Lightning rod missing on building

[Skybuck Flying]

Hello,

Today there was a thunderstorm and a lot of rain.

I went to the back of my appartment and I noticed the lightning rod on the
other building is missing.

I am 100% sure there used to be a lightning rod there. I have pictures to
prove it too.

So I have some theories why the lightning rod is missing:

1. It was stolen by a copper thief.
2. It was wrecked by a cat (unlikely).
3. It was removed by the owner of the building.
4. It was stolen by aliens for fuel

It seems most likely that it was human intention to remove it.

Now the question is why was it removed ?

Again a few theories come to mind:

1. To make profit from copper.
2. To make the situation more safe.
3. To make the situation more dangerous, and perhaps trigger a fire or
lightning strike.

I am now unsure what to think of this I will sketch the situation though, so
I do not have to provide a picture.

The situation was as follows:

(First time I attempt ascii art in windows live mail):

+--------------+
| |
| |
+------+ | |
| | | |
| | | |

In case it doesn't come through properly:

..|
..|
..|
||
||

So there are two buildings.

The lower building had a lightning rod as well.

This lightning rod is now removed.

So the question is:

Is it safer to remove lightning rods from lower buildings so the higher
building catches the lightning ?!?

Perhaps this is done so that the lightning does not split into my window
which is near the lightning rod... if I happen to be standing there.

Or perhaps now it will I don’t know...

Perhaps it's also in some kind of guide line or law how to apply lightning
rods...

Make me think a little bit of "empire state building in new york"... it
probably catches the most lightning if not all ?!?

Bye,
Skybuck.

 

[Orac]

Hello,

Today there was a thunderstorm and a lot of rain.

Jeetje!

 

[Spehro Pefhany]

Correction, 30m RADIUS, sorry

Too late, the cat's dead.

 

[Ken]

Lightning protection can be a very complex field but a widely used rule
of thumb is to take an imaginary sphere, 30 meters in diameter, and roll
it all over the landscape, anything it can touch is at risk of being hit
and should be protected.

Steve

Example
http://www.hvi.uu.se/Lightning/bilder/bild3t.gif

 

[Rich Grise]

Hello,

Today there was a thunderstorm and a lot of rain.

I went to the back of my appartment and I noticed the lightning rod on the
other building is missing.

I am 100% sure there used to be a lightning rod there. I have pictures to
prove it too.

So I have some theories why the lightning rod is missing:

1. It was stolen by a copper thief.
2. It was wrecked by a cat (unlikely).
3. It was removed by the owner of the building.
4. It was stolen by aliens for fuel

You missed 5: It took a direct hit and vaporized or just melted and
slumped over to where you can't see it.

Hope This Helps!
Rich

 

[Rich Grise]

Too late, the cat's dead.

Of course it's dead! Nobody's fed or watered the damn thing in 75 years!

;-)
Rich

 

[Skybuck Flying]

"Rich Grise" wrote in message

Hello,

Today there was a thunderstorm and a lot of rain.

I went to the back of my appartment and I noticed the lightning rod on the
other building is missing.

I am 100% sure there used to be a lightning rod there. I have pictures to
prove it too.

So I have some theories why the lightning rod is missing:

1. It was stolen by a copper thief.
2. It was wrecked by a cat (unlikely).
3. It was removed by the owner of the building.
4. It was stolen by aliens for fuel

"
You missed 5: It took a direct hit and vaporized or just melted and
slumped over to where you can't see it.
"

If it melted then there should be something visible shouldn't there be ?

Perhaps the top section was not connected to the bottom section and
therefore it was removed but I doubt it.

I will tell you what is left over:

A slightly blue trace on the wall... probably "copper rust"

Does copper turn into a blue substance ?!?

If not then it might have been something else.

Bye,
Skybuck.

 

[[email protected]]

Not true, idiot. The arc will occur along the path of least
resistance, which relates to humidity and ions and 'leader
propagation'.
It is rarely ever "the shortest path".

While the initial ionization will certainly start through the path
with lowest resistance, but when the actual massive current starts
flowing, you have to consider also the inductance.

The longer paths usually have bends, in which the inductance is much
higher, causing a large voltage gradient. This gradient can cause a
flashover to a nearby grounded object and the main part of the current
peak is redirected that way (i.e. it takes the shortest path).

For instance in one church, the lighting conductor was running about
30 cm above the roof, then making two sharp bends and then running
vertically down at 30 cm distance from the wall into a proper
grounding electrode. The high gradient due to the bends caused a
flashover through the roof into the internal electric wiring, causing
considerable damage inside. There was an article with a few pictures
in Wireless World a few decades ago.

 

[Seum]

"Rich Grise" wrote in message


"
You missed 5: It took a direct hit and vaporized or just melted and
slumped over to where you can't see it.
"

If it melted then there should be something visible shouldn't there be ?

Perhaps the top section was not connected to the bottom section and
therefore it was removed but I doubt it.

I will tell you what is left over:

A slightly blue trace on the wall... probably "copper rust"

Does copper turn into a blue substance ?!?

If not then it might have been something else.

Bye,
Skybuck.

Acid rain on copper will leave a green color.

 

[Uwe Hercksen]

I am 100% sure there used to be a lightning rod there. I have pictures
to prove it too.

So I have some theories why the lightning rod is missing:

1. It was stolen by a copper thief.

Hello,

they often use other metalls than copper for lightning rods.

Bye

 

[Anthony Guzzi]

Of course it's dead! Nobody's fed or watered the damn thing in 75 years!

I figured it was because the cat got struck by lightning...

 

[Don Kelly]

Agreed with the high E field outside the bend but wasn't the church inside
the bends?

2 sharp bends - can't be 90 degrees but surely sum must be 90 degrees
(assuming the over roof conductor was parallel to ground). The proximity of
the internal wiring and other metallic material (eavestrough, metal fascia,
etc) at some point near the roof could be a factor as well. One can also
consider that there can be reflection effects with fast front waves that
have caused "backflash" at the top of transmission line towers when there
is a strike to the shield wire. (down tower inductance is also involved ).
This would also be related to your comment about inductance of a bend- which
would become important in the case of fast front waves.

Possibly "shortest path" should be the "electrically shortest path"- least
impedance- not the physically shortest path.
With lightning, this path may be quite different than expected so all design
is based on probability and crossed fingers. I have known of a case of
lightning striking near a building- blowing out wiring in the building then
ploughing a furrow across a farmyard to take out some other equipment. The
ground rod nearest to the strike point was ignored.

Don Kelly
cross out to reply


"Phil Hobbs" wrote in message

While the initial ionization will certainly start through the path
with lowest resistance, but when the actual massive current starts
flowing, you have to consider also the inductance.

The longer paths usually have bends, in which the inductance is much
higher, causing a large voltage gradient. This gradient can cause a
flashover to a nearby grounded object and the main part of the current
peak is redirected that way (i.e. it takes the shortest path).

For instance in one church, the lighting conductor was running about
30 cm above the roof, then making two sharp bends and then running
vertically down at 30 cm distance from the wall into a proper
grounding electrode. The high gradient due to the bends caused a
flashover through the roof into the internal electric wiring, causing
considerable damage inside. There was an article with a few pictures
in Wireless World a few decades ago.

Bends in conductors cause huge E field enhancements at the outside of
the bend.

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs
Principal
ElectroOptical Innovations
55 Orchard Rd
Briarcliff Manor NY 10510
845-480-2058

email: hobbs (atsign) electrooptical (period) net
http://electrooptical.net

 

[[email protected]]

Agreed with the high E field outside the bend but wasn't the church inside
the bends?

2 sharp bends - can't be 90 degrees but surely sum must be 90 degrees
(assuming the over roof conductor was parallel to ground). The proximity of
the internal wiring and other metallic material (eavestrough, metal fascia,
etc) at some point near the roof could be a factor as well.

I have seen lots of old historical buildings, with the conductor
follows the roof, the roof extends beyond the wall, the conductor
makes a 90-150 turn to go around the edge of the roof, continues
horizontally towards the wall and then bends 90 degrees to go down
vertically along the wall .

 

[Don Kelly]

"Androcles" wrote in message

| Agreed with the high E field outside the bend but wasn't the church inside
| the bends?

Dogleg, Don. Chicane if you prefer.
http://en.wikipedia.org/wiki/Dogleg

| 2 sharp bends - can't be 90 degrees but surely sum must be 90 degrees
| (assuming the over roof conductor was parallel to ground).

Dogleg sums to 180 degrees.
Down the spire, across the roof, down the wall: dogleg.
----------------------
Since the original message didn't mention a spire- somewhat important
information- I did not assume one.
There are a number of churches in my vicinity- none have spires. However, I
did pass (a few days and 1000 miles away) an Orthodox church which had
several to spare.

Don Kelly
cross out to reply

 

[Don Kelly]

"Benj" wrote in message

Possibly "shortest path" should be the "electrically shortest path"- least
impedance- not the physically shortest path.
With lightning, this path may be quite different than expected so all
design
is based on probability and crossed fingers. I have known of a case of
lightning striking near a building- blowing out wiring in the building
then
ploughing a furrow across a farmyard to take out some other equipment. The
ground rod nearest to the strike point was ignored.

Don Kelly

Don is right. Lightning is known to do extremely strange things when
striking buildings/the ground/trees/people/etc. Mostly you try to
provide paths to grounds (lightening rods) and hope for the best.
Still any protection is better than none. The lightning rod was
invented by Benjamin Franklin because of the constant burning of barns
from lightning strikes. The "lightning rod salesman" has been a staple
of rural culture for much of the 20th century. The missing rod and
cable is probably due to "copper thieves". Electric companies have
been having huge problems with these thieves stealing ground wires
from systems to sell the copper. They don't care about the dangers
that this creates. In fact they just don't care period. A church near
me recently had a brand new $20,000 air conditioner stripped of all
copper (probably worth maybe $35). But also one of the functions of
lightning rods is to alter the sky-ground E field gradients. By doing
so you can alter the equipotential map such that lightning will tend
to strike in places other than your buildings (places of higher
gradients). I forget the values but the gradients can be quite high
something like hundreds of volts per meter? Maybe Don knows more.
------------------------------
1)Overhead ground wires (for lightning protection) are generally steel,
sometimes ACSR (aluminum cable steel reinforced) For calculation of the
characteristic impedance of such wires, an effective radius of 15cm is often
used to account for corona. typically Z=60*ln 2h/r where h is the height
from ground (horizontal wire). Actual conductor resistance is a minor issue
2) Fair weather atmospheric E fields of 100-300v/m are not uncommon. During
storms, fields near ground could be in the 50+KV/m range even if there are
no strikes nearby. Much higher fields have been measured in clouds.
Actually the rod will raise the E field above it - tending to make it a
better target. Corona might effectively lengthen the rod and increase its
diameter which would tend to limit gradients. There have been arguments
that rods tend to reduce local gradients by bleeding off atmospheric charges
(looky- they produce corona flares when a storm approaches) and at least one
"protection scheme" was based on that. In general this concept has received
little credence. The rod as target philosophy is still the general basis of
design.
3) as for the inductance of a down conductor- while it has an effect, in the
cases where backflash (from struck shield to phase conductor) is a factor
on transmission lines - tower inductance would make a difference for fast
front waves -say, rising to peak well under a microsecond -the average is
about 1.5 microseconds. Quite often the tower is treated as a cylinder
and wave reflections rather than inductances are considered.
This could be done with building protection- use strike distance design to
eliminate direct strokes above a tolerable level and then consider an
average stroke and the T-line surge models with regard to reflections. Throw
in lightning statistics and come up with what gives a reasonable probability
of such backflash. Add several ounces of Bougerre' factors cross fingers
and squat, not lie, on the ground.

Note:, it has been about 20 years since I was involved in this and it was
for transmission line design (much based on EPRI's EHV reference book and
other sources which I do not have at present) and only considered building
protection in passing- so I have a lot of rust accumulated.


Don Kelly
cross out to reply

 

[Skybuck Flying]

Please don't "shout" it makes it hard to read !

"The Ghost In The Machine" wrote in message

"Benj" wrote in message





Don is right. Lightning is known to do extremely strange things when
striking buildings/the ground/trees/people/etc. Mostly you try to
provide paths to grounds (lightening rods) and hope for the best.
Still any protection is better than none. The lightning rod was
invented by Benjamin Franklin because of the constant burning of barns
from lightning strikes. The "lightning rod salesman" has been a staple
of rural culture for much of the 20th century. The missing rod and
cable is probably due to "copper thieves". Electric companies have
been having huge problems with these thieves stealing ground wires
from systems to sell the copper. They don't care about the dangers
that this creates. In fact they just don't care period. A church near
me recently had a brand new $20,000 air conditioner stripped of all
copper (probably worth maybe $35). But also one of the functions of
lightning rods is to alter the sky-ground E field gradients. By doing
so you can alter the equipotential map such that lightning will tend
to strike in places other than your buildings (places of higher
gradients). I forget the values but the gradients can be quite high
something like hundreds of volts per meter? Maybe Don knows more.
------------------------------
1)Overhead ground wires (for lightning protection) are generally steel,
sometimes ACSR (aluminum cable steel reinforced) For calculation of the
characteristic impedance of such wires, an effective radius of 15cm is
often
used to account for corona. typically Z=60*ln 2h/r where h is the height
from ground (horizontal wire). Actual conductor resistance is a minor
issue
2) Fair weather atmospheric E fields of 100-300v/m are not uncommon.
During
storms, fields near ground could be in the 50+KV/m range even if there are
no strikes nearby. Much higher fields have been measured in clouds.
Actually the rod will raise the E field above it - tending to make it a
better target. Corona might effectively lengthen the rod and increase
its
diameter which would tend to limit gradients. There have been arguments
that rods tend to reduce local gradients by bleeding off atmospheric
charges
(looky- they produce corona flares when a storm approaches) and at least
one
"protection scheme" was based on that. In general this concept has
received
little credence. The rod as target philosophy is still the general basis
of
design.
3) as for the inductance of a down conductor- while it has an effect, in
the
cases where backflash (from struck shield to phase conductor) is a factor
on transmission lines - tower inductance would make a difference for fast
front waves -say, rising to peak well under a microsecond -the average
is
about 1.5 microseconds. Quite often the tower is treated as a cylinder
and wave reflections rather than inductances are considered.
This could be done with building protection- use strike distance design to
eliminate direct strokes above a tolerable level and then consider an
average stroke and the T-line surge models with regard to reflections.
Throw
in lightning statistics and come up with what gives a reasonable
probability
of such backflash. Add several ounces of Bougerre' factors cross fingers
and squat, not lie, on the ground.

Note:, it has been about 20 years since I was involved in this and it was
for transmission line design (much based on EPRI's EHV reference book and
other sources which I do not have at present) and only considered building
protection in passing- so I have a lot of rust accumulated.

Don Kelly
cross out to reply

GO WEATHER A THUNDERSTORM, IT'LL ALL COME BACK TO YOU REFRESHED.
JUST STAY IN THE CLEAR CENTER AND AVOID STANDING TALLER THAN WHATS
UNDER THE DARK NEBULAS......OR ELSE MY ADVICE TO Y'ALL IS CLIMATICALLY
VOIDED
BOOWAHAHAHAHA.......WE R WEATHERING ONE RIGHT NOW.
YOU DOONKOFFZ ARE GOOD FOR NOTHING..WE COULD BE SETTING UP AN ARRESTOR
ARRAY LIKE NEVER SEEN BEFORE IN THE HISTORY OF THE WEATHER CHANNEL.
TEEHEEHEE ....DAMMIT!
TGITM
PATECUM

 

[Skybuck Flying]

Are you trying to give me eye cancer ?

I don't read most of your shit, because it looks like shit.

So it's pretty pointless for you to post, at least for me.

Perhaps there are many others who find your capital nonsense unpleasent to
read.

Didn't they teach you anything in school ?! =D

Bye,
Skybuck.


"Michael A.Terrell" wrote in message

Please don't "shout" it makes it hard to read !

"The Ghost In The Machine" wrote in
message





GO WEATHER A THUNDERSTORM, IT'LL ALL COME BACK TO YOU REFRESHED.
JUST STAY IN THE CLEAR CENTER AND AVOID STANDING TALLER THAN WHATS
UNDER THE DARK NEBULAS......OR ELSE MY ADVICE TO Y'ALL IS CLIMATICALLY
VOIDED
BOOWAHAHAHAHA.......WE R WEATHERING ONE RIGHT NOW.
YOU DOONKOFFZ ARE GOOD FOR NOTHING..WE COULD BE SETTING UP AN ARRESTOR
ARRAY LIKE NEVER SEEN BEFORE IN THE HISTORY OF THE WEATHER CHANNEL.
TEEHEEHEE ....DAMMIT!
TGITM
PATECUM

YOU MUST BE IN A DIFFERENT DIMENSION...
IN THIS ONE IT IS EASIER TO READ.....THIS DOESNT MEANS YOURE COOL,
FOOL.
AND STOP TRYING TO TELL ME HOW TO POST, YOU TROLLING FLYBOY.
MR. PATECUM
TGITM CO. INC.
BOOWAHAHAHAHAHAHA
WOAH HOBOHOHOHOHO
AHHHHHAHAHAHAHAHAHAHAHA
LEAVE IN SYMPATHY.....I KNOW WHATCHA DID, TERRELL.

 

[Skybuck Flying]

The doctor would tell me to put you on ignore is that what you want ?

Bye,
Skybuck

"The Ghost In The Machine" wrote in message

Are you trying to give me eye cancer ?

I don't read most of your shit, because it looks like shit.

So it's pretty pointless for you to post, at least for me.

Perhaps there are many others who find your capital nonsense unpleasent to
read.

Didn't they teach you anything in school ?! =D

Bye,
Skybuck.
PERSNICKETY SNIPPETY

GO SEE A DOCTOR ABOUT THAT CANCER.
SIGHHHHH.....THOUGH YOUR CRAP IS RANK & TOTALLY OFF TOPIC, PLEASE COME
BACK WHEN YOURE READY TO DISCUSS LIGHTNING ARRESTERS AGAIN.......AND
**** SCHOOL! :-/ IT DID NOTHING FOR YOU.
PATECUM
TGITM

 

[Skybuck Flying]

Windows Live Mail should get an auto-text-beautifier just for ghosties like
this ghostie...

Bye,
Skyghost ! =D

Where's pacman when you need him ?! =D

"The Ghost In The Machine" wrote in message

All-caps is pretty hard to read, isn't it.


That's Pattycakes, the retarded pretend ghost. The problem is he drooled
on his keyboard and shorted out his caps-lock key, now it can't be turned
off.

WHO ARE YOU RESPONDING TO MICHELLE?
AND WHAT THE **** ARE YOU SAYING FOOL?
OHHHHH, NOW I SEE, ITS FLYING FUCKTARD....YOUR GAY LITTLE ANTICS HAS
FINALLY LANDED YOU A NICE BOYFRIEND...I HOPE YOU FIND THE GAY
HAPPINESS YOU DESERVE IN EACH OTHERS ASS.
IT'S PATECUM ......NOT PATTYCAKES...YOU FREAKY DICK JOCKEY.
TGITM

 

[Don Kelly]

"Michael Moroney" wrote in message

How could I be anti-ghost? I have never seen a ghost and I have never
communicated with one, either. Just a pretender.
---------------------------------
Please, Michael, don't feed it. When you do, you publicize its puerile
rants- which I don't get directly because I kill filed it long ago.


Don Kelly
cross out to reply