UC Engineer Helps Federal Investigation
Into Firestone Tire Failures

The University of Cincinnati is playing a key role in the federal investigation of why so many Firestone tires failed on Ford Explorers.

Professor Wim Van Ooij, a materials science and engineering researcher in the UC College of Engineering, is one of three outside experts selected to participate in the National Highway Safety and Transportation Administration (NHSTA) investigation.

Van Ooij has spent the last two weeks reviewing data provided by researchers with Ford and Firestone and listening to presentations at both companies. He is part of a team of eight invididuals. Five are with NHSTA, and three are academic experts chosen for their expertise in rubber chemistry, adhesion, fatigue, and other factors related to tire design and production.

"NHSTA puts together a project team, and the team leader chooses outside consultants if necessary," said Van Ooij. "I was chosen because of my experience with rubber formulations, rubber chemistry, and adhesion of rubber to tire cords."

Van Ooij is a native of The Netherlands who worked for the Dutch chemical company Akzo (a supplier to the tire industry) before coming to the United States. He was the first to study bonding of rubber to brass-plated steel cords in tires and has served as an industry consultant for many years.

"They [NHSTA] said I was high on the radar screen when they asked around for experts in the field," said Van Ooij.

Although Van Ooij can't discuss any proprietary information he received during the Ford or Firestone presentations, he said each company had a large team investigating the "root cause" of the massive tire failures. So, he has been able to review an enormous amount of data and has seen first-hand tires which failed.

"In many cases, the tire does not even deflate," he noted. "The tread simply comes right off along with one of the two belts. It's called BLB in the industry -- belt leaves belt."

Van Ooij is now producing his own report for the NHSTA which help the agency decide whether the industry investigation was adequate and whether additional recalls are needed. The report's due in Washington Jan. 5. That's a tight deadline, but Van Ooij said he's motivated by the urgency of the situation.

"This is a very serious matter, because so many people have been killed. I keep telling myself that as I work."

Van Ooij says the data he's seen so far indicate a variety of factors came into play:

1. driving at a high rate of speed (85 mph or higher)

2. under-inflation of tires

3. the load of the vehicle

4. the air temperature (Arizona had the highest failure rate)

All of those factors increase the temperature of the tire which affects aging and fatigue, according to Van Ooij. "Under good conditions, a tire can dissipate heat. But rubber will degrade and fail at higher temperatures."

There were also clear differences between tires made at the Decatur, Illinois plant which failed at a rate higher than tires made at other Firestone plants. However, Van Ooij emphasizes that there was no evidence of poor workmanship, poor quality control, or poor management in Decatur.

"The Internet is full of rumor sites related to the Firestone ATX," said Van Ooij. "They claim the workers were told to poke holes in bubbles in the tires ... that sawdust, grease, even cigarette butts went into the tires. These are absolutely untrue."

Finally, Van Ooij explained that all tires will fail eventually. Rubber degrades naturally under exposure to heat and oxygen. However, the tread normally wears down well before the belts would separate or the tread would peel off. That's the key difference with the Ford/Firestone problem. The aging process was somehow accelerated.

Van Ooij was joined by two other engineering experts in his outside review: Professor Les Lee of Penn State University and Professor emeritus Sam Clark from the University of Michigan.