Planning lightning prevention system on catamaran

[s/v Jedi]

Originally Posted by capn_billl

Woops, add the inverter to the list. it just smoked, and died.

I see you are in Naples. Jedi used to be the only sailboat in the Naples municipal marina and was hit badly twice there. Naples is a lightning magnet.

[s/v Jedi]

Originally Posted by smj

It’s what the boat came with, but I believe a good prayer would help just as much, and I’m agnostic.

Best to have both

On lightning rods, the ABYC recommendation (they call it an Air Terminal) is solid 3/8” diameter copper or solid 1/2” diameter aluminium rod, extending at least 6” above everything else and having a rounded tip facing the clouds.

Those are supposed to survive strikes. I know VHF antenna whips don’t, mine was half gone and had a drop of stainless steel metal running down what was left a couple inches down before it solidified again.

[smj]

Originally Posted by s/v Jedi

Best to have both



On lightning rods, the ABYC recommendation (they call it an Air Terminal) is solid 3/8” diameter copper or solid 1/2” diameter aluminium rod, extending at least 6” above everything else and having a rounded tip facing the clouds.



Those are supposed to survive strikes. I know VHF antenna whips don’t, mine was half gone and had a drop of stainless steel metal running down what was left a couple inches down before it solidified again.

Our VHF antenna was gone, except for the base. The SS ends of the lightning dissipater had melted SS balls on the end. Me don’t thinks it did it’s job!

[Piscis]

Thanks for all the great advice.

Planning the following:

Immediately. install removable shroud groundings outside the hulls, connected via
AWG 0 or 1 tinned copper cable to 2.5 sqft beryllium copper plate.
It is just too ugly to have those cables outside the hull permanently and I can install/remove them as needed via a wingnut with connection at the shroud tube.

Permanent install Mast grounding via Mast compression post and down through bridge deck/above waterline throughhull to the beryllium copper plate.

Permanent ground the bow aluminium cross beam to the beryllium copper plate.
This can be done more discrete and not that much visible.

Trying to route all cables as straight to grounding plate as possible.

Optimum would be a copper lightning rod at top of mast. Not sure if I will install it.

When leaving boat or when storm is approaching, will disconnect as much equipment as possible. Maybe installing some quick disconnect fittings to equipment not easy to disconnect, like the yanmar B20 panels...

Will keep you posted of progress of install...

Thanks again!

John

[s/v Jedi]

But but… then it’s not a boat anymore… you can’t sail with that…

A lightning rod is only for non conductive masts.

[Piscis]

Originally Posted by s/v Jedi

But but… then it’s not a boat anymore… you can’t sail with that…

.

Lol

The grounding of the shrouds are just attached with a u bolt and an wing nut. Grounding attached only when needed in storm season.

I might do the same to the grounding of the mast. Having the cables connected and setup for s quick bolt on connection with a wing nut, toolsfree.

So will only attach them when I have the vessel in the Marina or at anchor in the stormy season.

Under way, no performance rubbing installations.

That should do. Lol

[Piscis]

....maybe....

[team karst]

Ever watch that vid of a team of rocketeers that induce a strike with a small rocket trailing a length of small wire? That is a great example of successfully “encouraging” a strike path.
Similar to lightning protection systems on tall buildings. We cant seem to stop the strike, but we can provide a better, if not perfect path.

[s/v Jedi]

Originally Posted by team karst

Ever watch that vid of a team of rocketeers that induce a strike with a small rocket trailing a length of small wire? That is a great example of successfully “encouraging” a strike path.
Similar to lightning protection systems on tall buildings. We cant seem to stop the strike, but we can provide a better, if not perfect path.

It works both ways: you can’t prevent the strike from occurring but you can attract it or hide from it.

Before the strike happens, leaders are formed. Many leaders and only one or a couple get the strike. You can influence these leaders.

[team karst]

certain amount of chaos will prevail. Here is some vid of what happens when unlimited $ attacks the issue. Even then, in the midst of very high horiz. wires, and high mounted rods, a direct hit on the ground is seen.

https://www.youtube.com/watch?v=I5CNP-JXJjM

[s/v Jedi]

Originally Posted by team karst

certain amount of chaos will prevail. Here is some vid of what happens when unlimited $ attacks the issue. Even then, in the midst of very high horiz. wires, and high mounted rods, a direct hit on the ground is seen.

Yes but all those strikes are outside the protective cone. There are 4 of those towers around the protected launch site. I can see the launches from a window here

[EwenT]

Here are some well-researched articles on this:
https://loosecannon.substack.com/p/n...ing-guy-disses
https://loosecannon.substack.com/p/s...s-experimental
https://loosecannon.substack.com/p/p...rotection-that

[EwenT]

Originally Posted by s/v Jedi

Yes but all those strikes are outside the protective cone. There are 4 of those towers around the protected launch site. I can see the launches from a window here

This video very clearly shows the mechanism of upward-going streamers, both those that do and do not connect to the stepped leader channel.
https://www.facebook.com/watch/?v=698228935012203

[team karst]

This is a compelling argument: Thank you Ewen!

Between 1793 and 1839, 235 Royal Navy ships were struck by lightning.1 Nearly 100 seamen were killed, about 250 severely injured (sometimes dozens in a single strike). Ships caught fire in 40 cases. Spars were destroyed by the hundreds.

By 1846, the entire Navy had been outfitted with Franklin’s system. Lightning continued to strike the fleet, but lighting damage all but ceased. “The result has fully rewarded our expectations. The loss of life or destruction of spars is no longer known in the British Navy” Robert B. Forbes wrote in 1853. Forbes was an American sea captain and advocate for lightning protection on ships.

[Piscis]

Finished and final product...

4 copper berylium plates attached to Mast and shrouds via 35sqmm (approx. 2AWG) conductor cables. The plates have a lead diving weight to add some more stability, hanging in the water. Weights are painted. The plate/weight combination are fixed to the vessel with a red rope, 10sqmm to relieve tension from the conductor cables (minimal slag on the cable).
Mast is grounded through the mast compression post.

Set is designed to be mounted and dismounted without tools in less then 5 minutes by using wing nuts for the conductors and carabiners for the rope.

I have the protection installed when the vessel is in the marina, anchoring or at a mooring ball. Most of our sailing is during high season when there is very low probability of entering a TS or getting hit by lightning.

Thanks for helping me!

John