Federal Signal Q-Siren

The **Q-Siren** is an electromechanical vehicular siren produced by Federal Signal, and has been extremely popular with fire stations across the country since its introduction, being a simple siren with large output. The siren has one of the most recognizable sounds in the United States, with its sound being trademarked by Federal Signal. Despite many mechanical vehicular sirens being phased out in favour of electronic ones, the Q2B still has a large foothold in the market. The Q2B was compatible with the Pulsator attachment for pulsed signals.

## History and Design

The Q-Siren was introduced in the 1970s, replacing various other mechanical sirens such as the Model 28 and Model 66, which had been popular during the previous decade. The Q was designed to outperform most vehicular sirens of the time, and rapidly gained popularity due to its high performance and shrill sound. It was available in a wide variety of different configurations, including pedestal mounted models, flush-mounted bumper models, and different finishes.

The Q-Siren at its core is a 15-port siren, driven by a 12VDC electric motor at a high speed. Unlike nearly every other Federal siren, the Q uses curved vanes that are heavily reminiscent of B&M's air raid and Siro-Drift sirens. Federal may have been inspired by B&M, as B&M was enjoying significant popularity in the market at the time due to the high performance of their sirens. Every Q siren uses roughly the same design, with finger guards on each stator port, and a mesh screened intake with Federal's original Federal Electric logo featured prominently in the middle. The intake and finger guards are one piece, attached to the stator. On Q2 models, the siren has a bullet-shaped motor cover to protect the motor, while Q1 models lack these. The siren normally comes with a pedestal mount, though the siren can be ordered without one if it will be mounted inside a truck's bumper. The siren is available with a heavy-duty coaster clutch, which allows the siren to coast for a long period of time after being shut off, in order to reduce battery drainage. Clutch-equipped Q-sirens are also equipped with electric brakes to quickly bring the rotor to a halt when the siren needs to be silenced. On early models, the brake was located in the base of the siren, before being moved elsewhere.

There are a variety of models, whose basic naming terminology are as follows:

* Q = Siren model
* 1 = Painted, motor exposed with no motor cover.
* 2 = Chrome, with bullet-shaped rear motor cover
* A = No brake/clutch, free rolling
* B = Equipped with a brake/clutch
* PQx0A/B = Equipped with a Pulsator

The Q-Siren is typically finished with chrome, giving it a clean, distinctive appearance, although it could also be painted instead. In recent years, Federal has also began offering a chrome variant with a blackened finish, which is better suited for fire engines that have black painted bumpers.

The Q-Siren is still sold by Federal Signal to this day, and has proved to be one of the most popular mechanical vehicular sirens in service today. Its main competitors are B&M's Siro-Drift series, Eagle Siren's Screeching and Nesting Eagle sirens, and various other smaller manufacturers.