'Sound' Question to the Trafpol Guys..
Discussion
.. to do with the 'twos'.
I live near Hendon Police College and, close to that, is the new (big) Collindale Police station- so I often have to give way or pull over for a vehicle using 'blues & twos'.
On a few ocassions though, eg: as I approach a roundabout, I have heard sirens getting louder but have been unable to detect or anticipate which direction they're coming from.
That's led to a couple of "oh sh!t, they're behind me" moments when expecting to see the car appear from another direction!
Soooo, my question is, are the modern sirens designed to do this? ie: 'throw' the sound and disguise the origin.
If so, is the 'advantage' to confuse, say, bank robbers into turning into the wrong street?
I fully realise that on a motorway a siren getting louder can only be coming in one direction!
Are your cars fitted with a similar siren unit to the urban cars though?
Sorry if there's an obvious answer- just a bit puzzled,
Kenny
I live near Hendon Police College and, close to that, is the new (big) Collindale Police station- so I often have to give way or pull over for a vehicle using 'blues & twos'.
On a few ocassions though, eg: as I approach a roundabout, I have heard sirens getting louder but have been unable to detect or anticipate which direction they're coming from.
That's led to a couple of "oh sh!t, they're behind me" moments when expecting to see the car appear from another direction!
Soooo, my question is, are the modern sirens designed to do this? ie: 'throw' the sound and disguise the origin.
If so, is the 'advantage' to confuse, say, bank robbers into turning into the wrong street?
I fully realise that on a motorway a siren getting louder can only be coming in one direction!
Are your cars fitted with a similar siren unit to the urban cars though?
Sorry if there's an obvious answer- just a bit puzzled,
Kenny
It's just a side-effect of using electronically generated wails. There aren't enough different frequencies at once for the ears to get a fix on direction. It's the same effect as not being able to tell where the sound of a modern phone ringing is coming from if there are several possibilities, but that wasn't a problem with the old ones with proper bells.
Kenny chim 4 said:
.. to do with the 'twos'.
I live near Hendon Police College and, close to that, is the new (big) Collindale Police station- so I often have to give way or pull over for a vehicle using 'blues & twos'.
On a few ocassions though, eg: as I approach a roundabout, I have heard sirens getting louder but have been unable to detect or anticipate which direction they're coming from.
That's led to a couple of "oh sh!t, they're behind me" moments when expecting to see the car appear from another direction!
Soooo, my question is, are the modern sirens designed to do this? ie: 'throw' the sound and disguise the origin.
If so, is the 'advantage' to confuse, say, bank robbers into turning into the wrong street?
I fully realise that on a motorway a siren getting louder can only be coming in one direction!
Are your cars fitted with a similar siren unit to the urban cars though?
Sorry if there's an obvious answer- just a bit puzzled,
Kenny
A few years ago the 'Metsound' system used to have different settings for Town/Country etc but i believe that this was to control the loudness.
I remember a couple of years ago, the LAS tried a system as you describe but it hasnt made it onto our vehicles as yet.
One of the biggest problem with "Metsound" has always been that, in the vehicle in which it's fitted it's 'kin loud, suggesting that everyone in the vicinity can hear you. I've noticed that, outside the vehicle, the "twos" are useless outside a range of approx. 50 metres, an interesting observation as I used to rely on them to a certain extent! LAS and similar have experimented with a system which, apparently, makes it easier to identify the direction from which the noise is approaching, however, as with all Police/EU initiatives, cost and feedback are rare
diddly, sorry,
I guess part of my question was do you want your direction/ approach to be given away by the wail?
I mentioned a scenario where it can be advantageous, albeit urban, but my main point was that the seemingly 'directionless' wail can confuse Joe Public and, therefore, frustrate those of you needing to get somewhere very quickly!
As said, it's caught me out a few times- and I like to think I'm on the ball!
I guess part of my question was do you want your direction/ approach to be given away by the wail?
I mentioned a scenario where it can be advantageous, albeit urban, but my main point was that the seemingly 'directionless' wail can confuse Joe Public and, therefore, frustrate those of you needing to get somewhere very quickly!
As said, it's caught me out a few times- and I like to think I'm on the ball!
deltaf said:
Talking of sirens....i have a * genuine* code 3 model 3920 police siren generator!
Capable of outputs of 50-100watts.....
Question is, can i put it on the car and use it legally?
Definately a no no, even fitting is illegal.....except of course for a number of exemptions that are connected with emergency service vehicles, bomb disposal, Blood Transfusion Service,Coastguards etc etc.
(Reg 37 MV Con & Use Regs 1986)
If you have the desire to use one then down to your local nick and enrol as a Special.
DVD
madant69 said:
Our siren system (obviously bought from Lidls) has a really awesome "french ambulance" setting, which is fab! Everyone in a four mile radius stops to try and figure out what the hell it is!
ALSO, and this is important...
A ducks "quack" doesn't echo - and no-one knows why!
...on our switches it's called zode 4...(Feels like yours rushing down the Champs Elyesse.. As for cars getting out of the way.....Well what a parlarva at times..
Some go left, so speed up, some slow down, some do nothing and refuse to look at you, some emergency brake.. It's sexist yes I know, but the daftest and most bizarre of reactions comes from female drivers in 80% of occassions..
Street
OK, so how about this one that happened a few years ago. My mate's driving along a small-ish lane, nothing in front, just on the speed limit, with a lot of traffic coming the other way. Patrol car with 'blues and twos' on approaches from behind, so naturally we want to let it get on its way. Is it legal in those circumstances to exceed the 30mph, or does he risk a fine / points? You'd like to think there would be good judgement exercised as he would be genuinely trying to assist by getting out of the way, but it would be nice to be sure that if the call was suddenly cancelled for whatever reason, the officers wouldn't suddenly think of something else to do.
BTW this was a few years ago, before the recent interest in speeding. I don't recall exactly how we *knew* that he wasn't trying to stop my mate but I recall neither of us considered that for a second. As it turned out he was going to deal with a fight at a local pub.
BTW this was a few years ago, before the recent interest in speeding. I don't recall exactly how we *knew* that he wasn't trying to stop my mate but I recall neither of us considered that for a second. As it turned out he was going to deal with a fight at a local pub.
droopsnoot said:
OK, so how about this one that happened a few years ago. My mate's driving along a small-ish lane, nothing in front, just on the speed limit, with a lot of traffic coming the other way. Patrol car with 'blues and twos' on approaches from behind, so naturally we want to let it get on its way. Is it legal in those circumstances to exceed the 30mph, or does he risk a fine / points? You'd like to think there would be good judgement exercised as he would be genuinely trying to assist by getting out of the way, but it would be nice to be sure that if the call was suddenly cancelled for whatever reason, the officers wouldn't suddenly think of something else to do.
BTW this was a few years ago, before the recent interest in speeding. I don't recall exactly how we *knew* that he wasn't trying to stop my mate but I recall neither of us considered that for a second. As it turned out he was going to deal with a fight at a local pub.
Not in a million years...!
Obviously, if you tear off at 80 mph to get to a bit to pull in, there might be concerns.. (I once happened to be beind a stolen car as I was en-route to an accident. Due to the light/sirens, the car in front sped off and it ended up in a pursuit with other officers dealing with the accident. I caught chav in car following foot pursuit into gardens incidentally).
If there is nowhere for you to go, the Bib behind should knock off the 'sounds' and "plod" along behind you until a gap appears.
I often do that if i'm approaching a brow of a hill or a tight bend, as Mr/Mrs Nerves in front tend to stop right on the brow or curve of the bend
You can even venture across a stop line at a red light if it was allow an emergency vehicle to gain progress. Even if the 'camera' on the lights flashes you, if all you've done is move into the space of the junction in an obvious attempt to let the emergency vehicle through, you'll NOT be prosecuted.
Street
Ok a couple of years ago I entered a contra flow, about 1/2 mile into in I was approached by an ambulance with motorcycle escort (I know these are only used in very extreme cases) the first bike overtook (god knows how) and waved me on. Foot down and out the way. Sounds like they should have waited? To be honest I've had sped anyway and hoped to argue it out in court.
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