Headlines with the word miracle practically wrote themselves. Racing fans everywhere celebrated what looked like a mixture of luck and benediction. But to the quiet nerds who typically operate behind the scenes—chemists, engineers, and injury biomechanists like myself—Grosjean’s survival was far more exciting than blind luck.
From his hospital room after the wreck, Grosjean credited his relative lack of injury to the recently implemented Halo device, a ring positioned above the driver compartment that is designed to absorb crash impact. It is a sturdy structure of molded carbon fiber that looks like a circle above the driver’s “survival cell,” an area that is supposed to be most impervious to trauma. The Halo was certainly one factor; it kept Grosjean’s head from impacting the shredded roadside barrier. (Grosjean himself was formerly a skeptic about the relatively new safety device but says he is now a convert.) But there were at least three other brilliant scientific advances that, together, kept him alive: his Head and Neck Support system, his racing harness, and his logo-covered high-tech suit.
We are desensitized by cinematic images of grimy tank-top-clad heroes walking slowly away from blazing car explosions. But a real-life human being, one composed of easily singed meat, clambering out of the center of an orange-red inferno is nothing short of astonishing. What most fans and viewers don’t know is, the credit for Grosjean’s survival goes to a hundred years of automotive science.
Back in 2001, Dale Earnhardt Sr. was doing more than 150 mph in the NASCAR Daytona 500 when his car slammed into a barrier, causing it to drop in speed by 43 miles per hour in 0.08 seconds. His speed change alone was unremarkable, but because the crash occurred over such a short amount of time, the acceleration levels—or in this case deceleration—were about 25 Gs, or 25 times the acceleration caused by gravity. That means the impact on his body was the same as if the pilot of a fighter jet traveling at the speed of sound slammed to a complete stop in less than 1.5 seconds.
Earnhardt’s body was properly restrained, and it stayed in place. His head, however, was not. And it didn’t. Earnhardt’s tragic accident was the moment that it became clear that racing cars needed head and neck restraints.
Earnhardt’s head, made even heavier by the heft of a racing helmet, was flung forward. The internal structures of his neck were unable to absorb the force, which placed an extraordinary stress on the base of his skull. The skull cracked in response. Suddenly unrestrained by the now-broken bony infrastructure that normally supports our more malleable parts, the soft tissues of his brain, neck, vasculature, and spine suffered lethal damage.
This type of injury, called a basilar skull fracture, used to be shockingly common in racing, and it happened often in the decades of racing history before Earnhardt death. Since drivers need to be able to look around in order to be functional, restraint systems had focused on keeping the body inside the car, but they historically had ignored the head and neck.
Until, that is, Robert Hubbard came along in the 1980s. A biomedical engineering PhD and automotive crash test expert, Hubbard sometimes crewed as a racing pit member for his buddies on weekends. One day in 1981, Hubbard found himself with a new, unfortunately personal perspective on basilar skull fractures. That day, at the Mid-Ohio Sports Car Course, his friend, the driver Patrick Jacquemart, died of one. Hubbard and his brother-in-law, also a friend of Jacquemart’s, got to work.
The racing industry is a culture sometimes loathe to accept new safety standards. Drivers metaphorically snort octane for breakfast and prioritize speed over the safety provided by more sedate sports, so to them protective equipment can sometimes seem like added weight and inconvenience. But after the death of Earnhardt— a legend in the sport and a man known for his grit and courage—the industry was bludgeoned with the harsh reality that grit and courage are not relevant in determining the strength of the spine.
