Trant said...
In the UK, I was told that 999 was originally picked because electrical storms could produce static/clicks on the line which mimic a "1". So a 111 could be accidentally dialled.
Obviously not an issue now.
That's the one Bob.
In fact just tapping the handset cradle sends out a single pulse, same as dialing 1.
If you tapped the handset 3 times slowly, it was the same as dialing 111.
Prior to the new fangled rotary dial telephones, you used to phone up by just picking up the handset, cranking the magneto generator next to the phone and waiting for the operator to say "Number please?"
And you would say "Gimme Claremont 123 please."
And she would plug in and out a few cables on her patch panel and say "Putting you through nooooowwwwww,.."
And then she would proceed to eavesdrop.

(True.)
Phone numbers were just 3 digits back then, and I used to tie an onion to my belt, which was the style back then,.. No wait. That last bit's not true. The 3 digit phone numbers is true but.

Anyways, they were sometimes a bit slow responding so you would tap the handset cradle a few times to wake them up. Each tap would flash a light and ring a bell in the exchange where the operator girls were.
Sometimes they would get stroppy with this and it would make them take twice as long.

(That bit's true too.)
Sometime in about the mid '50s I think, when they changed to the rotary dial, it was thought that if this habit of tapping the cradle a few times persisted, they would get dozens of emergency calls each day, so 999 was a better option.
Almost no one tapped the handset 27 times in three groups of 9's.
It was also decided that since the 9 was right next to the dial stop tag it would be easier to find in the dark or in smoke if your house was burning down around your ears.
Just put your finger in the first hole next to the tag and dial.
There was quit a bit of discussion about it at the time because lots of people didn't want to sit there dialing 999 while their house burnt down around them.
But hey, that was back in the days when Telstra / Telecom / (Postmaster Generals Dept, as it then was), was a government monopoly and their motto was,
"The customer is ALWAYS wrong."
So we got 999 for emergencies.
(For all ex PMG / exchange operator girls, Red thumbs is the one on the left.

Ahhh just pithing mythelf here.

)
{EDIT} AN error has been made.
Sheesh! I must ease up on the after dinner drinks.
Of course we never dialed 999. It was always 000
All the rest looks ok. Logic is the same.
How come nobody pulled me up on this?

Doesn't anybody read my posts?
I'm going to have to say something controversial again.
(Can't think of anything right now. Sorry.)