Lightning protection options

[Frank C]

... 3 minutes from a beachable shore where I can watch the fireworks from a safe place...ill worry about the boat later.

... My first and closest experience with lightning was as a youth on a soccer field - I saw a bolt come down and hit the goalpost, then travel vertically back up to a lightstand on the staidum some 1/4 mile away, then sideways to a building several hundred feet away....

... a clever trick - we circled a large buoy in the river during a squall(visibility < 75 feet) ...

1. Agree wholeheartedly! But don't stand under a tree when you reach shore?? exactly where is safe harbor?

2. Agree again! Your story reinforces the seeming. Trying to channel lightning is akin to steering a hurricane? ... and a battery cable dangling in the water seems pathetic, indeed. If a mast is so prominent on the water, seems the lightning should just blast straight thru the hull. Casey says the grounding prevents side spikes. Hmmm

3. Clever indeed. That's one to keep filed for the fogbanks that sweep over SF Bay. In truth though, SF fog is predictable, just like your NY lightning ... getting caught in SF fog means you goofed.

[Catigale]

...with regards to standing under trees, I would stand in a grove of trees as opposed to sitting on water with a metal mast up in the air ....of course one would avoid a field with a solo tree in it...

Either way, even lying down (or sitting in a ball holding your ankles, the classic advice (gee that sounds useful)) you are better off than open water in a sailboat I would think...

Rounding the buoy was a clever thing - so simple too...never would have thought of it myself...

Stephen

[bscott]

A few years ago, a Catalina 25 on a mooring ball in Lake Granby, Co. had the bow blown off when a lightening strike hit the mooring ball---the strike traveled from the ball to the bow eye via the painter. Hard to imagine that the strike could (would) travel the line but it did. The marina shag guy saw what happened and retrieved the boat. Yikes.

[greybird-M]

We had a situation here in Florida a few weeks ago, in the Melbourne area, where a family had been caught in a thunderstorm while boating (a powerboat, I believe). They sought shelter on a small island in the Indian River, under a tree. The mother was holding her ten year old son in her arms when the tree was struck by lightning. The mother was killed instantly, as was their dog. Her son and another member of the group, a young woman, were injured enough to be hospitalized. The father dialed 911 and emergency assistance was provided. I have not seen or heard or read of any follow-ups by the media, but I assume the two in the hospital will recover. The lightning down here in Central Florida can be horrific, actually I think ANYWHERE in this state is bad for lightning.

-Walt

[Jack O'Brien]

Florida is the lightning capital of the US of A. Even if you play the state Lotto here you are less likely to win that than you are to be struck by lightning - and you don't have to play to lose. I once read Florida's lightning bolts average 50,000 volts versus 35,000 volts in other states.
See, youse guys, everythings just bigger and better here in Floridah.

I lived for three years in Bogor, Java, Indonesia in the foothills of the mountains south of Jakarta. The natives call it "Kota Hujan" which means Rain City. Bogor is in the Guiness Book of Records for "Most Days of Thunder in a Year". Guess that means we had a lot of lightning too. The average annual rainfall was 15 feet.

[Don B]

Were sleeping in the Mac 26X during lightening storms over the weekend in Oriental,NC which also has a lot of lightening like Florida. The next day the better half mentioned about the lightening to the "Dock master" he said you have to have a ground plain attached to all electronics to protect you and the electronics.

On the drive home I was asked by the better half if we have a "ground plain" I said that while we are in the slip that the SHore power provides some ground.

But I said we don't have any chunk of metal hanging over board or ground connected to any metal touching the water.

I did say that water is not a good conducter of electricity anyway and did not see where metal immersed in the slip water or while at sea would do much for protection.

I will concede that the water may be at a lower potential than the boat hull but not sure if considering the high voltage of a lightening strike if this would even matter to the lightening bolt.

I do like the analogy used in an above post of "Steering an Hurricane"

-Don B

[Dimitri-2000X-Tampa]

Perhaps a ground plane is where all the through hulls are connected together. This is the way it was on my former keel boat. Thick green cables (maybe 2/0) went between every thru-hull, engine, prop, etc.

I believe that non distilled water is a good conductor. The more minerals in the water, the better it conducts. Sea water conducts better than fresh water. Besides, the conductance of water is really a moot point...afterall, lightning travels through air...which is one of the poorest conductors.

[Chip Hindes]

Conductance is relative. Certainly lightning travels through air. It also travels through trees, the ground, or your body, even though all of these are relatively poor conductors.

Salt water is a relatively good conductor; fresh water, minerals or not, is a fairly poor conductor. The relative conductance of salt water versus fresh water is certainly not considered a moot point by those who specify grounding systems. They recommend a given size grounding plate for salt water, and a much larger grounding plate for fresh water.

[jklightner]

Errant sailboat mast knocks out the power

PORT ORCHARD - An attempt to move a trailered sailboat around the downtown boat ramp ran afoul of the overhead power lines Sunday night.
The power went out throughout most of the downtown area when the boat's mast touched a live line, and still was out more than an hour later.
Lt. Glenn Pappuleas of South Kitsap Fire District said an Allyn boat owner was trying to get his 26-foot McGregor sailboat out of the way of other boaters before lowering the mast. The wire burned a hole in the aluminum mast and the impact snapped three or four of the wire's five strands, he said. But the wire held and didn't fall to the ground.
After Puget Sound Energy had cut the power to the line, police told the driver of the pickup truck towing the boat he could get out. He was told to stay in the vehicle until then rather than risk electrocution by stepping outside. His name wasn't available.
The wire is the same one struck by a crane during construction of Port Orchard's new city hall more than a year ago. That also blacked out the downtown area and the power surge started a grass fire several blocks to the east.
Travis Baker
I wonder who is shopping around for a new mast? I guess it's true that no good deed goes unpunishished.

[Frank C]

There are probably 10,000 Macs out there that are capable of this trick. If we all try really hard, we might be able to completely eliminate all power lines near boat ramps!

[Chip Hindes]

No smiley here.

When I was stationed in Okinawa with the Marines in the mid seventies, I occupied nearly every one of my weekends as an active member of the Special Services Sailing Club, where I also taught basic sailing on Rebel dinghys. The Club President, a Marine Captain and one of the nicest guys I've ever met, also kept his absolutely immaculate personal Lightning there. Most of us had nasty old beaters of Japanese cars, but his was the only one with a trailer hitch and we frequently used it for shuttling the boats around.

Several weeks after I was transferred from Okinawa to mainland Japan, another member of the Club called to inform me the Club President had been killed in just the sort of accident you described. He hit a power line with the mast while pulling one of the Special Services Rebels through the parking lot with his personal car. Not realizing what had happened, he stepped out of the car and was electrocuted when his foot touched the ground. The Base Hospital was less than 1/2 mile away, but he was DOA.

He left a wife and two young daughters.

Every time I get ready to raise my mast in an unfamiliar location, this comes back to me. I check for power lines, not just directly overhead, but through the entire parking lot, launch area and ramp, for a considerable radius around where I might conceivably be trailering.

I realize that many of them were originally geared toward power boaters, but as a sailor, it's incredible that marinas and boat launches would permit power lines to remain anywhere near them.

[Dimitri-2000X-Tampa]

Powerboaters rip down lines too. When I pulled my mac out two weeks ago in advance of Hurricane Charley, the guy right in front of me (only lives a couple houses away) ripped down the telephone line with his VHF antenna attached to the sun cover on top of his center console fishing boat. I guess he would normally would bend it down....but I suppose everyone was freakin out with the hurricane coming. The power lines were a couple feet higher and didn't get hit. At least, I'm assuming that it was the phone line since he got out of his truck and pulled the wire off his hood!

[Don B]

It will be nice when most power lines are buried. I know it is expensive and energy ineffiicent but it will be nice.

-Don B

[Chip Hindes]

It will be nice when most power lines are buried. I know it is expensive and energy ineffiicent but it will be nice.

I'd be interested in knowing the life cycle costs of buried versus overhead power lines. My guess is that first cost is higher (digging trenches for burial versus boring deep holes and putting up poles for overhead) but I'm not even sure about that.

But once they're there, the buried lines must have way lower recurring maintenence and repair cost. The worst that usually happens to buried lines is the rare occasion some doofus digs them up by accident. On the other hand the overhead lines are a maintenance and repair headache; constantly being knocked down by traffic accidents, storms, ice and errant tall stuff (like sailboat masts). Trees have to be trimmed constantly, etc.

Besides, the overhead lines are ugly.

Regarding energy efficiency, do buried lines have higher line losses?

[Don B]

Chip,

When I was looking into running underground lines 1000 ft up the hill to my house I would have had to pick a larger diameter line to cover the loss into the ground. At least that is what I was told.

This was in the 80's and things change. Plus I may have forgotten all the particulars

Probably if it was DC it would have not mattered.

-Don B