LOUISVILLE, Ky.-More than 174,000 wall charts warning of the dangers of zipper ruptures have so far been distributed, according to Marvin Bozarth, executive director of the International Tire and Rubber Association and Chariman of the industry task force strdying these potentially fatal explosions. Mr. Bozarth detailed the task force's pregress at a Tire Indusrty Forum, April 17 during the ITRA's annual World Tire Conference. The forum consisted of a secries of reports from experts.
Mr. Bozarth told attendees that testing indicates structural damage leading to zipper ruptures can develop inside severly underinflated tires in as few as 300 miles.
"These tests and close inspection of many zippered tires examined by the task force point to underinflation as a mojor cause of zipper ruptures," he said.
Zipper ruptures occur when the steel cords in teh tire's sidewall weaken and break. They get their name from the appearance of the resulting wound whose shattered cord ends look like an open zipper.
The most important piece of safety equipment for inflating all-steel radials, he said, is a clip-on chuck and extended air hose allowing the operator to stand away from the potential explosion.
"You can't assume you're safe just because the tire is in a safety cage," he advixed, In two zipper related fatalities occurring druing the last six months the only thing striking the victims was the force of air escaping from the rupture.
Mr. bozarth said the biggest need in preventing further carnage is to alert everyone in teh tire service business to the danger.
"We've had several instances in which people heard the noise of the steel cords breaking and ran over to see what was wrong. That can be a fatal mistake," he said.
In addition to the previously mentioned wall chart, printed and distributed by the Rubber Manufacturers Association, Mr. Bozarth said the ITRA has distributed nearly 3,000 video cassettes warning of the dangers of zipper ruptures and recommending procedures for guarding against injury resulting from such explosions.
The task force also developed an inflation warning sticker for use on finished retreads. They're available from ITRA as well as some retreading material suppliers.
Roadside tire debris
Peggy Fisher, president of the former Roadway Tire Co. and head of the Tire Debris prevention Task force, brought attendees up to date on her group's pregress.
The task force was organized last year by the Maintenance Council of the American Trucking Associantion in response to attempts to persuade state and federal legislators to ban retreads, which are wrongly blamed for creating the roadside debris.
Rubber torn away during tire failures does pose a hazard to motorists and a serious public relations problem for both trucking and retreading industries, Ms. Fisher noted.
The task froce's main objective is to get commercial vehicle operators to properly maintain their tires in order to reduce the rubber on teh road and the resulting risk of regulations banning retreads.
Ms. Fisher said the task force hopes to develop educational materials for distribution to fleet operators, truck stops and government agencies.
Last summer, task force members visited parts of Ohio, North and South Carolina, Arizona and New Jersey, seeking to determine the cause of 1,700 pieces of tire rubber found on the roadside.
Of the tire pieces collected, she said, 1,070 came from medium truck tires, 619 from passenger or light truck tires and 35 were of unknown origin.
Contrary to what critics believe, separation of the tread from the retread casing accounted for only 1 percent of the failures whose cause could be determined.
However, banning retreads as a questionable means of solving this problem would cost the trucking industry $3.8 billion annually, use up an additional 850 million gallons of oil in tire manufacturing and greatly increase the number of tires entering the waste stream.
For the first time since 1970, the GSA does not have a national tire schedule for federal agencies to use in buying tires.
"This means you can now go to the blue pages of the phone book and start to call on local federal agencies to market your tires, both new and retreaded," he said.
Mr. Collings said the current plan has the GSA's Qualified Products List testing continuing until Dec. 31, after which it will stop. Approved QPL tires will remain on the list for four years.
While the GSA is considering ending QPL testing, Mr. Collings said he's learned the department of Defense has determined it needs the QPL.
Thus if the GSA should choose to end QPL testing, the defense Department ``will pick up what we're doing and add it to what they're already doing,'' he said.
Charles Duttweiler, president and publisher of Transport Topics newspaper, predicted new vehicle sales of Class 7 and 8 trucks would decline 20 percent in 1996 from 1995, which was
the biggest year ever for the industry. But even with the drop off, 1996 sales still would be better than 14 of the previous 16 years.
Intermodal trucking, which was weak last year, will be down again in 1996 and for several years to come, he said. Within the intermod