NASCAR hopes boxes yield crash data

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Posted: Thursday, January 31, 2002

UAW-Daimler Chrysler 400. Earnhardt was in Las Vegas this week preparing for the season-opening Daytona 500 on Feb. 17.

DAYTONA BEACH, Fla. -- The investigation into the racing death of Dale Earnhardt took thousands of hours, cost millions of dollars and was 2 inches thick once all the experiments were complete.

And yet, it represents only the very best guesses of the world's best experts on crashes.

As NASCAR released the report in August, it vowed to have more definitive answers in the future. The Witness, the sport's first data recorder, is supposed to do all that and more.

Starting with practice and pole qualifying for the Daytona 500, every car on the Winston Cup, Busch and Craftsman Truck series will be fitted with a black box that can provide pinpoint information in the event of a crash.

The unit, slightly smaller than a VCR tape, can measure force, direction and magnitude from all directions forward, sideways, up and down during a crash. By understanding all the forces inside the car, including roll, pitch and yaw, engineers can make changes based on well-founded principles, not best guesses.

''This is cutting-edge stuff, modern technology,'' said Scott B. McClellan, executive vice president and founder of Independent Witness Inc.

All units are owned by NASCAR and are mounted on the floor between the driver's seat and the driver's door. They snap into a pre-mounted harness and don't have to be connected to a battery.

They remain in the car throughout all practice sessions, time trials and the main event, and then they're removed after the race. The black boxes not only can help the sanctioning body with information about a crash, but they also can tell when a team removes it during the racing weekend.

Data recorders have been common on the Formula One circuit for years, but NASCAR has avoided any kind of computerized technology. The sanctioning body has been concerned teams will tap into the information and turn that information into an advantage.

''The piece we decided on is a very simple piece,'' said Joe Garone, the director of NASCAR's research and development center. ''When I say simple, it gives you just what you need and not a whole bunch left over.''

What the black boxes can provide is critical information about impact. NASCAR will study all crashes with particular interest in angle of impact, speed and the change of velocity.

''You collect the information over a period of time, from serious to non-serious accidents,'' McClellan said. ''If I have five accidents that are at a 25-degree angle, and four of them are grouped together and they are survivable, then you have one that isn't survivable. Never before have they known there was a difference. This will help us understand what we can do to the car to bring that fifth accident down to the level of the other four accidents that were survivable.''

The data recorders are waterproof and can withstand temperatures of nearly 300 degrees. They operate on a battery that has a two-year life so they can collect data even if the car's power system is turned off.

McClellan said one of the most important things the Witness will record is the change in velocity. It's more accurate than G-forces in describing the magnitude of a crash.

''G-forces are misleading,'' he said. ''You hear of people taking a 30-G hit, but when you bang your knuckles against a desk, that's a 50-G hit. The acceleration level is only half the story. The rest is how long did my knuckles experience that hit? A very short duration doesn't really hurt. You can sustain very high 100, 200, even 500 Gs for a very short duration. As that time period gets longer, though, you turn to Jell-O and things start breaking and falling off.

''What's important is the change in velocity. That's the accurate unit for the severity of an accident. If I'm going 10 mph, and I hit a wall and come to an abrupt stop, my change in velocity is 10 mph. If I'm going 190, and I hit somebody and slow down to 180 mph, that's still a change of velocity of 10 mph.''

NASCAR already has been crashing cars in sled tests to create a foundation for their research.

Reach Don Coble at

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