I don't know another group to post to and have gotten answers on questions here
in the past.

I was watching The Weather Channel on TV, and they were doing a helicopter
rescue in a flash flood in Vegas area.

The policeman who actually went down the cable to rescue the trapped girl said
:

Electricity follows down the cable and as you get near the water you start
grounding out and the shock hits you and feels like "twice the strength of
sticking your finger in a light socket".

NEVER HEARD OF THIS !

Where is the electricity coming from ?
Static from a cable going down a pulley ?
If true, why can't they put some kind of INSULATOR between the hook and the
cable ?
Construction workers experience cranes and cables on pulleys everyday with no
problem AFAIK.
Where is the electricity coming from ?


We always see these rescues on TV, and no rescuer looks like s/he is shocked at
240 volts.

TIA

Conase wrote:
I don't know another group to post to and have gotten answers on
questions here in the past.

I was watching The Weather Channel on TV, and they were doing a
helicopter rescue in a flash flood in Vegas area.

The policeman who actually went down the cable to rescue the trapped
girl said


Electricity follows down the cable and as you get near the water you
start grounding out and the shock hits you and feels like "twice the
strength of sticking your finger in a light socket".

NEVER HEARD OF THIS !

Where is the electricity coming from ?
Static from a cable going down a pulley ?
If true, why can't they put some kind of INSULATOR between the hook
and the cable ?
Construction workers experience cranes and cables on pulleys everyday
with no problem AFAIK.
Where is the electricity coming from ?


We always see these rescues on TV, and no rescuer looks like s/he is
shocked at 240 volts.

TIA

Static. Rather high voltage and difficult to overcome with an insulator
large enough to stop it and still suitable for the use. It would also
likely require a grounding of the line to the local earth prior to pickup,
not always possible.

Personally I think the description "twice the strength of sticking your
finger in a light socket" was poorly chosen at best.



--
Joseph E. Meehan

26 + 6 = 1 It's Irish Math

Conase,

The cables and cranes used in construction are usually attached to the
earth so if static electric charges are deposited on them by passing clouds
et c. the electricity will flow to the ground. Air craft, on the other hand
are not connected to the ground during flight. Static charges built up
during flight will be discharged via the rescue cable as it nears the
ground. If you are standing on the ground and reach for a cable that has not
yet touched the ground the static electricity will discharge through you.

Dave M.

The electricity comes from the rotors developing a static charge it can
be very high, the larger the blades , larger helicopters, and proper
weather conditions can knock someone over . IR [i beleive]
photography at night will show it visibly. Electricity could jump an
insulator as well its strength would be a problem.

m Ransley wrote:
The electricity comes from the rotors developing a static charge it can
be very high, the larger the blades , larger helicopters, and proper
weather conditions can knock someone over . IR [i beleive]
photography at night will show it visibly. Electricity could jump an
insulator as well its strength would be a problem.

If you would like to see Hollywood's interpretation of this phenomenon;
rent "The Hunt for Red October". In a scene, the character Jack Ryan
(Alec Baldwin) is transferred from a carrier to a submarine. Due to the
choppy water, a boat transfer was not advised, so they dropped him on the
sub via helo. The seaman on the sub has an insulated shepherd's crook to
catch their "electrically charged" passenger.

Not sure how accurate the scene is; but it is based on real
facts/experience.

Chris

Use to have the same problem when sand blasting, the new guys would often
grab a plastic 5 gallon bucket, put a bunch of small pieces of metal in it
and start blasting, they usually discovered very quickly that when the metal
head from their blast hose got to close to the bucket and grounded it they
would get knocked on their @$$ and we would hear a loud bang. If your smart
you only did it once. Never under estimate static electricity.




"Conase" wrote in message
...
I don't know another group to post to and have gotten answers on questions
here
in the past.

I was watching The Weather Channel on TV, and they were doing a helicopter
rescue in a flash flood in Vegas area.

The policeman who actually went down the cable to rescue the trapped girl
said
:

Electricity follows down the cable and as you get near the water you start
grounding out and the shock hits you and feels like "twice the strength of
sticking your finger in a light socket".

NEVER HEARD OF THIS !

Where is the electricity coming from ?
Static from a cable going down a pulley ?
If true, why can't they put some kind of INSULATOR between the hook and
the
cable ?
Construction workers experience cranes and cables on pulleys everyday with
no
problem AFAIK.
Where is the electricity coming from ?


We always see these rescues on TV, and no rescuer looks like s/he is
shocked at
240 volts.

TIA

I have a large deck surface covered with a composite (plastic) material.
Walking across this generates static electricity. You often get a shock when
you grab the door knob in the metal door, even though the door has no direct
grounding. Static can be generated in many ways. Even dirt and air being
sucked through a plastic vacuum hose will create a shock.

"R. Doornbosch" wrote in message
...
Use to have the same problem when sand blasting, the new guys would often
grab a plastic 5 gallon bucket, put a bunch of small pieces of metal in it
and start blasting, they usually discovered very quickly that when the
metal
head from their blast hose got to close to the bucket and grounded it they
would get knocked on their @$$ and we would hear a loud bang. If your
smart
you only did it once. Never under estimate static electricity.




"Conase" wrote in message
...
I don't know another group to post to and have gotten answers on
questions
here
in the past.

I was watching The Weather Channel on TV, and they were doing a
helicopter
rescue in a flash flood in Vegas area.

The policeman who actually went down the cable to rescue the trapped
girl
said
:

Electricity follows down the cable and as you get near the water you
start
grounding out and the shock hits you and feels like "twice the strength
of
sticking your finger in a light socket".

NEVER HEARD OF THIS !

Where is the electricity coming from ?
Static from a cable going down a pulley ?
If true, why can't they put some kind of INSULATOR between the hook and
the
cable ?
Construction workers experience cranes and cables on pulleys everyday
with
no
problem AFAIK.
Where is the electricity coming from ?


We always see these rescues on TV, and no rescuer looks like s/he is
shocked at
240 volts.

TIA

With the right weather and a big chopper death could result.

Taking a vacume cleaner to sensitive electronics can deliver a fatal
blow to your unit, car fires are started at gas pumps from static
electricity. Unloading a pickup with bed liner loaded with equipment
can give a jolt.

IF you want to scientific about it you don't really generate static
electricity as much as you attract it. So to be very basic everything in
life is either giving electrons or taking them, even if you don't always
notice. These electrons are just lazy, and very "Canadian" they like lots of
open space around them so they are always looking for more space. So they
jump onto big Rotor blades and then see some really big ground and it looks
even better. Just make sure your not in the way of them getting there

Conase writes:

Where is the electricity coming from ?

If there are high voltage power lines nearby, the field strength can be
many volts/meter even at some distance, and a long conductive cable can
induce a lot of voltage.

Conase writes:

Where is the electricity coming from ?

If there are high voltage power lines nearby, the field strength can be
many volts/meter even at some distance, and a long conductive cable can
induce a lot of voltage.


Holy static discharge, Batman !!!

Thanks for the intelligent discussion of a serious question.

Learned a lot about different forms of STATIC electricity that I never really
thought of.

Never knew they make the HORSE COLLAR hit the water first to discharge
potential electricity.

Thanks again.

The military has an interesting way of landing artillery from a
helocopter. The ground crew has a long pole that is grounded at one end
and has a hook on the other. They hook the piece first to ground it then
they lower it so the ground crew can grab it and move it into position

On 28 May 2004 11:45:49 GMT, (Conase) wrote:

I don't know another group to post to and have gotten answers on questions here
in the past.

I was watching The Weather Channel on TV, and they were doing a helicopter
rescue in a flash flood in Vegas area.

The policeman who actually went down the cable to rescue the trapped girl said
:

Electricity follows down the cable and as you get near the water you start
grounding out and the shock hits you and feels like "twice the strength of
sticking your finger in a light socket".

NEVER HEARD OF THIS !

Where is the electricity coming from ?

Static generated by the rotor blades.

Static from a cable going down a pulley ?

It's metal...

If true, why can't they put some kind of INSULATOR between the hook and the
cable ?

Static is both high voltage and tough to insulate.

Construction workers experience cranes and cables on pulleys everyday with no
problem AFAIK.

Not if they've been flying the crane through the air.

Where is the electricity coming from ?

Asked and answered.

We always see these rescues on TV, and no rescuer looks like s/he is shocked at
240 volts.

Have you been hanging on the line?

I've seen it in person, and it won't kill you but it will let you know
you're alive. Biggest danger is usually the reaction to the
discharge.

Jeff

Where is the electricity coming from ?

This is also interesting, I found a long quote from Feynam on Google
Groups. I remembered this from school days. I don't know if it applies
to helicopters. The link has the full text:

"Here's the real scoop (source: The Feynman Lectures on Physics, Vol 2,
chapter 9). Away from thunderclouds, the earth has a negative charge
relative to "the sky." The potential difference is quite incredible:
about 100 volts per meter. Why does this not electrocute you? Because
your skin is so much better at conducting than air, your skin can be
treated as a perfect conductor. Your head and your feet have the same
potential as the earth. A foot from your nose, the air is at a
potential of +200V."

http://groups.google.com/groups?q=fe...s.com&rnum= 1