Lightening strike

[goboatingnow]

My MD2030 requires two relays to start Both are fine. The ceramic encapsulated excitation resistor got hot due to the rotor coil failure but it survived as I quickly disconnected it. It does point out some key places to add in line fuses and I’m doing that ( rotor excite , AP clutch etc )
I’m designing some big sss TVS units to fit to the dc bus

[goboatingnow]

It’s been most interesting examining the various failed systems.

It has pointed out some issues. I had upgraded every interior light to Chinese led fixtures all but one survived ( I put a few through my scope etc ) , the one that failed blew a dc dc convertor which allowed about 250 mA to flow through the fitting. Because the breaker was sized for incandescent fixtures , this type of current was maintained and the led light got hot and the plastic melted ( leaving a black spot of the mahogany behind the fittings.

Hence I now need to significantly reduce the circuit breaker on that dc feed or perhaps fit small inline fuses to the light fittings to ensure that doesn’t repeat.

The failure mode of the Victron mppt again was the switching mosfets in the buck convertor , these in effect created a dead short across the battery bus , but there is an inline fuse near the battery protecting this wire and it opened.

It brings home the absolute need to ensure every battery feed is fused , in my examination of the wiring loom , I have located two feeds with small wires and no fuses at the battery. Bad marine electrician !

[capn jlp]

Originally Posted by goboatingnow

Do you think it needs an immediate haulout , I’ve a three hour motor trip back to my home base anyway , I won’t raise sail until I have the mast inspected

Insurance will cover survey etc. The instruments are old ( st 60) so I will get 70 of the new replacement value.

We had a direct hit years ago on a short weekend cruise. It was overnight at a marina dock in the midst of a violent thunderstorm, and we understand "vaporized" VHF antennas and broken glass on the deck from blown-out spreader lights.

Several good suggestions in this thread. Perhaps the most meaningful is to take it slow and easy. Virtually everything with a wire to it was fried in our event so they were easy to identify. Others took their own time to manifest. If it's suspicious, put it on the list. Our insurance didn't quibble one bit, and they ended up paying for replacement of essentially everything electric/electronic on the boat.

They sent a surveyor the next morning. He just shook his head and pretty much verified in his report that we were lucky the boat didn't sink. Haulout (he recommended) was about an hour away, and a tow was authorized. Our engine seemed to run fine (alternator and controller didn't), but we preferred to make it to the yard under our own power. Insurance authorized SeaTow to follow us there in case something unexpected were to happen. You might want to explore that avenue. Incidentally, the yard found no hull damage.

Morgan Out Island 41

[goboatingnow]

Originally Posted by capn jlp

We had a direct hit years ago on a short weekend cruise. It was overnight at a marina dock in the midst of a violent thunderstorm, and we understand "vaporized" VHF antennas and broken glass on the deck from blown-out spreader lights.

Several good suggestions in this thread. Perhaps the most meaningful is to take it slow and easy. Virtually everything with a wire to it was fried in our event so they were easy to identify. Others took their own time to manifest. If it's suspicious, put it on the list. Our insurance didn't quibble one bit, and they ended up paying for replacement of essentially everything electric/electronic on the boat.

They sent a surveyor the next morning. He just shook his head and pretty much verified in his report that we were lucky the boat didn't sink. Haulout (he recommended) was about an hour away, and a tow was authorized. Our engine seemed to run fine (alternator and controller didn't), but we preferred to make it to the yard under our own power. Insurance authorized SeaTow to follow us there in case something unexpected were to happen. You might want to explore that avenue. Incidentally, the yard found no hull damage.

Morgan Out Island 41

As I have extensively upgraded the electrics on this boat and I have good diagnostics gear on board , I am able to examine the wiring looms and most devices.

Most simple electrical devices that remained connected to the batteries shown no sign of damage ( this is now 7 days after the event ) resistance and insulation tests on a cross section of the looms show no degradation , it’s been an interesting experience. I just range tested my vhf today and it seems fine but I’ve let to verify the nmea2000 interface , as every other nmea 2000 device has failed. ( and I see no easy way to mitigate this issue in future )

My compass remains accurate

In any event all significant electronics , leaving aside some cheap Chinese stuff ( which is all still working ) will be replaced , the alternator will be replaced, I have even replaced key items that seemed to survive. Certainly with the exception of my own electronics , anything with a microprocessor will be replaced.


We motored home for 3 hours the day after , my bilges remain bone dry as always and my engine is running like a sowing machine. Nothing that remains is mission critical. As I said the evidence from the failures I examined is the dc bus took a pulse of approx 100 volts most likely coupled RF energy.

It’s been interesting to say the least , not just in what happened but also a few weaknesses in the fusing arrangements etc.

The surveyors here about have little or no direct experience of lightening strikes ( which surprises me ) none of them offered much practical advice .

Her insurance remains in place and to date despite a good examination , the damage seems ( touch wood ) “ limited “ to things with electronics in them or directly controlled by such electronics. In fact devices that were turned off , suffered more damage then devices that were turned on

[BobbyHR]

Regarding mast grounding, USCG specs a 12" x 12" x 3/16 grounding plate with #4 cable.
No multihull sailors want a grounding plate nor a hole in their boat.
In lieu of that, and what I do, is have a 30' coil of 1/2" aluminum lightning conductor cable aboard, such that it can be wound around the aluminum mast then the end tossed into the sea. I unwove the cable a few feet so the end in the sea is like a broom. On carbon masts use a linger length of the same continuous cable and haul it all the way up, attaching the halyard so a foot or so of cable is above the attaching point and proud of the top of the mast. The cable is cheap btw, about 25 cents a foot, and mine doesn't corrode.

There literally are millions of volts involved here, a single polarity, and it is hell bent on getting away from itself. Every conductor will polarize in kind, that is, the opposite charge, yes millions of volts, will result at the closest surface of any conductor like the engine, why strikes are explosive with crazy heat. Yes you are a conductor too.
When I speak on the subject I quote Franklin, as every other source is censored. Our speech includes it though, "Our President is a lightning rod for criticism".
I actually wrote a book on the subject, but Bezos would cancel me after getting a phone call from his insurance man, so what's the point?.
Let me repeat, if you have a well grounded lightning rod above your mast, you will not be struck by lightning. I've spoken with Megger, they can make such a piece of test equipment as they do for carbon windmills, but there is no demand because it's basically squashed by the insurance industry.

[garyfrankovich]

Call your insurance company and file a claim. They will send a surveyor on their nickle.

[smj]

Haul the boat and have a surveyor look at it.

[Capn Rick]

First call your insurance company. They should send a surveyor out to conduct an insurance damage claim. You are required to take steps to protect the boat, but unless the boat is in danger of sinking or other subsequent damage from the strikes, don't repair or dismantle anything until after the inspection. The surveyor will want to have the boat hauled and inspected for lightning exit damage. Damage from direct lightning strikes can be catastrophic and some damage may not show up for months. Insurance companies are aware of this and will reopen a claim if additional damage is found. Electrical, electronics, anything digital, LED lighting, engine modules, sending units, rigging and hull can all be damaged by lightning.

[boatpoker]

Originally Posted by BobbyHR

Regarding mast grounding, USCG specs a 12" x 12" x 3/16 grounding plate with #4 cable.

Where do they spec this ?

[goboatingnow]

Originally Posted by Capn Rick

First call your insurance company. They should send a surveyor out to conduct an insurance damage claim. You are required to take steps to protect the boat, but unless the boat is in danger of sinking or other subsequent damage from the strikes, don't repair or dismantle anything until after the inspection. The surveyor will want to have the boat hauled and inspected for lightning exit damage. Damage from direct lightning strikes can be catastrophic and some damage may not show up for months. Insurance companies are aware of this and will reopen a claim if additional damage is found. Electrical, electronics, anything digital, LED lighting, engine modules, sending units, rigging and hull can all be damaged by lightning.

The insurance company did not want the hull lifted or a surveyor appointed and anyway the two surveyors locally had little experience of lightening damage . The hull was dived and the through hulls checked inside and out. The insurers were happy with his report.

I’m an electronics engineer and I know what I’m looking at when it’s comes to electronics damage. I also have test gear and insulation testers on board. Millions of volts did not couple into the dc bus , because the failure modes of various components are entirely different in that case.

At this stage other then the cheap led fittings which are all still working , virtually everything electronic item is being replaced. No discernible damage to the rigging has occurred , so short of simply replacing bits for no reason , it’s hard to justify a rigging replacement


All the dead electronics are off the boat and being reported on by the dealers repair engineer. some items were agreed could be repaired in order to get the boat underway and this has been done as she had to moved from where the strike occurred.

I will go sailing locally for two weeks and leave the claim open during that period , if any further damage is detected I can amend the claim , the engine is ( seemingly ) fine and has no electronic control systems at all . Oil and temp pressure senders have been checked. The log and depth transducers are working and the local electronics guy in the dealers here , said in his experience these rarely fail in a lightening strike

While I accept that overstressed electronics can work and then fail ( this is especially true of capacitors ) no materially important or costly piece of electronics remains

I need to use the boat to see if anything else is problematic. I haul out anyway for 6 weeks in three weeks time and the claim will not be processed until after that. I have not proceeded with a formal rigging inspection as the riggers don’t realiy have relevant experience , I climbed the mast , toggles and clevis pins seem in good shape and no discernible issues could be detected. My insurers will not change the rigging unless provided with a damage reason.

Every motor on board has been tested for insulation failure and so far all motors pass the test.


Almost all the failures were centred around the seatalk and seatalk ng bus , the battery clearly dampened the spike on that bus because little damage occurred to these devices most damage occurred to devices that were switched off. Looking at the mppt controller that did fail showed the mosfet failure was typical of a high voltage spike in excess of the Max Vds but not “ millions of volts “

My main issue with surveyors is the two local ones are not well versed in such damage.

Hence right now I’m not sure what more I can do.

So at this stage unless I engage expensive surveyors myself , I’m not sure what else can be done.

[Frankly]

Because you are knowledgeable in the area of how them electrons behave your experience has some "extra value".

I want to be sure I understand as best as possible what happened and the conditions/ configuration.

1- The mast was well connected/grounded to the keel.

2 You took two direct hits separated by a few minutes.

Remnants of VHF whip and RM wind sensor on deck or obviously hit.

If those are accurate might not be too big a leap to assume the first hit got the VHF and with the whip now gone next in line was the wind transducer (and the wind couples into a display with Seatalk connections).

There is a lot of BS that passes for information on this subject on the WWW.
Your case is somewhat unique.

Glad you are insured, and not hurt.


Frankly

[smj]

Our latest boat purchase was a vessel struck by lightning. Only electronics lost were vhf and stereo, other than that no other electronic’s were damaged. The insurance company paid to haul the boat and have thermal imaging done of the hull by a specialist flown in from New Orleans and there was damage that couldn’t be seen by the eye. I would no doubt question your insurance company.

[goboatingnow]

Originally Posted by Frankly

Because you are knowledgeable in the area of how them electrons behave your experience has some "extra value".

I want to be sure I understand as best as possible what happened and the conditions/ configuration.

1- The mast was well connected/grounded to the keel.

2 You took two direct hits separated by a few minutes.

Remnants of VHF whip and RM wind sensor on deck or obviously hit.

If those are accurate might not be too big a leap to assume the first hit got the VHF and with the whip now gone next in line was the wind transducer (and the wind couples into a display with Seatalk connections).

There is a lot of BS that passes for information on this subject on the WWW.
Your case is somewhat unique.

Glad you are insured, and not hurt.


Frankly

Your summary is correct except ,

Since I haven’t found any remnants I can only assume any bit of the mastop wind and or vhf , fell into the water , I did not see the strike that hit the wind or antenna . I climbed the mast and other then two bolts happily sitting holding nothing , ( the wind instruments) and a vhf bracket without an antenna there is no evidence of any damage to the physical rigging at all. Nothing else is out of place

The AIS splitter seemed to take the damage as the vhf radio is working fine , as far as can be ascertained , I rigged a temporary antenna to test it

Yes I can only assume and this is consistent with the damage I see , is that the primary vector was the can bus , the dc bus clearly did get coupled in energy as one of the coils in the alternator rotor opened and the mppt controllers output mosfets failed.

[goboatingnow]

Originally Posted by smj

Our latest boat purchase was a vessel struck by lightning. Only electronics lost were vhf and stereo, other than that no other electronic’s were damaged. The insurance company paid to haul the boat and have thermal imaging done of the hull by a specialist flown in from New Orleans and there was damage that couldn’t be seen by the eye. I would no doubt question your insurance company.

I will ask the insurers again do they want further inspection , they have at this stage said they do not. Unless I can provide evidence or expert testimony or the insurers themselves demand it , I fail to see how I can force the issue unless I can provide evidence of a reason.

The insurers have confirmed my insurance cover remains in place and am aware I will be using the boat.

Given time might need to pass , I can use the boat as I don’t need any of the failed electronics, at this time , while keeping the claim open. This allows me to determine if anything else shows signs of damage , realistically if after a while nothing untoward fails or exhibits issues , I will have to settle the claim. I don’t see how I can do otherwise , but I’m open to suggestions

[BobbyHR]

Originally Posted by boatpoker

Where do they spec this ?

Sorry, I looked for a while without success, but I've seen it more than once and once a lecture attendee confirmed the size. The gauge is heavy lest the connection burn.

Huge voltages, when Ben put his 9' iron rod atop his roof in 1752 he wired it to a bell on the wall of his stairwell Another bell next to it was connected to the well pump in his basement. When there was voltage in the air a small brass ball suspended by a thread between the bells would travel back and forth ringing them, "Franklin's Bells". One famous portrait has them on the wall behind him. But I tell you this because one night he awoke to cracking and hissing, went to the stairwell and watched "fire as thick as my finger passing between the bells, enlightening the stair so well as you could see to pick up a pin", that from his autobiography.
If we knew how far apart the bells were we could guess pretty well the voltage, certainly hundreds of thousands of volts, passing to the air above, diffusing it while it attracted the stuff.
I've seen early photos of lightning rods that were like Ben's, very tall, and they work best. Also salt water is very conductive, fresh water not at all.
A very well grounded lightning rod will pump huge voltage into the air above keeping you safe. It is a crime that no test methodology exists to test a ground for same by giving the system a voltage blast and confirming an excellent ground exists.
Insurance companies are not your friends.