norcalbusa
Member
Any statistical data that demonstrates one or the other is better for one thing or another? Or no one hears either, so they are really more for the driver's benefit...
Flashguy said:From the driver operator book, sirens are outrun at speeds above 55mph. Longer sirens that go deeper and higher slowly will give a longer distance in front of vehicle. Quicker patterns will travel shorter distance.
Here's an interesting web page: Mechanical Sirens Frequently Asked Questions
norcalbusa said:I'm no audiologist, but my BS meter is pegged by several things stated on that site. No reflection on you of course.
Bigassfireman said:We were always taught that wail is easier for motorists to determine in which direction the sound was coming from, so it would be better for intersections. Then we were taught that changing the tones at intersections, from no specific tone to any other one, got peoples attention better. Seems to be little to no scientific research put into this. Wonder if I could get a multi million dollar grant to "research" this and publish the results. Just think of all the cool toys I could buy in the name of research. But personally, I can hear a wound out Q while sitting at an intersection than any other siren. We can also hear a Q coming thru the city long before any other siren, but once again, I have no science to back it up.
Zack said:Here is what Ive always been taught and what I teach my crews:
The Wail sound's wavelength (long) travels a far distance but is difficult for a human to determine the origin of the sound.
The Phaser sound's wavelength (very short) travels a short distance but is very easy to determine the origin.
Thus, I teach people to use Wail while on long straight-a-ways and with vehicles up ahead. About the time you'd be pulling your foot off the gas go to Yelp, and when you'd be applying the brakes go to Phaser.
As I'm actually at the line of the intersection I interject the airhorn "randomly" to further break up the noise and garner attention.
Additionally, if you are running priority with other emergency vehicles, it's best to "stagger" your tones, so if one person is using Yelp, you should use Phaser. Etc.
ryan81986 said:Here is how I've always told people to use the siren. Pretty much along the lines of what Zack said.
Wail - Empty stretches of road, whether or not there are vehicles ahead of you (more than a couple blocks)
Yelp - Approaching vehicles (One block or less)
Phaser/Piercer etc.. - When you are at the vehicles in front of you/cutting through traffic
Hi-Lo - Used for moving people only. I.E when at an event and cutting through crowds.
NPS Ranger said:I like this video, the driver forgets he's being filmed after about halfway and gets kind of lazy, but it illustrates this thread.
norcalbusa said:We're getting a bit off topic on an anecdotal "use" tangent. I'm looking for scientific data/study please, if anyone has it.
I knew if anyone wouldn't accept anecdotes, it would be you! I've often wondered why there isn't a more scientific approach and study on a lot of this stuff - light placements, flash patterns, sirens, traffic arrows, etc. I've never seen anything scientific - just LOTS of opinions.norcalbusa said:We're getting a bit off topic on an anecdotal "use" tangent. I'm looking for scientific data/study please, if anyone has it.
I think there are way too many variables for there to be a definite answer on this, even with many hours of testing and studies.norcalbusa said:We're getting a bit off topic on an anecdotal "use" tangent. I'm looking for scientific data/study please, if anyone has it.
RolnCode3 said:I knew if anyone wouldn't accept anecdotes, it would be you! I've often wondered why there isn't a more scientific approach and study on a lot of this stuff - light placements, flash patterns, sirens, traffic arrows, etc. I've never seen anything scientific - just LOTS of opinions.
RolnCode3 said:I knew if anyone wouldn't accept anecdotes, it would be you! I've often wondered why there isn't a more scientific approach and study on a lot of this stuff - light placements, flash patterns, sirens, traffic arrows, etc. I've never seen anything scientific - just LOTS of opinions.
I think there'd be a lot of money to be made if you could legitimately quantify safety increases based on various factors, and then do consultations with agencies to improve their fleet.
Title 13 doesn't include any explanation for why only wail and yelp are allowed in California - or what each should be used for. Do you know if there's any supporting documentation from when different sections were written in?
Good find. It's just a literature review rather than original research, however. I'd be curious how much of the cited literature is primary source, and whether there's any actual scientifically valid experiments amongst them. Plus, as you said, it's already 20 years old, and a bunch of the cited stuff goes back to the 60's and 70's.Zack said:Check out my post a couple above yours... I linked to a study (albeit a little old) that did scientifically look at this stuff.
Zack said:Here is what Ive always been taught and what I teach my crews:
The Wail sound's wavelength (long) travels a far distance but is difficult for a human to determine the origin of the sound.
The Phaser sound's wavelength (very short) travels a short distance but is very easy to determine the origin.
Thus, I teach people to use Wail while on long straight-a-ways and with vehicles up ahead. About the time you'd be pulling your foot off the gas go to Yelp, and when you'd be applying the brakes go to Phaser.
As I'm actually at the line of the intersection I interject the airhorn "randomly" to further break up the noise and garner attention.
Additionally, if you are running priority with other emergency vehicles, it's best to "stagger" your tones, so if one person is using Yelp, you should use Phaser. Etc.
Sorry to resurrect this - but I found this snippet from the UK TV show "Police, Camera, Action" in the late 90s. There's actually an old London Fire Brigade, Fire engine with this "siren" fitted....I'll try and find it..
I'd assume because it's being projected forwards, and away from the onboard person(s) of the emergency vehicle.If I might ask a dumb question, if it can't be heard in the cab, how can motorists hear it so well?
Doesn’t sound great but the benefits seemed to be pretty massive. I wonder why it never caught on