[Geezer (OP)]

In the UK you dial 999 for emergency services, but in the US it's 911. Why are they different?

[RD]

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

[Geezer (OP)]

All true, but I think 911 came into use in the US prior to new fangled push button phones.

[Donnah]

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?

[RD]

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).

[Geezer (OP)]

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.

[Don_1]

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.

[Donnah]

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.

[Mazurka]

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

[James Carl]

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.

[Mazurka]

 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...) 

[CliffordK]

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.

[Bored chemist]

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.

[cat_with_no_eyes]

Its just more easier to remember.

[Chemistry4me]

In NZ it is 111  []

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

[Geezer (OP)]

Thanks C4M. That's very interesting.

(And I refuse to make a cheap joke about it being because everything is upside down in NZ.)

[Chemistry4me]

Ah, ain't you jest so kind then []

[Donnah]

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

[rosy]

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".

[Geezer (OP)]

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.