Fire Alarm Telegraph
As early as the mid-1840s, telegraph systems were being used in large cities to transmit locations of fires and coordinate fire responses. These systems used keys, relays, and registers, much like the Morse telegraph systems we are familiar with. However, they were not used to send Morse Code messages, but rather they sent simple codes to identify the location in the city in which a fire was occurring.
The largest company making fire alarm telegraph equipment was the Gamewell Fire Alarm Telegraph Co, formed in 1879 by John N. Gamewell. Other companies include Conrad-Young (Baltimore), Utica Fire Alarm Co, Western Electric, and JH Bunnell.
Many fire alarm keys have camelback style levers, which fool many beginning collectors into thinking the keys are very old, when in fact they were most likely made in the very late 19th to early 20th century.
Other than the camelback style levers, other attributes that are common to fire alarm keys are:
- Very stiff spring. Fire alarm keys were not designed to send Morse Code messages all day. They were instead used to send short codes to identify fire locations; hence, comfort of the operator was not a concern. The stiff spring would help prevent the key from being accidentally pressed and sending out a code inadvertently.
- Normally closed contacts. A typical Morse Code key has a set of contacts that are normally open and are then closed during the act of sending a message. With fire alarm keys, the contacts are normally closed and then are opened during the act of sending fire codes. The reason is that it is much easier to open a set of contacts than to close one. If the fire alarm system relied on having to close the contacts to send a message, and there was any dirt or crud on the contacts, it could prevent the correct code from being sent. Hence, it is a reliability issue.
Fire alarm relays are also unique in appearance. Many have multiple contacts or multiple “legs” protruding from the bottom of table-mounted relays. Some have heavy brass bases rather than wooden bases. Others have a bell (called a Gong) attached to a post on the base so an incoming signal can be heard.
Below are some pictures of fire alarm keys, relays, and registers from the 19th and 20th centuries. Click on each thumbnail to view the full size image:
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You can reach me at telegraphdude@comcast.net