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Catalina/Capri 25/250 Sailor's Forums

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Lightning Protection

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frich
Captain

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USA
418 Posts

Initially Posted - 03/23/2002 : 17:52:11

I just had a Datamarine wind indicator repaired that was hit by lightning last summer. I think the bill hurts more than the lightning<img src=icon_smile_big.gif border=0 align=middle>
Question I have is there any precautions or protection that I can install on the mast to avoid similar circumstances. By the way the mast has been stepped.

Thanks
Frank Rich
84 C25

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Douglas
Master Marine Consultant

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1595 Posts

Response Posted - 03/24/2002 : 13:08:54

Lightning protection has been covered many times here on the Catalina site. Try going to search archives and you should find all you need to know.

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Bristle
Admiral

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USA
834 Posts

Response Posted - 03/24/2002 : 16:28:12

There are more opinions on this than there are alternatives... Check out http://www.thomson.ece.ufl.edu/lightning/ for one of the best analyses of the subject.

I've come to my own conclusion on this, but I don't want to be responsible for influencing anyone else. There is no consensus on the "right answer." BTW, some friends lost their radio and instruments due to an apparent hit, and replaced them with more up-to-date equipment with their insurance settlement.

Dave Bristle, 1985 C-25 SR-FK #5032 "Passage" in CT

Edited by - bristle on 03/27/2002 23:44:43

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Ken Cave
Navigator

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USA
148 Posts

Response Posted - 03/26/2002 : 00:24:03

I think it was Bill Holcolm that gave the best info on the subject of lightning. He suggested a pair of heavy duty battery jumpers attached to the back stay and the other end in the water if one is in an area of a lightning storm.

I carried my jumpers for years, but was fortunately enough not to try them out.

Ken Cave

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Ed Montague
Captain

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USA
499 Posts

Response Posted - 03/26/2002 : 00:48:15

OK, Blame it on Ken for restarting this thread of discussion. It never hurts to rehash. The major criticism for putting jumpers or any other sort of grounding device on the boat is that it may actually make the boat a more attractive target for lightning. On the other hand if you don't give the lightning strike a good path to ground then you just might wind up with cooked electronics. And that Frank, is the problem. You are damned if you do and damned if you don't. Now if I were cruising across the big blue Pacific and a lightning storm was approaching, being the only thing sticking up for hundreds of miles, I would want to be grounded. If I were sitting in a marina full of other sailboats, I would prefer that the lightning hit somebody else. That may sound selfish, but it's true. And anybody who has been through a storm will tell you they pray not to be hit. So let the discussion continue.

Ed Montague on 'Yahoo'
1978 #765 SK, Stnd, Dinette ~_/)~

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Tim Pinkham
Deckhand

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USA
4 Posts

Response Posted - 03/26/2002 : 13:12:10

"If I were sitting in a marina full of other sailboats, I would prefer that the lightning hit somebody else. That may sound selfish, but it's true."

I'm not sure where but I have seen "lightning rods" that you may place on the top of your mast to deter lightning. They function in the same fashion as the lightning rods you see on barns throughout the New Hampshire countryside. (and elsewhere I suppose ;)....)

-tap

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Champipple
Master Marine Consultant

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USA
6855 Posts

Response Posted - 03/26/2002 : 13:37:19

This has been a big story for quite some time on the board. Next to the swing keel v wing keel arguements of 19 and ninety-nine I reckon the ground don't ground arguement probably comes in second place.

I will say this... I know of a gentlemen, now an appraiser/adjuster/inspector who was in the industry as a boatyard manager for over 25 years. His policy at the yard was as follows. 1. We do not ground boats.
2. We do not remove any cabling that grounds the boat.
3. We do not recommend to any customer that they ground their boat for lightening strikes.
4. We do not recomment to any customer that they don't ground their boat for lightening strikes.

I too am the same way as Dave B. above, I have my own conclusion but don't want to be responsible for anyone else. Your kind of damned if you do and damned if you don't. The truly best defense is to have a really good manual bilge pump.

on a related note:The boat that I mentioned on the old site that was hit by lightening During Cleveland Race Week last year (all teak boat, one of a kind built by the owner with his father....) has been repaired and is ready to splash this spring....

Duane Wolff
"The Flying Wasp"
C-25, #401 std,sk
Chief Measurer C-25/250 national Org.
<img src="http://im1.shutterfly.com/procserv/47b2dc20b3127cce9cd2f45b211a0000004010" border=0>

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tinob
Master Marine Consultant

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USA
1883 Posts

Response Posted - 03/26/2002 : 15:37:27

ALL,

When in doubt do as dad did. He had lightening rods on every home he had. Worked for Consolidated Edison Electric as an EE. And so that's what I do. I use cabling clamped to the mast plate bolts and to the keel bolts and then as any intelligent atheist knows to do get on both knees and PRAY. Of course this is for an all alone boat in a "sea of plenty", strike oportunities...at the dock I hide in the car or go home. I'm a strike survivor and while it was a long time ago I do remember that it was uncomfortable, not much in the way of hurt but the smell of burnt hair and flesh persists to this day,when ever the subject comes up.
Best bet is, if there is a potential for lightening strikes, go home and get under the bed (next to me)and if that isn't comfort enough do as the atheists do.

Val on the hard DAGNABIT

Val Bisagni

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Ken Cave
Navigator

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USA
148 Posts

Response Posted - 03/26/2002 : 23:28:49

Having lost a new home to a lightning strike a few years ago (blew the electrical panel up and started one big fire!) I go for safety sake!!

Many boats are made with lightning strikes in mind, as my Cape Dory.

That boat has probably five heavy duty wires feeding into the bilge and connected to a huge plate to the "outside"

Last summer in Desolation Sound, we were sitting in a harbor (with a 30 foot Catalina and a taller mast) with a storm all around us for a period of five hours. Really scary-but no-where to go!

Nothing happened to our boats, but we were ready to jump into the Cape Dory if lightning did strike,as the Catalina had no protection!!

Ken Cave

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Arlyn Stewart
Master Marine Consultant

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USA
2980 Posts

Response Posted - 03/27/2002 : 12:14:03

Two summers ago, we were passaging between Michigans lower and upper peninsulas and experienced a strike so close that there was no distinguishable time differance between the flash and sound. It shook the boat. We were buttoned up below under autopilot and did not see how far off or indeed if it actually hit the water. But, thoughts after and a few calculations indicate that for no time differential....it had to be close.

About an hour previous...we had heard rumbling far distant...but this was the only strike in our vacinity. Why in such a big area had it hit so close....but not hit the boat? My best but speculative answer is....because we weren't grounded and therefor presented no closer a path to ground than the water surface nearby.

If we had been grounded, I'm thinking we would have taken this hit...then it would have been a question of the adequacy of the ground... I am afraid there is no comfort to be had... other than not sailing...and that's not an option.

btw... when we set out, the forecast was for possible thunderstorms for the lower 2/3 of the state. This experience did cause some adjustement in discipline. During adverse weather, I now log gps coordinates every 15 minutes. This way if the gps gets knocked out, I know a close fix to call for help if the radio still works...or using the handheld.

Arlyn C-250 W/B #224

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Derek Crawford
Master Marine Consultant

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3321 Posts

Response Posted - 03/27/2002 : 16:58:52

"During adverse weather, I now log gps coordinates every 15 minutes. This way if the gps gets knocked out, I know a close fix to call for help if the radio still works...or using the handheld."

Arlyn - that's an excellent safety tip. I'll remember it next time I'm offshore.
Derek (who goes offshore on "By George" 50' Prout)

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Douglas
Master Marine Consultant

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1595 Posts

Response Posted - 03/27/2002 : 18:06:35

Ken:
Next time we are together ask me about lightning strikes. Ruth and I were hit several years ago in Newport Beach. Ruth had chartered a 72' Hershoff called Bounty as a surprise for me. Well it turned out to be the most shocking experiance I have ever had. What is realy neat though was I had the video camera running and caught it all on tape. Including one big ahhh SH_T.

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Ed Montague
Captain

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USA
499 Posts

Response Posted - 03/27/2002 : 22:45:15

Ken, That hip replacement must be working pretty darned good if you can out jump a lightning strike.<img src=icon_smile_dead.gif border=0 align=middle>

Ed Montague on 'Yahoo'
1978 #765 SK, Stnd, Dinette ~_/)~

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Bristle
Admiral

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USA
834 Posts

Response Posted - 03/27/2002 : 23:43:28

Arlyn and others...

One thing the U. FL site points out is that protecting a boat in fresh water is more difficult than in salt. The reason is simply that salt water conducts, and thereby "accepts" the strike more readily--therefore, it's easier to create a satisfactory path to "ground." Another point is that many more power boats are struck than sailboats--I don't know to what degree they've adjusted that conclusion to the ratio of power boats (more) to sailboats (fewer), but it suggests that the mast is not as much of a target as intuition would lead us to believe. Your experience of the close strike suggests (but doesn't prove) that moist air is as good a conductor as an aluminum mast on top of a plastic boat with a 5+ foot "insulated," dry space between the mast and the water.

The FL site says grounding the rig does NOT attract lightning, but I have to conclude that not grounding it makes it SLIGHTLY less attractive. The problem is when those probabilities (which is all they are) work against you--when the boat just happens to be directly in the best path even if it doesn't really enhance that path. Then, the "insulators" (hull and deck) can get significant holes blown in them, and the things and people inside are at substantial risk--either of being fried or having their boat go down.

Now, what are the probabilities of that? I've heard of many very close strikes that, like yours, just missed sailboats, and even about some cases where electronics got fried by a strike very close to the boat. I can imagine that the chances of that would be increased by grounding--the conductors could pick up some of the charge in the water, especially fresh water which will hold it longer, and distribute it within the boat's rig, including the antenna on the masthead and the outboard in the water. I suspect, but can't prove, that some friends lost their electronics that way--not by a strike to their rig (since there was no sign of such).

Where does this lead? I don't know. My plan is not to be out there to find out, but if I am out there (we sail in salt water), I'll figure that I'm in roughly the same danger as I would be at home, where lightning can strike as well. A friend was talking on the phone and took a serious hit.

Conductors from the mast to the keel may be a good measure, but they should be very stout and very straight--I've read that lightning doesn't like to make turns. Also, the aluminum mast is a MUCH better conductor than the SS stays (due to size as well as material), so the jumper cable idea is somewhat dubious.

I'm sure that Catalina and most other manufacturers don't install any protection because it would create more of a liability for them than just staying away from the issue--as long as there is no solid consensus on what's the best solution. Responding to a suit claiming their grounding system "attracted the strike" could be tougher than responding to one claiming the boat should have been grounded, when NOBODY knows how to do that safely and reliably.

So, lotsa questions, but I ain't got no answers... <img src=icon_smile_dissapprove.gif border=0 align=middle>

Dave Bristle, 1985 C-25 SR-FK #5032 "Passage" in CT

Edited by - bristle on 03/28/2002 15:34:32

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Ken Cave
Navigator

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USA
148 Posts

Response Posted - 03/28/2002 : 01:28:24

A possible solution?

Many years ago, the San Juans (Washington) was experience a major storm system-and we were anchored in blind bay across from the Orcas Hotel, which had at that time a great bar!-------My wife and I spent a wonderful time off our ODay Mariner and at the hotel until the storm passed. Figured if the boat got hit, there was always the ferry to take us back to Anacortes!

Ken Cave

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Bristle
Admiral

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USA
834 Posts

Response Posted - 03/28/2002 : 15:26:24

<BLOCKQUOTE id=quote>quote:<hr height=1 noshade id=quote>
Figured if the boat got hit, there was always the ferry to take us back to Anacortes!
<hr height=1 noshade id=quote></BLOCKQUOTE id=quote>

Ken... That is THE solution! <img src=icon_smile_approve.gif border=0 align=middle>

Dave Bristle, 1985 C-25 SR-FK #5032 "Passage" in CT

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Champipple
Master Marine Consultant

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USA
6855 Posts

Response Posted - 05/16/2002 : 16:52:01

Sorry to resurrect this old thread, but I saw this Don Casey Story regarding lightening and your boat. Again without going into the details I do not hold a position either way (at least as far as this board is concerned), regardless of whether Don Casey wrote this or my mom wrote it. I just thought it would be good information for some of the members to make an informed decision.

DW

http://www.sailnet.com/collections/seamanship/index.cfm?articleid=caseyd0060&tfr=fp

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Sam Nelson
1st Mate

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USA
64 Posts

Response Posted - 05/16/2002 : 22:38:56

<BLOCKQUOTE id=quote>quote:<hr height=1 noshade id=quote>--the conductors could pick up some of the charge in the water, especially fresh water which will hold it longer, and distribute it within the boat's rig, including the antenna on the masthead and the outboard in the water. I suspect, but can't prove, that some friends lost their electronics that way--not by a strike to their rig (since there was no sign of such).

<hr height=1 noshade id=quote></BLOCKQUOTE id=quote>
This is valid, but I think you are talking about a static charge. The charge would have to suddenly dissapate to produce sufficient current to damage anything. I believe a sudden change in the charge surrounding the boat would be required for such instant discharge.... and that probably would be an adequate description of a strike?

Sam Nelson
C25 "Stratos" #3811

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Sam Nelson
1st Mate

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USA
64 Posts

Response Posted - 05/16/2002 : 22:47:02

In my business, which is two-way radio, we contend with lightning protection ongoing. There are the same two schools of thought, but it's a fact that the Corps of Engineers spent boku bucks on grounding radio system sites and statistically proved that both the frequency of strikes was reduced, and the cost of repairs decreased dramatically

However, far be it from me to advise you install or remove grounding! Besides, those sites weren't moving targets.

One interesting thing... we sometimes install devices atop towers that are intended to dissipate charges instead of provide a path to ground. The thinking is that if you are less attractive (less of a positive charge vs the negative charge in the atmosphere) then you are invisible to Mighty Thor.

Sam Nelson
C25 "Stratos" #3811

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