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The Federal Signal 3T22 and 2T22 are dual-tone, mechanical outdoor warning sirens made by Federal Signal Corporation (formerly Federal Sign and Signal Corporation) from 1952 through the early 1990s. Both have a very recognizable design, with a ten-port rotor (chopper) on the bottom with ten cones (horns) and a 12-port one on top with twelve cones.
The Federal Signal 3T22 was originally designed as the 2T22 in 1952 or 1954. The 2T22 has the same number of ports and cones. It can produce two main signals (it can produce more but the other signals are rarely used), hence the name "2T22" (the 2 at front representing the 2 choppers, and the 22 representing the amount of horns). The siren has no solenoids, so it cannot perform a "hi-lo" signal. In 1955, Federal designed the 3T22, which is similar, except for its name and that it has solenoids. The 3T22 is superior in design because it can perform the "hi-lo" signal, which is mainly used for fire calls. The 2T22 and 3T22 can produce 113db (measured 100 feet away from the siren). There are four models of this type of siren. the 2T22 A and B and the 3T22 A and B. In the name 3T22, the 3 stands for its three main signals: attack (wail), alert (steady), and hi-lo, and the 22 again stands for the twenty-two cones. The A or B determines whether the motor is three phase or single phase. A 3T22A is three phase, while a 3T22B is single phase. The siren was mainly used for air raid warnings during the Cold War era and weather warnings after the war. In the early 1990s, the siren's production was stopped when it was replaced with the newer 2001-SRN, which can reach 126db (also measured 100 feet away), hence the name. Like many other older siren models, these sirens are becoming more uncommon due to their age and because of newer technology.
The 3T22 came in only one port ratio: 10/12. It has ten ports and cones on the bottom and twelve ports and cones on the top. It also has a smaller cone on top to reduce rain and other water-related substances such as snow from getting inside. It has two solenoid boxes, one on top, and one on the bottom. There are also two air intake spots: also one on the top and bottom. The siren has a small stand with three legs so it can be mounted on a pole or roof. The stand can be removed and the siren can be mounted differently.
A loudspeaker is a combination of one or more speaker drivers, an enclosure, and electrical connections. The speaker driver is an electroacoustic transducer that converts an electrical audio signal into a corresponding sound.
A civil defense siren is a siren used to provide an emergency population warning to the general population of approaching danger. Initially designed to warn city dwellers of air raids during World War II, they were later used to warn of nuclear attack and natural disasters, such as tornadoes. The generalized nature of sirens led to many of them being replaced with more specific warnings, such as the broadcast-based Emergency Alert System and the Cell Broadcast-based Wireless Emergency Alerts and EU-Alert mobile technologies.
A tweeter or treble speaker is a special type of loudspeaker that is designed to produce high audio frequencies, typically up to 100 kHz. The name is derived from the high pitched sounds made by some birds (tweets), especially in contrast to the low woofs made by many dogs, after which low-frequency drivers are named (woofers).
A long-range acoustic device (LRAD), acoustic hailing device (AHD) or sound cannon is a specialized loudspeaker that produces sound at high power for communicating at a distance. It has been used as a method of crowd control, which has caused permanent hearing damage, having an extremely high decibel capacity. Other uses have included for negotiations in siege situations; to deal with piracy at sea; for mass notification during natural disasters or other emergencies; and by defense forces, including several navies.
A siren is a loud noise-making device. Civil defense sirens are mounted in fixed locations and used to warn of natural disasters or attacks. Sirens are used on emergency service vehicles such as ambulances, police cars, and fire engines. There are two general types: mechanical and electronic.
The four-minute warning was a public alert system conceived by the British Government during the Cold War and operated between 1953 and 1992. The name derived from the approximate length of time from the point at which a Soviet nuclear missile attack against the United Kingdom could be confirmed and the impact of those missiles on their targets.
An emergency population warning is a method where by local, regional, or national authorities can contact members of the public to warn them of an impending emergency. These warnings may be necessary for a number of reasons, including:
A loudspeaker enclosure or loudspeaker cabinet is an enclosure in which speaker drivers and associated electronic hardware, such as crossover circuits and, in some cases, power amplifiers, are mounted. Enclosures may range in design from simple, homemade DIY rectangular particleboard boxes to very complex, expensive computer-designed hi-fi cabinets that incorporate composite materials, internal baffles, horns, bass reflex ports and acoustic insulation. Loudspeaker enclosures range in size from small "bookshelf" speaker cabinets with 4-inch (10 cm) woofers and small tweeters designed for listening to music with a hi-fi system in a private home to huge, heavy subwoofer enclosures with multiple 18-inch (46 cm) or even 21-inch (53 cm) speakers in huge enclosures which are designed for use in stadium concert sound reinforcement systems for rock music concerts.
A train horn is an air horn used as an audible warning device on diesel and electric-powered trains. Its primary purpose is to alert persons and animals to an oncoming train, especially when approaching a level crossing. They are often extremely loud, allowing them to be heard from great distances. They are also used for acknowledging signals given by railroad employees, such as during switching operations. For steam locomotives, the equivalent device is a train whistle.
Federal Signal Modulators are electronic warning devices produced by Federal Signal Corporation that are used to alert the public about tornadoes, severe weather, earthquakes, fires, lahars, tsunamis, or any other disaster. They are identified mostly by their distinctive stacked "flying saucer" design. The Modulator II is sold based on the more compact chassis of the siren compared to the original Modulators.
SiraTone was a brand of electronic outdoor warning sirens produced by Federal Signal Corporation which began production in the early 1980s. These sirens were designed to broadcast high-intensity warning signals over a large area. SiraTone products are/were used for natural disaster notification, HAZMAT incident notification, fire call systems, and more. The SiraTone product line is no longer in production. The product line was succeeded by the Modulator and DSA electronic outdoor warning sirens.
American Signal Corporation (ASC) is an outdoor warning siren and mass notification company in the United States. ASC was founded in 1873 as Biersach and Niedermeyer (B&N). After performing poorly, the company reformed as Alerting Communicators of America (ACA) in 1968, and expanded the line of warning systems they produced. In 1992, ACA went bankrupt and was bought and reformed as the American Signal Corporation.
The ACA Hurricane is an electro-mechanical and rotating-directional, 130dB civil defense siren, created and produced by Alerting Communicators of America (ACA). ACA began manufacturing the Hurricane 130 in 1968, and ended production in 1981. The Hurricane 130 is very similar to the Federal Signal Thunderbolt series, being a supercharged siren.
In civil defense sirens, the ATI High-Power Speaker Station (HPSS) is an electronic outdoor warning siren manufactured by Acoustic Technology, Inc (ATI) that is used to alert citizens of air raids, and natural disasters.
The Public Warning System (PWS) is a network of civil defense sirens installed by the Singapore Civil Defence Force on over 2,000 strategic points in Singapore to warn Singaporeans of impending dangers, air raids and atomic bomb blasts. Thus far, the siren network has only been used for occasional public awareness drills, monthly noon chimes and for commemorating the island's Total Defence (February 15) and Civil Defence Days (September 15). It was also used to mark a minute's silence nationwide for the passing of former prime minister Lee Kuan Yew on the evening of 23 March 2015 and on 1 and 9 August 2020 to mark the first National Day at home.
The Federal Signal Model 2 is an omnidirectional outdoor warning siren produced by Federal Signal Corporation.
The ACA Cyclone is an electro-mechanical, omnidirectional, dual-tone outdoor warning siren produced from 1968 to 2007 by Alerting Communicators of America (ACA). Originally intended for civil defense purposes, early versions of the Cyclone are rated at 120dB from 100ft, and later models are rated at 125dB.
The Local Access Alert is a system designed to warn radio stations, television stations, cable television broadcast feeds or satellite signals of impending dangers such as severe weather and other civil emergencies. With a gradual transition from analog cable to digital cable, the Local Access Alert has been phased out and largely replaced with the Emergency Alert System in the United States.
On the morning of January 13, 2018, an alert was accidentally issued via the Emergency Alert System and Wireless Emergency Alert System over television, radio, and cellular networks in the U.S. state of Hawaii, instructing citizens to seek shelter due to an incoming ballistic missile. The message was sent at 8:08 a.m. local time and the state had not authorized civil defense outdoor warning sirens to sound.
The Thunderbolt is a mechanical outdoor warning siren that was manufactured by Federal Signal Corporation from 1951 until its production ended in 1991. It is a unidirectional, rotating siren with a large square-shaped horn, and can come in various colors, usually yellow, by request.
http://civildefensemuseum.com/sirens/manuals/255A152H-2T22-3T22.pdf