let nature take its course.
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Old 30-10-2017, 09:58   #15
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Re: Lightning protection for you boat

Quote:
Originally Posted by Stilllooking View Post
I am wondering what methods members are using to protect their craft from possible lightning strike.
Whilst the chance of being struck are slim it is a possibility.
I have a trawler. I try to stay around sailboats when there's a chance of lightning!
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