Boy killed by lightning in our anchorage, what would you do?

[MarioG]

Originally Posted by MarkSF

So far no-one has mentioned how dangerous the wheel and tiller are in a lightning storm. They both provide an excellent path to ground. Worst case would be one hand holding some rigging, the other the wheel. Best plan is to stay out of the cockpit entirely, and go below.

I learned this lession the hard way. As I said in a different post I was just sitting in the cockpit between the wheel and back rail watch a storm pass off in the distance when I felt the charge and watch the steering weel lite up then move thru me to the back rail. It felt like being zapped by the coil for an old car (15k volts) or 240 volt house current,I've been zapped by both.

I think sitting inside the cabin waiting out the storm is the only safe answer. Unlike Chef nothing other then me got crispped that night.

[Time Traveler]

The strategy of using the stove as a Faraday cage makes a lots of sense, in theory, and I do put the handheld in the oven when there's risk of lightning. But I'm also very curious whether anyone on the net has first-hand experience of equipment in the stove (or any other Faraday device) surviving a strike that disabled equipment elsewhere on the boat?

[zeehag]

we sailed thru a lot of that stuff--never but never swim or be in water of any sort in lightning storm. not fresh nor sea water.

we had zero lightning protection, zero hits, and i was nervous of the ss wheel --so i wore rubber everything outerwear....my boat has a wood wheel, no metal plates on mast---no anti lightning attraction devices--is virgin, and we pray a lot. and we have a cat on board....

i ssad about the kid being hit---too many folks think is better on land. actually, it isnt.

[steel]

Originally Posted by PeterSailer

What about steel sailboat?? if your inside would they act as a giant faraday cage? and if your on the outside of the boat? would the electricity run through the hole boat or hit the mast, shroud and stays and then use the shortest path to water??

Pierre

A full metal hull should do that. But don't forget about the mast top VHF antenna and the other wires going up there. There needs to be lightning arrestors on the antenna feed line and also on the power wires going to the lights. Else the surge will just come in through there and spread in to the whole electrical system.

As for the wheel and tiller, they should be electrically connected to the ground that the mast uses. This ensures that everything is at the same potential and there isn't a different voltage at your mast, rigging and lifelines than there is on your wheel or tiller.

[fallard]

Not being deliberatively argumentative, but steel's point about a steel hull providing a faraday cage would be true if there weren't any holes in the steel larger than the openings in the mesh on your microwave window. Lightning is a very short-duration electrical event with correspondingly high frequency (e.g., radio frequency) components that will pass through your hatches, companionway, etc.

Also, surge protectors can't hurt, but are not likely to make much of a difference in a direct strike, which will not only electrify your wiring with a conducted, transient high voltage, but will also generate a radiated electromagnetic pulse (EMP) that can impress a high voltage across a circuit board--well above the breakdown voltage of any semiconductor.

How do I know that? I lost a wheel pilot control unit in an indirect strike. It was sitting on a shelf, not connected to anything. I lost all of my other electronics, too, including a VHF that had in-line littlefuses that looked like popped flash bulbs. That radio circuit was electrified, even though its circuit breaker and the master breaker were in the "off" position.

I also wouldn't ground your tiller/wheel, unless you don't want your mast to act as your primary lightning rod to keep the main discharge away from the cockpit. There's a reason that injuries from lightning strikes are less severe or less numerous statistically on sailboats compared to power boats. It's all about the height of the mast and the larger cone of protection on a sailboat!

I've already indicated in previous post that I have had 2 lightning events with my current sailboat. Your best defense is an insurance policy that does not depreciate your electronics (as does BoatUS, last time I checked).

[hellosailor]

sallard, overall I agree with you but note that you don't need a theoretically perfect faraday cage in order to have an effective one. Aircraft windows are about the same size as boat hatches, yet avionics pros will tell you that the aircraft basically IS a very effective faraday cage and they rarely take damage even when struck by lightning. The skin still conducts most of the charge on the OUTSIDE of the aircraft, the same way that AC power is largely conducted on the outside skin of a wire. I don't know the physics, I just have the Cliff notes.
Similarly, if your electronics were "protected" only by having the brealers thrown, that's no protection. The air gap in a breaker flashes over and fails at around 3000 amps discharge. The lighning is pushing way more current and voltage than a breaker is designed to protect against, you might as well say that a spark plug's air gap can "protect" against an ignition system's coil power. Of course, it doesn't.
While professional broadcasters DO use more effective lightning protecction devices (like PolyPhaser) and those devices work very effectively to protect towers and transmitters that never are unplugged, those folks also do go off the air due to lightning damage at times. Despite the best of protection and expert installation.
Bottom line, to protect electronics you do what radio operators have done for a very long time: You ground the antenna cable, outside of the radio room (i.e. above deck or at the mast) and the antenna and cable iteself are sacrificial items. Once the electronics are really isolated, they are safer. But that means unplugging everything every time you step off the boat, and then the connectors fail, or the job becomes a nuisance that just won't get done.
Lightning: God's way of playing golf. Always hitting par, often scoring hole in one.

[fallard]

hellosailor has a point about not needing a perfect faraday cage to get some protection, with a car providing another example. That said, the whole boat as an approximation to a faraday cage only applies if the boat is all metal. The overwhelming majority of recreational sailboats are plastic.

It is more likely that the typical sailor can only get the benefit of a faraday cage that is much smaller, like an oven or an aluminum foil wrap. It can be inconvenient to disconnect and remove your electronics to an oven, so the aluminum foil trick may be more practical, as long as the wiring is disconnected. I agree that just switching off a breaker does not guarantee protection, as I noted in my previous post. But I also noted my personal experience that completely disconnecting your electronics does not provide protection against the electromagnetic pulse from a lightning strike.

[OPossumTX]

Normal fuses provide no effective lightning protection. The little wire in the fuse vaporizes instantly and coats the inside of the glass with a thin layer of conductive metal.

Now if the potential from the strike is high enough, the now metal metal film resistor which used to be a fuse will explode from the pressure inside and when you open your little plastic fuse holder, you will find what looks like grey sand in there between the two little cups that were the ends of the fuse. Needless to say, what ever that fuse was supposed to protect is probably smoked too.

[Flatballer]

Since I have some experience here I'll throw my two cents in. I was on a boat struck by lightning. Cruiser, connected to shore power, well grounded boat. Standing in companionway watching storm. There hadn't been lightning. Next thing I knew I was laying on the cabin sole. Not sure if I jumped or fell. Someone across the ICW in a house thought I was dead because I just stayed down below, they sent the Marina person down, thinking they were gonna find a body. It vaporized the VHF antenna on the mast, the SSB and VHF died, the little lightning thing on the mast was gone. Everything else was fine. Witnesses say it was a direct strike on the mast. All I know is it was the loudest thing I've ever heard. I'll take a well grounded boat any day over being anywhere else. Even though it's the tallest thing around and presents a good path to ground, it's a great place to be.

I'm an EE and I'll tell you we still know very little about lightning. We still can't even figure out which direction it goes or what really causes it, much less how to prevent it.

Shame about the death. I'd recommend staying in the boat and on the water.

Sent from my DROID RAZR using Tapatalk 2

[steel]

Has anyone had the VHF antenna hit while having a properly installed lightning arrestor on the VHF antenna feed line? The ground of the lightning arrestor has to be connected to the mast ground with its own wire.

Of course if the EM field created is so strong that it destroys electronics which aren't plugged in then there isn't much you can do except get military grade hardened electronics.

And why not ground the rudder? You want to have 20,000v between your wheel and the throttle control which is hooked to the engine which could be hooked to the different mast ground?