BRYAN, Ohio—Manufacturing the world's largest tires is, to say the least, “a real challenge.”
Because of their size and cure time, it requires an entire 8-hour shift to produce one 63-inch rim diameter, 10,000-pound, off-the-road tire at Titan Tire Corp.'s Bryan plant.
The 63-inch tire is the toughest to develop, said Don Long, customer supply manager at the Bryan plant.
“There's enormous interest in getting that size,” he said. “Michelin and Bridge- stone are the only other suppliers. So there is a desire to have an alternative. So that's good for Titan.”
The company, which introduced its behemoth in 2008, has developed a second-generation line with compound improvements and a multiply nylon radial carcass to reduce failures—just in time to meet a resurgence in demand for mining tires.
The market slowed down in 2007 but last year the worldwide demand returned, and that has prompted Titan to ramp up production at the plant this year.
“Right now, with the commodities prices since the second half of 2010, demand is tremendous,” Long said. The plant has implemented swing shifts seven days a week for the 57- and 63-inch tire production.
“We have moved the ag machines to the other plants and concentrated on OTR tires here,” Long said. The equipment the plant has “is not used to its fullest capacity. That's the next step.” Titan also has factories in Des Moines, Iowa, and Freeport, Ill., that produce farm and small off-the-road tires.
The Bryan facility has the ability to add curing presses and expand capacity in the 500,000-sq.-ft. building Titan purchased from Continental Tire North America Inc., as it was known in 2006. After the acquisition, Titan built a 250,000-sq.-ft. addition where it now makes the giant tires.
The factory, which employs 320, produces OTR tires ranging in size from 25-inches, weighing about 300 pounds, to the “ultra-class” tires—49-, 51-, 57- and 63-inch rim diameter sizes.
About 40 percent of OTR tire building at the Bryan site requires manual work and an assembly line process. Two people are needed to make a 63-inch tire to help reduce the physical work, Long said.
The factory houses a research-and-development lab and uses quality inspectors to X-ray the tire belt packages. Each OTR tire is molded with a unique serial number so the company can track the tire's production history if there should be a failure in the field.
About 20 percent of the tires produced are bias-ply. Long said there always will be a demand for bias tires from about 25 percent of the market because of the need for side flex in tires on such vehicles as loaders and port container handlers.
The 51-inch tire is considered “the bread and butter in mining,” according to the Titan executive. “Eventually it will be the highest volume tire we make in sheer numbers. There's a huge demand.”
The 63-inch tire is mainly used in large open mines, particularly on the massive 400-ton trucks driven on the oil sands of Alberta, Canada, which has the largest concentration of such trucks, Long said.
The company's main competitors in the 63-inch tire market are Michelin North America Inc. and Bridgestone Americas Tire Operations, although Goodyear is testing 63-inch OTR tires and hopes to launch them by April.
“The OTR business is cyclical. That's why companies are reluctant to invest (in ultra-class tire equipment). That's why there's been a shortage in OTR tires,” Long said.
The hard life of an OTR tire
There are challenges for the exclusive group of giant tire makers.
The 57- and 63-inch tires run about 5,000 to 6,000 hours—about 250 days—while mining vehicles run 365 days a year, Long said. The tires' greatest enemy is the heat they generate and to a lesser extent the rocks and road hazards on the mine roads.
So Titan developed the multiply nylon radial carcass so the tires would run cooler because nylon is less conductive than steel. The manufacturer also changed the tire compounds at different stress points.
“The basic design concept comes from aircraft tires,” Long said. Titan is offering the ultra-class tires with or without sipes. The sipes help the tire run cooler but they also can collect rocks within the grooves.
The changes to the compounding and belts are aimed at reducing impact breaks when the tire travels over rocks. “The carcass lasting is not the issue. Most tires fail in the belt package,” he said.
The nylon carcass also may help with a “huge”' issue now facing the mining industry—tire recycling. Long said the nylon carcass is more recyclable and could make the 63-inch tires retreadable. Historically, the 63-inch tires experience failure in the belt package before they can be retreaded, he said.
“The mines are realizing they need to keep their roads clean to avoid impact breaks,” Long said. Such issues may affect the future of giant mining vehicles. “More mines are rethinking the 400-ton trucks because of the extreme maintenance and tire costs, and the roads have to be maintained to use them.”
To help reduce the costs of the giant tires, Titan is looking at changing how tires are shipped from its plant. One of the major costs is shipping the tires on flat-bed, wide-load trucks. The company is working on a truck design that would allow the tires to be shipped vertically instead of on their sides, Long said. While transporting vertically reduces the number of tires per truck—about three 57- or 63-inch tires versus five—it would eliminate the costs for escorts, reduce state transport permit fees and cut travel time because some state regulations prohibit wide loads from travelling at night, Long said.
“The impact on transportation costs would be huge. It would be quicker.”
Meanwhile, Titan is developing a lar-ger wheel—a 73-inch diameter rim for a low-profile 63-inch tire that would reduce sidewall flex. Selling tire/wheel packages to OTR customers “is on the horizon,” Long said, but it may initially be a “tough sale” in the aftermarket because of the cost.
Is there a larger tire in the future? “That would be a huge challenge. A huge challenge,” Long said. “But that's what companies do.”