Thunderbolt siren

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The Thunderbolt siren was an electro-mechanical warning siren once manufactured in the United States by Federal Signal Corporation. The Thunderbolt siren consists of three motors. The blower motor is housed inside a large rectangular motor box typically found at the base of the siren (or in some installations on a wooden platform mounted half way up the utility pole, other methods include mounting a long wooden platform halfway up between two poles.). This motor is connected to a standpipe which blows or pumps air up to the chopper motor. As the chopper spins, the air forced into it escapes out of rapidly opening and closing holes, creating the siren's sound or "roar." Finally, a rotator motor turns the siren's projector horn 360 degrees when in operation. The Thunderbolt could be shipped as using single- or three-phase power and could either be pole-mounted or roof-mounted.

Contents 1 Thunderbolt history 2 Thunderbolt Siren Today 3 Thunderbolt Logo 4 U.S. Cities and Other Towns Using Thunderbolt Sirens, Past and Present 5 Trivia 6 External links

[edit] Thunderbolt history

The Thunderbolt was first produced by Federal Enterprises (now Federal Signal Corporation) in 1952. There were three models manufactured:

• Model 1000, a single-tone siren which generated 127 dB of sound (measured from 100 feet away from the siren);
• Model 1000T, a dual-tone version which generated 126 dB at 100 feet;
• Model 1003, a dual-tone version with the added capability of producing a Hi-Lo fire signal. This model also generated 126 dB at 100 feet.

The dual tone Thunderbolt 1000T/1003 models have often been described by siren enthusiasts and casual listeners alike as having the most eerie and ominous sound due to its very distinctive dual tone that is usually sounded in a minor third. On all Thunderbolt models, the pitch of the siren was adjustable; most often, no two Thunderbolt sirens in the same community sounded exactly the same (unless adjusted for consistency). Some lower-pitched 1000T's have been described as sounding like a very loud dial tone. On single-tone 1000 models, the sound from the blower motor can be more noticeable giving this version somewhat of a bass-like background sound, setting it apart from the sound of other single-toned siren models. The rotator motor/projector horn had three speed settings — 2, 4, or 8 RPM.

Typically, these sirens were/are often seen painted bright yellow. This has more recently come to be known as "Civil Defense Yellow," although on occasion, one might find a Thunderbolt painted in other various colors to meet the community's needs. Very early examples of the siren could be observed with the projector horn painted "zebra-striped" black and yellow, or red and white (most often the former). The projector horns on early models were fitted with two sets of metal grilles welded to the front opening of the horn. This was to exclude debris from entering and birds from building nests inside. By the late 1950s, the manufacturer removed the grille design in favor of a protective black mesh screen.

The Federal Thunderbolt was the siren of choice by many Civil Defense authorities and emergency management agencies from the early 1950s through the late 1970s. By the 1980s, sales of the Thunderbolt were beginning to decline. Despite its popularity, the Thunderbolt was a high-maintenance siren. Because of this, many of the cities and towns who had Thunderbolt sirens installed initially in the 1950s and early 60s were reluctant to replace them with newer ones, opting instead for more-advanced/low-maintenance models as suitable replacements. Even a later model 1000 (series C), producing 131 dB instead of 127 dB, could not compete[1]. In 1988 Federal Signal introduced a new single-tone siren called the 2001DC [2]. This siren utilizes a DC (battery) backup power feature, enabling the siren to be operated during a power failure, operates on only 2 motors, and requires far less maintenance. As the Thunderbolt only operates on AC power, the introduction of the 2001DC spelled the end of the Thunderbolt siren, and Federal Signal phased out the Thunderbolt series in 1990.

[edit] Thunderbolt Siren Today

Federal Signal no longer makes replacement parts for the Thunderbolt siren, with the exception of the rotator, which is used on the 2001 series siren, and the chopper, which is used on the Model 2 siren. Some towns in the US and some siren enthusiasts have taken to purchasing once-decommissioned Thunderbolts and other Cold War-era civil defense sirens, restoring the units, and giving them a second "life" by selling or donating them to towns or communities in need of a good refurbished unit.

[edit] Thunderbolt Logo

The Thunderbolt logo/decal insignia changed little in its 38 years in production. At the beginning in 1952, the name Thunderbolt was not seen on the siren, instead just the name "FEDERAL" immediately followed by Federal's logo at the time, a stylized circled "F" with a lightning bolt inside the circle striking towards the front of the F. In the mid 1950s the siren's logo was changed to read "THUNDERBOLT" preceded by the aforementioned circled F logo connected to a second lightning bolt running through the name "THUNDERBOLT," and there was a series of wavy lines above and a series of spaced lines below the name. The lines may have represented wail and pulsed warning tones respectively. Although this logo was not used on the siren in the beginning, it did appear in Federal's trade literature for the siren in 1952. This would be the siren's insignia for the remainder of its production life, except for the updates to Federal's "F" logo. Sometime in the early 1970s the "circled-F lightning bolt" logo was updated to a basic block style "F." When Federal Sign and Signal became Federal Signal Corporation in 1976, the company again updated the Thunderbolt logo to include its current block-stylized red "FS" logo. This is the most commonly seen example of the Thunderbolt logo as it is the most recent. Some older roof-mounted "T-bolts" (pre 1976) that house the blower/cabinet housing inside its respective building have been observed to have intact examples of the old "circle F" or early 70s "block F" Thunderbolt logos. This is one way of estimating a "T-bolt's" age from an exterior view. The Civil Defense logo accompanied the Thunderbolt logo on the blower motor and could be seen on either side of the rotator motor. The Thunderbolt logo was usually seen across both sides of the rotator motor, on the upper left and right hand corners of the blower motor, and sometimes on the control cabinets.

[edit] U.S. Cities and Other Towns Using Thunderbolt Sirens, Past and Present

• Honolulu, HI Many Thunderbolt 1000Ts in active use as tsunami warning sirens, tested on the first working day of every month at 11:45 A.M.
• Madison, SD Two ThunderBolt 1003s still in service.
• Newark, OH One Thunderbolt 1000 mounted on Chase Bank building in Downtown region. Still operational, tested every Wednesday at 12:15 P.M.
• Elmhurst, IL One or more Thunderbolt 1000s or 1000Ts in sevice.
• Jacksonville, FL (1000s) Silenced in the early 1980s and all were removed in 2003.
• Dallas, TX (1000s & 1000Ts) Still operational.
• Denver, CO Several still in use.
• Sterling, CO
• Duncanville, TX (1000s & 1000Ts) Replaced in mid 90s with the FS Modulator series.
• Waco, TX (Twenty 1000Ts) Replaced in 2000 with 31 ASC T-128 sirens. [3]
• Chicago, IL (1000Ts & 1003s) Replaced in mid 1990s with FS 2001DC and Modulator series.
• Detroit, MI (1000s & Thunderbeams) Currently being replaced with new 2001SRNBs.
• Plymouth, MI (1000Ts & 1000s) Used for weather warnings.
• Omaha, NE (1000Ts & 1000s) Replaced in 2004 with ASC T-128 sirens.
• Bellevue, NE (1003s) Replaced in 2005 with FS 2001SRN sirens.
• Valentine, NE One 1003 still in service.
• Gordon, NE Two 1003s still operational.
• Lincoln, NE (1000Ts & 1000s) Replaced in 2001 with FS 2001DC/SRN sirens.
• Grand Island, NE (1000Ts) Still operational.
• Memphis, TN Still used today.
• Des Moines, IA Replaced in late 1990s with ASC T-128s and FS 2001DC sirens.
• Washington D.C. Taken down in late 1980s.
• Barrington, IL Replaced with FS 2001s.
• Lancaster, WI Still operational.
• Rock Rapids, IA One 1003. Still operational. Time signal Mon-Sat 6:00 PM. Hi|Lo disabled, solenoid problems. Also three FS 2001 sirens.
• Grundy County, IL In the process of being replaced by ASC T-128s and T-135s.
• Gering, NE (Three 1003s) Replaced in 2002 with 6 FS 2001DC/SRN sirens.
• Scottsbluff, NE (Five 1003s) Still operational.
• Bayard, NE One 1003 still operational.
• Morrill, NE (Two 1003s) Still operational.
• Louisville, KY (1000Ts) Still operational.
• Shawnee County, KS Over fifteen 1000s/1000Ts. Still in use.
• Sedgwick County, KS Still in use.
• Leavenworth County, KS
• Johnson County, KS
• Salina, KS Still in use.
• Liberty, NY Still operational.
• Indianapolis, IN Soon to be replaced.
• Baltimore, MD Has several Whelens.
• Canajoharie, NY Has Whelen which sounds off every day (except Sunday) at noon.
• Austin, TX Five 1000s No longer operational.
• Jackson, MI 1000T.
• Lansing, MI 1000s/1000Ts.
• Chattanooga, TN Silenced in the early 1980s, still standing.
• Battle Creek, MI
• Springfield, IL Replaced by 60 ASC T-128s.
• Moffett, OK One 1000.
• West Lafayette, IN (One 1000 and one 1000T) Still operational.
• Cowlitz County, WA 1000s. Power removed in 1997, over half still standing.
• La Crosse, WI At least two, one located next to the Three Rivers School on the north side and one near Badger Corrugating Co.
• Madison, WI At least a couple still exist. 2 Thunderbolt 1000s.
• Laramie, WY At least four 1000Ts, still operational.
• Brea, CA One Thunderbolt siren on Berry st. Installed in 1965
• Oswego, NY Part of the Oswego County Nuclear Safety Program.
• Scriba, NY Part of the Oswego County Nuclear Safety Program.
• Apex, NC Part of the Shearon Harris Nuclear Power Plant Safety Program.
• Reading, OH Still operational.
• Lockland, OH Still operational.
• Amber, OK Town Civil Defense siren, still operational.
• Bartlesville, OK Some 1000Ts, still operational.
• Norman, OK Some 1000Ts, still operational.
• Jenks, OK Some 1000Ts operating (5-8?), faulty models replaced with (2) FS 2001 series sirens
• Andover, KS One 1003, still operational?
• Grand Haven, MI Several 1000s. Replaced by FS 2001 series.
• Lawrence, KS Replaced by 2001s in 1990s.
• Coffey County, KS Several 1003s still in use. Used for tornadoes, fire, attack, and Wolf Creek Nuclear Power emergencies.
• Ankeny, IA Replaced by a 2001-130.
• Rochester, MN Replaced with 2001 sirens in 1994.
• Houston, TX Began removing many Thunderbolts in the mid 1990s due to sound pollution ordinance. None were operational by 2004. No sirens have been put back in their place.
• Austin, MN Replaced with 2001 Sirens.
• Eagan, MN At least one known still operational.
• Rosemount, MN Still operational.
• Harper Woods, MI Three 1000Ts still in use
• Oak Park, MI One 1000 still in use
• Madison Heights, MI One Thunderbolt 1000T still in use
• Monroe, MI One still standing, surrounded by 2001DCs.
• Columbus, OH Some operational.
• Grayslake, IL One Thunderbolt still operational.
• Streator, IL Replaced in 2006 by FS 2001 series.
• LaSalle County, IL 30+ 1000s for LaSalle County Nuclear Generating Station. Tested first Tuesday at 10 am (statewide). Replacing with 2001s, T-135s, and T-128s as they fail.
• Caledonia, NY One still in operation.
• Alton, NY One still in operation, fire department siren.
• Manchester, NY One still in operation, fire department siren.
• Palmyra, NY One still in operation, fire department siren.
• Ottawa, IL One ancient 1000 (with an inoperable rotator) on a high rise roof. Tested first Tuesday at 10:30 am (statewide test) along with five 2001s and a 2T22.
• Siloam Springs, AR Four Thunderbolt 1000s still standing but replaced with 8 ASC Tempest T-128s. Thunderbolts are sold to a city in Oklahoma.
• Atkins, AR At least three Thunderbolt 1000/1000Ts that are still in service.
• Kennesaw, GA Some still intact, some others are broken.
• Canton Twsp, MI Five 1003s with 4 still in service (most have been replaced with 2001s or T-128s).
• Warren, MI One 1000 still in use at the Detroit Arsenal on top of the Base's Fire Station.
• Riverview, MI One 1000 still in use, on the central Fire station.
• Pontiac,IL At least five 1000T sirens still running very well.
• Enid, OK (1000T) Still operational along with T-128s, T-135s and 2001s.
• Mabelton, GA Six most around fire stations about five 1000s and one 1000T Thunderbolt, all operatonal.
• Copaigue, NY Two 1003 Thunderbolts still operational.
• Blytheville, AR Four Thunderbolt 1000/1000Ts still in service.
• Brodhead, WI One known Thunderbolt 1003 in service, east of the depot, just off the rail-line.
• Rapid City, SD Around 8 or 10 assorted Thunderbolt sirens still in service. Thay are mainly used for tornado warnings. Newer model Federal Signal and Whelen Omni-Directional sirens are also used along with the Thunderbolts.
• East Farmingdale, NY 2 1003 dual tone sirens on the roof of the fire houses. Installed April 2008.
• Glenview IL 1 FS Thunderbolt 1000T located by walgreens it is still in use but it soon wil be replaced with a FS 2001

FS/FSC=Federal Signal Corporation AS/ASC=American Signal Corporation

[edit] Trivia

Trivia sections are discouraged under Wikipedia guidelines. The article could be improved by integrating relevant items and removing inappropriate ones.

During the early years of its production, the Thunderbolt siren's main purpose was to be sounded in the event of a nuclear attack/drill or air raid. By the late 1960s and early 1970s, the majority of cities and towns that had Thunderbolts and other outdoor warning sirens would begin using them more for severe weather/tornado warnings. (Although a few American cities were using sirens for weather warnings as early as 1960). By the 1980s as the Cold War began to "thaw" the Thunderbolt (along with most outdoor warning sirens) became better known to the American public as "tornado sirens" rather than "air raid" or "civil defense" sirens.

In the movie Forrest Gump at the very beginning, a Thunderbolt siren can be seen on the roof of one of the buildings in the camera pass.

The siren was featured in many Civil Defense films including one from the early 1950s titled "Let's Face It" (a close up of a single tone model 1000 painted "zebra striped" black and yellow (sounding the alert tone.)

In 1959 Chicago Mayor Richard J. Daley ordered his fire chief to sound the city's air raid sirens (all Thunderbolts at the time) at the moment the White Sox won the pennant, prompting many unaware citizens to be alarmed of an air raid or nuclear attack.

The early versions of the 2001DC siren utilized the same exact rotator motor design as the Thunderbolt.

The chopper of the Thunderbolt siren is based on the Model 2 siren, which is still in production.

[edit] External links

• Civil Defense Museum has a number of mp3 audio files of sirens.
• Buddy Harris has located and is currently restoring a model 1000 that was in Jacksonville, Florida.