CB Radios, Cellphones and Gasoline Vapor Ignition

[Active8]

On Thu, 18 Mar 2004 00:09:30 GMT, Roger Gt wrote:

"Paul Burridge" wrote
: Jim Thompson wrote:
:
:>I was struck by a thought when I heard the latest Palestinian
:>terrorist trick is to send a kid through the border with a
back-pack
:>bomb triggered by a cell phone....
:
:>The Israelis should get a telemarketer's speed dialer and
constantly
:>dial away... boom... boom... boom...
:
:>ROTFLMAO!
:
: Yes, I'm rolling on the floor laughing at all these deaths, too,
as
: I'm sure we all are.

Huh?
He seemed to be laughing at the lame Idea! I also thought it
funny that anyone would try something which would almost totally
wipe out the cellular phone service for the entire country...

does a 200 station phone room with auto-dialers all calling one
state wipe out POTs? WTH are *you* talking about?

All
to provide a SMALL measure of confidence that no one had a bomb
attached to a phone. Like it would even work!
WTH are you referring to? GAL!

--
Best Regards,
Mike

 

[Active8]

On 17 Mar 2004 12:02:15 -0800, John Michael Williams wrote:

Claims that people have started fires by using
their cell phone while refueling a car apparently
are false: See
http://www.snopes.com/autos/hazards/gasvapor.asp
and other sites.

There was discussion of this and bad electric fuel pump designs last
year, but I don't recall anyone testing it out.

snip

So, I think sliding over on a car seat, and thus generating a
possible static charge, would be more likely to ignite gasoline
vapor than talking on a cell phone while refueling.

It is more likely and there's a gas station here that has a memo to
that effect (static - mainly in winter) posted where the customers
can *not* see it, duh! No signs on the pumps... The memo says you
should shock yourself on the car befor going to the pump. No one
thought about the vapor from the car on the other side of the
island.

However, it
would be useful for someone to repeat this kind of test with an
actual cell phone, as opposed to a CB radio. The wires should
be shorter, for one thing . . ..

I'm cross posting to an antenna group, looking for criticism.

John
jwill@AstraGate.net
John Michael Williams

--
Best Regards,
Mike

 

[Active8]

On Wed, 17 Mar 2004 19:16:45 -0800, DarkMatter wrote:

On Thu, 18 Mar 2004 10:02:37 +1300, "Ken Taylor" <ken123@xtra.co.nz
Gave us:

snipped previous

It's a bit of a stretch to think that cell-phones are a problem, whereas the
car driving off next to you, with a set of spark plugs going for their
lives, is not. Hmmmm.



Yes, I agree. At 40kV these days too, and sure... none of that
closed system leaks anywhere.... sure. It is ten orders of
magnitude more dangerous than any handheld (or ear held) transmitter
is to flammable liquid vapors.

One should turn one's engine off whenever not using the car, let
alone at fuel pump islands. Always!

The old adage that it costs more to restart an engine than to leave
it running is bullshit today. Fuel injected (or throttle body)cars do
not suffer the idle mixture swings or flooding risk of old carbureted
engines. Unless you are in a very very cold place, turn your friggin'
engine off when you aren't driving the friggin' car!

The guy next to you with the dangling plug wire arcing away, though.
Make me more determined to have fuel delivered to a home tank.

I got yelled at for leaving the engine running at a deisel pump
once. Some people just don't know how hard t is to ignite the stuff.

--
Best Regards,
Mike

 

[Active8]

On Wed, 17 Mar 2004 21:50:35 -0600, Crazy George wrote:

IIRC, the Apollo capsule wire insulation was FEP, and was ignited when the
power conductor it insulated was mechanically pinched and shorted to ground.
It overheated enough from fault current to ignite before the breaker
tripped.

Kapton tape was blamed in the Swissair 400(?) cockpit fire and crash in
Newfoundland(?) a few years back.

Gasoline vapor fuel fires were ignited by early pagers and first generation
cell phones which used tiny universal motors with eccentric weights as
silent ring annunciators.

My Motorola Classic has one of those. What are they using now?

Find one of those old beasts and try running that
motor in a flammable environment.

OK

The technical basis of this is covered in a text: "Intrinsic Safety" by
Redding, published by Mc Graw Hill.

--
Best Regards,
Mike

 

[Roger Gt]

"Active8" wrote
: Roger Gt wrote:
: > "Paul Burridge" wrote
: >: Jim Thompson wrote:
: >:
: >:>I was struck by a thought when I heard the latest Palestinian
: >:>terrorist trick is to send a kid through the border with a
: > back-pack
: >:>bomb triggered by a cell phone....
: >:>
: >:>The Israelis should get a telemarketer's speed dialer and
: > constantly
: >:>dial away... boom... boom... boom...
: >:>
: >:>ROTFLMAO!
: >:
: >: Yes, I'm rolling on the floor laughing at all these deaths,
too,
: > as
: >: I'm sure we all are.
: >
: > Huh?
: > He seemed to be laughing at the lame Idea! I also thought it
: > funny that anyone would try something which would almost
totally
: > wipe out the cellular phone service for the entire country...
:
: does a 200 station phone room with auto-dialers all calling one
: state wipe out POTs? WTH are *you* talking about?

Gee - Primitive! Not a Telephone guy I guess......
The last autodialer I worked on was a Dual DS3 line unit with a
router.
2 times 864 lines wide. A few of those would really choke a
network!

: > All
: > to provide a SMALL measure of confidence that no one had a
bomb
: > attached to a phone. Like it would even work!
: > WTH are you referring to? GAL!
:
: Best Regards,
: Mike

 

[Tim Auton]

Active8 <reply2group@ndbbm.net> wrote:
[bombs]

Do you all think that tangos are dumb enough to trigger the bomb
with the ringer or would the detonator answer first and listen for a
DTMF sequence. Hmmm? Achmed the bomb maker gets a wrong number just
as he's connecting the thing.

I very much doubt they bother with DTMF decoders. I mean, how often do
you get a wrong number? I've had about 4 in my life. They'll just
connect the ringer (or vibrate function) to the detonator (with
whatever minimal circuitry in between is required - I've never used a
detonator!) and then only turn the phone on at the last minute.

It's not dumb to design a remote detonation system that requires the
absolute minimum of specialist knowledge and equipment to construct.


Tim
--
Love is a travelator.

 

[Tim Auton]

Jim Thompson <thegreatone@example.com> wrote:

I was struck by a thought when I heard the latest Palestinian
terrorist trick is to send a kid through the border with a back-pack
bomb triggered by a cell phone....

The Israelis should get a telemarketer's speed dialer and constantly
dial away... boom... boom... boom...

You would have to have every phone in the nation ring every couple of
hours. They're not going to be stupid enough to have the phone both
switched on and connected to the bomb until the last minute.


Tim
--
Love is a travelator.

 

[John Michael Williams]

'Doc <w5lz@cwis.net> wrote in message news:<4058BDCC.340A95BF@cwis.net>...

John,
It's also possible to start a fire rubbing two sticks
together, but it isn't as likely to be an accidental thing.
I would tend to doubt any claims about cell phones starting
accidental fires unless there has been some modification
to the phone, or other unusual circumstance. Turning off
cell phones and radios seems like a reasonable precaution
while fueling, I don't have a problem with that. I also
don't understand why anyone else would either. Do I turn off
my two way radio when fueling? Yes, but mainly because of
how it's connected (ignition switch).
If fuel vapor liable to ignite because of RF? Not unless
the RF field is very strong, or the antenna arcs for some
reason. Very likely? Not really. Possible? Sure. So using
a little common sense... what's the problem?
'Doc

PS - Cross posting is a sure way of causing misunderstandings.

I was just trying to add some factual information to the
link I gave, which was just a lot of rumor--both pro and con
RF hazards. Check it out.

From time to time, I read postings about people complaining
about others gabbing on a cell phone while (self-serve)
refueling.

I don't follow what you say about cross-posting. I'm not a ham
operator, so if I am making some obvious mistake, I thought
adding the antenna group would get a correction. Is that your
interest?

Hopefully, this thread will end up by putting to rest
fears of cell phones around gas stations, at least from the
RF standpoint. Also, if I'm wrong, and there IS danger
from the RF, someone should be able to correct me. Either way,
it's an interesting topic, don't you think?

John
jwill@AstraGate.net
John Michael Williams

 

[KLM]

On Thu, 18 Mar 2004 05:39:21 +0000, Tim Auton
<tim.auton@uton.[groupSexWithoutTheY]> wrote:

Do you all think that tangos are dumb enough to trigger the bomb
with the ringer or would the detonator answer first and listen for a
DTMF sequence. Hmmm? Achmed the bomb maker gets a wrong number just
as he's connecting the thing.

I very much doubt they bother with DTMF decoders. I mean, how often do
you get a wrong number? I've had about 4 in my life. They'll just
connect the ringer (or vibrate function) to the detonator (with
whatever minimal circuitry in between is required - I've never used a
detonator!) and then only turn the phone on at the last minute.

It's not dumb to design a remote detonation system that requires the
absolute minimum of specialist knowledge and equipment to construct.

To use the unique cellphone ID to detonate a remote bomb is actually
a very ingenious innovation. No timers to mess with. The terrorist
has full and instant control of the time and place to set off the
bomb.

As Tim says its relatively easy to connect the ringer wires to a
simple circuit to output enough juice to trigger the detonator. Frist
year student project - like using a battery to keep a capacitor
charged and the ringer closes the discharge switch. Boom.

The countermeasure I think, is fairly simple. Every vulnerable public
place which may be targeted by terrorist bomb attacks, should install
cellphone signal blockers.

I believe these are already available and smart dining places and
concert halls have them so that their patrons won't be interrupted by
cellphones. I'll skip the arguments, mostly from cellphone service
providers, against signal blockers that may cause doctors and
emergency workers to miss their calls. Until some better solution
comes along I think this is a good solution. (Hint. Buy shares in
signal blocker companies.) If this suggestion is taken up perhaps
we'll get some peace from those incurable cellphone yakkers who think
the world wants to hear every word they say anywhere.

 

[Terry Given]

"Tim Auton" <tim.auton@uton.[groupSexWithoutTheY]> wrote in message
news:4ndi50loirkshdi00l8eh03qfrk1pjrli5@4ax.com...

Jim Thompson <thegreatone@example.com> wrote:

I was struck by a thought when I heard the latest Palestinian
terrorist trick is to send a kid through the border with a back-pack
bomb triggered by a cell phone....

The Israelis should get a telemarketer's speed dialer and constantly
dial away... boom... boom... boom...

You would have to have every phone in the nation ring every couple of
hours. They're not going to be stupid enough to have the phone both
switched on and connected to the bomb until the last minute.


Tim
--
Love is a travelator.

this will probably go down like a cup of cold sick, but:

a better technique would be for the israeli government to pull their heads
in, and start acting like humans instead of nazis (deliberate comparison - I
am continually astounded that this behaviour comes from a people who
survived the Holocaust - surely the darkest moment in human history).

Actually attempt to reach a meaningful peace settlement, thereby getting
on-side with the bulk of the palestinian population, most of whom just want
to get on with their lives.

this would of course not deter the individual fanatical palestinian
lunatics, but would seriously erode their support base. The individual
nutters could be whacked one at a time (dont blow up an entire apartment
building killing dozens of kids to get one suicide bomber - that doesnt
help, and is no better than the suicide bombers behaviour).

No, I am NOT an apologist for suicide bombers - not those that target
civilians at any rate. I find it odd that its not OK for suicide bombers to
kill soldiers though, but it is OK for soldiers to kill suicide bombers

unfortunately its not likely to happen. Little things like the clearly
observable FACT that decades of repressive behaviour towards the
palestinians has NOT resolved the problem, but made it WORSE, seem to have
escaped the notice of successive israeli governments. so much for "an eye
for an eye" being of any practical use.

I am not interested in arguments about whether or not Israel should exist
(it does), who was originally right or wrong (6-day war etc) or any other
pointless arguments. The current situation exists, time doesnt flow
backwards, and if a real solution is not found, the terrorism will not only
continue, but will coninue to get worse. Neither side seems interested in
moving forward though, they are caught up in an ever-escalating round of
murderous tit-for-tat.

France, Spain and Britain on the other hand have endured terrorism for
decades, pretty much without resorting to such behaviour (bloody sunday is
probably a good example of the brits losing the plot, and its pretty clear
that it was a BAD idea)

 

[Terry Given]

"DarkMatter" <DarkMatter@thebarattheendoftheuniverse.org> wrote in message
news:n65i50p1gr3ionsq5vhvcthg4qumcdlau6@4ax.com...

On Wed, 17 Mar 2004 16:26:54 -0500, "Dave VanHorn"
dvanhorn@cedar.net> Gave us:

I noticed that the appearance of the no cell phone signs came around the
same time that gas stations started running audio commercials through
speakers at the pump.

Interesting observation.

we dont have audio commercials at the pump here in New Zealand (thankfully),
but we do have the no-cellphone signs though. It is likely to be no more
than corporate paranoia - can we get our asses sued off if we dont tell
people to do this.......I suggest we blame the lawyers

 

[CW]

"KLM" <klmok88@yahoo.com> wrote in message
news:t0ni509cbms3mkkti2arad2b9guuq6mggd@4ax.com...

On Thu, 18 Mar 2004 05:39:21 +0000, Tim Auton
tim.auton@uton.[groupSexWithoutTheY]> wrote:
The countermeasure I think, is fairly simple. Every vulnerable public
place which may be targeted by terrorist bomb attacks, should install
cellphone signal blockers.

Not in the US. Intentional interference is illegal. It likely is in most
places.

 

[Paul Burridge]

On 17 Mar 2004 12:02:15 -0800, jwill@AstraGate.net (John Michael
Williams) wrote:

So, first conclusion: To get even a 1 V spark would take a
wire at least 9 m long, all somehow kept within 1 m of the
transmitter. Thus, it appears it is not feasible to create a
hazardous spark with a CB at a gas station.

I'm not entirely surprised. When CB first took off in the UK about 25
years ago some bright spark (no pun intended) discovered that the then
petrol pump meters could be slowed down by keying-up whilst filling up
and you could get a tank full of juice for a fraction of the price. As
soon as the petrol companies cottoned on to this they put around the
scare story about CBers risking explosions by making use of this scam.
I never bought it, partly because | have a big static problem and
during very dry days I get a massive spark discharge upon closing the
car door. This invariably happens at petrol stations, of course, as it
does everywhere else. I've never been blown up yet.
--

The BBC: Licensed at public expense to spread lies.

 

[Rene Tschaggelar]

Jim Thompson wrote:

I was struck by a thought when I heard the latest Palestinian
terrorist trick is to send a kid through the border with a back-pack
bomb triggered by a cell phone....

The Israelis should get a telemarketer's speed dialer and constantly
dial away... boom... boom... boom...

Not really. The technology is far better.
Here you can get those industial mobiles with a serial
output. You can send an SMS which's string can be decoded by
software of you own microcontroller.

Rene
--
Ing.Buero R.Tschaggelar - http://www.ibrtses.com
& commercial newsgroups - http://www.talkto.net

 

[Spehro Pefhany]

On Thu, 18 Mar 2004 14:08:26 +0100, the renowned Rene Tschaggelar
<none@none.net> wrote:

Jim Thompson wrote:
I was struck by a thought when I heard the latest Palestinian
terrorist trick is to send a kid through the border with a back-pack
bomb triggered by a cell phone....

The Israelis should get a telemarketer's speed dialer and constantly
dial away... boom... boom... boom...

Not really. The technology is far better.
Here you can get those industial mobiles with a serial
output. You can send an SMS which's string can be decoded by
software of you own microcontroller.

One could easily imagine a semi-smart anti-convoy bomb that could be
remotely triggered by a hidden operator to go off after a programmable
delay (with password), so signal jamming would be relatively
ineffective. Nasty, and hobbyist-level technology once you have the
phone.

Best regards,
Spehro Pefhany
--
"it's the network..." "The Journey is the reward"
speff@interlog.com Info for manufacturers: http://www.trexon.com
Embedded software/hardware/analog Info for designers: http://www.speff.com

 

[Bob Masta]

On Wed, 17 Mar 2004 21:33:43 GMT, Dave Shrader
<david.shrader@comcast.net> wrote:

John Michael Williams wrote:

SNIP

However, the first radios transmitted
sparks, so in principle it should be possible to
transmit near a long wire separated by a small gap from
ground or another wire and get a small spark. So, I
decided to try an experiment.

SNIP

There is one other potential source for a spark that you did not
investigate.

A make/break contact in a switch causes sparks when opened. The US
Military specifies special shielded switches for their explosive, gas
vapor, etc., environments.

This reminds me of a story... (pause while room clears out).
Years ago I was an engineering student working for Cadillac
Motor Car. Electronic fuel injection was new then, and there
had been a couple of fires in the field that were suspected to
have been caused by leaky fuel lines, which were at higher
pressure than on the old carbureted cars. There were competing
theories, however, as to what exactly was setting off the fire.
I got assigned to help the guy doing the experiments to find out.

He had a car fitted with a plexiglas hood, topped by a small tower
with a high-speed movie camera pointing down for a good look
at anything happening in the engine compartment. Two fire
extinguishers were arranged to cover the under-hood area,
and a fuel vapor sensor was also installed there. The way
it was supposed to work was that he would drive and I would
operate the hand-pumped sensor, and at the first sign of fire
he would trigger the extinguishers. We ran all the tests
at the GM Proving Grounds in Milford, Michigan.

We tried making leaks in the fuel injection hoses. We had gas
spraying all over under the hood, collecting in pools on the
hot exhaust manifold. We tried poking holes in the spark
plug wire insulation. Nothing, no fire.

Finally I got a bright idea, and loosened the ground for the
air conditioner compressor clutch. The idea was that this
was a big inductor, and if the circuit opened there would
be a big spark. Then all we needed to do was get the
wire to bounce. We tried swerving from side to side,
and driving on bumpy tracks, but no deal. I was *sure*
that this spark would do the job, but we couldn't tell
if we were really getting the spark. So finally I stood on the
hood, holding on to the camera tower, so I could see
for myself if there were sparks. He drove down the
bumpy road one more time, and I did in fact see a spark:
The high-speed movie shows the fire spreading out
from it, more and more on each frame. Also on each
frame was the back of my head, moving away more
and more on each frame, until the extinguishers doused
everything. What a rush!

Them was the good ole' days.....


Bob Masta
dqatechATdaqartaDOTcom

D A Q A R T A
Data AcQuisition And Real-Time Analysis
www.daqarta.com

 

[Cecil Moore]

Paul Burridge wrote:

I've never been blown up yet.

You've never died yet, either.
--
73, Cecil http://www.qsl.net/w5dxp



-----= Posted via Newsfeeds.Com, Uncensored Usenet News =-----
http://www.newsfeeds.com - The #1 Newsgroup Service in the World!
-----== Over 100,000 Newsgroups - 19 Different Servers! =-----

 

[Jan Panteltje]

"Terry Given" <the_domes@xtra.co.nz> wrote in message news:<MJc6c.8716$rw6.174739@news.xtra.co.nz>...

a better technique would be for the israeli government to pull their heads
in, and start acting like humans instead of nazis (deliberate comparison - I
am continually astounded that this behaviour comes from a people who
survived the Holocaust - surely the darkest moment in human history).

Actually attempt to reach a meaningful peace settlement, thereby getting
on-side with the bulk of the palestinian population, most of whom just want
to get on with their lives.

this would of course not deter the individual fanatical palestinian
lunatics, but would seriously erode their support base. The individual
nutters could be whacked one at a time (dont blow up an entire apartment
building killing dozens of kids to get one suicide bomber - that doesnt
help, and is no better than the suicide bombers behaviour).

No, I am NOT an apologist for suicide bombers - not those that target
civilians at any rate. I find it odd that its not OK for suicide bombers to
kill soldiers though, but it is OK for soldiers to kill suicide bombers

unfortunately its not likely to happen. Little things like the clearly
observable FACT that decades of repressive behaviour towards the
palestinians has NOT resolved the problem, but made it WORSE, seem to have
escaped the notice of successive israeli governments. so much for "an eye
for an eye" being of any practical use.

I am not interested in arguments about whether or not Israel should exist
(it does), who was originally right or wrong (6-day war etc) or any other
pointless arguments. The current situation exists, time doesnt flow
backwards, and if a real solution is not found, the terrorism will not only
continue, but will coninue to get worse. Neither side seems interested in
moving forward though, they are caught up in an ever-escalating round of
murderous tit-for-tat.

France, Spain and Britain on the other hand have endured terrorism for
decades, pretty much without resorting to such behaviour (bloody sunday is
probably a good example of the brits losing the plot, and its pretty clear
that it was a BAD idea)

Agreed, they have lost sense of being human.
Hey, I am ADSL now! But in win98.... so I have to use google...
untill I write scripts to post via google..... in Linux, anyways,
you can complain about little kids blowing themselves up, but Israel
blows up civilians randomly from helicopters (usually they fail to hit whoever
it was they ware after).
In my view they are just a buch of religious fanatic killers with black hats.
Without compassion, some sort of easing the tension, it will stay
an impossible situation.
Unil the terrorists get nukes, then there will be no Jerusalem.
It is as predictable as a TTL timer, only one outcome possible.
It is probably far to late for Israel to change that outcome.
JP

 

[John Woodgate]

I read in sci.electronics.design that Terry Given <the_domes@xtra.co.nz>
wrote (in <MJc6c.8716$rw6.174739@news.xtra.co.nz&gt about 'Cellphones and
Bombs', on Thu, 18 Mar 2004:

France, Spain and Britain on the other hand have endured terrorism for
decades, pretty much without resorting to such behaviour (bloody sunday
is probably a good example of the brits losing the plot, and its pretty
clear that it was a BAD idea)

I think it's almost certain that that was simply a normal British Army
cock-up that went tragically wrong. You know, everyone's keyed up,
someone hears what might be a shot but wasn't, gives orders to fire
(maybe in the air), someone else hears those shots .... before senior
officers can react (especially if the radios don't work, which was
normal at the time, I believe), there is a fire storm.
--
Regards, John Woodgate, OOO - Own Opinions Only.
The good news is that nothing is compulsory.
The bad news is that everything is prohibited.
http://www.jmwa.demon.co.uk Also see http://www.isce.org.uk

 

[N. Thornton]

jwill@AstraGate.net (John Michael Williams) wrote in message news:<4032bf27.0403180038.1d17764@posting.google.com>...

I was just trying to add some factual information to the
link I gave, which was just a lot of rumor--both pro and con
RF hazards. Check it out.

From time to time, I read postings about people complaining
about others gabbing on a cell phone while (self-serve)
refueling.

I don't follow what you say about cross-posting. I'm not a ham
operator, so if I am making some obvious mistake, I thought
adding the antenna group would get a correction. Is that your
interest?

Hopefully, this thread will end up by putting to rest
fears of cell phones around gas stations, at least from the
RF standpoint. Also, if I'm wrong, and there IS danger
from the RF, someone should be able to correct me. Either way,
it's an interesting topic, don't you think?

You may have missed out one thing: did you try this with any resonant
loads? Resonant loads are not so hard to come by at the higher
frequencies.

Another question concerns spillage of gas: if youre yacking away its
much easier to spill fuel. I cant draw any conclusions but one has to
at least look at these factors.


Regards, NT