Body Armour
Today
Myth and
Misconceptions
An artilcle by A W Hellweg, founder and Managing
Director of Hellweg International Pty Ltd
Body armour is nothing new. Ancient warriors have worn bronze, copper and iron
breastplates as far back as recorded history. During World War II flack jackets
were introduced and by the Vietnam War nylon filled jackets were issued to
troops. Unfortunately, the jackets were very bulky and rather hot.
In the early 1960s fibre research scientists were
driven by two goals - to create a fibre with the
heat-resistance of asbestos and stiffness of glass. A breakthrough occurred in
1965 when a research scientist found that para aminobenzoic acid could be polymerized and solubilized under special conditions to yield a rigid spinnable polymer. And so was the super fibre
which we know as Aramid discovered. Aramid is now used world wide by
manufacturers in the production of soft body armour and in many hard armour
applications.
Today we use a fifth generation Aramid and it is 25% stronger, 25 lighter and
30% thinner and softer than the original Aramid. This allows the manufacture of
lighter weight personal body armour which is more wearable.
There are other materials available which are used in soft body armour and
cheaper than Aramid, but incurring some trade off in regard to weight, comfort
and/or bulk.
To begin to understand how Aramid works, imagine several wooden sticks. With
your fist you can break them one at a time. If they are tied together in a bundle,
none can be broken. When Aramid is woven as a cloth and layered, a bullet
encounters many threads at once. The denser the weave (the more threads per
unit area) the more resistance the bullet encounters.
Understanding this, we can understand some other properties of Aramid body
armour. A small bullet fired at Aramid encounters fewer threads than a large
bullet. A fast small bullet with the same total energy of a large slow bullet
will penetrate body armour much deeper. A .357 magnum from a revolver is
therefore easier to stop than a .22 magnum from a rifle. Additionally, the
harder bullets do not deform on impact as much and penetrate more than softer
bullets. A deformed bullet will encounter more Aramid and is more likely to be
defeated.
Stopping the bullet is only part of the problem. As Aramid does not stretch,
when a bullet is contained, the energy is absorbed and dispersed from the
struck fibres to other fibres
in the weave of the fabric and ultimately to the body. This shock to the body
is known as blunt trauma and must be kept at a level where injury from it does
not occur. The human body can withstand a certain amount of blunt trauma and
this tolerance to it is referred to in millimetres of
“back face signature” during testing of body armour.
There are numerous different test standards around the world. The oldest and
best-known standard is by the U.S. National Institute of Justice and known as
NIJ 0101.04. This standard allows for a back face signature of 44mm when body
armour is tested; this is regardless of level of protection the body armour
offers.
As there is a lot of confusion about the various test standards, the harder NIJ
standard is used by law enforcement agencies in the
There are basically six protection levels under the NIJ Standard ranging from
Level I for .38 Revolver to Level IV for .30-06 Armour Piercing Rifle
Ammunition and allows to test with any type of ammunition using the prescribed
test methods. The main level of protection used in Australia by Police Forces
is Level III-A, as protection is required against the .22 magnum rifle. This
round must not be confused with the .22LR which is a much slower round and not
metal jacketed. The .22 magnum is a widely used round in
We have been supplying Australian Police and Government Departments since 1982
with body armour, all tested to NIJ Standards. We are
There is a lot of myth and misinformation being spread about body armour in
regard to test standards, weight, water resistance, UV light, perspiration and
comfort. The weight of a Vest will vary according to its protection level and
to body area covered. When comparing weight of body armour of the same level of
protection from different manufacturers, one must first establish the weight
per square metre of the armour. This is the only way
to compare weight of body armour as the more body area that is protected, the weight of the garment will increase. The
smaller the body armour panels, the lighter the weight. Also
the finer the fibre, the lighter the fabric. Fibres are measured in deniers. A 750 denier fabric is much
lighter and softer than a 1420 denier fabric, but also more expensive. Other
factors that contribute to weight are the use of materials other than Aramid
such as ballistic nylons and other substitutes, which require more layers of
fabric to achieve the same threat level.
Personal body armour has protected hundreds of police officers from death or
serious injury during handgun, shotgun pellet, club and knife assaults (will
not protect against sharp, pointed knives or ice picks!). It has also helped
minimize injury during falls, explosions, automobile accidents, fires,
motorcycle spills, and even bull gorings!