Lightning and Thunderstorms
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Harrison
- First Officer
- Posts: 307
- Joined: Tue Jan 04, 2005 12:57 pm
- Location: Frederick, CO. '05 M, Merc 60 Bigfoot
Yes. That is correct. I tested this theory before I installed the wick. Since I've been shocked so many times, I planned on tossing a copper wire into the water which was attached to the standing rigging during a sparking episode. The sparking stopped immeadiatly upon the wire contacting the water.walt wrote:I would geuss that the under the conditions when the shocks occured, you have an ungrounded mast.
Anything is possible with mother nature running things. Could it be coinsidental? Sure! Could it actually work? Sure. Do I feel that I am reducing and "possibly" elimanating small potential static buildup? Yes. Do I feel that I am now invincible from lightning? DEFINATLY NOT.walt wrote:Its also possible that the summers were simply different and that you will eventually see the shocking effects again if you did nothing else to the boat but put on the disipator.
---Harrison
On edit: Someone mentioned about the wheel being metal and possible problems steering home. The strange thing is, the dozen plus time I've experienced sparking, the wheel offered no shocks. The mast, boom, standing rigging, and the lifelines were sparking 2-3 times per second, but the wheel was safe to hold on to. Go figure.
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Frank C
My bad ... it was the second embedded link, now quoted below, in which Rich linked to the items he uses on his tower:walt wrote:Frank, the disipators I was wondering about would be used on the big radio towers. I was assuming they would be at least larger and possibly a different structure than those intended for boats.
Hamin' X wrote:Just a slight rehash from before. Grounding your boat's rigging will only make it more attractive to lightning. Your best protection is to dissipate your charge buildup into the atmosphere via a static wick.
Marine version, or Electronics version.
I have been using the electronics version for years on mountain top tower installations, with no strikes. Other towers around me, have trouble all the time. The same idea has been used on aircraft for years.
Rich
Admitting that I'm an Electri-dunce, but did I miss something?walt wrote: . . . if you could hear sparks occuring, do you know about where they were comming from on the boat? I would guess its from two metal structures which come very close to each other ...
I thought Harrison was pretty explicit, either above or in a related thread.
The sparks were jumping between shroud and lifeline, once per second.
Isn't that evidence of a Faraday cage at work?
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Hamin' X
- Site Admin
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- Joined: Sat Aug 27, 2005 6:02 pm
- Sailboat: MacGregor 26X
- Location: Hermiston, OR-----------2001 26X DF-50 Suz---------------(Now Sold)
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Walt,
Remember that the ground charge is not a free electron charge that moves around the structure on wires. It is an ION charge that flows over a structure in a fluid (the atmosphere). In spite of bonding and grounding wires provided for the purpose, the ground charge will flow, even over insulators and accumulate on a structure according to point-discharge principles.
This concept of ground charge motion helps address the question of the need for a bonding wire from the dissipator to the grounding system. Obviously, the ground charge gets to the top of the structure all by itself, or else the structure would not have a lightning problem. Therefore, the structure of the boat is sufficient to convey the ground charge to the dissipator.
Please do not confuse ion charge with electron charge. It is the accumulation of a positive ion (cations) charge that initiates the upward ion-streamer, that creates the ionized path that the lightning strike (electrons) follow. Once the electrons flow to the boat from the cloud. they will find the most convenient path to ground.
I find it curious that there are so many naysayers to the dissipator systems, but no peer reviewed studies to disprove their worth.
Also, at the frequencies and voltages of lightning, it is more affected by the skin affect aspect of conduction, much like RF. This means that it's conduction is more dependent on the surface area of the conductor than the thickness. Round conductors minimize the surface area, while flat maximizes it. If you are willing to drape your boat in copper foil, connected to a zinc keel, go for it. Might make for an unusual sight.
The main problem with grounding systems is the quality of ground connections. With the peak voltage of lightning reaching 1.0E+9 V, that's, one billion Volts folks, and a current of over 1,000 amps, this is 1,000,000,000,000 (one trillion) Watts of power. You must make a ground system capable of handling this amount of power. If you have a connection that has only .1 Ohms of resistance (not much), you will have 10,000 watts of heating at that point. More important, you will be forcing the current to find a better path. Most likely through your electronics.
Don't you think it would be much easier to get your boat's potential closer to the cloud's by bleeding off the excess ions to the atmosphere via dissipators?
Only my 2 cents worth from 40 years of practical experience.
Rich---Hamin' X---N7ZH
Remember that the ground charge is not a free electron charge that moves around the structure on wires. It is an ION charge that flows over a structure in a fluid (the atmosphere). In spite of bonding and grounding wires provided for the purpose, the ground charge will flow, even over insulators and accumulate on a structure according to point-discharge principles.
This concept of ground charge motion helps address the question of the need for a bonding wire from the dissipator to the grounding system. Obviously, the ground charge gets to the top of the structure all by itself, or else the structure would not have a lightning problem. Therefore, the structure of the boat is sufficient to convey the ground charge to the dissipator.
Please do not confuse ion charge with electron charge. It is the accumulation of a positive ion (cations) charge that initiates the upward ion-streamer, that creates the ionized path that the lightning strike (electrons) follow. Once the electrons flow to the boat from the cloud. they will find the most convenient path to ground.
I find it curious that there are so many naysayers to the dissipator systems, but no peer reviewed studies to disprove their worth.
Also, at the frequencies and voltages of lightning, it is more affected by the skin affect aspect of conduction, much like RF. This means that it's conduction is more dependent on the surface area of the conductor than the thickness. Round conductors minimize the surface area, while flat maximizes it. If you are willing to drape your boat in copper foil, connected to a zinc keel, go for it. Might make for an unusual sight.
The main problem with grounding systems is the quality of ground connections. With the peak voltage of lightning reaching 1.0E+9 V, that's, one billion Volts folks, and a current of over 1,000 amps, this is 1,000,000,000,000 (one trillion) Watts of power. You must make a ground system capable of handling this amount of power. If you have a connection that has only .1 Ohms of resistance (not much), you will have 10,000 watts of heating at that point. More important, you will be forcing the current to find a better path. Most likely through your electronics.
Don't you think it would be much easier to get your boat's potential closer to the cloud's by bleeding off the excess ions to the atmosphere via dissipators?
Only my 2 cents worth from 40 years of practical experience.
Rich---Hamin' X---N7ZH
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Harrison
- First Officer
- Posts: 307
- Joined: Tue Jan 04, 2005 12:57 pm
- Location: Frederick, CO. '05 M, Merc 60 Bigfoot
You are correct. Yes this was at Union in Longmont. One particular time the sparking was going on for about 1/2 hour. This particular time, I (luckily) was off the boat and it was tied up at the dock right next ot my brothers sailboat (22 Merrit). This was a croud pleaser as the onlookers were watching my boat spark and crack, while my brothers boat remained un-reactive. It was dark at night so the show was quite spectacular. I have to admit that being on the shore watching this go on is a much better place to be than on the water. Additionally my steaming light was flashing as the charges built and dissapated. With that in mind, on two seperate occasions this episode blew my starting fuse on my motor making my motor useless. It has also blown out my fishfinder and my GPS. So. . . I feel that during these charges, NOTHING IS SAFE.walt wrote:The spark probably occured where the two parts of each system came the closest. Each time the spark occured, some charge was transferred and the potential voltage between each structure was reduced. So in order for there to be a spark occur again, the electric field had to be increasing. I wonder how long the sparking lasted? (was this at Union lake?).
---Harrison
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Hamin' X
- Site Admin
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- Joined: Sat Aug 27, 2005 6:02 pm
- Sailboat: MacGregor 26X
- Location: Hermiston, OR-----------2001 26X DF-50 Suz---------------(Now Sold)
- Contact:
Walt,
I misstated my case for the dissipators in a previous post. The dissipator is not shedding ions, but rather excess electrons. The negative charge in the cloud is causing an ionization of the objects below it. This is a surface, or skin effect and turns the objects into semiconductors, as it were. This allows electrons to flow over the objects toward the cloud. As this is a semiconductor effect, the objects do not have to be real conductors. (Like dead trees, or people.) The reason that the commercial towers have the dissipators connected to the ground system is for insurance. No system is 100% effective. If the flow of electrons through the ionized layer of the structure is too great, the dissipator may become swamped and emit an upward leader that would permit a downward strike to follow the ionized path through the atmosphere. Grounding alone without the dissipator however, will make you a more attractive target, as there is only one way for the excessive charge to dissipate. By upward leader to the cloud. The job of the dissipator is to bleed the charge off at less than air ionizing levels. Also, since this is a semiconductor like effect, the insulating properties do not matter much. Remember the balloon. Also, in old time physics classes, the instructor would rub a Lucite rod with cat fur to create a charge. Walking across a carpet with hard soled shoes is another example. The electrons can flow over the surface of fiberglass antennas just fine and the flow through rusted joints and bad connections actually radiate RF, creating interference with communications equipment.
There is no perfect solution and much is not known about lightning. What is known is that it is near impossible to create an effective grounding system on a fiberglass boat. For my money, I will go with the avoidance system. It has served me well for many years.
As to a previous question that you ask, I do not connect my dissipators to a grounding system, as I believe that this causes more problems that it solves. Without a perfect ground system and at the voltage and current levels of lightning, you will be forcing the charge to find alternate routes to ground. (though your equipment) I do bond all of my equipment to a common ground inside the buildings. This way everything is elevated to the same potential, at the same time. It is the difference in potentials that destroys electronics. I am not a commercial operator, but rather a radio amateur (Ham). As such, I do not have the multi-thousands of dollars to dump into my repeater installations for a chemical, ring grounding system that is required on rocky mountaintops. My method is avoidance only
Rich---Hamin' X---N7ZH
I misstated my case for the dissipators in a previous post. The dissipator is not shedding ions, but rather excess electrons. The negative charge in the cloud is causing an ionization of the objects below it. This is a surface, or skin effect and turns the objects into semiconductors, as it were. This allows electrons to flow over the objects toward the cloud. As this is a semiconductor effect, the objects do not have to be real conductors. (Like dead trees, or people.) The reason that the commercial towers have the dissipators connected to the ground system is for insurance. No system is 100% effective. If the flow of electrons through the ionized layer of the structure is too great, the dissipator may become swamped and emit an upward leader that would permit a downward strike to follow the ionized path through the atmosphere. Grounding alone without the dissipator however, will make you a more attractive target, as there is only one way for the excessive charge to dissipate. By upward leader to the cloud. The job of the dissipator is to bleed the charge off at less than air ionizing levels. Also, since this is a semiconductor like effect, the insulating properties do not matter much. Remember the balloon. Also, in old time physics classes, the instructor would rub a Lucite rod with cat fur to create a charge. Walking across a carpet with hard soled shoes is another example. The electrons can flow over the surface of fiberglass antennas just fine and the flow through rusted joints and bad connections actually radiate RF, creating interference with communications equipment.
There is no perfect solution and much is not known about lightning. What is known is that it is near impossible to create an effective grounding system on a fiberglass boat. For my money, I will go with the avoidance system. It has served me well for many years.
As to a previous question that you ask, I do not connect my dissipators to a grounding system, as I believe that this causes more problems that it solves. Without a perfect ground system and at the voltage and current levels of lightning, you will be forcing the charge to find alternate routes to ground. (though your equipment) I do bond all of my equipment to a common ground inside the buildings. This way everything is elevated to the same potential, at the same time. It is the difference in potentials that destroys electronics. I am not a commercial operator, but rather a radio amateur (Ham). As such, I do not have the multi-thousands of dollars to dump into my repeater installations for a chemical, ring grounding system that is required on rocky mountaintops. My method is avoidance only
Rich---Hamin' X---N7ZH