Lighting protection

Status
Not open for further replies.
Nov 19, 2011
1,489
MacGregor 26S Hampton, VA
After reading the suggested "The sailing misadventures of the wild hair" and looking at the skies this morning, it occurred to me to Google for lighting strikes on sailboats.

In the following PDF, there is discussion on lightning systems. I guess my question for those of you that have done extensive work ONI their Mac.... Is there a ground wire from the mast on a Mac 26s? Being on the chesapeake bay and leaving the boat in its slip, there seems a decent likelihood that the boat may get tagged at some point since its the only sailboat in the small marina and ultimately the highest point. Oh I have no plans on sailing in storms, but I don't want to blow the hull out either while it's sitting there and I'm sure at some some time we'll get caught in a quick storm at some point.

http://edis.ifas.ufl.edu/pdffiles/SG/SG07100.pdf

in the book, Mr. Giles mentions pushing jumper cables but it sounds like he is going from shroud to shroud or stay.

Should we have a set to attach to the base of the mast into the water or is this already done internally?

After all that, it looks like a 50% chance of storms today but I have some work to do on the boat. Obviously I will abandon ship if it storms but it got me thinking.
 
May 4, 2005
4,062
Macgregor 26d Ft Lauderdale, Fl
Walt had a pretty good thread on this a year or so back.

2 schools of though, ground the boat by putting copper rod in the water, connected with cables (or simialr concept).

or go bare.

some think grounding might make the boat more attractive to lightning.



I'm going bare. but don't sail much in summer, when we get most of the electric storms.
 
Sep 16, 2011
346
Venture 17 Hollywood,FL
Thats a good article. It goes along with Nigel Calders thoughts too in an issue of Sail magazine. Some protection seems better than none. I am going to look into setting this up. I may get two sets of jumper cables and split them up. At the water end, I would place a copper plate or tube or something? The tops of the cables would clamp on individually to the mast, shrouds, and forestay. This set up would allow the whole thing to be removed and stored below. Probably cost less than $50 for the whole thing.

We got stuck about 20 miles offshore once in a really bad lightning storm on my center console boat with no protection. We were never more scared in our entire lives. That lightning was hitting the water all around our boat with the sound of a gun each time. Storms suck. I learned that planning and prevention is the best protection. But if it happens again, I want to have something in place. Oh yeah, good idea to put on your life vest before the storm in case you get struck and end up unconcious in the drink.
 

walt

.
Jun 1, 2007
3,546
Macgregor 26S Hobie TI Ridgway Colorado
I am involved in a lightning protection future business so keep this in mind (bias..)

This concept/design which is tailored for a trailerable sailboat has been in process for many years now and uses the surface sparking/discharge concept developed by Ewen Thomson (referenced in the first email). This was shown at the Havasu event and is not for sale yet but some info is available here http://zenpole.com/

Regarding the question of does grounding influence your chances of a strike, here is somewhat of an interesting video http://zenpole.com/ground.html

Both Sumner and I have been using these (myself for a long time) and Sumners write up is here http://purplesagetradingpost.com/sumner/macgregor2/outside-43.html
 

Sumner

.
Jan 31, 2009
5,254
Macgregor & Endeavour 26S and 37 Utah's Canyon Country
.... Some protection seems better than none. I am going to look into setting this up. I may get two sets of jumper cables and split them up. At the water end, I would place a copper plate or tube or something? The tops of the cables would clamp on individually to the mast, shrouds, and forestay....
Ruth and I have been in bad lightning in the west, but not real bad in Florida....yet. I'm sure that will change. If you go out for more than a few days you can't pick your weather, but are stuck with what you have.

I considered the jumper cables and with a large enough plate on the water end they might have some merit in salt water. The problem is that we have had the worst lightning in fresh water and there the plate has to be much, much larger in surface area and would be impractical to carry or implement. Personally I think jumper cables alone are worthless as they don't have enough surface area in the water.

I really believe in what Walt is/has developed and feel it has a lot of merit. Lightning does hit the surface of the water and what he has developed tries to take the lightning to that point and should be as effective inland as coastal. We feel that it is our best bet and have it on the Mac now and I'm even putting it on the Endeavour. The Endeavour though is a lot better candidate for handling a lightning strike vs. the Mac since the mast is stepped through the cabin top all the way down to the lead keel. Still if the Zen Pole diverted the strike to the water outside of the cabin I'd be in favor of that.

As Walt mentioned I've written a much longer view of what could happen to a Mac and why we are now using the Zen Pole here...

http://purplesagetradingpost.com/sumner/macgregor2/outside-43.html

It is a long read, sorry, but the key to me is that there is good reason to believe that you won't attract lightning with grounding and NOAA and articles like above back that up. That only happens on very, very tall structures and things like really tall towers on hill or mountain tops and results from a different type lightning than what could strike a boat in my opinion and others.

So if you are of the opinion that you aren't attracting lightning then consider a sensible approach to controlling a strike. Of course like seat belts and air bags nothing works all of the time, but would you drive around without those?

With our boats having water ballast and no steel/lead keel I think the chance of a hole blasted through the bottom with a hit is high, yet I've never read of one with a Mac,

Sum

[FONT=Arial, sans-serif]============================[/FONT]

Our Endeavour 37

Our MacGregor 26-S Pages

Our Trips to Utah, Idaho, Canada, Florida

Mac-Venture Links
 
Oct 6, 2011
678
CM 32 USA
Traveling salesmen looking for victims, look for houses with lightning rods on the roof tops. It says two things, one, the person is gullible, and will buy anything, and it also says the person is gullible and will buy anything. At 50,000 to millions of volts, amps, watts, lightning hits anywhere it wants to.

As a teen, my Mother and I looked out the back door of our house in a storm to see a lightning bolt come down, and shake like a snake tongue, between us, then we watched it go back into the sky. We both saw it. It left an ozone smell behind, and our hair had static electricity. It did not leave the impression of being inanimate. One guy has hit by lightning 8 times in one day, he was on the Johnny Carson show years ago. He said he learned why he was hit, but would not tell anyone.
 

Sumner

.
Jan 31, 2009
5,254
Macgregor & Endeavour 26S and 37 Utah's Canyon Country
Traveling salesmen looking for victims, look for houses with lightning rods on the roof tops. It says two things, one, the person is gullible, and will buy anything, and it also says the person is gullible and will buy anything. At 50,000 to millions of volts, amps, watts, lightning hits anywhere it wants to. ...
So I guess you are saying that all of the people/corporations that own commercial boats, planes, buildings, towers that employ lightning protection are gullible and those people that listen to someone on the Johnny Carson show are getting the real facts?

True there is no lightning protection that is going to work 100% of the time, but there are figures that show that boats that employ it don't seem to incur as much damage.

I hope you have lightning free experiences on your boat :),

Sum

[FONT=Arial, sans-serif]============================[/FONT]

Our Endeavour 37

Our MacGregor 26-S Pages

Our Trips to Utah, Idaho, Canada, Florida

Mac-Venture Links
 

walt

.
Jun 1, 2007
3,546
Macgregor 26S Hobie TI Ridgway Colorado
Traveling salesmen looking for victims
Since I dont have anything to sell and cant sell, hope this is within the forum guidelines but the cost would need to be just under $350.. All opinions (including Gary's) welcome.

There is another interesting thing I wanted to point out and will probably need to defend but this http://zenpole.com/Corona_current_rev_0.pdf has some theories regarding some of the odd things that you experience on sailboat during a storm and possibly what the wire brush dissipaters do at the top of the mast.
 
Jan 19, 2010
12,754
Hobie 16 & Rhodes 22 Skeeter Charleston
Don Casey's book has a section on this. It is a good read. He suggests flattening the ends of a copper pipe, drill holes in it and use that to connect a bolt from your tabernackle to a grounding plate. On my boat I connected to the keel bolt and I figure my 800# keel is a decent grounding plate.

He also stated that since lightning travels along the edges of a piece of metal the pipe is actually a good choice because you have more surface area.... likewise if you install a grounding plate under your boat a long strip of copper will do a better job than a square with the same surface area.

He also suggests grounding wires from all of your chain plates to the grounding plate. I have not done this yet but have it on my to-do list (kind of low down on the list).

I've done the jumper cable thing in the past but I've never taken a hit so I can't say if either approach works... for me it is just piece of mind to know that I did what I could.
 
May 4, 2005
4,062
Macgregor 26d Ft Lauderdale, Fl
Sum, what is in the water? (weight/sq ft)

and (Walt), do you think a few feet (4-6') of copper water supply pipe be a reasonable alternative?


-fwiw we came back from cat cay in 2005, and went through the worst lighting I'd ever seen. Really scary, lightning ever 30-90 seconds for around 45min, and we were still 8miles out.... clearly an attractive target. (along with buckets of rain)


-We did turn off all the electronics, and said some prayers....

ps: direct link to walts video
http://www.youtube.com/watch?v=X-siV6L5SVg&feature=youtu.be




its always good to be lucky!

-rgranger, for keel ballast boats I would ground.
Water ballast boats have a problem there.
 
Jan 19, 2010
12,754
Hobie 16 & Rhodes 22 Skeeter Charleston
-We did turn off all the electronics, and said some prayers....its always good to be lucky!

-rgranger, for keel ballast boats I would ground.
Water ballast boats have a problem there.

Dang! That does not sound fun. I hope I never get caught in a bad lightning storm. I once read (it might have been here) about someone who had used their oven as a faraday's cage and they disconnected and put all of their electronics in their grounded oven. They said it worked very well. I'd imagine wrapping your electronics in metal window screen and grounding that would also produce a faraday's cage effect,... might help?. Just turning them off (or even just disconnecting them) might not be enough (still worth doing but...). A strong current (like a lightning strike) can induce currents in neighboring wires so it might not be enough to save your stuff. But like you said... "its good to be lucky"... so I hope I never get the chance to test these theories. :eek:
 

Sumner

.
Jan 31, 2009
5,254
Macgregor & Endeavour 26S and 37 Utah's Canyon Country
Sum, what is in the water? (weight/sq ft)...
Are you talking about...



... the electrode that is floating above? If so I'll let Walt answer. The very important difference of the technology that Walt is using, and that is currently used on larger vessels, is that the idea is not to try and dissipate the charge down in the water with a cable going to a plate or tube, but deliver the charge to the water's surface where it normally hits and disperses over the water's surface (there again Walt could explain this better). His floating electrodes have the discharge electrodes between the two pieces of foam where...



...my hand is above. They are located around the body of the floating part and are the actual electrodes. Walt could explain their purpose better, but if I understand it he is actually looking for the charge to jump the spark gap from one of the electrodes above the water to the water's surface.

What makes his system different than the other commercial one that takes the charge to the surface is that it is designed for our trailered boats and is easy to deploy when needed.

Walt please correct any of the above as needed.

...-rgranger, for keel ballast boats I would ground.
Water ballast boats have a problem there.
Yep, if you have steel/lead keel ballast you are much better off, but only if you do as you say and run the appropriate size ground wire from the mast at least to it and since it pivots on the bolt that makes things more difficult to achieve vs. a "fix" keel.

With our water ballast boats if the lightning went from the base of the mast to the water it could blast a hole through the top of the water ballast tank and then through the bottom of it. As I said before I've never read of this happening, but we have to remember that there are thousands of these boats out there and a small percentage of their owners actually post on these forums.

Also don't forget that it is much easier, relatively, to disperse a lightning strike into salt water vs. fresh water. If I remember right if you have a ground plate in the water it needs to have something like 7 times the surface area in fresh water,

Sum

[FONT=Arial, sans-serif]============================[/FONT]

Our Endeavour 37

Our MacGregor 26-S Pages

Our Trips to Utah, Idaho, Canada, Florida

Mac-Venture Links
 
Oct 6, 2011
678
CM 32 USA
Sumner said:
So I guess you are saying that all of the people/corporations that own commercial boats, planes, buildings, towers that employ lightning protection are gullible and those people that listen to someone on the Johnny Carson show are getting the real facts?

True there is no lightning protection that is going to work 100% of the time, but there are figures that show that boats that employ it don't seem to incur as much damage.

I hope you have lightning free experiences on your boat :),

Sum

============================

Our Endeavour 37

Our MacGregor 26-S Pages

Our Trips to Utah, Idaho, Canada, Florida

Mac-Venture Links
Give out your address, I am sure someone would love to sell you lightning rods. In storms, the people that follow in after to sell clean up services love homes with lightning rods because they know someone was there before and they are an easy sale. Just facts. No one here will mind that you often times grump at me as is your custom by the way, chip on your shoulder from the clique Mac forum I suspect, no matter, but I doubt very seriously people are going to stand buy and let you tarnish the name of a guy millions of Americans went to bed with four nights a week with for thirty years. Lol. There is a dirty jobs episode where the host is putting on lightning rods on new homes. Pretty entertaining.

Lightning is too out of control to predict and to big an event to control. You can try, but results are spotty. Do insurance companies give discounts for lightning rods. I have not heard of them doing so.

Lightning struck close by my business weeks ago, and every light went out, TVs out, fish pumps out. Everything went out for a split second and came back on. My lights are like street lights, so they were off 10 minutes before they came back on. I was using my computer at the time. The screen went out and you hear the fans power off. It was fully out. When stuff lit back up again, so did my computer. Same screen, same web site. As if nothing happened. I have no emergency power source or a lightning arrestor. I have no explanation how my computer did what it did. I would say the power was off a half of a second.

In rainstorms things get wet. Lightning usually follows the water to the earth or ground. It follows the water because it has the same "signature" as the environment the lightning is in, in the sky. Same ph, similar temperature, same dust particles in the rainwater as in the lightning clouds. This is why people struck by lightning that are wet from rain are seldom killed and why dry people struck by lightning are hurt much worse or killed. Wet objects are covered in natures perfect lightning protection. The problem with lightning is it often strikes before the rains start. The dumbest thing one can do in a thunderstorm is stand under a tree for protection from the rain. Best to stand in the rain as you seek an indoor structure well out of the weather

Deadly Facts

  • On average, about 200 people are killed by lightning in the United States every year.
  • The state of Florida holds the title of the “Deadliest State.” There are twice as many lightning casualties as in any other state.
  • The chance to be killed by lightning is 1 in 2,000.000. You have the same chance dying from falling out of bed.
  • Never talk on the phone while a storm is breaking outside. Not only do cell phones “attract” lightning, but about 1% of all lightning deaths in the U.S. are a result of people talking inside the home on a corded phone during a thunderstorm.
  • About 71% of all people struck by lightning survive. The fatal cases are usually the result of cardiac arrest. However, those who survive often suffer from serious health and psychological problems like loss of memory or sensitivity, insomnia, impaired hearing, or constant pain.
http://www.nws.noaa.gov/om/lightning/resources/LightningFactsSheet.pdf
 

walt

.
Jun 1, 2007
3,546
Macgregor 26S Hobie TI Ridgway Colorado
rgranger, I always have the greatest respect for anything from Don Casey and I wonder if his article on what you implemented mentioned that it only has a chance of working in salt water? I see you’re in fresh water (Smith Mountain lake) and I would propose that what you have wont do much because of the fresh water.

What I understand... I believe there plenty of examples of sailboats in salt water that have successfully dissipated a lightning strike to the mast through a metal keel. In order for this to occur, you have to limit the voltage rise of the mast by having a low impedance, low inductance connection to something underwater (such as a keel) and the underwater conductor must have a low impedance connection to the water. If the resistance of either of the above mentioned is too high, current flow into the impedance results in too much voltage rise (ohms law) and conditions allow for ionized air to take over and since the charge wants to get to the water surface, you get a side flash - bad.

A basic idea here is that water pretty much does not ionize in a lightning event (because of its density and having a very high dielectric constant). So the low resistance of the keel in water must come purely from the resistance of the water. Salt water is something 1000 times more resistive than fresh water and this is apparently low enough resistance. In fresh water, to get the same resistance, the surface area of the underwater structure would need to be 1000 times as large to get the same effectiveness in fresh water. In fresh water, the high resitance to water results in a high potential at the base of the mast and a side flash occurs.

Mr. Bill, regarding your question about dragging something in the water, could work but you have to very much also take care of how you connect the mast and shrouds to that underwater object. Don Casey suggested flat pipe and this does give low inductance for the weight and also a lot of surface area. Since we don’t have the metal keel in the water ballast boat, I would use 4 gauge wires which is basically the minimum size that you can rely on to not melt no matter how nasty a strike is. Why he drills holes in the flat pipe - I have no idea. One of these over each side of the boat is twice as good.

I also want to point out that its at the water surface where the positive charge is and where the lightning dissipation naturally heads to (read this paper in a little more detail to understand surface charging) http://www.lightningsafety.com/nlsi_lhm/Radials.pdf Since the water surface is where the positive charge is (for either fresh or salt water), the idea behind these new types of dissipaters is not to try and put the charge underwater but to simply re-create the spark in the air above the water and then let ionized air distribute the electrons to the positive charge at the water surface. There are some pictures illustrating this in the pdf file on the zenpole site but it appears that if you create the spark at the water surface, it will spread out for a larger distance in fresh water and smaller distance in salt water. Fresh water has less charge carriers and also the surface charges much slower than salt water (see the radial paper) and that could explain why the ionized radial patterns at the water surface are larger for fresh water than salt.

I’m just taking an educated guess here – but my opinion is that the surface discharge method could result in low enough impedance in fresh water to at least reduce the odds of the bottom of the mast flashing directly to the water surface through the air.
 

walt

.
Jun 1, 2007
3,546
Macgregor 26S Hobie TI Ridgway Colorado
Sumner, I think everything you said is correct (at least if its not correct, we are both wrong).

The idea with the floating electrodes is to keep at least two optimal discharge electrodes just above the water suface in the air - and do this regardless of waves or the boat heeling or motoring. If you look at the link at the first of this thread, you can see the design uses three "mostly pointy" rods that are rotated 60 degrees from each other. "Mostly pointy" reduces corona currents but still is good at creating a spark.
 
Jan 19, 2010
12,754
Hobie 16 & Rhodes 22 Skeeter Charleston
rgranger, I always have the greatest respect for anything from Don Casey and I wonder if his article on what you implemented mentioned that it only has a chance of working in salt water? I see you’re in fresh water (Smith Mountain lake) and I would propose that what you have wont do much because of the fresh water.

Thanks Walt: Good point. When I sail at SML I DO NOT stay out on the water in a lightning storm... Land is always a moment away.

The Darwin award is not on my bucket list...:D

I sail the Albemarle and Pamlico sounds several times/year and the Chesapeake bay occasionally... So far I have managed not to get caught out in a storm.... Did have a close call two years ago when a T-head chased me to shore but no lightning near our position. We ran with storm jib only that was enough to plane just a bit. Luckily I was close to the end of my cruise for the day. (Elizabeth City to Columbia) It was a short lived blast of a T-cell and I was glad to tie up to the pier and head into town for a burger and coke until the storm blew out. It was that storm that motivated me to put a ground from my mast to the keel. If it had blown in an hour earlier I would have been in the middle of the Albemarle and would have had to deal with it with my kids on board. I'm kind of a safety freek when my kids are on board.

W.R.T. Don's chapter on lightning protection. It was a section of a chapter from this book

http://www.amazon.com/Caseys-Comple...1?s=aps&ie=UTF8&qid=1336076496&sr=1-1-catcorr.

He goes into some detail about statistics and studies done ... he comes down on the side of "better to have it than not" from a statistics point of view. But nothing is fool proof and you should get off the water if you can. He does mention the fact that your ground plate needs to be larger in fresh water... and it is the perimeter length that is more important than the total surface area. For instance it is better to have a ground plate that is 6.75' x 1" (81sq inches) than one that is 9" x 9" (81sq inches). Even though the surface area is the same. Something about the lightning dissipating along the edges. So more edge is good. He also goes into some detail about how to run bonding grounds from chain plates so as not to induce currents in any of the on-board electrical systems in the event of a strike (ground wires should cross other wires at 90 degrees). It is a good read.
 

Attachments

Oct 6, 2011
678
CM 32 USA
National Lightning Safety Institute ~
May 3, 2012​


http://www.lightningsafety.com/nlsi_pls/boating.html


National Lightning Safety Institute May 3, 2012

Boating Lightning Safety

Lightning safety means recognizing a high-risk situation and evacuating in time to a low-risk situation.
Section 4.9


~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Their best recomidation is evacuation, not lightning rods floating in water.

People die from lightning, and it is nothing to fool around with, or try to jurry-rig protection measures that in the final result most likely will not work, but only give a false sence of security. Storms, evacuate the boat to a safe location till the storm passes if at all possible.




Lightning Photos. PowerPoint presentation.

Personal Lightning Safety Tips from National Lightning Safety Institute (NLSI).

When Thunder Roars, Go Indoors! from National Oceanic & Atmospheric Administration (NOAA).

Lightning: Its Frightening, Fascinating Power, from Boston Channel - Chronicle.


Lightning Segment One Video - 6:19 min.

Lightning Segment Two Video - 5:40 min.

Lightning Segment Three Video - 6:28 min.

Lightning Kills, Play It Safe from Farmers' Almanac.

Lightning KILLS! from NOAA's National Weather Service.

Lightning Myths: Fact or Fiction.What You Should Know About Electrical Storms by Maureen K. Fleury.

Lightning - The Underrated Killer from National Oceanic & Atmospheric Administration (NOAA), National Weather Service.

Lightning's Danger Isn't Always Seen by Chris Cappella, USATODAY.com.

Light on Lightning! Danger! from The Why Files.

How Does Nature Make Lightning? from The Why Files.

What are the medical effects of being struck by lightning? from The Why Files.

A Lightning Safety Mandate for the Game of Golf by Richard Kithil, President & CEO, National Lightning Safety Institute (NLSI): "A good rule for everyone is: 'If you can see it (lightning), flee it; if you can hear it (thunder), clear it.'"

Lightning Safety Quiz from Museum of Science, Boston.

Saving Lives, Protecting Property from Lightning Protection Institute (LPI).

Lightning Safety from WeatherEye.

Thunderstorms and Lightning from Federal Emergency Management Agency (FEMA), part of the U.S. Department of Homeland Security (DHS).

Lightning Statistics from Struck by Lightning.org. "There were 43 lightning fatalities for 2007 (in U.S.), 38 men and 5 women, all were outside when they were struck."
 
Jan 22, 2008
423
Catalina 30 Mandeville, La.
Give out your address, I am sure someone would love to sell you lightning rods. In storms, the people that follow in after to sell clean up services love homes with lightning rods because they know someone was there before and they are an easy sale. Just facts. No one here will mind that you often times grump at me as is your custom by the way, chip on your shoulder from the clique Mac forum I suspect, no matter, but I doubt very seriously people are going to stand buy and let you tarnish the name of a guy millions of Americans went to bed with four nights a week with for thirty years. Lol. There is a dirty jobs episode where the host is putting on lightning rods on new homes. Pretty entertaining.
Gary, I don't want to come off here like I'm picking at you, but I work in radio communications and am very familiar with lightning protection for communications facilities. I have had extensive training on the subject. Based on that, I really disagree with a lot of what you are saying here. What you are claiming sounds more like folklore and not actual facts. There's no 'mystery' regarding lightning. Some buildings, including houses, can benefit from having lightning rods. For example: a house or building on a hilltop, on the beach, or a wide open plain. Anyplace where it's the tallest structure around, would be a good candidate for lightning rods. I agree though that there are situatons where it isn't necessary and assume that's what you're talking about.


Lightning is too out of control to predict and to big an event to control. You can try, but results are spotty. Do insurance companies give discounts for lightning rods. I have not heard of them doing so.
This is not true and the facts are that lightning strikes are controlled daily all over the world. Maybe your interpretation of controlling a strike and mine are different. When engineering the grounding on a tower for instance , we assume it will be struck sooner or later - probably dozens of times or more . We attempt to control the surge on the tower by creating a low impedance path to ground. I have been involved with hundreds of installations over a long period of time and can't recall any serious lightning damage to any communications gear. I have had several destroyed antennas - all on towers without lightning rods. The radio equipment attached to those antennas suffered no damage.

Lightning struck close by my business weeks ago, and every light went out, TVs out, fish pumps out. Everything went out for a split second and came back on. My lights are like street lights, so they were off 10 minutes before they came back on. I was using my computer at the time. The screen went out and you hear the fans power off. It was fully out. When stuff lit back up again, so did my computer. Same screen, same web site. As if nothing happened. I have no emergency power source or a lightning arrestor. I have no explanation how my computer did what it did. I would say the power was off a half of a second.
What you experienced, was the surge protection equipment of your power company kicking in. A nearby strike creates an electromagnetic field that can induce voltage surges on suspended power lines. It doesn't have to be a direct hit. Your computer has a power supply that converts AC to DC. Initially, the DC has a lot of ripple in the output. To smooth that out and provide a more steady DC output, a large capacitor is used to fill in between those ripples. A capacitor charges up almost like a battery and discharges in this case as the voltage drops between the ripples of voltage. It is likely discharging as the voltage is dropping in the supply when the power goes out and keeps the voltage high enough to maintain your computer. If it had been much longer, it would have shut down.
In rainstorms things get wet. Lightning usually follows the water to the earth or ground. It follows the water because it has the same "signature" as the environment the lightning is in, in the sky. Same ph, similar temperature, same dust particles in the rainwater as in the lightning clouds. This is why people struck by lightning that are wet from rain are seldom killed and why dry people struck by lightning are hurt much worse or killed. Wet objects are covered in natures perfect lightning protection. The problem with lightning is it often strikes before the rains start. The dumbest thing one can do in a thunderstorm is stand under a tree for protection from the rain. Best to stand in the rain as you seek an indoor structure well out of the weather
This is not true either. This "signature" stuff makes almost no sense. I say almost because your theory on wet people surviving more often could be the result of water (which isn't a good conductor of electricity- contrary to popular belief), being more conductive than human flesh and the fact that lightning surges travel more on the surface of conductors. That's actually called 'skin effect', but has nothing to do with actual skin. It's reference to what others here have pointed out regarding the use of wide straps and braided cables over large solid conductors. More surface area for the skin affect. What typically kills is the surge crossing your chest and stopping your heart. I don't follow much about people being struck and statistics, but it might be possible. It certainly has absolutely nothing to do with "nature's perfect lightning protection".

Deadly Facts

  • On average, about 200 people are killed by lightning in the United States every year.
  • The state of Florida holds the title of the “Deadliest State.” There are twice as many lightning casualties as in any other state.
  • The chance to be killed by lightning is 1 in 2,000.000. You have the same chance dying from falling out of bed.
  • Never talk on the phone while a storm is breaking outside. Not only do cell phones “attract” lightning, but about 1% of all lightning deaths in the U.S. are a result of people talking inside the home on a corded phone during a thunderstorm.
  • About 71% of all people struck by lightning survive. The fatal cases are usually the result of cardiac arrest. However, those who survive often suffer from serious health and psychological problems like loss of memory or sensitivity, insomnia, impaired hearing, or constant pain.
http://www.nws.noaa.gov/om/lightning/resources/LightningFactsSheet.pdf
I know for a fact that cell phones don't attract lightning. I doubt that came from the NWS, but maybe they have an agenda against the cell phone companies. I don't know where you got these deadly facts, but I would challenge the 1% talking on the phone too.

Like I said initially, I don't want to disagree just to disagree with you. It's just that I find much of your post contrary to commonly known facts, physics, and personal experience.
 
Status
Not open for further replies.