Model 5

Federal Signal Model 3 Federal Signal Model 5 Federal Signal Model 7
A Federal Signal C2 1/2 Model 5.
Company	Federal Enterprises Company Federal Sign & Signal Company Federal Signal Corporation W.S. Darley & Co. General City Service Co.
Produced	1948-1987
Type	Omnidirectional Electromechanical
Sound output	105-113 dB @ 100 ft
Frequency	50/60 Hz
Horsepower	3-10 hp
Voltage	208-240/480 V 1 or 3 ph
Preceded by	Federal Electric Type Mach. B Federal Electric Fedelcode
Succeeded by	Federal Signal STH-10 Federal Signal STL-10 Federal Signal Model ECLIPSE
Documentation	Manual

The Federal Signal Model 5, also called the General Alarm Siren or Vertical Siren, refers to a line of medium sized omnidirectional sirens produced by Federal Signal over the span of 50 years, going through many design changes and variants throughout the years. Popular as fire sirens, tons of these sirens remain in service despite being discontinued roughly 35 years ago. They were also rebranded and resold by other siren manufacturers, such as GCS and W.S. Darley & Co.

While the Model 2 is part of this lineup, it is covered in its own article and will not be covered in this article. See link for more details.

"Model 5" is used as the article's title due to its common usage by the siren community, as well as referring to a specific name given to 5 horsepower models in this lineup. However, not all sirens in this lineup are called "Model 5". There are many different models that are included in this lineup, which will be discussed below.

History

The Model 5 is a line of vertical omnidirectional electric sirens that was produced by the Federal Signal Corporation (originally Federal Enterprises) over a span of 4 decades and was a design refresh of Federal Electric's Fedelcode series of sirens which had been discontinued upon Federal Electric's rebranding to Federal Enterprises in 1948. By the time the Fedelcode series had been discontinued, the series had been streamlined to feature only the models 1, 2, C1 ½, C2 ½, and C3 ½. The main changes involved improvements to the weatherproof housing, adding screens for the output and intake, and most notably, changing the design of the cowl to project sound further outwards rather than downwards, as pole mounts were becoming more popular than roof mounts by the late 1948s.

Up until 1959, C2 ½ and C3 ½ sized models included a service panel for the motor, which was likely removed as it could fall off and compromise the weatherproof housing. Early Model 5s came with the option to add a damper, which used a motor-driven (early) or electromagnetic (later) damper to block and unblock the siren's intake, allowing it to produce a "pulse" of noise. This was used to tell volunteer firefighters where a fire was, using a numbered series of "fire zones" and blasting a number of pulses corresponding to which zone the fire was in. These coded models generally have the "OC" suffix, such as the Type 5OC or 7OC for example. The option would be dropped by the late 1950s as code sirens were abandoned as other forms of communication improved. The design of the sirens was largely finalized as Federal Enterprises became Federal Sign & Signal in 1955. The sirens in the series were also sold by other companies who partnered with Federal Signal, such as GCS and W.S. Darley & Co. These sirens had their own custom housings but were otherwise identical to their Federal counterparts.

By the time Federal Sign & Signal had become the Federal Signal Corporation in 1976, the Type C1 ½ and C2 ½ had been discontinued, leaving the C3 ½ as the only model left in production. To simplify the naming scheme, Federal Signal opted to simply name the siren the Model 5, regardless of whether or not it was 5 or 7.5 hp, and 10 hp units were usually named Model 7s. The 8-port units ceased production around the same time, leaving 12-port single tone and 9/12-port dual tone as the only option until the dual tone option was discontinued in the 1980s. The siren would continue to be produced until 1987, when it was finally discontinued in favor of the STH-10 and STL-10. The series would partially live on as the 1st and 3rd generation of the Model 500, Federal's mid-range rotating siren, which made use of the C2 ½'s rotor, and the Model 2001, which used the 15" rotor from the C3 ½. Federal Signal would eventually release the Model ECLIPSE in 2006, continuing the Model 5's purpose as a general purpose/fire siren. Today, the C3 ½ is one of the most common sirens in North America, being found at fire stations, factories, and other places across the continent.

Design

The Model 5 consists of three different sizes, the C1 ½, C2 ½, and C3 ½ (also known as the B1 ½, B2 ½, and B3 ½ on the tags of some units; the difference between them is unclear) and each had a unique housing. Federal named each individual siren by their motor horsepower, as "Type X" and later "Model X" (X being the horsepower). With the exception of the C1 ½, each model came with a variety of different horsepower motors which makes discerning the exact model impossible without reading the tag. The sirens consist of a siren core protected by a weatherproof housing resembling a roof vent, which serves to both prolong the siren's life and project its output. The sirens make use of either an 8 or 12-port single tone rotor and stator powered by a motor of varying horsepower. 12-port is by far the most common, as it was the standard. 9/12-port dual tone became available as an option for civil defense purposes, though only on C2 and C3 models. Dual tone models are given the T or TT suffix.

C1 ½

A C1 1/2 Model 3 located in Parsippany, NJ.

The C1 ½ was the smallest sized siren in the lineup, as well as the quietest. The C1 ½ bridges the gap between the small Model 2 and the larger sirens in the series and was only a small step up from the Model 2. The C1 ½ makes use of a 13" aluminum rotor, which was available in only 12-port single tone. Unlike the C2 and C3 models, no 8-port models are known to have been produced. The C1 ½ is driven by a 3 hp AC motor exclusively, giving it the Type/Model 3 designation. It was available in either single or 3 ph AC. The C1 ½ is able to reach 105 dB at 100 ft. The siren uses a rotor-over-motor configuration, and air is drawn into the siren's intake through the upper openings on the housing.

The C1 ½ is easy to differentiate from the other two sizes. The C1 ½ uses a shorter weatherproof housing, with a single, small skirt helping to project the sound downwards and outwards from the rotor. There are 4 openings underneath the skirt with a mesh screen that exposes the rotor and stator, as well as 4 openings above the skirt where the intake pulls air. A rain shield on top both protects the siren itself, and projects the sound from the siren's intake outwards. The housing itself is attached to the siren by several screws. The C1 ½ has a distinctly short housing due to the small motor used, and the skirt is much smaller than the larger models and not as wide as the top rain shield. The C1 ½ also lacks an eyebolt on the housing, as the A-frame was often substituted with an angle iron or simply left with nothing. No 1 ph models have been strictly identified, though it is presumed they would be slightly taller than 3 ph models.

The C1 ½ was the first in the series to be discontinued, with production ending in May 1967 according to a Federal bulletin. The siren did not perform much better than the Model 2, which was much smaller, cheaper, and easy to run on 1 ph power. The C1 ½ sold poorly, and it was ultimately discontinued. The C1 ½ is the rarest model today, with very few in service and in private possession compared to the other models. The siren was also sold under Federal Electric for a short period, with their own special housing designs, commonly mistaken as GCS sirens. It is unknown if W.S. Darley & Co. ever sold these sirens.

C2 ½

An 8 Port C2 1/2 (Model 5) in Kidron, Ohio

The C2 ½ was the middle-sized Model 5. The C2 ½ was a step up from the C1 ½, using a 15" aluminum rotor. The siren was originally available in 8, 12, and possibly 6 port single tone, and 9/12-port dual tone became an option soon after. Dual tone models have the "TT" designation. The siren is driven by either a 3 hp or 5 hp AC motor, with 5 hp being by far the most common for this size. The siren was available in single or 3 ph AC but were not designated as "A" or "B" as these predated phase designations by model. The C2 ½ was able to reach 107 dB at 100 ft, matching the performance of the larger C2 ½. 3 hp models are known as the Type/Model 3, while the 5 hp models are known as the Type/Model 5. As with the C2 ½, the C2 ½ Model 3 and Model 5 are identical in appearance.

In appearance, the C2 ½ resembles an enlarged C1 ½. Between 1948 and 1952, the siren used a housing nearly identical to its Fedelcode counterpart, before being redesigned. The siren uses a tall cylindrical weatherproof housing, with a single skirt that helps project the sound from the rotor downwards and outwards. There are 5 openings underneath the skirt with a mesh screen that exposes the rotor and stator, as well as 5 openings above the skirt where the intake is located. The siren uses a rotor-over-motor configuration, and air is drawn into the siren's intake through the upper openings on the housing. The siren uses a rain shield on top which both protects the siren itself, and projects the sound from the siren's intake outwards. The housing itself is attached to the siren by an A-frame attached to the stator, held together by two bolts. An eyebolt connects the A-frame with the top of the housing, which the C1 ½ lacks.

The skirt on the C2 ½ has the exact same width as the rain shield, which makes them easy to differentiate from the C2 ½, though short run models during late Federal Electric and early Federal Enterprises were sometimes equipped with wider skirts. From 1948 until 1959, the siren had a large service panel on the lower housing allowing easy access to the motor. It was later removed as the panel could fall off and expose the motor to the elements. 1 ph models can often (though not always) be differentiated by their slightly taller housings compared to the 3 ph models, due to using a taller motor. Later on, during production, a dual tone model was unveiled, using a 9/12-port rotor and stator. The 3 hp Type/Model 3(TT) and 5 hp Type 5(TT) were designed for civil defense purposes, often being installed alongside larger sirens. These were painted yellow from the factory to differentiate them from standard units. These were discontinued at the same time as the single tone model.

Rebranded units were sold in Quebec and surrounding areas by the Pierre Thibault Co., a fire apparatus dealer who also sold various Federal products, one of which was the C2 ½. These rebranded units use an improved weatherproof housing to protect the siren from harsh Canadian winters, with a taller, steeper rain shield and a much larger, steeper skirt to help force snow to slide off of the siren instead of building up on top. Due to the sheer weight of accumulated snow, the housings of a regular C2 ½ could be damaged. Like their Federal counterparts, they follow the quirk of 1 ph units being taller than 3 ph units. These sirens are exclusive to Eastern Canada, with units having been found in the provinces of Quebec and New Brunswick. It is one of the most common sirens in Quebec and are largely only found in that province. Little is currently known about the internals of the sirens, although it can be assumed that they share the same core as the standard C2 ½, although this is completely speculation.

The C2 ½ was discontinued around 1976, when FS&S became the Federal Signal Corporation. The C2 ½ was redundant by this time, as it performed near identically to the C2 ½, and it was not worth the cost of producing two identically performing sirens.

C3 ½

A diagram of the internals of a C3 1/2 Model 5.

The C3 ½ was the largest, loudest, and most successful Model 5. The C3 ½ was a significant step up from the previous models, using an 18" aluminum rotor. The siren was available in 8 or 12-port single tone, or 9/12-port dual tone. Dual tone models have the "T" (FS) or "TT" (Enterprises/FS&S) designation. The siren is driven by either a 5, 7.5, or 10 hp AC motor, although all are more or less identical in performance and appearance. The siren was available in single or 3 ph AC, with 3 ph models being designated Type/Model 5A/7A and 1 ph models being designated Model 5B/7B. The C3 ½ was able to reach 107 dB at 100 ft, matching the performance of the C2 ½, though the frequent changes in housing proportions could enhance or worsen performance by generation. The reason for the C3 ½'s existence was to skirt regulations about motor horsepower and is the reason why the C3 ½ ultimately became the standard model. The 7.5 hp and 10 hp models were discontinued in May 1967 due to their lack of significant increase in volume over a standard 5 hp model.

The C3 ½ has a distinctive appearance compared to the other models, using a significantly wider skirt to help project the sound from the rotor downwards and outwards evenly. This skirt could be customized from the factory, as one was ordered with an even larger skirt than normal. Between 1948 and 1952, the siren used a design reminiscent of the Fedelcode C3 ½, before switching to the design it used for the rest of its production run. The siren uses a tall cylindrical weatherproof housing, with a single wide skirt that helps project the sound from the rotor downwards and outwards. On the C3 ½, the skirt is much wider than the rain shield. There are 5 openings underneath the skirt with a mesh screen that exposes the rotor and stator, as well as 5 openings above the skirt where the intake is located. The siren uses a rotor-over-motor configuration, and air is drawn into the siren's cylindrical intake through the upper openings on the housing. The siren uses a rain shield on top which both protects the siren itself, and projects the sound from the siren's intake outwards. The housing itself is attached to the siren by an A-frame attached to the stator, held together by two bolts. An eyebolt is included on top of the siren to mount the A-frame to the housing.

At some point, Federal experimented with new intakes for the C3 ½, which started out as a cone shaped intake with a custom flat sided A-frame to fit the extra wide intake. This was later simplified to a straight cylindrical intake to save on materials, make more room for the regular A-frame, and create a more focused sound beam that would hit the top of the shroud and be deflected outwards from the intake screens. From 1948 until 1959, the siren had a large service panel on the lower housing allowing easy access to the motor. It was later removed for unknown reasons. 1 ph models can often (though not always) be differentiated by their slightly taller housings compared to the 3 ph models, due to using a taller motor. Later on, during production, a dual tone variant of the siren was introduced, using a 9/12-port rotor and stator. The 5 hp Type/Model 5T(T) and 7.5 hp Type/Model 7T(T) were designed for civil defense purposes, often being installed alongside larger sirens. 10 hp units could also be ordered, generally still designated as Model 7T(T). Dual tone units were painted yellow from the factory to differentiate them from standard units. Due to using a less efficient dual tone rotor, the Model 5T(T) and 7T(T) perform at only 108 dB at 100 ft. These were discontinued around the 1980s, when the need for dual tone sirens was nearing the end.