Hi all Anyone know the difference between the the following Air Raid siren warnings: "Alarm" / "Release" "Alert" / "Raiders Past" Apparently "Alarm" would take precedence over "Alert". I also know "Raiders Past" was basically the all clear. Thanks Dave
I always thought the rise and falling 'wail' was 'Raiders approaching' and the Raiders past was a constant 'wail' ,
A siren still sounds regularly here in Southampton. across the water at Marchwood Army maritime port. Whenever ammunition is being moved for loading onto RFAs the sirens can be heard.
You can hear all the siren sounds here: BBC - School Radio - World War 2 Audio Clips - Air raid in progress It still gives me the heebies From one who heard these sounds for real. Ron
Whilst we were growing up we always went down the road to the local residential Home to visit the people, upon this building was the Air Raid siren, it was operated by a switch and would run to a set pattern. They tested the siren half yearly, when the building was demolished some appropriated the siren which upset most of us as we wanted it. It always stared with a very load wail then after a couple of minutes moved to a more even note.
A link below Sound Generation. The electrically driven sirens composed of an electric motor, usually 3 phase, with shafts at either end on which were mounted impellers or fans. One end having 10 blades and the other having 12. Around these two impellers were housings with 10 and 12 slots to match the impellers. The impellers were so designed that upon rotation they drew in air at the end and forced it out through the corresponding slots in the housing circumference. Due to the design of the impeller and its housing the air output was cut on and off alternately thus producing the basis of sound production. Assuming a motor rotational speed of 2840 rpm the output frequency would be 473.33 and 568 Hertz, a sound that would become very familiar to civilians 1939-1945. (It used to scare the wits out of me!) To convey a state of "ALL CLEAR" the siren was switched on to produce a steady note. To convey a state of "TAKE COVER" a device was wired into the motor circuit which cut the power supply for a short while at intervals thus allowing the motor speed to drop and then rise again when reconnected. These devices were commonly supplied with two push buttons. One, "TAKE COVER" the Red Warning, which brought into use the automatic cut-outs. The other White Warning for "ALL CLEAR" or "RAIDERS PAST" which over-rode the cut-outs and produced a steady note. The Air Raid Siren
The air raid warning siren was known as 'moaning minnie' (sometimes wailing winnie) because of its two note whine and people hurriedly took cover; the 'all clear' was one prolonged note and was the signal to leave shelter and return to home / daily activities. When there were successive raids during daylight, we took our workbooks and songbooks to the shelter; when we had finished our usual lessons, the teachers used to lead us in singing songs from the National School Song Book (mostly folk songs). If we were there for a very long time, we progressed to Run Rabbit Run, Blue Birds Over....., Wish me luck as you wave me goodbye, Wings Over the Navy, etc. Edna
I must say that the sound of a air raid siren is one of the things that has stuck with me from pre-invasion Iraq when I was in Kuwait. Like Ron I found them rather un-nerving when the Iraqi's were ment to be launching Scubs at us. The other sound was the NBC now CBRN alarms going off warning of a suspected chemical attack..
If you're in the vicinity of Crowthorne in Berkshire on a Monday morning at 10.00 you can hear the Broadmoor escape siren being tested. Originally it was a standard ARP siren but I gather it's now been updated as the version on Sound recording of a warning siren test at Broadmoor maximum security hospital | London Sound Survey sounds nothing like the one I remember (although there are apparently now thirteen of them and the recording is of one in Wokingham).
In Guernsey they have just Decommisiond 11 of the 12 warning siren's the one remaining is used for special events like the anniversery of the 1940 bombing of the harbour Liberation day popey day and the like and yes I do get to sound it
Hi All I think you all have question of the difference between "Alert" and "Raiders Past" - as someone who has never lived through anything like an air raid I can only imagine the fear the 'moaning minnie' must have caused! (the nearest I've got is the regular testing of the Sizewell Nuclear Power Station sirens!). I've basically come across the terms "Alarm" and "Release" in reference to centrally controlled systems such as the "Ripple" System (Manufactured by Metropolitan-Vickers) or the "Cuckoo" System (was this a Post Office System??) and assume their must be some sort of difference given "Alarm" would take precedence over "Alert". Dave
Hi all Anyone know the difference between the the following Air Raid siren warnings: "Alarm" / "Release" "Alert" / "Raiders Past" Apparently "Alarm" would take precedence over "Alert". I also know "Raiders Past" was basically the all clear. As one who lived throughout WW2, I can assure you that none of the four terms cited was used by the ordinary civilian population. It is possible that the first three might have been used by Civil Defence, ARP and the like, but I cannot imagine that the meaningless "Raiders Past" would have been approved by the Nobel literature laureate Winston Churchill. "Raiders Passed" sounds more likely as well as meaningful. As to what real people said: "Air raid warning" or Air raid siren" at the beginning, and "All clear" at the end.
The attached will answer many of the questions. It is from a 1939 ARP training manual, later editions became the official Home Office ARP/Civil Defence manual. You will see Raiders Passed is different to All Clear. It means simply raiders have passed, All Clear means danger (including GAS) is over remember after an attack, Gas detection checks were carried out; All Clear meant raiders have passed and no GAS danger exists. The system was modified several times during WW2, but the basic system remained in use until the end of the Cold war. For interest :: During the Cold war We would initially receive a yellow warning, then an attack warning red during which you would go to cover. After an air attack the message "Hostiles Clear of the area" would be tannoyed and passed over radio and telephone nets, but no siren would be sounded. Only after full NBC checks proved negative would the ALL Clear be given. On the sounding of attack red the NBC state would automatically go to BLACK, the final All Clear would be WHITE. I will see if any of my books reveal the changes made during WW2 but the attached will go some way to answering the questions.
Every first monday of the month exactly at 12 o'clock those things begin to moo. A terrible noise, especially when you are close to the siren. It seems they have to test it in case a disaster is happening. We all have to close the windows and doors and put the telly/radio on if that's the case. When they go off you automatically check wether it is the 1st monday of the Month or not. Ron...
Raiders Passed is different from All Clear. It means simply raiders have passed, All Clear means danger (including GAS) is over. Remember, after an attack, Gas detection checks were carried out; All Clear meant raiders have passed and no GAS danger exists. For those not around at the time, it is worth mentioning that, although gas masks were issued to everybody and initially carried around all the time, what people really worried about when the sirens went was bombing rather than gas attacks. After the first year or so, gas masks were mostly forgotten by ordinary people.
For those not around at the timer it is worth mentioning that, although gas masks were issued to everybody and initially carried around all the time, what people really worried about when the sirens went was bombing rather than gas attacks. After the first year or so, gas masks were mostly forgotten by ordinary people. And hence my statement that the system changed as the war progressed. The attachment I posted was that in existance January 39 and no doubt actually changed to some degree before hostilities commenced. Thankfully Gas was never used.
Every first monday of the month exactly at 12 o'clock those things begin to moo. A terrible noise, especially when you are close to the siren. It seems they have to test it in case a disaster is happening. We all have to close the windows and doors and put the telly/radio on if that's the case. When they go off you automatically check wether it is the 1st monday of the Month or not. Ron... We get that here too - every month. Makes my Mum shudder when it sounds. Horrible noise. Jules.
Some interesting stuff here -the original question was about sirens and I think it is clear that there were only two signals - an Alarm (whatever it was called) and an all clear. These were for the general population, other alarm states were passed (by telephone?) between the various Civil & Military authorities to indicate the progress/development of a raid. I also read that seperate alarms were passed to (large) factories - presumably to keep production going as much as possinle and because the air raid shelters would be closer (in the factory). Noel
