Last Sunday’s mayhem started, as mayhem often does, with just the slightest nudge. Formula One cars leapt off the starting line of the Bahrain International Circuit, clustered together to gain early position in the cramped, frenzied, critical opening lap, swerving a sharp right around the first turn like a herd of hungry predators chasing panicked prey.
It was all normal so far for the sport, which is popular precisely because of its roaring engines and jaw-clenching acceleration. The race cars’ oversized tires, spinning at unimaginable speeds, roared a less acute left around turn two, then a swerve around turn three that was virtually a gentle angle in the world of racing.
That’s when disaster struck. Romain Grosjean’s car drifted to the right. Weaving through a labyrinth of potential catastrophes is part of the appeal for race drivers; they have to navigate this high-speed maze using reflexes, skill, and grit, dodging each other and risking injury and death in the process. But during Grosjean’s drift, which was perfectly normal on its own, his whirring massive right rear tire and the left front tire of car 26 glanced together. They bumped, and that bump was enough.
The onboard footage from car 26 shows the rest of the story. Grosjean’s tire bounces, jostles, leaves the pavement for the briefest of moments, and he careens off to the right. Then, mayhem.
Barriers wrap the entirety of the racetrack in some form. But the one he collided against, unlike the barriers near some of the sharper turns and higher-risk areas, was just a bare, rippled ribbon of steel, similar to those along civilian highways. In less than a second, the steel ribbon shredded open. The barrier did its job, it stopped the car, but from the harrowing speed of 137 miles per hour, the car was stopped almost too quickly. Its rear end, hefty with the weight of the engine, spun the car around nearly 180 degrees.
The spin proved too much. The car tore in half, clean open, rupturing the full gas tank and spraying gasoline everywhere. Gasoline, when aerosolized and in the presence of extreme heat, such as the heat from a high-performance engine or even the heat generated by the friction of the crash itself, makes fire.
The terrifying orange-red plume was massive. It engulfed everything—the steel barrier, the front end of the car, and Grosjean himself. Emergency personnel were on the scene within seconds, tackling the fireball with extinguishers, courage, and the desperation born of determination to save a life, while the racing world waited, holding its breath, to see if it would be enough.
A car engulfed in flames can exceed the temperatures required to cremate a human body. But after a 137-mph collision and 10 to 15 seconds in which he had to unbuckle his harness, grab blindly for support in the inferno, and pull himself out of the car, Grosjean emerged like a phoenix with nothing more than minor burns and injuries to his hands, feet, and ankles—and not one broken bone.
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.
The HANS—the Head and Neck Support—is a horseshoe-shaped rigid collar that nestles firmly around the shoulders of racers and has straps that clip onto their helmets. Unattached to the seat or the car itself, the HANS moves with the driver, providing safety yet enough flexibility for a driver to look around and spot oncoming hazards on the lightning-quick racetrack. It’s a bit like a seat belt that, rather than keeping the body attached to the seat, instead keeps the head firmly attached to the body.
Hubbard’s HANS invention had slowly grown a voluntary fan base, but after Earnhardt’s accident, sales erupted and racing agencies made it mandatory. Since then, as of 2016, the most recent year for which data were found, not one single racing death from basilar skull fracture has occurred. Advanced biomedical engineering sometimes poses as magic.
Analysis of the crash video indicates Grosjean’s accident may have forced his body to decelerate at up to 67 Gs, or 67 times gravity. That means his body may have decelerated at double to triple the rate of Earnhardt’s. Grosjean’s neck was almost certainly saved by Robert Hubbard and the HANS.
Keeping a head attached to the body is important, but keeping the body inside the car is also key. A human body that starts out intact doesn’t usually stay so if it hurtles against pavement at high speeds. For that trick, we can largely thank the adrenaline-hungry genius John Paul Stapp, an Air Force surgeon nicknamed “the fastest man on Earth.”
In the 1940s and 1950s, Stapp was on a mission to figure out how much deceleration the human body could handle. Fighter jets were essential during the combat of WW II, but they were still rudimentary compared to today’s models and they came with high fatality rates. Engineers wanted seats that could eject from planes if they were damaged or were about to be destroyed by enemy combatants, so that if a plane was lost the aviators might still be saved, but suddenly ejecting from a fast-moving airplane would slam them to a rapid stop.
A member of the group that included test pilot Chuck Yeager, Stapp watched as aerospace engineers determined to break the speed of sound continued to build bigger and badder jets to do so—without waiting for the answers about safety. Dozens of test pilots kept dying in the process, many of them Stapp’s colleagues and friends.
So Stapp decided to answer the urgent safety questions using the most accurate technology he could think of: himself. (This was before usefully instrumented test dummies had been invented.) Projects MX-981 and 7850 were born to find how quickly the human body could be slammed to a stop, and how to restrain it to minimize trauma.
Stapp and his crew, in the deserts of California and later New Mexico, built themselves a rocket sled—literally a sled with a single seat that could be configured to try out any design inspiration for straps, that was propelled down a track by rockets. (Out at these desert bases, rockets were the most convenient and aggressive propulsion mechanism these Air Force mavericks had on hand.)
For each test, the group would set up a different contraption of webbing or straps to restrain a mannequin and send the creature out for a trial. If the mannequin, playfully named Oscar Eightball and sometimes sporting a jaunty Air Force cap, made it back in one piece, Stapp strapped himself in to see what damage the harnessing systems would do to the—his—human body.
The rockets would light. The sled would take off. In one test, Stapp blasted to 632 miles per hour in five seconds, literally faster than a speeding bullet. This feat earned him a Guinness record for speed and the wry title “fastest man on Earth.” (Test pilots technically outpaced him in the sky.)
At the end of the track, the track dipped into a pond of water. This meant the sled would slam to a stop against a wall of liquid, smashing Stapp’s bones and organs against whatever contraption of webbing or straps was on the menu. His injuries were numerous. Broken ribs were common. He fractured his wrist, and at times the vasculature in his eyes would burst open, flooding parts of his eyeballs with blood and causing temporary blindness.
Stapp and his team conducted at least 166 documented human runs in the sled, and most on Stapp. One of his colleagues, Eli L. Beeding, reached an astonishing 83 g’s in 1958. As a result, the group figured out that the human body can survive even the crash of an airplane—so long as the full width of a person’s pelvis is properly restrained and a strap extends over each shoulder.
The five-point racing harness—two straps on the shoulders, two spanning the width of the pelvis, and one strap connecting downward between the driver’s legs–was the gold standard for decades. In recent years, a sixth and sometimes a seventh strap have been added, but the spiderwebs still focus on the pelvis and shoulders.
Following his career with the Air Force, Stapp became a global advocate for the mandatory factory installation of seat belts. His platform led to temper-tantrum cries of “but my freedom” (There didn’t seem to be much logic to the objections, beyond the inexplicable claim that the very presence of seat belts in the cars “would be a nuisance.”)
It is now estimated that seat belts save tens of thousands of lives every year in America alone and prevent untold numbers more from incurring life-altering, debilitating injuries. Stapp’s research was the impetus behind Ralph Nader’s more famous seat belt advocacy, and both men were in the room together when Lyndon B. Johnson signed the bill that mandated their factory installation.
Today, if a passenger in the back seat of a car isn’t wearing a seat belt, the person in front of them has 2.4 times the chance of dying in an accident, because the noncompliant fleshy “back seat bullet” could burst through a front headrest—and the head and neck of anyone in the front seat. In an accident where we don’t have time to react, our bodies react to the physics like giant bags of sand and hurtle freely forward, unless they are properly restrained.
The speed of Grosjean’s crash—137 mph—was disquieting. But it was the fireball the accident produced that really grabbed global attention. Even people who were not racing fans watched on repeat until videos racked up millions of views in less than two days, hitting the share button and spreading the news like … well, you know.
Enter our humbly named, unexpected hero of the fireball, DuPont chemist Wilfred Sweeny. In 1961, working at a lab bench in the heart of the “better living through chemistry” mecca in Delaware, Sweeny managed to string together lengthy polymer garlands of carbon, hydrogen, nitrogen, and oxygen. It turned out that, when twisted together, the combination had a rather auspicious trait: It could resist fire. DuPont, seeing a world of applications for fire-resistant materials started twisting those garlands into threads, then those threads were woven or knitted into sheets to make the fabric we now know as Nomex.
Every fabric will burn while it is directly in contact with a sufficiently hot flame, explains DuPont Nomex guru Paul Schiffelbein, whose formal title is Thermal Protective Testing Technology Guardian. With more than 30 years working on testing, analyzing, and creating protective fabrics, Schiffelbein’s enthusiasm for his science bursts through in his voice. “We’re constantly learning,” he says of the job he’s held for decades, before describing how even the pandemic has reinforced the importance of careful testing, which let him determine quickly whether Nomex fabrics could be used safely in fire-resistant face masks for Covid-19 mask requirements in areas requiring workers to wear flame-retardant protection.
What makes Nomex special in contrast to other fabrics, he says, is that not only does it burn slowly and require a high temperature to do so, but after the flame is removed, it does not continue to burn or melt, it self-extinguishes. This property is the key to the racing suit that let Grosjean emerge almost unscathed. “The flame ball in this instance was for such a long period of time” that more conventional fabrics would have had horrifying results, Schiffelbein says, as most will fully ignite in less than three seconds.
Polyesters and most other synthetics are cheap to make, precisely because they are spun and whipped out of chemical chains that melt easily. They therefore happily reverse the process when exposed to flame, leading to a molten adhesive goo that adheres to skin and can melt through flesh while also being heartbreakingly difficult to scrape off during medical burn treatments. Natural fibers like cotton, even heavy denim, will ignite “like a candle,” engulfing the wearer in flames.
Sign Up Today
Sign up for our Longreads newsletter for the best features, ideas, and investigations from WIRED.
DuPont has a YouTube channel showcasing many of the company’s thermal threat tests for Nomex. In “Stationware Nomex Versus Polyester,” a matte-black male mannequin dubbed “Thermo-Man” is suspended in the center of a small, grimy, ash-coated room, wearing, of course, polyester. Split screen, next to him, is a Thermo-Man in a full Nomex suit. Suddenly, gray tubes in the room spew jets of fire at the two mannequins, lighting the entire frame ablaze in orange and white and consuming him. (The salvo that would make any pyromaniac gleeful.)
In one video, the racing suits sewn out of Nomex extinguish the moment the flamethrowers fall silent, and they survive relatively undamaged. The cotton suits continue to burn spectacularly. The polyester suits both burn and glorp into molten chaos. Movie action heroes might not drive so recklessly had they known their deltoid-baring tank tops are 100 percent breathable, soft, cozy fuel.
In 1969, eight years after the invention of Nomex, Mario Andretti survived a flaming wreck during a car crash at the 1969 Indy 500 because of the Nomex fabric of his suit. The racing world hasn’t looked back since; now over 95 percent of racers swath themselves in the advanced fabric.
In addition to the fabric, Grosjean’s special Nomex-powered AlpineStars suit almost certainly incorporated decades of precision garment design. According to standards set by the Fédération Internationale de l’Automobile, the governing body of Formula One, those snazzy epaulettes must be strong enough to use as handles to pull a driver out of a wreck if they are unconscious. Some suit designs also have fancy features like quilting— stitched patterns of air pockets that expand when exposed to heat and that give the driver additional thermal barrier to further delay any burning of flesh. Even the thread used to attach the advertising badges is regulated and tested in a process they call homologation, to ensure it doesn’t melt into a driver’s skin.
Watching a survival video like Grosjean’s, you can almost picture the combined work of Hubbard, Stapp, Sweeny—and everyone else who contributed to materials safety—joining forces to save a life. And it’s not just race car drivers who owe them a debt of thanks. All of that work has now saturated the civilian world. Millions of lives have been saved by advances in seat belts, Nomex-crafted gear for firefighters, and car designs that protect the head and neck.
Perhaps Paul Schiffelbein described it best when he said these crashes “are revelations.” Watching Grosjean’s car smash into a wall that should have killed him, then seeing him climb out of a fire that should have burned him, is, indeed, a kind of miracle. Knowing the racer suffered nothing more than minor wounds to his hands, feet, and ankles, all because of science, Schiffelbein says, “just floored me.”
More Great WIRED Stories
- 📩 Want the latest on tech, science, and more? Sign up for our newsletters!
- One man’s search for the DNA data that could save his life
- Wish List: Gift ideas for your social bubble and beyond
- The “dead zone” could help this car take on Tesla
- The vulnerable can wait. Vaccinate the super-spreaders first
- 7 simple tech tips to keep your family safe this holiday
- 🎮 WIRED Games: Get the latest tips, reviews, and more
- 🏃🏽♀️ Want the best tools to get healthy? Check out our Gear team’s picks for the best fitness trackers, running gear (including shoes and socks), and best headphones