Different emergency tones and sirens

culabula88

Most emergency vehicles now have a selection of sirens. Is there any reason to use different sirens when going to an emergency - ie low tone if stuck in traffic or trying to get past a crowd. I remember few years ago that university in England developed a totally different sound like a hissing siren which was more effective in telling drivers where they were, but it was never taken up universally by the authorities.

Which siren do you find most effective? I know that sometimes when Im in traffic , it can be difficult to find where the ambulance or guard is coming from.
What do you tink of this Rumble siren?http://www.buzzle.com/articles/new-police-siren-rumbles-drivers-to-attention.html


Is there a slight difference between garda and ambulance sirens?

Paulzx

I have no idea if this answer has an basis in scientific fact but i'll give you my take anyway.

Switching between differnt tones especially approaching a junction seems to help people hear you better. Maybe the different frequencies etc. help.

One of the most risky situations on blues for us is if two or three fire engines turn out of the one station going to the same call. They end up approaching junctions in convey. Most people hear the sirens, let the first motor thru but assume there is only one and then pull out. The second and subsequent motors are nearly more at risk of collisions than the first one. If the motors are using different tones it can sometimes help people identify the different vehicles.

I'm sure somebody will come up with some mad study on sirens ( nerds!!!) that gives a proper answer

metman

Here police response vehicles have three tones; hi-lo, yelp and wail. As Paul says above the tones are varied to alert traffic to the presence of an emergency vehicle near them as often drivers will hear a siren and assume its nowhere near them if they can't see the vehicle. Similarly we'll alter tones when approaching a junction for the same reason.

Usually on a blue light run I'll use the wail tone on an open road, alerting traffic further down the road of an approaching police car, the yelp in traffic mixed with the hi-lo at junctions.

As mentioned if you have a number of vehicles in a convoy on a blue light run its important that the tones used are different so usually the lead car will run with the yelp and the second car will have the wail or hi-lo......and so forth and so on. Again its from a safety point of view so the tones don't all blend into one and traffic crossing a junction don't mistake multiple vehicles for just one police unit.

And my mrs always finds it amusing that I can distinguish Fire/Ambo/Police sirens........they are different here but only to the trained observer

vulcan57

I can often tell the difference between the fire, ambo and gards flying up past west side SC in Galway before I even see them. The Gards seem to be slightly higher pitched and a bit slower. I was in London last year and heard the siren that I think culabula88 is talking about, short 2-tone bursts interspersed with a burst of white noise. It was very effective as you could instantly know where the vehicle was coming from for some reason, strange there isn't more use made of it.

Fyr.Fytr

The NOG said something about this a while back.

With wail its travels further so use it on open roads etc to let those ahead know.

Yelp is shorter and grabs peoples attentions quicker

Then there is others like hi-lo, phaser etc for junctions

And the good oul air horn for "MOVE NOW YOU BLIMMING IDIOT"

metman

The newer response cars have air horns and have a different tone that Trojan has had for a while, we call it the machine-gun tone, no clue what its official name is.

Fyr.Fytr

The one LAS have, think its phaser your on about, will search for sound clip


Found:

http://www.youtube.com/watch?v=t9jdGlvG5KI activated with wail at 00:06-00:07

metman

Fyr.Fytr wrote: »

The one LAS have, think its phaser your on about, will search for sound clip


Found:

http://www.youtube.com/watch?v=t9jdGlvG5KI activated with wail at 00:06-00:07

LAS? You could pass as a local

Seriously though, yep the last tone on that vid is the tone that Trojan have been using for ages and has now filtered down to borough response vehicles; strangely this is only the case with IRVs and not RT cars, the same being the case with the replacement of blue lightbars with white LED 'thin' lightbars. To date this is filtering out through the Met for IRVs but not for RT cars.

I never really saw the point of this tone; all it ever said to me was 'Armed Response Vehicle'. Now that's gone out the window, so god knows what the public makes of it.

JonAnderton

We had a replacement Golf2, which was one of the first model BMW's, which had one of them light bars... and it looked Sh*te... lol

Not a proper police car at all!

BTP had that tone long before we did.. It did always get my attention. I think people in traffic get attuned to the usual sirens and pedestrians maybe even ignored themI i think this 'wakes them up a bit' when needed... Think it came before the air horn...

I remember when on an emma call to Tottenham High Road and this bloke as on his phone blocking the junction. The blue light and sirens didn't alert him... Took an asp on the window to shake him out his trance...