FEATURE
HOW THEY ARE MADE: B E L L H E L M E T S
P96
(Top) This master helmet is
for one of test lab engineer
Alex Szela's research
projects. Anything above the
silver line is a testing area
for Snell. The green dots
mark standard locations
for testing and the red dots
mark additional locations of
testing when Bell develops a
helmet from the ground up.
(Bottom) Snell's drop
tests use a head form with
a specific weight for the
helmet size and then they
are dropped at specific
heights onto various steel
test anvils - flat, hemisphere
(pictured here), or an edge.
DID YOU KNOW?
According to Alex Szela the testing standards for
Snell came about from a lot of research that was
generated by dropping cadavers. They were testing
to find out how much energy the human head could
take before the skull fractured.
One testing tool that is proprietary to the Bell lab
is the chin bar tester. It drops a five-kilogram mass
onto the chin bar of a helmet on the ground. They
have high- speed cameras to measure the flex of
the chin bar. They're looking to make sure that the
chin bar doesn't flex too much or too little.
Snell and ECE use similar weights in testing
but the locations and velocities differ. Snell can
hit anywhere in a specified area of the helmet,
whereas ECE calls out four specified locations that
research shows are common impact areas. Also,
Snell requires a double impact on each site and
ECE requires only one.
In the U.S. ECE helmets also have to pass DOT.
The DOT standard will certify at 400gs from a
six meters per second drop. It is a self-certifying
standard, but the government can randomly test
the helmet to check that it meets the certification.
