OnStar and Explosives

[Cancerman]

My company has issued a safety alert that I thought should be passed on to everyone.
There is a potential explosion hazard due to the OnStar System. The following is some information that I have pulled from the alert.

"The OnStar system utilizes a GPS transceiver AND a 3 watt cell phone system. Even if the system is turned off, remote unwanted communications with the system MAY activate a transmission. The system cannot be turned off unless the vehicle's battery is disconnected. Vehicles with the OnStar system are believed to pose the same radio transmission hazard as ordinary cell-phones.
In order for explosive operations to be permitted, the vehicles must either have their batteries disconnected or they must be removed to a minimum distance of 250 feet (76.2 meters) from any area where armed devices are being utilized."

Also, to any Terrorist Suicide Bomber; please ignore this message!

[GBurton]

Cancerman

I will not try to tell you or your company that there could not be a problem with the cell phone. However I would like to address a very common error in your post.
"The OnStar system utilizes a GPS transceiver".

Nope, the GPS is receive only, there is no transmitter related to the GPS system. The GPS receiver listens to the timing signal transmitted by the GPS satellites and determines your location based on the timing differences from the different satellites. It is a very common error that in some cases is caused by the car dealers not understanding how the system really works. On-Star does NOT communicate with any satellites. On-Star does communicate to the On-Star center using normal cell phone service providers.

Ask your company if removing the cell phone antenna from the roof of your truck will satisfy their requirements? In most cases the antenna will un-screw by hand, which is easier than pulling power to the unit. Removing the antenna will not shut the cell phone down but it will greatly reduce the field strength that can be radiated by the cell phone. It is the amount of electromagnetic energy that is radiated that is the concern, this might meet the requirement. Removing the antenna might provide the same or more field strength reduction as moving the vehicle 250 feet away.

George

[SDWA]

Here's a question: When was the last DOCUMENTED case of explosives or blasting materials being accidentally detonated by a cell phone or two way radio in use in the area?

Scott

[FirstDiesel]

How about the last case of someone blowing up a gas station by using their cellphone while fueling?? I love those little signs on the pump!

[ 06-29-2002: Message edited by: FirstDiesel ]</p>

[GBurton]

IMHO

I have been using and/or working on two-way radios since 1962 or there about. In those days radios used vacuum tubes. Some of you might remember those things. The point is, in most cases those radios required the use of voltages much higher than 12vdc. Potentials of several hundred volts were very common in those tube type radios. These voltages were produces using various methods. Most of them produced electrical sparks during normal operation.

Most two-way radios were large and occupied a good portion of the trunk of the vehicle. While fueling a vehicle it was possible for gas fumes to enter the trunk area. I know it is not very likely but possible. If that occurred and the two-way radio was in operation you had the possibility of an explosion.

The second possible source of ignition was from sparks from the antenna. Again, not too likely but if the antenna was touching a part of the structure of the gas station it could happen. In those days the antennas were much longer that what you see today.

Could it happen, I am sure that some time in the past it did and that is why the signs started being posted. Just like now you will see signs warning about filling a gas container when sitting on a plastic liner in a pickup bed. From what I have read there have been fires caused by that action.

Now have you ever seen anyone who is willing to remove a warning sign that

[Redhawk]

Gosh George, why don't you tell us what you REALLY think about all this. The funny thing is, if you have seen these documentaries about people who demolish whole buildings with high explosives, they are all talking to one another on handhelds of one kind or another.

[AVfan]

It maybe interesting to note that an Onstar representative at an autoshow stated very clearly that Onstar DOES USE A GPS TRANSCEIVER. GM has a contract with DOD to use the GPS sats for communication back to the Onstar center. This communication is not for voice but data only. The cell phone system is used for voice communications. This is how Onstar system can signal the Onstar center when the air bags have deployed and where to send help eventhough there is no cellphone signal available.

[DmaxMaverick]

The reason for the cell phone ban near many commercial fueling stations and explosive storage/use areas may be warranted for one of several reasons. Personally, I don't care to test a theory. The reason you see that sticker on the gas pumps at your local station has nothing to do with the transmitted signal at all. It's the battery connection. The FCC and the Department of Consumer Affairs has deemed the battery connections in MOST cell phones to be a possible cause of ignition. There are exceptions, but I can't afford to purchase one of those certified to be spark free (big bucks!). I've had cell phones for years and have yet to actually pay for one.

Cell phones and satellite communication devices operate at a frequency well beyond any used by explosive devices. Not to say that a person couldn't use the frequency for such a device, but FCC says no way, not even close.

As far as a company's concern of possible transmitted interference, I think I would be more concerned with all the other arcin' and sparkin' related things on a vehicle (alternators, starters, ignition coils, etc.). The 3 watt system in my truck will transmit a signal further than I can see, and I don't think that even 250 feet away is far enough if the stuff does blow up. If frequency bleeding is a concern, it won't make a difference between 250 feet or 10 feet. I might feel safe a mile or so away. What does a company with such a policy intend to do about the EM fields and signals transmitted by a normally operating computer system found in most new vehicles? If an alternator or spark plug can interfere with common AM band (much closer to frequencies used with explosive ordinance)......Someone is way off base here.

If your company says, "Don't do that", then don't do that. I'd bet that several times every day someone will do just that. Generally, I like things to make sense. Having been employed by the government for most of my adult life, policies like this really don't surprise me.

I'm just curious, but how do you get the vehicle into the "kill zone" if the battery is disconnected? I can't see anyone pushing a 7000 pound truck 500 feet (250 in, 250 out) on a regular basis. I've done it in my youth, but that was before I learned the difference between the top half and bottom half of a gas tank.

SDWA:
According to FCC, DCA, FBI, CIA, DOD, FEMA, YMCA, etc, there is no documented case of explosion due to the use of cell phones (at least no info available to us regular folks). It could happen, but then we all could get cancer from eating lab rats (you never know what's in hot dogs these days!).

Guess I'm done rambling now. Cheers

[SDWA]

Somehow, I'm thinking the Onstar "Rep" had a pantload when he said Onstar uses a GPS transceiver. There would be more warnings in the owners manual for sure! I'm sticking with receive only.


As far as blowing up the neighborhood while refueling your vehicle, I found *one* report where a person went back into their car to get a ringing cellphone, presumably built up a static charge in their body from moving across the seat (we all know how that works, I get zapped every time I get out) and then touched the fill nozzle which created a spark and there was a small vapor fire. Now that I can believe. Maybe that's why most warning stickers on the pumps also say to stay outside your vehicle while fueling...

Scott

[SoCalDMAX]

Hi Guys,

As an ex-Navy ET and nav tech I can assure you of the following:

The GPS system is transmit only to users, the only signals it receives is from the injection stations run by the govt. For more info, check out: http://tycho.usno.navy.mil/gps.html

Onstar receives it's position from GPS and transmits it's info back through the Onstar satellite system, completely separate. The Onstar rep was probably a marketing type and was looking at the fan belt at the time...

IMHO:
A lot of warning labels concerning RF radiation are based on old, high power systems and will always err very much on the side of safety, probably more so now that attorneys determine the price of goods sold in the US.

Although I've seen gas station attendants smoke while filling up, and I'm 99% sure a cell phone won't cause any harm, I don't take any chances, it would likely happen to me.

The last person to blow up the gas station was talking on the cell phone while lighting a cigarette and filling up a plastic gas can on the bed liner of the truck. :eek: No one is sure exactly what caused it. ;)

I never guessed this would be such an explosive topic. Sorry :D

Regards, Steve

[SDWA]

OnStar is GPS receive only, and transmits everything thru the cellphone system, of which service is provided by Verizon. Every feature of Onstar is worthless if the battery is disconnected.

http://www.onstar.com/visitors/html/ao_faq.htm#installation
(I like the question about the Batmobile here...)

http://service.gm.com/techlink/html_en/pdf/200105-en.pdf

Scott

[DMAX Daddy]

Id hate to be the first person to have my (ENTER BODY PART HERE) fried from a cell phone/gas fume explosion. :eek:

[2K2AD]

Okay folks, this is kinda long...

An electric current is used in electric detonators to rapidly heat up a small wire similar to a lightbulb filament. This wire causes the sensitive explosive surrounding the wire to detonate and initiates the less sensitve main charge. The electrical energy required to initiate these detonators is relatively small, and they can be accidentally initiated by stray currents, lightning, electrostatic discharge and energies induced in the wires by electromagnetic waves. These waves are produced by a variety of sources including radar, microwave signaling towers, radio and TV towers, satellites, navigation systems such as LORAN and GPS, power lines, and portable and fixed two-way communications devices including CB, VHF, and portable and cellular phones.

A blast usually consists of one or more charges, each initiated by a detonator. In the case of electric detonators, the wires are connected using extension wires (the blasting circuit) so that the blaster -- the person setting off the blast -- is safely removed from the actual site.

The blasting circuit can behave like an antenna, much like the antenna for a radio, and can convert electromagnetic waves into electrical current. If sufficient energy is created, the detonator(s) can function. A number of factors need to be considered: the length and arrangement of the detonator and extension wires and their relative angle to the waves (efficiency as an antenna); the power of the transmitting device; the distance between the transmitting device and the blasting circuit; and the frequency that is used by the transmitting device.

A blaster can perform a survey of fixed transmitters and determine if a hazard exists using established guidelines. Portable transmitters such as CB radios in vehicles, portable VHF radios and cellular phones are difficult to survey and yet need to be controlled -- hence the use of warning signs to turn off radio transmitters.

The AM and FM radios in cars are receivers and do not constitute a hazard. Cellular phones pose a unique problem in that when they are turned on but not in use, they are interrogated several times per hour by a cell transmitter to determine whether they are within the range of the cell and if they are on. A cell phone that is turned on replies and this may pose a hazard. Accidents have been attributed to transmitters being too close to the blasting circuit.

Perhaps some examples can be used for clarification. For AM stations with a transmitter power of 50,000 watts, the minimum safe distance is 2900 ft. (880 m). For amateur radio mobile units having a maximum power of 1000 watts operating in the VHF range of 50-54 MHz, the minimum distance is 820 ft. (250 m), whereas for a radio of the same power operating in the VHF range of 150.8-161.6 MHz, the safe distance is reduced to 310 ft. (100 m). For portable 5 watt radios (150.8-161.6 MHz), the safe distance is 20 ft (6 m). For cellular phones, typically operating at less than 1 watt, the safe distance is approximately 10 ft. (3m).

With explosives, it is always best to err on the side of safety and turn off all transmitting devices on or near a blasting site.

Kevin

[fred]

hi, ive been around gasoline and gas stations all my 41 year life and have yet to see a lit cigerete start a fire if it goes into a puddle of gas, we used to throw cig's into coffee cups of gas and they just got wet(ya we were 16 and a little dumber then)i even snow plowed at a station that had a pump run over(they didn't turn off main pump breaker when they closed station and somebody ran over pump after they closed)i didn't see it until i had plowed 1/2 the station,then i got out of there and called the fire dept.,they said 1000 to 2000 gals had been pumped out :D

[SDWA]

Check this out:

http://www.pei.org/static/index.htm

Very interesting reading about 150 documented cases of fires while refueling that were attributed to static electricity!

Scott

[ 08-05-2002: Message edited by: SDWA ]</p>