Question about London blitz and alert sirens?

Question:I am wondering how much warning time people had at the beginning of the bombing attacks on London during the Second World War, in the period before the V2s.
Many thanks.

Best Answer - Chosen by Asker: I am wondering how much warning time people had at the beginning of the bombing attacks on London during the Second World War, in the period before the V2s.
Many thanks.

Britain had a secret weapon during the Battle of Britain and the later Blitz (Aug 10-Sept 30 1940, Oct-Jan 1941) called radar, which allowed them to plot the courses and height of the German bombers targeting London. It wasn't perfect and there were lots of mistakes, but people had anywhere up to 20 minutes to get ready, but usually a lot less, say under five. Personal air raid shelters (basically steel cages) called Anderson shelters were popular, which gives you an idea the time frame wasn't very long, ie not long enough to make it to the nearest underground station.

V2s were a lot different. They were too fast to be detected or intercepted, the first thing you knew was "BOOM". V1's had a distinctive sounding motor and rudimentary guidance systems, they could hit greater London but that was about it. The engine cut out and then they fell, about 15 seconds after the putt putt putting stopped.

I cant find that answer anywhere but I would asume that it was not very much time. They did not have the technology that we have today.

when the coastal radar picked junker bombers enroute to london the alarms would sound. the central london alarm was a terror in itself, a v-12 roll royce motor was hook up to the sirene, and its high pitch wail would cause defacation for 20 miles. old folks today say they feared the siren worse then the bombs

It varied greatly. At first the warnings were only a few minutes but with the development of radar this improved at later stages of the war.
Against the V2 there was no warning as it was supersonic and the first anyone knew of an attack was the explosion

Depending where you lived you had between 2 - 30 mins to escape. People living on the costal areas would have about 20 minutes to get ready, since it would be easier to spot the enemy from the distance. People living far in land would have about 20 - 30 mins to get ready since they would have time for the advanced warning to reach them and they could prepare. People living in between would only have around 5 mins to get ready though since there was not enough time for the advanced warning to reach them, before they saw the enemy.
in big cities like London and B'ham they would have about 10 minutes to get ready since the systems were much more advanced in cities and they could be alerted quicker.
Like previously mentioned, In big cities they used the Rolls Royce V12 (Which was invented by a guy who used to live near where i live)
And in the smaller areas they would of used the littler sirens.
If you have ever heard the Rolls Royce ones though, they are murderingly loud and i agree with the person saying that peopl feared it more than the actual bombs.
There is a seaside resort, i think it is in norfolk, that has and old V12 siren, and it went off on holiday once. (they have to tets it every so often, usually five years, to make sure it still works, for the sentimental value, or if we go to war again) There was a local man talking about how horrible it was because he livied right next to it and it was constantly going off during the wars.
When i actually heard i though hell had broken loose (I had watched silent hill recently, you understand now why i was s*** scared, if not , watch it)
It was horrible and lasted for about 30 mins.