At All Times, Service Above Self

The Sounds of Sirens Don't be alarmed ... be informed by Brian Humphrey LAFD Firefighter/Paramedic Dear Friend of the LA Fire Department: No Fire Service equipment topic seems to garner as much interest as sirens, and judging from the many who have asked, a new type of mechanical siren on LAFD emergency response vehicles is arousing a great deal of interest among fire buffs.

We often hear both the piercing rise and fall of mechanical sirens as well as the synthesized rhythmic wail and yelp of electronic sirens in films and television shows. Is there a difference or a reason that we use one over the other?

The benefits and drawbacks of mechanical sirens (often referred to as "growlers" or "coaster sirens") vs. electronic sirens has been debated by fire service safety and fleet maintenance professionals for many years. The results of such discussions are far from conclusive, and as a result, there is still much being assessed about these devices. Such is the case today at the Los Angeles Fire Department.

The LAFD historically used the famous B&M Super Chief mechanical siren - and not the ubiquitous Federal Q2b - on heavy apparatus until the early 1980's. Often times this was as an adjunct to electronic sirens, which gained popularity during the 1960's.

To listen to a professional recording of (Hall-Scott gasoline powerplant equipped!) LAFD Task Force 10 leaving their station in the mid-1960's and very gently tapping their Super-Chief's with the signature "Siro-Drift" sound:

http://www.lafd.org/hs.wav

Most of the LAFD's light vehicles, including ambulances have exclusively used electronic sirens as their primary warning device since their inception. Rather than having a motor that spins an impeller, these microchip equipped devices work much like a music synthesizer (albeit playing but two not so catchy tunes). Highly durable, easy to use and less-taxing on the battery and alternator of light vehicles these electronic sirens have proven popular across North America.

With a massive increase in warning lights, radios and other electronic equipment on the Engines and Trucks, the LAFD phased out the use of mechanical sirens, which are notorious electric power hogs. The tremendous and often unpredictable amperage draw (which can be a killer to Mobile Data Terminals and laptop computers) and which spurred maintenance and reliability concerns - combined with the previous need to constantly control the siren with a foot switch, spelled the demise in the use of mechanical sirens at the LAFD.

Beginning in 1988, the entire LAFD fleet was switched over to an electronic siren, which along with a Public Address system, was fully integrated into the Motorola radio control head that arrived with our then new 800 MHZ radio system.

With civilian passenger vehicles becoming more well insulated, and an increase in electronic "siren-like" sounds appearing in everything from video games to car alarms and with Fire Service responses - and collisions - on the rise nationwide, there has been a notion that we as Firefighters and Paramedics may wish to return to a more unique or traditional sound.

In fact, that very notion has led firms to introduce several *mechanical sounding* electronic sirens, including an electronic version designed by Federal Signal to sound like their renowned model Q2b. Contrary to what some have surmised, the LAFD is not using the new generation of "mechanical-sounding" electronic sirens in new apparatus.

The most recent delivery of ambulances to the LAFD's 140+ unit fleet are indeed equipped with an adjunct mechanical siren, which is produced by San Bernardino-based:

http://www.timberwolfsirens.com

...at 28 amps running and 78 amps peak - and with a convenient automatic cycle feature and the ability to be operated or overridden by a floor switch - they are far less thirsty for precious on-board electric power than the venerable Q2b, which is reported to gulp 125 amps running and a walloping 350 peak!

Again, the newest LAFD ambulances are still equipped with an electronic siren (wail and yelp) that meets all State of California Class A warning device standards, as well as the new Timberwolf mechanical siren as an adjunct. The ambulances also are equipped with the hi-lo air horns as an auxiliary signaling and warning system. The use of the Timberwolf siren (and a host of -far- more important equipment on the new ambulances) will be formally assessed by the LAFD's Equipment Engineering Unit on a continuing basis.

As far as heavy apparatus, the City's MICLA program has funded a split-order of new Pumpers from both Seagrave and Pierce. The new rigs will also be equipped with a mechanical siren as an adjunct. Half of the new deliveries will have the Timberwolf, while the other will be fitted with the Federal Q2b. This to my knowledge, will be the first time that an LAFD apparatus has been officially equipped with a Federal brand mechanical siren. As mentioned above, the LAFD's Equipment Engineering Unit will be similarly assessing the commonalities and differences of these products.

Regardless of the type of siren though, the law - and common sense - clearly dictate the seven simple steps that California Drivers (and those in most States and Provinces) should perform when they hear a siren and see an approaching emergency vehicle.

1) Avoid making any sudden or abrupt move.

2) Signal your intention

3) Slowly and carefully move to the rightmost portion of the road as quickly as possible without endangering or obstructing other motorists or emergency responders.

4) Bring your vehicle to a full and complete stop as close to the right shoulder - or off the road if practical.

5) Fire Department vehicles often respond in convoys or from different directions. Be certain that all emergency vehicles have passed before you safely attempt to re-enter traffic.

6) Follow no closer than 300 feet from any emergency vehicle that is sounding a siren or displaying warning lights while in motion.

7)Fire Engines and Ambulances often make sudden stops, U-turns or block traffic lanes on their way to help others. If being a spectator becomes a priority, the next siren you hear may be coming for you!

Remember... When you get behind the wheel: Heads Up, Easy on the Throttle and Expect the Unexpected!

If you'd like to learn more about the technology and training being used to make Los Angeles Firefighters more safe and efficient, please stop by your Neighborhood Fire Station: http://www.lafd.org/visit.htm

Respectfully Yours in Safety and Service,

Brian Humphrey

Firefighter/Paramedic
Public Service Officer
Los Angeles Fire Department
E-Mail: beh9593@lafd.lacity.org

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