Heath Engineering Laboratories, Inc.

**Heath Engineering Laboratories** was an early manufacturer of vehicular, industrial, and large outdoor warning sirens, based in San Francisco, CA. They were one of the first manufacturers to produce electric sirens, with mentions of founder Harry C. Heath inventing his first electric siren in 1912.

Heath sirens were fairly popular in California, and continued production until around 1926, where the company was then bought out and became the Siracode Signal Corporation.

## History

In 1912, Harry C. Heath of San Francisco invented a type of siren practically unheard of at the time, a siren driven by an electric motor. This invention brought Heath nearly 15 years of success selling warning sirens under his company, Heath Engineering Laboratories, who supplied many in the surrounding area with an efficient warning signal previously unheard of. Heath's Type K outdoor warning siren was their most popular choice, often used for fire and marine warning. The city of London also chose Heath sirens for air-raid protection during the First World War. Heath had fairly concentrated sales in California, mostly in areas near San Francisco, where the company was located.

Despite their concentrated popularity in California, Heath sirens seemed to not sell well outside of the state. There are currently only two known Heath sirens outside of California, both in Texas. Their biggest competitor was the Sterling Model M, which had two larger rotors than a Heath siren, yet was sold at a very similar price. By around 1926, the motors used on Heath sirens were no longer available, and an adequate replacement could not be sourced. As a result, Heath Engineering Laboratories went defunct and went on to become loosely associated with Siracode Signal Corporation through asset purchases, and Harry C. Heath went on to take up another of many endeavors.

## Products

### Vehicular Sirens

#### Type H

The Heath Type H is a small 12-port vehicular siren, which was used as a long-range signal on fire engines and boats. It has a flat, roughly 8" wide rotor, and a large intake horn to direct sound forwards. The stator is covered by a finger guard to prevent injury from misuse of the siren. The Type H is mounted upon a tall stand, with a triangular shaped base. 3 holes are present of the base, with 1 being in each corner, allowing for the siren to be mounted to a flat surface. Not much is known about the Type H, and only 3 or 4 are known to exist.

### Industrial Sirens

#### Type F

The Heath Type F is a small industrial and general-purpose siren, which came in many different styles and configurations over the years. Most Type F sirens appear to be 8-port, with ¼ hp, 110 V motors. The Type F came in two forms, a **Suspension Type** and **Mounted Type**. The Suspension Type F could be hung from any height and had an intake horn to send sound down and outwards. The Mounted Type F has a cone shaped stand and four legs connected to the intake, to direct all sound outwards. Only two Type Fs are known to exist today, one being a mounted type with the model name "F28." It is unknown what the name means.

### Outdoor Warning Sirens

#### Type K

The Heath Type K is a fairly small outdoor warning siren and was the company's best seller. Their horsepower varies around 3 to 5 hp, and rotor sizes vary as well, but they generally seem to be around 12-13" in diameter and larger on some models, available in a low tone 8-port and high tone 12-port. There is one double end, 8/12-port unit in Dinuba, CA. The Type K was very well designed for its time, with its main feature being a large intake horn supported by a cone shaped intake stand, which directs sound outwards.

    Throughout the years, the Type K went through many changes, big and small, and it is extremely rare to find two Type Ks that look alike. For instance, earlier Type Ks had split port rows like Federal's Type Mach. B. Most have 2 port rows, but Heath put out an advertisement displaying a Type K with 3 port rows. Intake stand styles vary as well, some with a wider opening and six thick legs, compared to others with a tighter horn and four thinner legs. About 12 Type Ks are known to exist, only one of which is still confirmed to be in service, in Kenwood, CA for fire calls.

#### "Instant-Blast" horizontal siren

    In 1918, Heath built a large horizontal siren and had it installed on the famous San Francisco Ferry Building. On New Year's Eve that year, the siren sounded for the first time, starting a tradition that lasted for over half a century. This 35 hp siren was the loudest of its time, with two large 12-port rotors and a unique braking system to bring the siren to a growl in seconds after each run. It sat on a large metal bed, similar to a Denver Duplex, and had two large intake horns to direct sound towards Market Street into the city, and towards the bay.

This one-of-a-kind siren, heard in 5 counties, punctuated every workday for the majority of San Francisco, sounding off three times a day, and was also sounded off for special events, such as holidays or welcoming a high-profile visitor. In 1966, the rotor facing Market Street gave in to a fault and broke apart, and for six years the daily siren tradition was continued with only one end of the siren in operation.

In 1972, after 2 people made complaints about the noise, the siren was shut off and replaced with an electronic carillon, and a 54-year tradition came to a sudden end. During the 2001 restoration of the Ferry Building, it was broken apart by sledgehammers, as workers did not understand the siren's historical value or even what it was. Harry C. Heath's son, Harry W. Heath, noticed the siren was gone, and a search was made for the siren's remains, which wielded nothing more than parts of a destroyed motor, and the two iconic horns that stood over San Francisco for 83 years. Supposedly, the remains of the siren currently reside in the San Francisco National Maritime Museum, but no images have been found from there. Another unit was also supposedly sent to London, England to be used for air raid warnings, though this siren appears to no longer exist.

#### Alcatraz fog sirens

While there is no confirmation Heath created these sirens, based on the time they were built, and the fact that Alcatraz is right next to San Francisco, it is believed that Heath is who created these strange sirens. They were built in 1913 and came with a special electric timer. They had extremely large intake horns, but seemingly tiny rotors, assumed to be around 12-14" in diameter. They were installed in a special foghorn shack, paired up with each other with their motors housed inside the building. Not much else is known, and they have likely been removed.