When was the last time you felt serious G-force? The most likely case is a car crash, in which case you probably don’t remember it. If it was for fun then a roller coaster probably offers the leisure seeker the highest G out there. In sports Luge riders can reach up to 5 times their bodyweight, and air racers hit 9G in tight turns.
The effects of any sustained G-force aren’t particularly fun – blackouts, tunnel vision, inability to move the limbs at all, unconsciousness and death are all possibilities. People believed that the human body could only take so much. One man set out to explore the limits of G tolerance, and in the process saved a huge number of lives by endangering his own.
Colonel John Stapp
Colonel John Stapp was a USAF flight surgeon who dedicated his career to transport safety. In the late 1940s he was assigned to the Aero Medical Laboratory’s most pressing research – the effects of deceleration on humans.
At the time it was assumed that no one could survive more than 18G and planes were being designed to this specification. Evidence gradually emerged that pilots were surviving higher G impacts only to be killed after the structural failure of their aircraft.
It became clear that research was necessary to measure what the human body could tolerate. The initial plan was to use a 13 stone dummy named Oscar Eightball, the reasoning being that if 18G was fatal it would be ridiculous to subject a live subject to anything approaching that.
Dr. Stapp inspected Oscar and announced that he had done the calculations and he himself would eventually be the test subject, despite warnings that he would be turned into a sack of jelly.
To simulate the forces in a crash a rocket sled was used. It was located at Muroc Army Air Field (now Edwards Air Force Base – the home of the X planes and The Right Stuff) on a track originally built to test captured V2 rocket motors.
The Gee Whiz
The sled was designed to replicate aircraft landing velocities followed by the violent deceleration of a crash. Rocket motors brought it up to 200 mph over a 2000 ft railed track and metal scoops plunged into water generated the effects of a sudden slow down.
In December 1947 after 35 test runs with Oscar, Stapp rode the rocket. His first ever run simulated 10G which he described as ‘exhilarating’. Over a period of time speeds and impacts increased and Stapp made a nonsense of existing theories, taking up to 35G, forcing designers to start making helmets, harnesses, seats and cockpits much stronger.
His list of injuries began to grow as the experiments progressed. He cracked collarbones, ribs, broke his wrist twice, burst blood vessles in his eyes and went temporarily blind on several occasions, but his dedication never wavered.
Research moved on to the effects of ejecting at high speeds during the 1950s and Stapp was once again the willing test subject. A new rocket sled named ‘Sonic Wind’ reached 632 mph and came to a dead stop in 1.4 seconds to replicate ejection at 1800 mph. Stapp experienced 46G and survived.
Stapp in action
He was soon dubbed ‘The Fastest Man on Earth’, ‘The Bravest Man in the Air Force’, around the base itself he was known as the ‘Careful Daredevil’, a B Movie was made about his exploits, but Stapp was only interested in using his newfound celebrity to push the issue of car safety as he realised his findings were just as applicable to the road.
By demonstrating to the Air Force that as many pilots were dying in car crashes as plane crashes, he persuaded them to build one of the very first car crash test facilities and it became a cause he dedicated the rest of his life to. He brought together manufacturers, legislators and researchers to act on his results and to this day the Stapp Car Crash Conference is one of the world’s leading forums in improving crash safety.
Next time you put on your seatbelt you know who to thank.
