The two most noted rocket sled human deceleration events in history are shown.
First, on December 10, 1954, John Paul Stapp, facing forward, was accelerated to a speed of 632 mph, breaking the land speed record and making him “the fastest man on earth.” The sled was then slowed by water, and Stapp took 46.2 g for 1.1 seconds.
In the second event, on May 16, 1958, Eli Beeding, facing backward, was accelerated to 35 mph, then stopped in less than 1/10 second (over a distance of 1 foot). Sensors showed Beeding took a momentary peak of 82.6 g while sustaining an average of 40.4 gs for 0.04 seconds.
World Record 83 G Deceleration Peak on Rocket Sled 1958-05-16 (1967) USAF
Eli Lackland Beeding Jr. (December 17, 1928 – December 21, 2013) was a U.S. Air Force captain and rocket test subject. In 1958, a series of experiments using a miniature rocket sled began at Holloman AFB under the supervision of Colonel John Stapp and Captain Beeding. Participants rode the “Daisy Sled” (so-called because it was originally designed to be air, and not a rocket, powered) at various speeds and in many different positions — even head first — in an attempt to learn more about the g-force limits of the human body.
On May 16, Capt. Eli Beeding prepared to make a 40 g run. The Daisy shot down the track, reached a top speed around 35 mph, and came to a screeching halt in less than a tenth of a second. “When I hit the water brake,” Beeding recalled in a recent interview, “It felt like Ted Williams had hit me on the back, about lumbar five, with a baseball bat.” Beeding had barely informed flight surgeon Capt. Les Eason of his troubles when he began to experience tunnel vision and passed out.
It was a scary moment since the standard protocol for shock would be to elevate Beeding’s feet. Yet there was a chance his back was broken, in which case he shouldn’t be touched. Taking a calculated risk, Eason, and Tech. Sgt. Roy Gatewood gently moved Beeding onto the side of the sled and elevated his feet. Ten minutes later, Beeding emerged from shock and was rushed to the base hospital. Doctors determined his back was only badly bruised. “I thought that was the big excitement of the day,” Beeding recalls. “But later my boss came to me and said, ‘The chest accelerometer tracing shows you got 82.6 g!’”
Subsequent tests with bears showed that the reading was not a fluke and that Beeding had indeed endured a massive g load. When word got out, the young captain made headlines as the man who had topped John Stapp’s g-force record. Beeding however is quick to point out that he rode the sled backward, and that his time at 83 gs was “infinitesimal” compared to the 1.1-second durations Stapp faced during his own tests. “That doesn’t sound like much (time),” Beeding notes, “But I guarantee you, having been through it at lesser durations, one second is an eternity.”
Still, the incident was wholly remarkable and made Beeding a hero, and, for several decades thereafter, his name appeared in the Guinness Book of World Records. Guinness and many other sources incorrectly reported that Beeding endured 82.6 gs for 0.04 seconds. Beeding’s sled in fact decelerated at 40.4 gs for 0.04 seconds as it slowed from 35 mph to a stop over a distance of one foot. 82.6 gs was a brief peak acceleration measured by a sensor on his chest due to the elastic response of his rib cage.
Beeding retired from the Air Force in 1971, later moving to Colorado where he died in 2013 at the age of 85.
Colonel John Paul Stapp, (July 11, 1910 – November 13, 1999) M.D., Ph.D., was an American career U.S. Air Force officer, flight surgeon, physician, biophysicist, and pioneer in studying the effects of acceleration and deceleration forces on humans. He was a colleague and contemporary of Chuck Yeager, and became known as “the fastest man on earth”…
…in his 29th and last ride at Holloman Air Force Base in New Mexico, Stapp demonstrated that a human can withstand at least 46.2 g (in the forward position, with adequate harnessing). This is the highest known acceleration voluntarily encountered by a human, set on December 10, 1954. Stapp reached a speed of 632 mph (1,017 km/h), which broke the land speed record and made him the fastest man on earth…
Stapp died peacefully at his home in Alamogordo at the age of 89.