|
Question: Why must I wear a helmet?
When man was created, he was quipped with a
skull to protect his brain. This original protection measure
" set-up" was effective in the then soft environment
which was man's normal habitat'. As man evolved, he started
by taming the horse, as he outgrew the speed capability of
the horse, he began searching for faster modes of travel.
He first developed the steam engine, followed by the internal
combustion engine and then the turbine. Man, while he has
succeeded in propelling himself at speeds that would have
scared his ancestors, has also changed his surroundings to
hard unyielding surfaces both horizontal and vertical.
Unfortunately, he has not been able to transform himself to
the protective needs of his new lifestyle and environment.
The helmet is, therefore, necessary and just a link in the
long chain of safety equipment and counter measures man has
to use in his present surroundings.
Question: Why do Governments make Helmet use
compulsory ?
The wealth of any nation is in its people.
With the continuing popularity of the two-wheeler amongst
college going youth and executive cadre, it is necessary for
the government to protect its intelligentsia and prevent "brain
drain" of another sort. Helmets are made mandatory by
law, since statistical studies conducted almost all over the
world have proven beyond any doubt that " a helmet is
the single most effective counter measure against brain injury
in the life of a two wheeler user."
Additionally safety measures in every form are never implemented
unless the government has enforced them.
Question: How does a helmet work?
The brain is the most delicate organ in the
human body, which is suspended within the skull in a fluid
called the Cerebral Spinal Fluid (CSF).When the skull is hit,
it accelerates and moves towards the suspended brain, until
the pressures within the skull move the brain forward in the
CSF. When the skull is stopped, ( as in a motorcycle accident
),the brain being suspended continues its forward motion,
and depending upon the speed during impact, the forward moving
brain will touch the inside of the skull and can be damaged.
The brain is said, in such a case, to have suffered from linear
concussion, and penetration from protruding objects and to
stay fastened position in the event of an accident.
Energy management, as we call it in the helmet
trade, is the management of the energy that must be dissipated,
so that the brain is never subjected to damage from contraction
the skull. To achieve this, we construct a skull, rather a
very rigid shell from fiberglass, or thermoplastic. The inside
of the helmet is lined with expanded polystyrene (EPS ) of
controlled density. The shape and thickness of this EPS liner
as well as its density is of paramount importance. Under an
accident impact condition, the shell of the helmet behaves
like the skull; the EPS liner like the CSF and the skull is
treated in the same way as nature intended it to treat the
brain.
In case of an accident
a) The helmet strikes the road, curb of whatever
and comes to a stop. Momentarily.( Measured in milliseconds.)
b) The skull and brain are still in motion.
c) The EPS begins crushing progressively.
d) The skull is not permitted to stop "suddenly",
by the crushing EPS.
e) The brain is also slowing progressively within the CSF
and the job is done.
All of the above happens very quickly (within
milliseconds) and that is how a helmet works.
Questions: What comprises
a good helmet?
Good helmet have fiberglass or thermoplastic
outer shells.
EPS (Thermocole) is considered to be the best energy absorbing
liner available and must be present in the helmet.
Nylon or Terylene woven tape of tubular instruction
is found to be the best for chinstraps.
Steel Anchor plates are a must for securing the
chinstraps to the shell. Fastening by double "D"
rings; bar-n-buckle or all metal clasps are most secure.
Rivets of copper or brass are best for fixing
anchor plates to the shell.
The helmet must fit snugly and not wobble or
move, ones fastened on the head. Beadings, paints etc. are
frills that are applied to promote the helmet. Look for these
features in a helmet before making your choice.
Question: Why must I wear a helmet
then I
do not normally exceed 55 km while riding?
At 55 kmph you are traveling at 49 feet per second
i.e. the speed at which you will hit the ground if you jump
out a window on the fourth floor of a building. Must I say
more????
Question: What is the lifetime of a helmet and how should
a helmet be handled?
A helmet, since it is constructed from plastics,
i.e. thermoplastics: ABS, Polycarbonate, Polypropelene or
thermosets i.e. Fibreglass reinforced plastics, are subject
to change from exposure to ultra-violet and infrared rays
in sunlight.
A helmet should be replaced every two or three
years, However, if a helmet has been involved in an impact,
it must be changed without question. DON'T TAKE CHANCES.
Don't drop it; Keep it out of reach of children.
Don't press the EPS liner inside, don't carry groceries in
it. Clean it regularly.
Question: Do helmets cause balding?
Not at all, this aspect of helmets was studied
in the U.K. in 1981 by a leading authority on baldness and
a consultant dermatologist Dr. Arthur Rook. It was found that
the wearing of helmets does NOT promote balding.
Question: Do Helmets impair hearing?
You will be interested to learn of findings from
a study conducted at the California Institute of Technology
and the USDA forests service. At highway speeds (approximately
80 kmph) wind noise levels with a helmet on, can reach 100
db (A) which is the permitted mechanical sound level of a
motorcycle sold in the USA). In case you feel then, that riding
without a helmet is better, let me hasten to inform you, which
at the same speed the wind noise level without a helmet are
120 db (A).
So, to come back to the original question, you
can now see that what may appear to be a loss of hearing while
wearing a helmet in a stationary situation is actually quite
the reverse while in motion on a motorcycle.
Question: How should a helmet fit?
A helmet must fit snugly, rather, slightly tightly
than comfortably. After fastening the chin strap, push back
on the front of the helmet, if it sides back on your head,
select one that grips well and does not wobble and move when
worn.
Question: Do we have a safety standard for
motorcycle helmet?
Yes, we do. There is an Indian Standard Specification
for motorcycle helmets, IS 4151. There are other IS standards
for police, industrial and mining helmets too. These helmets
are constructed very differently from motorcycle helmets and
cannot be depended for protection in a motorcycle accident
situation. The two energy management requirements of these
two end uses are poles apart. I will explain.
a. In the case of the police, industrial or mining
helmet, the helmet in expected to protect the wearer from
objects coming towards him, projectiles like stones or bricks
for the police, and nuts or bolts etc. in industrial usage.
b. In the cast of the motorcyclist, the helmet must protect
him when he is the projectile going to hit a solid object.
ADVICE WHILE BUYING HELMET
Check for ISI 4151. Industrial and Miners' helmets
have different ISI standards that are no approved for two
wheeler use.
Take time to check proper fitting. A tight helmet
will give you a headache. A loose helmet will wobble every
time your bike crosses a bump on the road. Ensure a comfortable
fit.
Try on the helmet before a mirror. You will see
how the helmet suits your personality.
Buy from a reputed dealer displaying "Authorized
Dealer" Certificate. Also select a dealer who offers
you an opportunity to choose between several brands of helmets.
Never buy a helmet from a roadside hawker. It
would most likely be a squrious product with a false ISI marking.
Insist on a proper printed Bill of sale showing
the correct brand and model. Never buy a helmet without a
Bill. Do not accept a "Quotation" in place of a
Bill. Preserve the Bill.
Ask for the instruction card provided with each
helmet by the manufacturer. Follow the instructions on the
card for proper use and maintenance of the helmet.
Buy a Helmet Lock. You will not have to carry
about your helmet when not in use.
Compulsion or not, always use a helmet when using
a scooter or a motorcycle, either as a rider or as a pillion
passenger. Remember that the life of the pillion passenger
is as precious as that of the rider. Buy more than on helmet
if necessary.
|
