Lighting strike on an all electric boat????

[nwdiver]

I'm interested in going all electric on my 38 foot boat, but lighting makes me nervous, we don't get lighting much in the PNW but the tropics do........with all the electronic controllers, even on a set of house lithium batteries not including motor, galley appliances, inverters, charge controllers, that have electronics that are required....what happens if you get hit by lighting........do you become a sail only boat?

My boat is properly ground from mast to keel, but if hit by lighting I expect to lose my lithium batteries,nav and com gear......I do have portable backups that will keep me sailing.

[boatpoker]

Originally Posted by nwdiver

I'm interested in going all electric on my 38 foot boat, but lighting makes me nervous, we don't get lighting much in the PNW but the tropics do........with all the electronic controllers, even on a set of house lithium batteries not including motor, galley appliances, inverters, charge controllers, that have electronics that are required....what happens if you get hit by lighting........do you become a sail only boat?

My boat is properly ground from mast to keel, but if hit by lighting I expect to lose my lithium batteries,nav and com gear......I do have portable backups that will keep me sailing.

Your backups may not survive a strike either unless you keep them in a Farraday cage.

[nwdiver]

Originally Posted by boatpoker;280 0789

Your backups may not survive a strike either unless you keep them in a Farraday cage.

They are in a farraday cage and insulated from the cage......it was built by an MRI tech......handheld vhf, 7 inch plotter with chart card and extra tablet...

Can't easily build a cage around lithium batteries and electric motor....

[AedanC]

Originally Posted by nwdiver

They are in a farraday cage and insulated from the cage......it was built by an MRI tech......

I’m very interested in that aspect, do you have any photos of the faraday cage?

[boatpoker]

Originally Posted by AedanC

I’m very interested in that aspect, do you have any photos of the faraday cage?

A microwave oven makes a decent cage.

[GordMay]

Originally Posted by nwdiver

... Can't easily build a cage around lithium batteries and electric motor....

Metal boat?

[smac999]

stay in vancouver and you won't have an issue....

[Paul L]

In a lightning strike your electronics are very likely to be disabled. How many of them will die is at the whim of the gods. Newer commonrail diesels are also susceptible because they are electronically controlled. You can significantly reduce your risk by timing what seasons you are in the tropical lightning areas. In rainy season in Panama you are lucky to not be hit. In the 'dry' season you are unlucky to be hit. In the end lightning sux. Even a steel boat can loose all electronics on a strike.

[coopec43]

Right now I'd hate to be sailing in the Eastern Mediterranean. WOW!

https://www.lightningmaps.org/?lang=...d=2;dl=2;dc=0;


Patterns of Lightning Activity

https://earthobservatory.nasa.gov/im...tning-activity

Clive

[Paul Howard]

I know from personal experience that lightning strikes when far at sea kills everything. Batteries burst, inverter and circuit breaker panel nothing but melted wiring. LED lighting burns out, even bilge pumps had to be replaced. The engine the system was grounded through (on a catamaran with twin engines) was toast, thought the second engine with its own isolated system did work after the strike. The only thing that still worked was a handheld VHF.
Autopilot, compass light, refrigeration, even the solenoid for the propane cooking stove was all gone. Took three days to get to nearest port plotting a DR on a paper chart and using small LED flashlight while hand steering to light the compass. Not fun at all.

[thinwater]

Originally Posted by Paul L

In a lightning strike your electronics are very likely to be disabled. How many of them will die is at the whim of the gods. Newer commonrail diesels are also susceptible because they are electronically controlled. You can significantly reduce your risk by timing what seasons you are in the tropical lightning areas. In rainy season in Panama you are lucky to not be hit. In the 'dry' season you are unlucky to be hit. In the end lightning sux. Even a steel boat can loose all electronics on a strike.

^^This. You are just as likely to loose the use of a fossil fueled motor.


But not on my list of worries. The odds are low and you have sails. You can bail water out of the tank and you don't need the other stuff.

[Montanan]

Place "essential" disconnected portable electronics, EPIRB, handheld VHF, GPS, chart plotter tablet in a closed metal box. Do not use a gasket separated lid, such as an ammo can, unless you also electrically bond the lid to the sides, such as with a stout gauge of wire. Keep the box separate from other circuits.

Properly ground and bond the rest of any sizeable metal on your boat and lead the conductors as straight as possible to a ground plate on the exterior of your hull, intent to minimize side flashes and arcs to ground. An aluminum mast makes a great rod, just need to complete the circuit pathway to the dedicated through hull ground as direct as possible and with properly sized wire. There seems to be difference of opinion on the appropriate sizing of the cabling. Copied are a couple of references. My opinion the bigger the better.

What is the minimum size of down conductor for lightning protection? What is the individual resistance and combine resistance of electrode? What is the resistance of grounding network? - E&S Grounding

"There are two (2) classes of material requirements found in NFPA 780, the Standard for the Installation of Lightning Protection Systems. Class I materials are required for structure less than 75-ft in height, and Class II Materials are required for buildings greater than 75-ft in height. The down conductor is properly listed in the standard as a “Main Conductor Cable”.

Class I – Copper: Minimum Gage is 2 AWG, with a minimum individual strand size of 17 AWG.
Class II – Copper: Minimum Gage is 00 AWG, with a minimum individual strand size of 17 AWG.
Class I – Aluminum: Minimum Gage is 0 AWG, with a minimum individual strand size of 14 AWG.
Class II – Aluminum: Minimum Gage is 0000 AWG, with a minimum individual strand size of 14 AWG."


https://www.westmarine.com/WestAdvis...unding-Systems
West Marine has a good Marine Grounding webpage which a portion states for Lightning Grounds
Connect a 4 AWG battery cable from the base of your aluminum mast to the nearest keel bolt from external ballast. If you have internal ballast, you should install a lightning ground plate. One square foot is recommended for use in salt water; fresh water requires much more. Do not rely on a thru-hull or a sintered bronze radio ground (e.g. Dynaplate) for use as a lightning ground.

For additional comfort, also run a 6 AWG wire from your keel bolt or ground plate to the upper shroud chainplates, and to your headstay chainplate and railings. Don't bother with the backstay if it is interrupted with antenna insulators. Have each of the cables that are used for lightning ground wires lead as directly as possible to the same keel bolt, with any necessary bends being smooth and gradual.

Given that you have grounded your mast solidly to the ocean, your mast will be at exactly the same electric potential as the ocean. There is no chance that you can dissipate the charge between the ocean and the atmosphere, so don't bother with a static dissipater at the masthead. Wire "bottle brush" static dissipaters may be useful to dissipate seagulls, however, but that is beyond the scope of this article.


Hope that you only have an indirect hit and not a direct hit.

Damages from lightning strikes are a leading cause of insurance claims on yachts, be prepared to have to shell out the deductible and it will take a lot of work and time to have a professional repair.

Your sails will continue to work, albeit any electric powered winches may need to be operated manually.

[Mike Banks]

If you get a good hit you become a sunken boat. Use lightning protection and encase any vital switching equipment in a Mu-metal shroud

Pay no attention to the nay-sayers. They will not be severely burned or killed if even a light strike hits your vessel. Nothing will withstand a heavy strike--which is why protection is used to make it a whole lot less likely. Use protection--it is always better

I had protectrion oin my boat, but the guy next door to me in the marina was a steel trawler, and he copped a medium strength strike. I was protected from the eletrostatic strike, but I was within the range of the magnetic pulse from his strike, and it destroyed some of my equipment. Fortunately the engine alternator was ok, but some of the radios were shot, so was the radar, and the power supply for the battery charging was absolutely cooked. One of my radios survived, the el-cheapo vhf. The rest were ruined.

[nwdiver]

FLA batteries may not survive......so lithiums with thier electronic control systems are toast.......I guess that's why it's called a sailboat.....

I think a diesel hybrid and as pointed out extensive grounding will be in order I do have my mast grounded to the keel with very heavy (5/8 inch, I think) solid copper rod....it's the 12-15k in lithium I don't want to experiment with....

In all the EV (electric vessel) threads I have not seen anything about lighting protection......lots of babble but the basics are not covered.....

[nwdiver]

I was also thinking of synthetic rigging.....this would make my mast the only way to the water