No lightning protection - should I be concerned?

[reverie]

Hello all,

I purchased a 2004 SO35 in March and am loving the boat.

Looking out the office window, it's a bit of a stormy day. The weather gets me thinking, so I send a note off to my Jeanneau dealer (who has been great), and ask him whether the mast is grounded to the keel in the event of a lightning strike. He responds promptly (as usual) and let's me know that in fact the mast is not at all grounded to the keel.

Now I know what you're thinking: Why didn't you ask this before you bought the boat? Good question. I frankly assumed that this would be standard stuff for a boat built this decade that's being sailed in stormy waters around the world. But apparently not.

Should I be concerned? Other than obviously not sailing in T'storms, are there any modifications I can make or precautions I can take? What are the consequences of a strike? I assume the electronics will be toast, but could there be other trouble?

Many thanks in advance for your insights!

John
Toronto

[so40gtb]

John,

You should be concerned and should investigate this promptly, as I will do to my SO34.2 tomorrow evening. Don't rely on the dealer, pull the floorboards and the head liner and inspect the reality yourself, to see if there is a conductive path from keel bolt to mast step to mast. However, the effectiveness of keel grounding is questionable if the appropriate epoxy layers are intact on the keel and thereby insulating it. A choice between chronic rust or poor lightning protection is not good.

With a bit of searching online, you can find a good bit of info on marine grounding and lightning protection. There's a professor in Florida that has patented a number of techniques and sells components for lightning protection, but he also requires users to license his patents, some of which cover techniques that have been in general use ashore for years and arguably not eligible for patent protection.

We are particularly vulnerable on the Great Lakes due to the modest conductivity of fresh water and the frequency of summer thunderstorms. If you are surrounded by taller masts in your marina, your probability of damage is lower - as long as you're in port.

One of the general principles of effective lightning protection and grounding is to ensure that all "grounds" are at the same potential under fault conditions. That means a good, high-quality copper conductors linking all significant "ground" and "common" tie points on the boat, i.e., at the power distribution panel, the mast, engine, etc. The conductors that do this should be at least #8AWG and probably larger. Some boats have #12 or #10 ground wiring, which isn't anywhere near sufficient under fault conditions. Now that I've said this, I'll probably find this missing on my own boat! For a simple and easy-to-read discussion of the topic, refer to Don Casey's Sailboat Maintenance Manual starting on page 569.

-- Karl

-- Karl

[reverie]

Many thanks, Karl.

I was poking around the bilge last weekend, and did not notice any cables running to the keel bolts, which also drove me to probe this further. But I will certainly scrutinize much more closely when I get back aboard in a week's time.

I'm still wondering why suitable grounding isn't standard fare on a 2004 Jeanneau?

I will indeed do more research on this. Now I'm a bit concerned...

Thanks for the reference to Don Casey's book.

John

[Don Reaves]

John,

Is your boat Reverie, formerly at Navy Point in Sackets Harbor? My friend sold his boat this spring to a Canadian buyer, and I was wondering if it is now yours.

There have been many things written about grounding masts. The main concept is that a grounded mast will (hopefully) conduct the energy of a lightning strike safely to the water. But some studies have concluded that grounding the mast actually makes it more likely to be hit. So is it better to be grounded? The one thing that's certain is that if you are grounded, you should be grounded properly.

Don

[davideso37]

John,
I was also concerned and did some searching on the internet and found the advice that Karl has suggested. So far I have left my SO37 in it native state as I found the same conflicting advice that Don reports. I'm interested in any strong opinion one way or the other.

Regards
David

[reverie]

Hello Don,

Yes, indeed the same boat. My brother and sister-in-law just finished moving the boat through the Trent Severn waterway to Collingwood, Ontario, which is at the south end of Georgian Bay where we have a summer place. They had a great trip. I joined them on the Sackets Harbor to Kingston run - fabulous! Mike obviously took great care of the boat - it's in fabulous shape.

I also did a bunch more internet searches last night on lightening protection (SailNet has some good threads) and am really no further ahead. One school of though suggests that grounding the mast to a keel that is insulated from the water by epoxy coat and paint, and then placed in freshwater, which is a much poorer conductor of electricity than salt water is not particularly effective. And I also certainly understand the argument that a grounded mast is more likely to be struck.

I think I'm going to follow Karl's suggestion and go read Don Casey's book for his thoughts.

John

[tegolin]

There are opposing schools of thought on this, If you are going to lightning protect your boat it should be done properly. What I do, if tis any help is keep a long length of 00 grade battery cable with a pair of alligator clips handy, and in the event of a thunderstorm attacht it to the shrouds and throw the other end in the water.

[Zanshin]

tegolin - I like that idea. I'd rather lose a shroud and some 00 cable than the whole mast, compression post and some keel bolts!

[MartyB]

You folks have it all wrong. Just put a "1 iron" at the top your mast, and all will be good! No one can hit a "1 iron" or so I have been told! ;D ;D ;D ;D ;D

Marty

[Zanshin]

Marty - it was Lee Trevino who said "not even God can hit a 1-iron" You might have something going there, though....

[MartyB]

Zan,

I knew it was a "even God can not hit a 1 iron" But I was trying to keep the potential religious tone out of it.

I was also hoping someone would get the "joke" part too. Then again........hmmmmmmm.........

Since you sail where there is ground contact lightning, maybe you can try it out eh! Up here in the Puget Sound region of N America, we get "cloud to cloud lightning" a few ground hits, but not too many. I may be on to something here..............

[so40gtb]

One irons notwithstanding, here are some interesting data points on my SO34.2, based on resistance measurements with a Fluke 187 DMM:

a) The keel is not electrically connected to the mast or shrouds.

b) The mast and shrouds are electrically connected to the mast step.

c) The mast/shrouds are connected to the electrical system ground ONLY BY THE OUTER CONDUCTOR OF THE VHF RADIO CABLE! (lightning hit = toasted VHF!)

d) The toe rail (and lifeline stanchions) are not electrically connected to the mast or shrouds.

I have yet to check continuity between the electrical system common and the keel.

Not much electrical bonding between significant metal components on this boat.

-- Karl

[jhiller]

I have a new 50 DS arriving in about 3 weeks. I've hired Professor Ewen Thomson PhD the founder of Marine Lightning Protection in to design and install a lightning protection system for the boat. I find it astonishing that Jeanneau would not at least offer it as an option
www.marinelightning.com/

[reverie]

The professor has a great website.

Could you share the approximate cost of the system?

John

[mtmilam]

I have been STRUCK, on a Nonsuch 33 and had very Little Damage......I had the mast grounded to the keel and a lightening dissapator on the mast (hairbrush type) A guy at the Marina SAW the hit.....He said Sparks flew off the dissapator like a 4th of july fire works. Only lost the VHF and a computer board for the Air. cond. control and blew out some LED indicator lights on the 12 volt panel ......all electronics still worked...Amazing.....

Now....for our 42 DS.....I had them ground the mast to the keel (4 ga. cable), when they stepped the mast and installed a disspator on the top of the mast. I figured it was better than nothing and It DID WORK on the Nonsuch.

Just a Real life experience....FYI

Mark M. 2007 J 42 DS "White Caps" Lafafyette, LA.

[saxofon]

Hi guys,

Well, in my opinion it is very wrong to try to lead the thunder current *inside* your bout. We are talking massive amounts of energy here!
Best way is to simply to drive to your local petrol station, buy two sets of those car battery connector cables that you can hook up two cars with in case of one of them has drained the battery. Clamp one to the forestay and let it hang down in the water, do the same on backstay and "sidestays" (whatever that is in english :-) )
This will lead the currents to ground safely away from any electronics.
Simple and doesn't cost a fortune :-)

[so40gtb]

Untimely post, sorry for the delay. I did some further checks and found out that the electrical ground point behind the distribution panel is not connected to the keel or mast on my SO34.2. So here's the summary:

Engine and prop shaft are electrically bonded to the common (ground) point of the electrical system.

Keel lives in its own world, electrically. Ditto for the mast and shrouds. Ditto for the toerail.

As an electrical engineer who deals with lightning-prone television transmitter facilities in my day job, I have a very hard time accepting this scheme as advantageous. For salt water boats, this lack of bonding is just plain improper. There might be an argument for the isolation in fresh water, perhaps on the basis of electrolysis, but I'm skeptical.

However, I have the lowest mast on my dock and avoid going out in thunderstorms, so what's to worry?

-- Karl

[rxc]

My SO43DS is not grounded, either, and during our Transat passage we passed thru LOTS of cells with LOTS of lightning, and were never hit. We did think about it a bit, and if I could buy something that I was sure would protect the boat, I would, but I don't think that is possible, given the unpredictability of lightning. My old boat was a Catalina 34, and Catalina does not provide any lightning protection for any of its boats. I believe that none of the high-volume producers(Catalina, Beneteau, Hunter) do, either. The user's manual explains that lighting protection is a controversial subject, and it includes the ABYC recommended plans for providing protection (tie the mast, all the shrounds, backstay and forestay, and all on-deck metal such as lifeline stanchions to the keel with 4ga wire).

I am also an engineer, but not electrical, and I think that lightning protection is a black art, with few guarantees. Read all you can, and if you have the money and time and the access to run the wires (remember that they should not have any sharp angles, anywhere in the path to ground!), then go for it.

I think the real reason the manufacturers don't provide this protection is the lawyers - if they do and the boat is hit, they get sued. Better for them to provide a clear disclaimer up front and let the buyer provide the level of protection they deem appropriate.

[jhiller]

I think it is inexcusable for Jeanneau not to provide or make available some lightning protection on their boats. Every quality yacht builder on the planet from Nautor to Oyster andHinckley and everyone else I can think of recognizes the added safety provided by a system that takes a charge from the boat to the water. I understand that because of the painted iron keel it is more expensive but a good grounding plate made of copper plate and connected to the shrouds, stays and spar would increase the protection of the occupants and maybe the boat.
I know that there is les than full agreement about what is a perfect system but aircraft designers have been using them for years and aircraft are hit daily with no damage.

We should demand that the company design and offer such a system

[critenour]

we sail a jeanneau ds40 and have been hit twice - the first was a side stike in chub cay bahamas just after we dropped the hook - we guess the lightening hit the radio antenna (pieces all over the deck) ran down the jib stay and out the anchor - but of course when you get that much electricity on the boat it ran wild and $20+k later we think we got her fixed - the second was an idoit who decided he could run the icw in a driving ran thunder storm while we were hiding mid current under some trees - the minute he cleared the trees he got a direct hit and we lost our radio (blew the connection apart but once together it was ok) and the wind thingy at the top (had to replace it) -
we have a thing up there that is suppose to help prevent that sort of stuff and some say they work and if we did not have it on the first strike we would have gotten a direct hit instead of a side strike
we currently are at anchor in cape may and the boat beside us decided to stay at anchor when a major blow came through the other day - winds in excess of 50k - we went to a marina to hide out- he said he saw lightening hit the water about 200 feet from his boat and lost a few insturments - so when it comes it comes
chuck patty and svsoulmates
full time cruisers
on the hook cape may nj

[athinoula67]

I was told but never had to try it thanks god!!
For lightning protection the best you can do if you do not have protection is to put around mast the chain of the anchor and put your anchor in the water from the side of the boat but deep enough so as to avoid any damage on the boat.
This is done from a friend who travel from America to Europe with a sailing yacht

[mtmilam]

Like Critenour, We Were Hit in a Nonsuch...I think the Brush thingys (dissapators) on the top of the Mast Helps. I've heard this before and the same story...It wasn't near as bad as it could have been. I have one on the Jean 42 DS and had one on the Nonsuch 33, that got hit.

I DID Run a #4 ga. from Mast to Keel bolt. Hanging stuff off the side WON"T work....The Lightning will NOT make a turn and follow the chain or Battery cables to the side of the boat. IT wants to go straight and its powerful....It will Go down the Mast Mostly and when It gets to the cabin Top...If IT AIN'T Got no where to go, It's going WHere it wants......THAt's why I put the #4 ga wire from mast to keel bolt...at least you get it Almost to ground, rather than bouncing all over the boat.

Just from personal experience...take what you need, leave the rest.

[jhiller]

Don't think grounding to a keel bolt in a Jeanneau will work at all ! The keel is completely encapsulated in epoxy and has no contact with the water. It is one more reason that iron keels are poor choices.
The spar, chainplates and fore and back stay need to be attached to a sizeable copper ground that has contact if you want to do more than hope for the best. It is incredible that Jeanneau does nothing to reduce this risk a standard. They will when ABYC adopts a grounding standard or the lawyers will have a heyday.

Every major manufacturer from Swan to Oyster and even lessor quality builders like Catalina and Hunter ground their sailboats.

[sailbleu]

Would it be wise to switch off all of the instruments (and battery) during a lightning storm ? Would that save the instuments by all means ?
Infact , what does Don Casey's book tell us on that issue ?
Thanks

[jhiller]

Switching them off makes no difference. Disconnecting may help but the bigger problem is that the blast of 2 million volts will have no path to ground provided for it so it will find its own. That may mean blowing a hole through your boat.