A woman wearing a cycling helmet
A
helmet is a form of
protective gear worn on the
head to protect it from injuries, a variation
of the hat. The oldest known use of helmets was by Assyrian
soldiers in 900BC, who wore thick leather or bronze helmets to
protect the head from
sword blows and
arrows. In the 2000s, soldiers still wear helmets, now
often made from
Kevlar rather than metal, to
protect the head from bullets and shell fragments.
In civilian life, helmets are used for recreational activities and
sports (e.g.,
jockeys in
horse racing,
American football,
ice hockey,
cricket, and
rock climbing); dangerous work
activities (e.g.,
construction,
mining,
riot
police); and transportation (e.g.,
Motorcycle helmets and
bicycle helmets). Since the 1990s, most
helmets are made from
resin or
plastic, which may be reinforced with fibers such as
aramids.
Military origins
A "Brodie helmet" used by British
Commonwealth officers in both World Wars and US forces in
predominantely the First.
Helmets were among the newest forms of combat protection, and are
known to have been worn by
Romans,
throughout the
Middle Ages, and up to
the end of the 1600s by many combatants. At that time, they were
purely military equipment, protecting the head from cutting blows
with
swords, flying
arrows, and low-velocity
musketry. Some helmets, in order to protect the neck
as well, have a sort of extension made of leather strips called
pteruges, particularly common in the Middle
East.
They were initially constructed from
leather, and then
bronze and
iron during the
Bronze and
Iron Ages, but
soon came to be made entirely from forged
steel in many societies after about 950A.D. Military
use of helmets declined after 1670, and rifled
firearms ended their use by foot soldiers after
1700. By the 18th century, cavalry units often wore steel body
cuirasses, and frequently metal skull
protectors under their hats, called "secrets".
The Napoleonic era saw ornate cavalry helmets reintroduced for
cuirassiers and
dragoons in some armies; they continued to be used
by French forces during
World War I as
late as 1915, when they were replaced by the new French
Adrian helmet. It was soon followed by the
adoption of similar steel helmets by the other warring
nations.
The Prussian spiked helmet, or
Pickelhaube, offered almost no protection
from the increased use of heavy artillery during
World War I, and in 1916 was replaced by the
German steel helmet, or
Stahlhelm, and afterwards it was worn merely
for tradition.World War I and its increased use of heavy artillery
had renewed the need for steel helmets, which were quickly
introduced by all the combatant nations for their foot soldiers. In
the 20th century, such helmets offered protection for the head from
shrapnel and spent, or glancing, bullets.
Today's militaries often use high-quality helmets made of ballistic
materials such as
Kevlar, which have
excellent bullet and fragmentation stopping power. Some helmets
also have good non-ballistic protective qualities, to protect the
wearer from non-ballistic injuries, such as concussive
shockwaves from
explosions, motor vehicle accidents, or falls.
Military helmets can be worn with radio earmuffs, and other
equipment such as night vision goggles, can be added. Military
helmets are often worn with a removable cotton-polyester helmet
cover, which allows the user to change the pattern of the
camouflage (e.g., from dark green forest camouflage to tan-coloured
desert camouflage).
Design
A protective helmet worn during rock
climbing
Despite various designs and requirements, all helmets attempt to
protect the user's head through a mechanical energy-absorption
process. Therefore, their structure and protective capacity are
altered in high-energy impacts. Beside their energy-absorption
capability, their volume and weight are also important issues,
since higher volume and weight increase the injury risk for the
user's head and neck. Anatomical helmets adapted to the inner head
structure were invented by
neurosurgeons at the end of the 20th
century.
Helmets used for different purposes have different designs. For
example, a
bicycle helmet would
chiefly need to protect against blunt impact forces from the
wearer's head striking the road or a car hood. A helmet designed
for rock climbing, however, would need to protect against objects
(e.g. small rocks and
climbing
equipment) such as an ice axe falling from above. Practical
concerns also dictate helmet design: a bicycling helmet would
preferably be aerodynamic in shape and probably well ventilated,
while a rock climbing helmet would be lightweight and with a
minimum of bulk so that it would not interfere with climbing.
Some helmets have other protective elements attached to them, such
as a face
visors or
goggles or a
face cage, and
ear plugs and other forms of
protective headgear, and a
communications system. American football, hockey, and lacrosse
helmets usually have an integrated face protector (
face cage) made from metal.
- Baseball batting helmets have an expanded protection over the
ear, which protects the jaw from injury.
- Motorcycle helmets often have flip-down face screens for rain
and wind protection, and they may also have projecting visors to
protect the eyes from glare.
- Hard hats for construction workers are
worn mainly to protect the wearer from falling objects such as
tools.
- Helmets for riot police often have
flip-down clear visors and thick padding to protect the back of the
neck.
- Modern firefighter's helmets protect the face and back of the
head against impact, fires and electricity, and they can include
masks, communication systems, and other accessories.
- Welding helmets protect the eyes and face and neck from flash
burn, ultraviolet light, sparks and heat. They have a small window,
called a lens shade, through which the welder looks at the weld;
for arc welding this window must be much
darker than in blowtorch goggles
and sunglasses.
In rare cases, people with some medical conditions must wear a
helmet to protect the brain, due to a gap in the
braincase, e.g. because of
cleidocranial dysostosis or in
separated
craniopagus twins.
Materials
Types of synthetic fiber used to make some helmets:
In former times availability and usefulness of helmets was limited
by lack of suitable materials to make them of, except metal (which
is heavy), and lack of any strong transparent material to make
visors out of.
In Greece in ancient times helmets were sometimes strengthened by
covering the surface with
boars'
tusks (= their
canine
teeth) laid flat.
In Britain in the 18th and 19th century
gamekeepers, for head protection in fights
against
poachers, sometimes wore helmets
(perhaps more describable as thick
bump
caps) made of
straw bound together with
cut
bramble.
Types of helmet
Military
See
Combat helmet for
a list of helmets worn in (ancient and modern) battle combat
Motorcycle and Bicycle helmets
A motocross helmet showing the
elongated sun visor and chin bar
Sporting activities
Helmets for work
Protective and emergency services
Other helmets
Images
Image:Musee-de-lArmee-IMG 0976.jpg|Pith helmetImage:VMA-311Flight
Helmet.JPG|Vietnam War Era Marine
Squadron VMA-311 Flight HelmetImage:US soldiers wearing
the PASGT helmet, Hawaii.jpg|PASGT helmetImage:Chris Osgood
2008.jpg|Hockey Helmet - GoalieImage:BattingHelmet.png|baseball
batting helmetImage:White-helmets.jpg|full face and open face
motorcycle helmetImage:FF_Helmet.JPG|Leather Firefighting
HelmetImage:Aa lifeboatmanshelmet 01.jpg|Lifeboatman's helmet, Southport
, England
Heraldry
As the
coat of arms was originally
designed to distinguish combatants on the battlefield or in a
tournament, even while covered in armour, it is not surprising that
heraldic elements were often also used for
the decoration of
knightly helmets, while it
was also possible to use different elements than on the shield, but
equally standardized.
Furthermore, it became common to use a helmet (and/or some other
headgear, e.g. a crown or coronet) as part of the coat of arms,
above the shield, a practice maintained long after its use in
reality was ended by military technology and the demise of
jousting. In some systems, the rank of the bearer was reflected in
the model of the emblematic helmet, e.g. the metal and the number
of bars in the
visor, as in France. Either
way, the rank can be reflected by a
coronet
or
wreath placed on the helmet (often instead
of directly above the shield).
The
heraldic convention in the United Kingdom
is as follows:
- Sovereign: a barred helm of gold, placed affronté
- Peers generally: barred helms of silver decorated with gold,
placed sideways and showing five bars
- Baronet's or Knight's helmet:
- Esquire's and Gentleman's helmet: closed helm or visored helm
with visor down, Steel, placed sideways
See also
References
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