Saturday, 7/08/2000
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Safety innovations make NASCAR fatalities a rarity
By Royal Ford / c. The Boston Globe
Another driver has been killed at New Hampshire International Speedway, the second in less than two months to die in a wreck during practice.
Inevitable questions follow: Is it the track? Is it a safety problem with the cars? Is it the speed?
The answer: none of those. It is the sudden stops.
Think back to a spectacular, but nonfatal, wreck last spring at Daytona International Speedway in Florida. Ricky Rudd, in the Bud Shootout, bounced off a couple of cars (a good thing), flipped his Winston Cup car onto its roof (a good thing), and slid the length of the straightaway (another good thing).
Rudd walked away.
It was the sort of wreck that gets the adrenaline pumping in the grandstands. A wreck, in itself, is not a good thing, but Rudd was relatively uninjured because his car was built to take all the things Rudd's car did. Bouncing off other cars, flipping onto the roof, and sliding on that roof dissipate the energy of a crash.
As fans gather at NHIS in Loudon, N.H., Kenny Irwin and Adam Petty are on the minds of all. Irwin died yesterday when his car slammed viciously into the wall at Turn 3 just yards from where Petty was killed May 12.
It may be hard to hold this thought, but fatalities are now rare in NASCAR racing because of how the cars are built. Petty ran straight into the wall at about 135 miles per hour. Accounts say Irwin hit the wall hard and then flipped. He likely would have been better off had he flipped and then slid into the wall.
The problem in this type of crash, drivers and designers say, is that although you can "cage" the driver's body -- strapping him securely into a seat, surrounded by crumple zones -- you cannot protect the neck and the brain in a sudden stop from high speed. All else stops securely, but the head, heavy with helmet, keeps moving, possibly resulting in a snapped neck or the brain smashing against the skull.
The car you drive on the highway is basically a stamped piece of steel with soft crumple zones meant to withstand crashes that, by NASCAR standards, are relatively slow-speed events. Winston Cup cars crash at speeds of 130 miles per hour and far higher. The challenge, then, in building a Winston Cup car is to balance stiffness that will protect the driver with enough softness front and rear to absorb the kinetic energy of a crash.
Winston Cup cars are, in basic form, a body made of welded pieces slipped onto a complex, tubular frame. The frame is made up of four sections: front and rear clips (ends), center section, and roll cage.
John Valentine, chief engineer/racing, research and vehicle technology for Ford Motor Co., described these sections. The most important, he said, is the center section where the driver sits. It combines the center section with the roll cage. The whole package, Valentine said, "is literally a cage." Steel tubing with wall thickness of one-eighth of an inch protects the driver on the sides, rear, front, and roof.
"You want to maintain the structural integrity and keep the occupant encased," Valentine said. In addition, he said, "it forms the backbone of the car. You don't want a racecar flexing in the middle."
Thinner, collapsible tubing .083-of-an-inch wall thickness is used in the front and rear clips. Up front, the tubing crumples in a crash, absorbing energy. In addition, the motor and transmission are positioned so they will slide beneath the car, after the motor mounts shear, rather than projecting into the driver's compartment. In addition to the engine, the front clip also holds the suspension. The suspension system is attached with restraining straps so wheels and suspension parts don't go flying into the stands, along the track, or back into the cockpit.
Tubing of the same thickness is used in the rear clip as are suspension straps. It, too, is designed to crumple in a crash, but also holds the fuel cell, a fire-retardant fuel source far safer than the gas tanks of old. There are check valves in the fuel lines to shut off fuel if the engine is separated from the chassis.
NASCAR design, Valentine said, "is all about energy management."
That is why the crashes that crowds like to see are often the safest, he said. "One where the car is sliding a great deal, the tires are smoking, it's scraping off other cars, off the wall, skidding into the grass. You're scraping off the energy," he said.
Valentine, who spoke before Irwin's crash, said the worst crashes "are the ones where there's not a lot of energy absorption."
Crashes like Petty's and Irwin's.
But these types of crashes -- direct hits to an immovable surface -- are rare.
Safety evolves race by race, accident by accident. The airborne crashes of the late 1980s have been mostly halted because of flaps now installed at the rear of the roofline. They pop up when cars get sideways or backward (and lose their aerodynamics) and keep them from flying.
Driver's seats have evolved, too, and today hug the driver tight in an aluminum frame that is meant to hold up under huge crash pressures while bending just enough to absorb energy.
Nets on the window and behind the driver are "basically to contain the driver in the vehicle," said Valentine. They keep head and arms inside and help prevent whiplash.
Richard Petty, who lost his grandson, Adam, in May, said yesterday, "There ain't nothing the matter with the racetrack. These guys run those things 200 miles per hour. It's circumstance with the way you stop them so quick. The body just can't take it."
DRIVERS KILLED RECENTLY IN SANCTIONED EVENTS
-- Formula One
Ayrton Senna, 1994, San Marino GP
Ricardo Paletti, 1982, Canadian GP
Gilles Villeneuve, 1982, Belgian GP
-- IRL
Scott Brayton, 1996, Indianapolis
-- USAC
Swede Savage, 1973, Indianapolis
-- CART
Greg Moore, 1999, Fontana, Calif.
Gonzalo Rodriguez, 1999, Monterey, Calif.
Jeff Krosnoff, 1996, Toronto
Jovy Marcelo, 1992, Indianapolis
Gordon Smiley, 1982, Indianapolis
-- NASCAR
Kenny Irwin, 2000, Loudon, N.H.
Adam Petty, 2000, Loudon, N.H.
John Nemechek, 1997, Homestead, Fla.
Rodney Orr, 1994, Daytona, Fla.
Neil Bonnett, 1994, Daytona, Fla.
Clifford Allison, 1992, Brooklyn, Mich.
J.D. McDuffie, 1991, Watkins Glen, N.Y.
Grant Adcox, 1989, Hampton, Ga.
