``All documents and procedures shall reflect the policy of not intentionally running any OTR tire to destruction.''
That phrase, part of a draft of a Society of Automotive Engineers (SAE) standard on tire safety, potentially could alter tire maintenance, service and, ultimately, demand, according to OTR tire manufacturers and dealers who discussed the proposal at the recent Tire Association of North America Off-The-Road Conference held on Bermuda.
The new safety standard being drafted by SAE is at the request of the Mine Safety & Health Administration, which discovered during an internal review of their procedures that ``their inspectors had no knowledge whatsoever of tire safety,'' said Bob Ochsenhirt, manager, OTR sales engineering, for Goodyear.
MSHA wanted to be able to give its mine inspectors clear-cut direction on what makes a viable tire, Mr. Ochsenhirt said.
After examining the issue from multiple angles, Mr. Ochsenhirt said, the SAE committee concluded it would be impossible to write one comprehensive standard because each type of mining presents its own operating environment and hazards. Initially, MSHA asked for a book detailing what cuts are acceptable, for instance.
Instead, the SAE will recommend that each mining operation write its own document, based on SAE guidelines.
The result of that decision is the guideline quoted in the first paragraph of this article-and that position statement ``runs counter to industry practice,'' Mr. Ochsenhirt said.
If mine operators take this situation at face value, it could mean tires being taken out of service earlier, making them more suitable for retreading, conference attendees noted. On the other hand, others said, old practices die hard, even in the face of such standards.
The SAE committee working on the standard has representatives from makers of tires, rims and heavy equipment.
Another SAE committee is helping MSHA draft proposed guidelines for fighting fires in mines when tires are involved. Tires and fire safety in general cropped up in two other presentations at the three-day conference.
Lee Woods, of Northern Tire Inc. in Ishpeming, Mich., and TANA OTR Group chair, profiled two fires at the Tilden iron ore mine near Marquette, Mich. Both incidents were machinery fires that turned into potentially deadly situations because local firefighters were unaware of the explosive potential stored in an OTR tire being heated in an equipment fire.
In both cases, tires exploded, but fortunately, there were no serious injuries or deaths to report. During his own inspection of the premises afterward, however, Mr. Woods found, 600 feet from the burning truck, a chunk of one tire too big for a person to lift.
Unfortunately, the MSHA does have cases on record where deaths have occurred from such incidents. Mr. Woods and others urged OTR tire dealers to make themselves available to consult with local mining operations on writing fire safety guidelines.
Also related to the topic, Rimex Supply Ltd. of Surrey, British Columbia, described its ``De-Fuzer'' valve designed to act as a type of ``pop-off'' valve when temperature or pressure exceed proscribed limits. The De-Fuzer is retrofitted to existing tubeless rims or wheels 25-inches in diameter or greater.
The De-Fuzer uses a rupture disc set to rupture at approximately 190 psi at 200 degrees F, Rimex said.
Farther down the road, an SAE committee is working on developing test procedures to measure rim slip. If rim slip can be accurately measured, it could then be predicted and corrected by computer modeling of tires and rims, Mr. Ochsenhirt said.