The Human Crash Test Dummy, Who Withstood Forces Previously Thought Fatal To Humans

Stapp experiencing forces previously believed to be fatal. Image credit: US Air Force via C-Tech.

With Jeff Bezos and (perhaps) Richard Branson about to blast off into space onboard crafts made by their own companies, let's take a look at an engineer and air force scientist who wasn't afraid to test out his own design. 

The human crash test dummy

Shortly after WWII, with the advance of aircraft tech, the US Air Force realized they would need to study the effects of deceleration on the human body. During the war, aircraft designers believed that humans could only withstand forces of 18G. As such, the planes they produced would only survive 18G impacts also. Why make a plane that can withstand 25G when the person inside will be dead anyway, especially if it costs extra.

However, Col. John Stapp began to question this while analyzing plane crashes, and disputed the figure. He believed that some pilots had survived higher Gs, while others had died on impact at much lower Gs, and suspected that the pilots were really being killed by the design of the harnesses keeping them in, and the cockpit surrounding them. He and his team decided to look into it for themselves, and discover what forces the human body could withstand on impact.

To do this, they built a rocket-powered sled nicknamed "Gee Whiz", which was capable of withstanding 100Gs. Following testing on a dummy, they gradually designed harnesses that would withstand crashes and keep Oscar (the dummy) from smashing into pieces on the wooden windshield. The idea was to test it only on crash test dummies, given that people believed that humans would die when the sled was cranked up to 18G forces anyway.

Stapp soon demanded that he be allowed to have a go.

He began tests at 10G, which he described as quite pleasant. By varying the rockets and brake setups, the team was able to keep cranking up the Gs at Stapp's insistence. 

This was no trivial matter. His ribs were cracked and wrists snapped, his fillings lost and he suffered many concussions. Yet still he made his way through the Gs. By the time he was going faster than 18G he was proving that it was survivable, but his blood vessels expanded painfully (known as a redout) as blood was forced against his retinas, bursting capillaries as it did so. 

When he traveled backwards, the blood would rush to the back of his head, and his vision would become blurry. He demanded to go faster. 

On his final test run, he began going forward at 1,017 kilometers per hour (632 miles per hour) (20G), before slamming on the brakes, stopping within 1.4 seconds. At this braking speed, he was experiencing 46.2G, well above what engineers had previously believed was fatal. Virtually all of the blood vessels in his eyeballs burst, but he remained (just) conscious, though disorientated. His vision did not return until the following day.

“I felt a sensation in the eyes," he said of the experience. "Somewhat like the extraction of a molar without anesthetic.”

He was apparently a fan of that feeling, as he tried to push the team to allow him to try it again but at 1,609 km/h (1,000 mph).

The human crash test dummy had proven that pilots could withstand much higher Gs than previously thought and that deaths could be avoided by focusing efforts on making aircraft that could withstand the impact too. His work led to higher standards for pilot safety, as well as higher standards for automobile safety. Oh, and he broke the land speed record in the process.


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