IEEE Spectrum October, 2007 - 33

His bare buttocks

rest on the cold steel
shelf; the smooth, hairless skin has a ghastly pinkish-orange hue.
His toeless feet lie nearby, alongside his head, rib cage, arms, hands,
and legs. Could this be the grisly scene of some ritualistic slaying?

Not quite. A white-coated technician enters the room and
transports the body parts to a wooden workbench. He takes an
Allen wrench and screws the feet to the legs, the hands to the
arms, and then the limbs and head to the torso. When he's finished, another Hybrid III midsize adult male anthropomorphic
test device has begun to come to life. Or at least what passes for
life for a crash-test dummy.
This Hybrid III is the handiwork of Denton ATD, a
170-employee company with facilities in Michigan and Ohio that
manufactures some of today's
most advanced crash-test
dummies. These human surrogates simulate how a real
person's body would respond
in a car crash and help ensure
that a new car's seat belts,
air bags, head and armrests,
structural frame, interior
padding, and other elements
provide good protection.
In a few days this new
Hybrid III unit will be instrumented with force, torque,
and acceleration sensors and
then shipped to an undisclosed automaker in the
Detroit area. There he'll be
placed into brand-new cars
and endure a torturous range of injury and insult: head-on collisions, rollovers, rear and side crashes-all to certify that the
carmaker's vehicles can protect their human occupants in the
event of an accident.
The dummy's ordeal, in other words, could someday save your
life. But you'll probably never get to meet this electromechanical
marvel. He doesn't even have a name. In the records that register
the dummy's parts, his crash-test history and, ultimately, his
retirement date, he'll simply be known as No. 0200-137.
THIs pAsT sUMMer, I visited Denton to see how the company
makes its extraordinary dummies. Denton's assembly plant sits
amid cornfields just outside the picturesque town of Milan, Ohio
(population 1445), birthplace of Thomas Edison.
When I step inside the company's unassuming building, the
first things I see are body parts-everywhere. "Here's a thorax,"
says Mike Beebe, a senior vice president at Denton and one of the
world's leading experts on the art and science of making dummies. "There's a spine box, with all the different pieces. That's
an abdomen. Those are arms. Legs. Heads." I try to mentally

44 IEEE Spectrum | October 2007 | NA

arrange a full body out of the disordered parts, but what springs
to mind is something alarmingly Picasso-esque.
Beebe points to a photo showing a group of dummies. "Family
portrait," he quips. The family includes the most widely used
dummy, the Hybrid III 50th-percentile male, meant to represent
the average North American man. He weighs 78 kilograms and
is 1.75 meters tall-or would reach that height if he could stand,
which he can't, because he's in permanent sitting mode. Hybrid
III has a petite wife (Hybrid III 5th-percentile female), three
kids (Hybrid III 10-year-old,
6-year-old, and 3-year-old),
and an oversized cousin
(Hybrid III 95th-percentile
male), who tips the scales
at 100 kg-the "big guy," as
Beebe puts it.
This family of dummies is
designed for use in crash tests
simulating frontal impacts:
cars running squarely into
other cars, trees, walls-
that kind of thing. Also in
Denton's catalog of 40 dummies are models for testing
side impacts, rear impacts,
accidents involving pedestrians, and air-bag blows on
small children. Denton's customers include Chrysler, Ford, Honda, Hyundai, Nissan, Porsche,
Volkswagen, India's Tata Motors, and China's FAW. The company ships 20 to 25 dummies a month.
Beebe explains that in a crash test, a dummy's sensors register a range of parameters: the force of a blow to the thigh, the
torque on the neck during sudden deceleration, the compression of the chest against a seat belt. These measurements are
then converted into injury criteria, which reveal the harm-
anything from minor concussion to death-that would have
been done to the vehicle's occupants had they been human.
Such injury knowledge comes mostly from researchers studying
how Newtonian mechanics applies to the human body, usually
by performing impact and deceleration tests on cadavers, pig
carcasses, or eager graduate students.
sMArT pArTs: Denton's most complex force sensor [this page], the pelvis load
cell of a WorldsID dummy, can record 12 data variables. FOCUs, an enhanced
dummy face [opposite, top], has multiple load cells behind its eyes and facial bones.
Waiting to receive new parts, a Hybrid III family sits in the Dummy emergency
room [bottom, left] at Denton's assembly plant in Ohio. A dummy's vinyl and metal
parts converge in the assembly area [bottom, right].

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Table of Contents for the Digital Edition of IEEE Spectrum October, 2007