AKRON-Motorists have never really liked 18-wheel rigs. Too big. Too noisy. Too many.
So it isn't hard to understand why the public outcry in Ontario has come to such a fervor after runaway truck wheels killed two people earlier this year.
It seemed as though trucks were always throwing their wheels in Ontario. Seventeen were reported in the first few months of 1995.
The outrage prompted the Ontario Ministry of Transportation to beef up roadside inspections and the Mississauga, Ontario, coroner to begin, on Oct. 2, what is expected to be a month-long inquest into both deaths.
But the ultimate result of the tragedies could be the establishment of required training and certification for all who service truck tires and wheels in Canada.
The Ontario Trucking Association (OTA), Canadian Transportation Equipment Association and the tire service industry are developing a mandatory training program for servicers of heavy-duty wheel-end systems in Ontario, OTA President David Bradley said.
``We are proposing that we, as an industry, develop the minimum standards,'' he said. ``We're asking for legislation that makes it mandatory that people meet those standards.''
The initial concept of the certification program would put the onus on employers to train their employees, he added.
The necessity for training has come to the fore following a technical brief on wheel separations prepared by the Association of Professional Engineers of Ontario and sent to several Ontario provincial departments.
``There appear to be a number of possible causes of wheel separation, ranging from the liberal axle weight and configuration regulations in Ontario to wheel assembly component failures,'' the brief stated. ``However, the most common cause of wheel separations is inadequate servicing and maintenance of double-cap nut disc wheels. . . .''
The brief's authors concluded that training standards for maintenance and inspection of heavy-duty vehicles need to be established and implemented-espec-ially for tire mechanics.
The brief also stated mechanics and inspectors should continually pursue training opportunities.
The engineers group called attention to a number of practices they believe contribute to wheel separations, including improperly fastening the wheels, and poor, unqualified or lazy inspections.
Correctly torquing the stud assembly is one critical issue, according to John Clayton, vice president of FAMEX Engineering and head of the group that drafted the brief. Under-torqued assemblies cause high stress levels in the stud, nut and wheel and can cause cracking and allow nuts to back off.
Threads fouled by dirt, corrosion or mechanical damage can give technicians the false impression that a stud assembly has been torqued properly, the brief noted.
Over-torqued assemblies can cause disc distortion, damage to the disc bearing area and the stud as well as increase the risk of hydrogen embrittlement, a type of corrosion that can cause steel to become brittle and break.
Thus, Mr. Clayton recommends a manual torque wrench instead of an impact wrench during installation.
``It has also been shown that the repeated application of an air gun to several nuts in succession results in a drop in the applied torque,'' the brief stated. ``Therefore, final torquing should be done with a (manual) torque wrench.''
Among other recommendations are: developing ways to mitigate the effects of corrosion; having only formally trained people inspect wheels; requiring a permanent log book documenting every trailer's service history; searching for substandard and counterfeit parts; and adopting penalties ``sufficiently severe to provide a deterrent'' for those not following maintenance and safety requirements.
``Tire mechanics are not licensed, but these people are making what amounts to life-and-death decisions when they change a tire or a wheel,'' said Mr. Clayton, who is scheduled to testify during the coroner's inquest.
Recommendations from that probe could be included in whatever training and certification program is proposed in Ontario, Mr. Bradley said.