Fire is always a danger in
auto racing. You are strapped in a car so tightly your body cannot easily move. In fact, if you can turn your chest even a bit, you aren't in tightly enough. Your
helmet is bulky and restricting in closed roof cars. If the car has doors, you will have
door bars and a top loop from the
roll cage impeding your exit. Usually the
steering wheel must be removed before the
driver can exit the car. When I first started racing, one test my crew made me do is to time my exit from the car when I was fully strapped in, helmet on. It took me twenty-five seconds. That's good, but twenty-five seconds is a long time in a burning car.
Race cars burn. First of all they carry lots of fuel, which is usually gasoline. Champ cars burn alcohol which produces an invisible flame. Oil can burn. Long races require refueling, and any time gas is not in a container their is a risk of fire and explosion.
Fuel is usually in or near the cockpit. In formula car the tank is usually integrated into the tub which means it is just below the driver's seat. That location isn't an accident. As fuel is burned that changes the weight balance of the car, which affects its handling. Putting the tank near the center minimizes the effects of the weight change, making the car more neutral in its balance. In modified automobiles the fuel lines usually run through the passenger compartment, usually under where the passenger seat used to be. The General Competition Rules of the Sports Car Club of America requres they be made of armored cable, usually aeroquip, for safety. Fuel lines still can leak or become damaged. I personally witnessed catastrophic clutch explosion during qualifying at the Runoffs in 2001. The bellhousing of a GT-3 Mazda RX-7 was reduced to tiny metal fragments and the driver bailed out, his car aflame from cut lines.
In the old days fire used to kill drivers right and left. Fuel cell technology was only developed in the 1970's. That meant race cars used a conventional fuel tank which was easily penetrated during a crash. The first driver's suits were made of cotton with maybe a leather helmet. In 1970 I got to see Swede Savage drive in a Trans Am race at Mid Ohio. He gave a great drive, and led for a time against an all-star field. In 1973 he crashed while leading the Indianapolis 500. His fuel tank burst, and Savage recieved 3rd degree burns over 60% of his body. The national media carried a picture of him as he was loaded onto the ambulance fully conscious and in utter angony as he stared at his charred skin. Three days later he died. It used to be that every major race series would lose one driver every year, and fire was a major cause. The year Savage died, three people were killed at Indy, including one of Savage's crew, Armondo Teiran. Burns take a long time to heal, and burned people take their time dying.
The first real fire suits appeared in the 1970's and they were made of Nomex. Top fuel drivers often coated their suits with a metallic layer in order to protect themselves from oil spray, as drag racing engines at that level are basically bombs waiting for an excuse to go off. The protective layers would keep flame from the body, and provide a protection from heat that was disproportionate to weight. Most importantly, they won't burn, whereas previous suits would add fuel to the fire.
The SCCA requires that all drivers wear at least two layers of nomex, to provide a minimum SFI rating of 4.5. That means the driver is protected for four point five seconds. A 6.5 rating is possible with a three layer suit and underwear. That's not long in a fire, but all cars also carry a fire extinguisher and in the faster classes all that is required to discharge it is to punch a button. Fuel cell technology has all but eliminated the massive fuel dumps that used to accompany accidents. When a car goes off and it looks like trouble, a corner worker will run to the car from the nearest corner station. He or she always carries a fire bottle, which they are trained to use. I practice fighting car fires every year, and we discharge live bottles on burning cars in training. Corner workers can signal for a fire truck at the drop of a hat, and even request that a race be cut off.. The combination of suit, extinguishers, and your friendly neighborhood F&C worker gives drivers a fighting chance. Today burns are relatively rare, and usually minor.
A good firesuit and helmet combo costs about a thousand US dollars. It should be custom fitted if possible, it costs a bit more, but makes you much more comfortable in the car, while preserving mobility. It consists of a crash helmet with a Snell 95 rating or later, suit, gloves, neck support and shoes. Open-wheeled and open top racers must use a full face helmet. For stock bodied cars, the closed helmet is optional, but I chose to use one anyway.
Two layers of nomex are required. I use a single layer suit, with full underwear ( which resembles long johns) including socks. Bearded drivers must wear a nomex balaclava. Gloves and shoes are also required, and must be carefully fitted. The driver must also wear either a neck brace or HANS device. I learned to believe in mine when I backed into a tree at 80 MPH.
With two and three layer suits available, the driver has many protection combinations available. Each layer insulates, and that means that more layers means a hotter driver under normal conditions. Race cars can get very hot inside, particularly during a summer endurance race.
Racing is not a safe sport. Even the great Ayrton Senna was killed racing. But it is not the great crapshoot it was during the fifties and sixties, when death was to be expected. Today most drivers survive to retire. Fire suits are a big reason why.
Today all racing wheels are designed to be detachable, by pulling a little ring inward at the hub. In the past this is not always so. There is a story of the great Graham Hill being trapped upside down in his Lotus unable to get out because he could not remove the wheel. After that day, every lotus went out with a small wrench taped to the steering wheel, so the driver could unbolt it. Imagine how long that would have taken during a fire. And the suits were cotton back then. When Dan Gurney won the Belgian Grand Prix at Spa his Eagle race car had no seat belts, in the hopes that he woud be thrown from the car. That says something.