Escape through Time
by Albert Lee and Rob Meyer
Turnout gear, or the protective clothing worn by fire fighters, has come a long
way since the last century. In that era, fire fighters wore Civil War-style
uniforms that featured heavy wool trousers, a cotton or wool shirt (usually
red), and a heavy wool tunic. Wool was the obvious choice, because of its
ability to shield against heat and cold, and because of its mild water and
flame resistance. Rubber slickers were sometimes worn over the wool uniforms.
Fire fighters brought their own gloves to the job, usually standard leather
workingmen's gloves. Knee-high leather boots worn in the early years eventually
gave way to rubber boots, some of which could be extended to the hips like
modern waders (called "three-quarter boots").
"Always Ready"—This Currier and Ives painting illustrates the clothing of the early American fire fighter. The mid-19th century gear consisted almost entirely of wool, which was used both to ward off the heat of the flames and the cold of the winter air.
Turnout gear took a great leap forward after World War II, when various
organizations, foremost among them the National Fire Protection Association
(NFPA), began issuing standards. The NFPA 1971 Standard on Protective Clothing
for Structural Fire Fighting, for instance, called for an outer layer of
flame-resistant fabric that would not be destroyed through charring,
separating, or melting when exposed to 500°F for a five-minute period; a
second layer to prevent moisture from penetrating through to the wearer; and a
third layer to provide thermal insulation from radiant, conducted, and
convective heat. Similar standards required gloves that could withstand flame,
heat, vapor, liquids, and sharp objects, and footwear resistant to puncture,
flame, heat, abrasion, and electrical current.
In the 1980s, fire fighters began wearing turnouts made of three advanced
materials: an outer shell material that raised the fire resistance level to
about 1,200°F before the material began to break down; a layer that
allowed the fire fighter to release moisture from inside the gear; and a
fire-resistant synthetic material. Ideally, the latter will last about seven
seconds in a flashover situation (when all combustible materials, including
walls and floors, suddenly ignite) before catching on fire, which is usually
enough time for someone to bail out of room. Further, it is self-extinguishing,
meaning once out of contact with a fire, it will not continue to burn. These
materials have become the standard for virtually all American fire departments.
Modern turnout gear has become so effective in insulating the fire fighter from
heat that new equipment is now being introduced that has an internal alarm to
alert him or her when the external temperature exceeds a set limit. These
next-generation turnouts consist of six silicone-encapsulated heat sensors
located at the shoulder, back, and chest of the turnout coat, just under the
Modern protective clothing, or turnout gear, such as the Smart Coat System above, incorporates sensors to help the fire fighter assess dangerous conditions, ranging from thermal saturation to the location of a colleague who may be injured or lost in the black smoke.
Finally, NFPA 1982 called for Personal Alert Safety System (PASS) devices. Fire
fighters trapped in smoke-filled buildings can become disoriented as they
attempt to escape, sometimes leading to incapacitation from smoke inhalation.
Using small motion detectors, PASS devices set off an alarm if motion is not
detected after 30 seconds.
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In the last century, the leather firefighter's helmet was common. The helmet's
long rear brim and curled up side brims helped prevent water from running down
the firefighter's neck and into his coat. The earliest leather helmets featured
four combs, which are ridges of leather marking stitched seams. Theoretically,
the more combs a helmet had, the stronger it was, so later helmets came
equipped with eight, 12, or 16 combs.
An essential part of any fire fighter's gear is the helmet. Traditionally, the helmet was made of leather strengthened by the use of combs, or leather seam reinforcements. The helmet pictured above has 8 combs.
At the turn of the century, aluminum helmets began to be popular. Though they
were molded to look like leather helmets, they were cheaper. However, fire
fighters quickly learned that these helmets had problems of their own. They not
only conducted heat but electricity. As a result, a move back to leather
helmets became inevitable. Strong enough to provide protection from falling
objects, the leather helmet of the early 20th century shed water effectively
and prevented objects from dropping down the back of the fire fighter's neck.
Helmet design really took off after World War II. By 1979, when NFPA issued its
Standard on Structural Fire Fighter's Helmets, designers were taking into
consideration a mind-boggling array of factors, including impact force and
acceleration; penetration, heat, and flame resistance; resistance to electrical
current; effectiveness of chin strap and suspension system; flammability and
resistance of ear covers; resistance of the face shield to heat and flame; and
brightness and surface area of fluorescent markings.
Beginning in the 1970s, high-tech plastic and composite material helmets came
into vogue. These featured a suspension system and energy-absorbing foam impact
liners; a face shield for partial eye and face protection from heat, sparks,
liquids, and flying debris; flame-resistant flaps to protect the ears and neck;
and a lighweight-fabric protective hood.
The modern firefighting helmet has a smaller brim but uses ear covers and a flame-resistant hood (worn underneath). Using high-tech plastics and composite materials, the helmet must be puncture-proof and resistant to heat, flame, electricity, and sudden impacts.
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The first breathing devices used air pumped from a bellows through a hose to a
"smoke mask" worn by the fire fighter. These devices were rarely used because
of their bulky construction and unreliable performance. World War I led to the
introduction of the gas mask proper. A few fire departments began to make these
available to fire fighters in limited numbers, even though most did not protect
well from carbon monoxide, and none worked in an oxygen-deficient atmosphere.
In the 1920s, the U.S. Bureau of Mines commissioned the design and introduction
of "rebreather" devices for mine rescue, and these were eventually adapted by
the fire service. Rebreathers mixed a small stream of pure oxygen with exhaled
air, which had been passed through chemicals that removed a portion of the
carbon dioxide. These early rebreathers were better than their World War I
predecessors but were clumsy, fragile, and difficult to control. In addition,
the oxygen bottles for air supply were costly, and extensive training was
necessary. As a result, they were seldom used by fire fighters.
The World War I era saw the emergence of the first self-contained breathing
apparatus, or SCBA (not to be confused with self-contained underwater breathing
apparatus, or SCUBA). The devices featured metered compressed breathing air,
which was sent directly into the face mask. As with the earlier rebreathers,
however, there were drawbacks for fire fighters. SCBAs were expensive and
uncomfortably heavy, adding to the fatigue and strain of fire prevention.
Before World War II, most SCBAs were closed-circuit rebreathers, which did not
rely on the local atmosphere to supply breathing air or dissipate exhaled
gases. But following the war open-circuit SCBA became the norm. The advance was
based upon breathing oxygen systems used in high-altitude aircraft, where
compressed oxygen was supplied by high-pressure cylinders through regulators
and half facepieces to individual aircrew members, either on demand or through
World War II pilots used oxygen breathing systems in high-altitude flights, which led to the development of open-circuit, positive-pressure firefighting SCBAs (self-contained breathing apparatus).
In the 1970s, the U.S. Occupational Safety and Health Administration required
the use of positive pressure SCBA for firefighting. By maintaining a small
amount of pure oxygen in a mask at all times, positive pressure above ambient
prevents toxic smoke and gases from entering the face mask and being inhaled. A
1981 NFPA standard for SCBA mandated, besides positive pressure, a minimum
service life of 30 minutes and 100 liters per minute airflow.
In 1981, the National Fire Prevention Agency issued a standard on modern SCBA systems mandating positive pressure airflow at 100 liters per minute and a minimum service life of 30 minutes.
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Smoke and darkness no longer inhibit the fire fighter from seeing the thermal
image of a fire—and its potential victims. With the help of thermal imaging
cameras, fire fighters can detect the slightest variations in thermal energy,
even at extreme temperatures. A smoke-filled room contains millions of minute
carbon particles, which block visible light as effectively as a wall. But since
infrared travels in longer wavelengths than visible light, infrared cameras can
see right through smoke. These cameras display their readings of infrared in
variations of gray. Objects devoid of heat appear black; warm or hot objects
appear white. These devices also help fire fighters detect stress points—signs of a potential flashover, for example, or floors that have been
dangerously weakened from a fire below.
The use of thermal imaging cameras may improve the ability of the future fire fighter to navigate in a smoke-filled room to find potential victims or to pinpoint areas in the walls or floors that may have been weakened by the fire.
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Albert Lee is Originations Production Assistant and Rob Meyer is Online Production Assistant, respectively, at NOVA.
Photos/Illustrations: (1) Museum of the City of New York;
(2) SunnyCor Inc.; (3) L-W Book Sales; (4,6,7) NOVA/WGBH Educational Foundation;
(5) Corbis Images, Hulton-Deutsch Collection.
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