History of the Fire Alarm

THE UNKNOWN HISTORY OF THE FIRE ALARM: FROM BELLS TO BUZZERS

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The fire alarm, though deafening, became our salvation."

—Sarah Wakefield, factory worker in 1880s Boston

In this post, we will explore the largely unknown history of fire alarms—from the very first automated signals to the vexing sirens littering commercial buildings today.

THE FIRST AUTOMATED FIRE ALARM USED TELEGRAPH TECHNOLOGY TO SEND AN ELECTRIC SIGNAL TO THE FIRE STATION

What the first fire alarm might have looked like
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In 1852, Boston, William Channing invented the world's first automated fire alarm system—using the telegraph to send electric signals directly from the site of a fire to local stations.

It was initially celebrated as miraculous.

However, the first fire alarm had a tendency to trigger false alarms.

It was largely problematic in the beginning.

FACTORY WORKERS HATED THE NOISY ALARMS & OFTEN DISABLED THEM

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The late 19th century factories installed fire alarm systems to protect workers from the constant fire hazards via machinery and flammable materials.

It also faced challenges when workers began disabling the unbearably loud bells.

The workers hated these alarms.

This widespread practice of silencing alarms led to devastating fires and eventual reforms.

Eventually, factory owners and legislators mandated quieter warning systems that workers wouldn't disable.

THE FIRST HEAT SENSOR FIRE ALARM USED THE EXPANSION OF METALS TO TRIGGER AN ALARM BELL

A fire alarm that detects the heat from this fire
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Later in the 1800s, Francis Robbins Upton invented the first heat sensor fire alarm.

It improved upon existing manual systems by automatically detecting fires through an ingenious mechanism using metals with different thermal expansion rates.

The design required no external power source!

It worked by sensing the heat from a fire, which would cause the metals to bend and complete an electrical circuit—automatically triggering an alarm bell—and this invention led to how modern fire detection systems work today.

MANY EARLY FIRE ALARMS HAD TO BE MANUALLY TRIGGERED

A fire alarm that needs to be handled manually
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Early fire alarms were rudimentary.

However, they got a little better with the introduction of manual pull stations that allowed building occupants to sound alarms in case of fire.

However, alarms were dependent on human intervention.

It proved to be a fatal flaw.

Fires in unoccupied areas could spread unchecked, and response times were often fatally delayed because of the time required for someone to notice the fire and activate the alarm.

DURING WWII, GERMANY DEVELOPED REMOTELY TRIGGERED ALARMS

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Entering World War II, Germany developed radio-triggered fire alarm systems to protect facilities from Allied bombing raids and prevent sabotage—the wireless nature allowed warnings to be broadcast remotely while being resistant to tampering.

After the war, this invention spread globally.

There were clear advantages of wireless alarms over traditional hardwired systems.

MOST FIRE ALARMS STILL USED LOUD BELLS

School children freaking out about the loud fire alarm
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In the 1960s, a small but telling change occurred in schools as traditional fire alarm bells—which had long startled and frightened students with their harsh clanging.

The old alarms were gradually replaced with gentler chimes and buzzers.

90% OF US FIRE DEPARTMENTS USE SIRENS IN THEIR ALARM SYSTEMS

a fire truck with loud sirens
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Fire sirens—while serving as a vital emergency response tool used by over 90% of American fire departments—have become a source of tension between firemen and residents.

Firemen view them as a call to civic duty.

While residents see them as disruptive noise pollution.

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