Naked Science Forum
Non Life Sciences => Technology => Topic started by: Geezer on 12/11/2010 20:35:54
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In the UK you dial 999 for emergency services, but in the US it's 911. Why are they different?
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With the widespread use of mobile phones the use of "999" as the emergency number is now a problem as carrying a phone can cause the same digit to be repeatedly pressed accidentally.
Silent {999} calls are now common. Between July 2001, when the Silent Solutions system was introduced, and September 2008, there have been more than 40 million such calls - averaging about 5.5 million a year. The overwhelming majority of these are unintended 999 calls, says a Met spokesman.
http://news.bbc.co.uk/1/mobile/magazine/7748046.stm
The old rotary dial phones would produce a pulse for each number: nine pulses for a nine ...
Because of loop disconnect dialing, attention was devoted to making the numbers difficult to dial accidentally by making them involve long sequences of pulses, such as with the UK 999 emergency number.
However in modern times, where repeated sequences of numbers are easily dialed on mobile phones, this is problematic as mobile phones will dial an emergency number while the keypad is locked or even without a SIM card.
http://en.wikipedia.org/wiki/Emergency_telephone_number#History_of_emergency_services_numbers
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All true, but I think 911 came into use in the US prior to new fangled push button phones.
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Since these numbers were chosen while phones were rotary, wouldn't it have made more sense (and been about 8 times faster) to dial 111 instead of 999?
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dial 111 instead of 999?
111 (three pulses) could more readily occur by accident*, causing false alarm, than 27 pulses (9+9+9).
(* e.g. short circuit in a swinging windblown telephone line).
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Since these numbers were chosen while phones were rotary, wouldn't it have made more sense (and been about 8 times faster) to dial 111 instead of 999?
I think that's the reason. It takes a long time to dial 999 on a rotary dialer. 111 is much faster, but too likely to happen accidentally, so they settled on 911. However, that's only my guess.
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Since these numbers were chosen while phones were rotary, wouldn't it have made more sense (and been about 8 times faster) to dial 111 instead of 999?
Yep, so far as I am aware, that was the reason. It also had to be far enough from any area dial code so as not to be dialed mistakenly.
999 still remains the number most associated for emergencies, but 112 has also been in use for some years in the UK and much of Europe.
101 is being introduced as a means of getting help in the event of problems which do not come within the scope of an emergency. I'm not too sure exactly what that means, but I think it may be to report burst water mains, nuisance and so on. This I think is a chargable call.
Gas emergencies can be reported on 0800 111 999. This is a free to call number.
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Our number here for directory information is 411. When I was about 20 my mobile home had an electrical fire and in my fluster I dialed (yup, rotary) 411 instead of 911, probably because I'd used 411 several times, and never used 911, so it was an automatic response. Incidentally, the operator told me to hang up and dial 911 instead of putting me through. The firefighters told me that those older models have about 2 minutes before they are consumed by fire.
My point is that when choosing numbers it's good to think of a simple number for a panicked brain.
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As a child I was always told it was 999 so that it on a rotary dial it could be easily found in the dark / smoke filled room.
On refelction I think I was mislead
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I will suggest emergency numbers in all countries should be same (911 or 999) so it everyone could get fast call with the emergency centers, rather than wondering what could be the emergency number in a new country.
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A service initialy brought in for the deaf means that in the UK you can "call" 999 via sms text message.
http://emergencysms.org.uk/
has details but broadly, the phone needs to be registered by texting "register" to 999.
Climbers and walkers are also being encouraged to do this as in many mountainous areas mobile signal can be patchy or too weak for voice, but a text will get through.
http://www.grough.co.uk/magazine/2010/11/22/rescuer-backs-call-to-sign-up-to-emergency-text-service
(and don't expect satellite phones to be any better in steep areas, Kendal Mountain Rescue recently had a call out to the Kentmere Valley sometime after the initial incident because the satellite phone could not get signal...)
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Silent {999} calls are now common. Between July 2001, when the Silent Solutions system was introduced, and September 2008, there have been more than 40 million such calls - averaging about 5.5 million a year. The overwhelming majority of these are unintended 999 calls, says a Met spokesman.
Ouch!!!
The problem is that a "silent call" in the USA can generate a response.
There would be a number of reasons why one might not be able to talk...
Active Home Robbery/Home Invasion
Domestic Violence
Heart Attack
Allergic Reaction
Choking
etc.
I suppose the emergency operator/system should be able to tell the difference between a cell phone and a land phone, most callers should be able to give some nonverbal indication of the nature of the call. But, all such calls could potentially be serious. I'd hate to think of the consequences if they would ignore a kidnap victim call which ends with a murder.
If the Britts are dropping 5 million emergency calls a year, they need to change their emergency number. IT JUST ISN'T SAFE.
Change over to 911 (hopefully). Lots of big announcements in the news for a date like Jan 1.
Then answer both numbers for a decade or so with continued efforts to extinguish the old number.
As far as 1 vs 9.
1 has been used as a long distance and international prefix for many years. If the number started with a series of 1's... the system would necessarily have to pause to determine if additional numbers were forthcoming. I assume that 911 had never been assigned an area code prior to its adoption as an emergency number, thus quicker routing.
Since "9" is a common prefix to obtain an outside line at a business... I have wondered a bit about the choice.
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999 has worked for a while. It's origins seem well understood
The General Post Office, which ran the telephone network, proposed a three digit number that could trigger a special signal and flashing light at the exchange.
The operators could then divert their attention to these priority calls.
In order to find the new emergency number in the dark or thick smoke it was suggested an end number was used so it could be found easily by touch.
111 was rejected because it could be triggered by faulty equipment or lines rubbing together. 222 would have connected to the Abbey local telephone exchange as numbers in the early telephone network represented the first three letters (ABBey = 222, 1 was not used due to the accidental triggering). 000 could not be used as the first 0 would have dialled the operator.
999 was deemed the sensible choice.
Incidentally, in the rest of Europe it's 112
I believe that most mobile phones will accept any of the 3 emergency numbers and put you through to the exchange but, unlike a land line 'phone, the operator doesn't automatically get your location.
The odd side effect of this is that if you happen to spot a fire and there is a public phone nearby it is better to use than than your mobile.
Save the mobile for taking pictures to (sell to the news media) Oops! I mean help the emergency services with later.
Incidentally, I suspect the "best" number is the one you grew up with so it would be rather hard to change.
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Its just more easier to remember.
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In NZ it is 111 [:o]
111 was specifically chosen to comply with the positioning of Britain's 999. With pulse dialling, New Zealand telephones pulse in reverse to the UK - dialling 0 sent ten pulses, 1 sent nine, 2 sent eight, 3 sent seven, etc. in New Zealand, while in the UK, dialling 1 sent one pulse, 2 sent two, etc. In the early years of 111, the telephone equipment was based on British Post Office equipment, except for this unusual orientation. Therefore dialling 111 on a New Zealand telephone sent three sets of nine pulses to the exchange, exactly the same as UK's 999
http://en.wikipedia.org/wiki/1-1-1
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Thanks C4M. That's very interesting.
(And I refuse to make a cheap joke about it being because everything is upside down in NZ.)
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Ah, ain't you jest so kind then [:)]
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I think we are the upside-down and backwards ones. NZ and Australia have a lot of things right that we have yet been unable to get our "representatives" to implement. This one is Australia's drinking and driving campaign; very graphic and very effective. Brings the reality home. http://www.youtube.com/watch_popup?v=Z2mf8DtWWd8 (http://www.youtube.com/watch_popup?v=Z2mf8DtWWd8)
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Hm. I haven't watched that, Donnah, I don't need drink-drive campaigns to stop me drinking and driving, and I don't need the nightmares... but the UK's drink drive ads rarely pull any punches.
As to the original question.. I suspect this is probably accurate, it's an end number to ensure you can find it in the dark, and not 1 because 1 (single pulse dialling) can be triggered by accident.
http://news.bbc.co.uk/local/london/hi/people_and_places/history/newsid_8675000/8675199.stm
Interesting tangential point about the early days of direct dial exchanges... I've been told (possibly by Dave's dad) that it used to be possible to make "trunk" calls at local rates (which covered the local exchange plus nearest neighbours) by dialling through to the neighbouring exchange, then (because you appeared to be a local call) the next one over, then the next one, and so forth, thereby bypassing the transition to (much more expensive) national calls. Of course, it was a lot of extra effort, you had to have a complete list of the exchanges you needed to make the call and then actually dial the numbers every time, so it wasn't generally worth it... but I think it was an interesting challenge for people who like to get one over "the system".
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Not that I ever tried it myself you understand, but I seem to remember it was possible to dial numbers in the UK from a call box by tapping the handset cradle to simulate the pulses produced by the rotary dialer. Consequently, it was possible to avoid the tiresome inconvenience of actually inserting money into the device.
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Hi all,
There were multiple reasons which led to the adoption of 999 by the British G.P.O. in the 1930's. One of the major considerations was to use a number which involved minimum disruption to the existing numbering schemes in use.
London used a step-by-step director system in which the first three digits of the seven-digit number (dialed as letters at that time) determined the exchange the call was to be routed to. Except for the special case of dialing 0 for operator, all calls thus required a minimum of three digits before the equipment could decide how to connect the call, so a three-digit emergency number was needed. As the digit 9 corresponds to the letters WXY, from which no useful names could be made up, the code 999 was vacant. The same was true for the other major cities which used the director system, such as Glasgow (which was to get 999 service soon after London).
Elsewhere in the country, no subscriber numbers started with 9, because the 9 level on first selectors was used to access various services (directory enquiries, telegrams, etc.). Moreover, from many rural and village exchanges, a first digit of 9 already connected to the parent exchange to allow subscribers to dial directly to that larger place. As emergency calls needed to go to such places where the operators were located, the initial 9 of 999 already routed the call to the parent exchange without the need for any modifications at those smaller exchanges.
The other very important factor which affected the choice was to allow for payphone users to call without needing to deposit any coins. The prepayment phones which were standard at that time worked by preventing the dial from operating until the correct minimum fee for a local call had been deposited (2d. in the 1930's). However, extra contacts on the dial opened when it was rotated right round to the zero position in order to permit callers to dial the operator without coins. It was relatively easy to modify the dials to allow for both 9 and 0 to be dialed, thus allowing coin-free calls to 999 as well.
As far as the adoption of 911 in the U.S.A. is concerned, this happened much later (the first place to get 911 service was Haleyville, Alabama in 1968). Codes such as 211, 411, 611, and so on were already well established, having been in use for several decades by that time in many parts of the country. 911 was part of this reserved service-code sequence so fitted the need well. Another consideration at the time for using 911 rather than some other spare n11 code was to make it easier to implement in areas using step-by-step switching equipment, since the 9 level was more likely to be unused for subscriber numbers. More complications arose with 411, 611 etc. in step-by-step systems, which is why many of these had traditionally used codes such as 113 for information and 114 for repair service instead of 411 and 611.
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Great answer Paul! Many thanks.
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You're welcome. And to pick up on a few other comments:
All true, but I think 911 came into use in the US prior to new fangled push button phones.
DTMF (TouchTone) dialing started to appear in the U.S. in the early/mid 1960's, but only in a few places, so certainly wasn't in widespread use when the decision to adopt 911 was made.
I assume that 911 had never been assigned an area code prior to its adoption as an emergency number, thus quicker routing.
None of the n11 numbers have ever been used as area codes, as they were already in use in many places as service codes (information, long distance etc.) when the area-code plan was drawn up in the late 1940's.
The original plan was that the middle digit of an area code would be 0 or 1 (which continued to be true until the 1990's). The reason for that was to allow equipment to distinguish between area codes and a number within one's own area from the second digit dialed. Seven-digit numbers within each area code with the first two dialed as letters was to be the norm (as in, for example, the famous PEnnsylvania 6-5000 number in New York). As there are no letters on the 0 or 1 digits, that meant that if the second digit dialed was 0 or 1, then the caller must be dialing an area code and the equipment knew to wait for ten digits in total.
Because the n11 numbers were already in use as service codes, however, they were excluded from being assigned as area codes, and the equipment "knew" that if both second and third digits were a 1, then it wasn't an area code after all.
I've been told (possibly by Dave's dad) that it used to be possible to make "trunk" calls at local rates (which covered the local exchange plus nearest neighbours) by dialling through to the neighbouring exchange, then (because you appeared to be a local call) the next one over, then the next one, and so forth, thereby bypassing the transition to (much more expensive) national calls.
Yes, in the old British network that was possible in some places. Long before STD (Subscriber Trunk Dialling) came along, there were local dialing codes to permit calling nearby exchanges without the assistance of an operator. Typically you dialed 9 (as noted above) to reach the parent exchange in town, and subscribers there dialed codes such as 81, 82, 83, etc. to reach the outlying places. Calling from one rural exchange to another which was parented on the same town exchange often involved dialing 981, 982 etc., the stages of the call progress there being fairly obvious. There were numerous other variations to cater for local needs, and subscribers were issued with booklets containing all the local dialing codes for places they could dial direct (officially). Steps were usually taken to prevent calling beyond the official local area, but it wasn't always easy and sometimes it could still be done with the right sequence of codes. The local dialing codes finally vanished from the system during the 1980's.
Not that I ever tried it myself you understand, but I seem to remember it was possible to dial numbers in the UK from a call box by tapping the handset cradle to simulate the pulses produced by the rotary dialer. Consequently, it was possible to avoid the tiresome inconvenience of actually inserting money into the device.
Yes, with the old prepayment boxes (the ones which had the "A" and "B" buttons on them) that was possible. As noted above, the dial didn't work (except for 9 and 0) until the local call fee had been deposited. In normal operation, making that deposit also shorted out the transmitter in the handset so that you couldn't talk to your distant party until you pressed button "A" to drop the coins into the box and restore the contacts (pressing button "B" also restored everything, but returned the coins and disconnected the line for a few seconds to release the connection).
So if you didn't make any initial deposit, the dial wouldn't work, but the transmitter was still active. Pulsing out the number on the hookswitch would thus give a free call.
That ceased to be possible with the postpayment coinphones which gradually came into use during the 1960's, as all the coin control was done by relay sets at the exchange and both the dial and the transmitter were active all the time.
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Interesting note about phones.
As far as Geezer's suggestion... I don't think it worked for international calls from Italy.
I remember getting a pocket full of "Gettone" phone tokens.
I'd fill the phone up with as many Gettone as it would take, perhaps 10 or so.
Then once the call began, I'd continue to stuff them into the phone as fast as I could possibly do it. The calls would normally last a couple of minutes before I just couldn't keep up with the coins.
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As far as Geezer's suggestion... I don't think it worked for international calls from Italy.
I'm not familiar with the arrangements used in Italy, but as far as the old British A/B coinphones were concerned, pulsing out the number on the hookswitch to get a free call worked only for local calls, since all long-distance calls (and international, if you had a pocket big enough to hold the coins!) were placed via the operator who would then listen to the bell and gong signals as you dropped coins into the phone, just as with the old three-slot coinphones in America. Although you could dial beyond the local area with this method by using the local routing codes as described, if you knew what to dial and there were routes which weren't barred in your particular area, as described above.
Because of the way the coin mechanism worked, as described previously, it was actually possible to call TIM (the speaking clock) or any of the other prerecorded services such as weather for free from a coinphone by actually using the dial, so long as you had the coins to make the initial deposit. You could hear the distant party answer before pressing button "A" to drop your coins into the box, but could not speak to him - Something which clearly wasn't needed when just listening to a recorded announcement! So you just deposited the local call fee, dialed the number as normal, listened to the announcement, and then pressed button "B" to get your money back when finished. So coinphone users could call those services for free while regular residential customers were charged for them.
All of these "tricks" became impossible with the postpayment phones which were introduced for STD and which could be used to dial long-distance as well as local.