Worldwide,car accidents kill about 400,000 people and injure 12 million more every year. Despite these grim statistics our roads are much safer than they were 50 years ago.

The reason is simple. New cars are repeatedly crash-tested by their makers, until they are safe as can be made for the price. Inside almost every doomed car sits one or more very expensive and very life-like anthropomorphic test devices. You and I call them crash test dummies.

Hybrid III head and neck (photo courtesy Denton ATD Inc.)

Packed inside each dummy are sensors that record the accelerations, forces and movements felt by its head and body throughout the crash. This data allows engineers to see what happens to the driver and passengers millisecond by millisecond. It enables them to pinpoint how particular injuries occur.

Such complex capability did not appear overnight. Sixty years of development has taken crash test dummies from simple mannequins to today’s complex biomechanical marvels.

Sierra Engineering built the first test dummy, for the United States Air Force, in 1949. Christened ‘Sierra Sam’, he tested ejection seats in jet aircraft. Weighing over 90kg, Sam was not very life-like and so the air force also used human volunteers. Strapped into seats on a rocket-powered sled, the volunteers experienced up to 45Gs of deceleration while testing harness designs and seating positions.