MAKING FARADAY CAGES
The reality
of needing to protect all
electronic equipment against EMP from a
nuclear explosion over our shores is becoming
imminent. We now live in perilous times. The
world is a becoming dangerous place, with
China now threatening Taiwan with
annihilation from hundreds of neutron bombs.
Russia is modernizing their military
infrastructure with an emphasis on first
strike capability, they have an stretegic
alliance with China, and Putin is
exporting "special nuclear materials" to
Iran, Syria and Egypt. President Clinton
renounced "launch on attack" in favor of
absorbing a first strike without retaliation,
while President Bush wants "first strike"
authority to attack anywhere with nukes
without warning, and it is easy to see that
our enemies are virtually being invited to
hit us with nukes! Iran has plans to do
just that!
Nuke Over U. S. Could Unleash
Electromagnetic (EMP) Tsunami
The
information to follow on building "Faraday
cages" is timely indeed. A single atmospheric
nuclear detonation releases enough
electromagnetic pulse (EMP) to equal 100,000 volts per meter
(V/m). A single detonation 200
to 400 miles over the center of the
continental United States would fry every
unprotected computer chip from coast to
coast, and from the middle of Canada to the
middle of Mexico. And we are now into Solar
Cycle 23, with solar flares common and
expected to continue until the first of next
year. CME's are capable of extreme damage to
modern computerized equipment! Sure, we have
our windup BayGen radio's and spare lap top
computers, but unless electronic equipment is
protected from an electromagnetic pulse, they
will be fried!
When
Einstein and the others first refined and
purified uranium, they took time off and
studied its properties. That is when they
discovered the "rays" that were harmful, as
well as the phase transformations. In the
course of their work, one of the scientists
discovered that simply covering an object
with a grounded copper mesh would stop
virtually all electromagnetic radiation,
whether proton or neutron. Obviously, they
had to protect their monitoring equipment!
Thus was born the "Faraday cage."
The copper
mesh, like 1 inch chicken wire, worked well
in large uses, like covering buildings, and
it is still in use today: FEMA headquarters
buildings are dome-shaped earth-bermed
structures, and under the earth is a copper
mesh that extends out from the base and is
secured by grounding rods.
As an
Electro Magnetic Pulse (EMP) travels to
earth, whether from a Coronal Mass Ejection
(CME) or a nuclear detonation in the
atmosphere, it hits and runs along electrical
power lines as well, building up voltage and
amperage, which is what happened during the
last solar storm a dozen years ago, blowing
out transformers and leaving 6 million people
in eastern Canada without power for
weeks.
To prevent
that problem, if you have a hard-wired
generator, the wiring from the generator to
the house should run in conduit that is
grounded. The generator itself can have the
frame grounded for added insurance, but that
ground wire MUST be insulated and run to a
different ground rod well away from the
ground rod for building and conduit!
See the article on EMP
and various grounding techniques for
electrical appliances, plus grounding metal
sheds for generators.
"Electric
fields travel in straight lines, unless bent
by other fields. Theoretically, the bottom of
a cage doesn t need to be closed. If someone
could offer me actual EMP test data that an
open bottom is OK, I d consider believing it.
However, if you re in an area of high
ionization, the field could bend around.
Complete enclosure is the best technical
solution.
"Faraday
cage material: Electric fields are best
conducted by materials that conduct electric
current the best silver is #1 and copper is
#2. Aluminum is ~60% of copper. Iron/steel is
farther down the scale. Aluminum is a good
poor man s foil against EMP; double wrap it
to be safe. I prefer copper
foil." Ikstrums,
Sept. 2, 2005
|
|
|
Here is the tiny Survival
Radio and Faraday Cage in my
Survival
Shop.
Steel tinned EMP box, hinged
lid, 4 1/4" x 3 1/8" x 1".
Holds
the Survival radio nice and secure.
With strong, thin cardboard inside to
provide insulation, the radio is
protected against dust, dirt, etc,
and EMP!!! Stronger and
easier to make than a cardboard box
covered with tinfoil.
|
With
radio's and smaller appliances, a Faraday
cage can be built by using two cardboard
boxes: one should fit tightly inside the
other, and the item to be covered should
itself fit reasonably well inside the smaller
box. That is about the most work
involved--finding the right size boxes! The
outer box is then covered with aluminum foil
or Mylar, as from a cheap "space blanket." A
grounding wire is then taped to the foil. I
then cover the foil with black 6 mil plastic,
taped securely in place, to protect the foil
from ripping. At the end of the ground wire I
attach a cheap small alligator clip from
Radio Shack. The item to be protected is
placed inside the inner box, which acts as
insulation from the outer box, and any EMP
hitting the foil and is bled away by the
ground wire.
Some medium
sized electrical equipment can also easily
fit into boxes covered with foil for EMP
protection. My laptop computer, for example,
fits easily into a Faraday box made from a
box that held reams of paper: the entire lid
is removable, allowing easy access to the
laptop in its case, but is safely stored when
not in use.
For larger
items which cannot be boxed, such as living
room TV sets, etc, I tape a Mylar space
blanket to a piece of 6 mil black plastic
sheet, using double-sticky tape every foot or
so to make sure the Mylar stays in place (it
is slippery). I leave a 2 inch edge of black
plastic showing all around the space blanket,
and while taping down the edges I put on a
short lead of ground wire. When it appears
that EMP or CME's are on the way, the blanket
can be draped over the appliance, the
alligator clip attached to a small,
unobtrusive ground wire behind the cabinet,
and any electromagnetic radiation will be
diverted to the ground wire. Very cheap,
simple, and once done, items can be "draped"
for protection very quickly indeed. The "EMP
Blankets" roll up for storage, but can be
unrolled and thrown over a TV/VCR setup, a
computer/monitor combo, etc. As EMP comes
from altitude and is line of sight, it's OK
that the bottom isn't covered, as the bottom
of the units sit on non conductive
wood.
The time to
build Faraday cages or blankets is NOW, as
when they are actually needed it will be far
too late. Each box should be labeled on the
ends and the top for the exact appliance they
were built for, to eliminate any confusion
when they must be protected in a hurry. Any
electrical appliances not in use should be
stored in the Faraday cage, where they will
be kept clean, neat, in a known location, and
protected against any sudden EMP
surge.
NOTE:
There are electrical engineers who say that
only ferrous metal boxes will protect against
EMP-enhanced weapons, while other sources say
EMP is not a problem at all. I'll take
the middle ground.
|
|
Back, left
corner of metal shed is grounded with
1/4" ground wire to a ground rod. The
wooden floor of the shed is non
conductive. |
A nuclear
ground burst over 200 miles away should only
result in 50,000 volts per square centimeter
(sc) on your equipment, so the above Faraday
cages should work. An air burst within
200 miles can result in up to 100,000 volts
per sc, and that would require grounding of
any Faraday cage to a separate ground
rod well away from any house ground
rods. An enhanced EMP weapon exploded
at 200 miles elevation can yield over 120,000
volts per sc within up to 600 miles below the
detonation point, and that would definitely
require insulated metal boxes which are
grounded. Remember, in the battle of
warhead versus armor, the warhead usually
wins, as the warhead can be made
bigger. However, for those who build
simple Faraday cages and live in an area not
likely to receive a direct or close nuclear
attack, the foil cages described should
work. Those under a direct or close
nuclear attack would probably not survive to
use their electronic equipment in any
case.
For a more
details examination on EMP
and its effects, click at
left.
~~~~~~
Question
from reader Augustino: August 11,
2010
Miles -
Question... I'm reading that one should have
electronic equipment such as 2 way radios, AM
- FM - SHORTWAVE radios, etc... stored in a
faraday cage or box to protect from EMP.
And sure you can use a microwave oven to
stash radios in but most are rather small. So
as I'm reading and researching I see
something that really floors me! They say the
best faraday is a galvanized garbage can.
Place doubled up contractor grade trash bags
one inside the other, inside the trash can.
Place items you want protected into the trash
bags that are inside the garbage can. Place
the lid on tight and for added security
attach a copper wire to the galvanized can
and then to a grounded rod! There you
go a super sized faraday container.
augustino
Response.
Virtually any metal container can be used as
a Faraday cage. Actually, galvanized
garbage cans are an inefficient method
because of two reasons: wasted space
and insulation. They are round and
things put into them are rectangular or
square, so a lot of "corner space" cannot be
used.
Second, the garbage bags are not sufficient
insulation. One little tear in the bag
allowing one item to touch the side of the
metal can could be enough to electrocute
everything inside. Cardboard is a much
better insulator.
Garbage cans can be used, but old filing
cabinets or freezers are better. Pieces
of cardboard can be easily cut to line the
inside for insulation. The shape of the
interior space provides more items to be
stored per square foot of exterior
space. The shelving allows items to be
separated and organized, used as needed, and
then easily stored safely again. With a
garbage can, half the items would be deeply
buried. Retrieval of one item could
mean removing half the items, and use such as
that could easily translate into a tear in a
garbage can liner which would endanger all of
the stored items.
Miles
BACK
Site Index