A female wearing a cycling helmet
A helmet is a form of protective gear worn on the
head. Traditionally, helmets have been made of metal. In recent
decades helmets made from resin or plastic and typically
reinforced with Aramid fiber (e.g. Twaron or Kevlar) have become preferred for most applications. Designed for protection of the head in combat, or in
civilian life, from sports injuries, falling objects or high-speed collisions.
Helmets are common in the military, construction,
mining, and some sports, including American football,
baseball,, ski, snowboarding, ice hockey, equestrian
sports, motorsports, and rock climbing.
Motorcycle helmets and bicycle helmets are
compulsory headgear in some jurisdictions; in the United Kingdom only Sikhs are allowed to ride motorcycles without wearing motorcycle helmets.
Bicycle helmet compulsion and even strong promotion has been a heated subject of debate
amongst cyclists and scientists since at least the 1990s, lately focusing on alleged net protective effect at the population
level.
Military origins and symbolism
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a "Brodie helmet" used by British and US forces in both world wars
Helmets were among the oldest forms of combat protection, and are known to have been worn by ancient Greeks, 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, particularilly 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 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.
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.
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.
The use of protective helmets by millions of fighting men in the two world wars increased awareness of "hard hat" protection.
By the 1950s, hundreds of new applications for helmets were found. The helmet offered an unexpected advantage: Symbolism. It can signify that, like a soldier, the wearer is someone qualified for or capable of a certain
task or activity, such as construction, operation of heavy machinery, or participation in certain sports.
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,
though many do not. Non-ballistic injuries may be caused by many things, including (but not limited to) concussive
shockwaves from explosions, motor vehicle accidents, or
falls.
Function and structure
Despite various designs and requirements, 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.
Classical helmets from the ancient Greeks to today treat the head uniformly and are currently tested on rigid headforms.
Anatomical helmets adapted to the inner head structure were invented by neurosurgeons at
the end of the 20th century. Since the materials are disposed according to the anatomical structure of the head, they are smaller and lighter than the classical helmets.
Images
1500s helmet in forged steel (compatible Anachrome 3D).
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Rendering of an American football helmet.
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Types of helmets
Helmets used for different purposes differ greatly in their design. For example, a bicycle
helmet would chiefly need to protect against blunt impact forces. A helmet designed for rock climbing, however, would need
to protect against objects (e.g. small rocks and climbing equipment) falling from
above. Consequently, bicycling and rock climbing helmets little resemble each other. 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 to reduce any detrimental effect on the climber's technique.
Goggles, face guards and ear plugs are other forms of
protective headgear. Hard hats are
typically preferred in modern times for construction workers. Helmets are often used by riot
police.
Sometimes medical conditions need a helmet to be worn to protect the brain because of a gap in the braincase, e.g. because of cleidocranial dysostosis or in
separated craniopagus twins.
Heraldry
Motto
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
Other meanings
- Helmet (band) is a musical band.
- Elmet is a post-Roman kingdom in north England.
- "Policeman's helmet" is a British colloquial name for the Himalayan Balsam plant,
from the shape of its flowers.
- A slang term for the head (or tip) of the penis, due to the shape of this body part.
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