The official Broadmoor Hospital SIREN {{NOISY VIDEO!!}}

Mr BlueSnowballMic recorded the audio for you this morning for the best quality! This video also features the TRL siren.
They were quite far away but may I say it, the sounds were lovely and helped with my development of this video.

By the way: TRL=Transport Research Laboratory. A secure site in Bracknell.

Both activate at 10am on a Monday. The sirens have been edited with a time off-set so that you can see (and hear) the stages of each siren separately, rather than everything happening at the same time.

There is one fault to report - The TRL siren "low tone" shutter does not open. It's typical that it "had to be the one facing the camera that didn't work" :(

\/\/\
   • SIRENS - Finding the 13 Broadmoor sirens (...  
(this video features SIREN F and SIREN G)
/\/\/

ABOUT THE SIRENS:
Here are two sirens from a system containing 13. They are located in the neighbouring towns surrounding a secure hospital in the UK.
Me and Chay went out to find them all - this is now complete. See all my other videos here:
   • SIRENS - Finding the 13 Broadmoor sirens (...  )

It was a very interesting bank holiday Monday lol! Chay was a bit apprehensive while waiting for the first siren to sound, but loved it afterwards :)
He liked it enough to stay with me whilst tracked them all down.
It was a good day as we did other things like play football in the parks, McDonalds and see the sirens of course!

It was a mixed bag - some viewable from the street, some hidden so much that you'd never know they were there (unless it went off!), some in council depots, compounds, parks and believe it or not - in the middle of housing estates metres from houses! (would scare the living daylights out of residents if they went off at 3am!)
Some are in secure places with no access at all.

The sirens are tested at 10am each Monday.

I have recorded most of them in action (lots of Monday's@10am!) - in this video there are two of them.


HOW THEY WORK:
The Klaxon CS8 siren.

A 415volt 3 phase motor spins two rotors on either side. One rotor is for the high tone and the other for the low tone (the one with most holes is the HIGH tone).
During the escape siren, the airflow is cut alternately to each rotor by a shutter on each end producing the distinctive high-low tones. I believe these are known as CODED SHUTTERS - hence the model name Klaxon "CS"8.

Both shutters are opened together for the all clear tone. You can just make out the high and low frequencies being produced together if you listen.