SOMERSET, Pa. (Feb. 11, 2000) — In this age of high-tech tire-manufacturing plants that turn out thousands of tires an hour, the 22 that workers at Walters Tire Service Inc. in Somerset, Pa., process in an average day doesn´t seem like much.
However, the tires these workers repair and retread cost thousands of dollars each.
Walters Tire uses about 1.3 million pounds of rubber each year to repair and retread giant off-the-road (OTR) tires for the mining and construction industries. This 59-year-old company — No. 10 on the 1999 Tire Business ranking of OTR retreaders — is one of a relatively small number of companies in the U.S. that serves the OTR market.
Although a lot of commercial tire dealers service OTR tires, President James M. Walters said, "there are only about 14 to 16 viable companies in the U.S. to do giant-size tire retreading."
Walters Tire regularly handles tires that have outside diameters approaching 10 feet, weigh several tons and cost thousands of dollars. It may take a ton or more of rubber to retread one of these behemoths.
For example, a size 45/65-45 tire used on a Caterpillar front-end loader weighs 6,000 pounds and has an outside diameter of 9 feet. Mr. Walters said it takes between 2,200 and 2,400 pounds of rubber to retread it.
His dealership handles about 100 different sizes and types of bias and radial tires, he said.
Retreaded OTR tires sell for about 50 to 70 percent of the new-tire price, depending on the size and type, he said, meaning the buyer of a retread OTR tire can save several thousand dollars on a single tire.
Walters Tire distributes almost exclusively through a group of 12 to 15 commercial tire dealerships within about 300 miles of Somerset. The dealership has featured General-brand commercial tires for more than 40 years, Mr. Walters said, but about 75 percent of its sales are from retreading, repairing and servicing OTR tires.
°Walters Tire projects total sales of about $3.3 million this year, including a 10-percent increase in retreading sales to more than $1.9 million.
About 60 percent of the OTR tires Walters Tire repairs and retreads are used by aggregate industry companies that mine rock and gravel for concrete production and road construction. Tires used in road construction, in steel mills and on graders to prepare construction sites account for another 15 percent.
Tires used in coal mining — once the major industry in central Pennsylvania — now account for only about 10 percent of Walters Tire´s business.
Walters Tire purchases rubber by the truck-load, mostly from Oliver Rubber Co. with additional shipments from a Canadian source, International Technical Rubber Manufacturing Inc. in Kitchener, Ontario.
The rubber arrives in sheet form on rolls or as strips of rubber criss-crossed on wooden pallets. Scrap rubber buffed off giant tires is recycled and used for repairs.
The small number of tires means each tire casing can receive a thorough visual inspection before repair and retreading is begun. Many casings are rejected before their first retreading, while others may be retreaded two or three times.
Via its dealer network, Walters Tire generally receives casings from end-users, which are repaired, retreaded and returned. The turnaround time generally is about two weeks, although a one-week turnaround can be arranged in an emergency, Mr. Walters said.
When time is even more critical, Walters Tire will supply a cap and casing, often taking the end-user´s casing in trade.
"The conditions that we run off-the-road giant tires in are so much more brutal than over the road," Mr. Walters said. "It´s so much more severe that we´ll see tires that were ruined the first day."
Damage from rock cuts and sidewall damage from underinflation and/or overloading are the major factors that compromise an OTR tire´s retreadability.
While radial OTR tires may have a longer initial tread life, Walters Tire has experienced about a 30-percent higher rejection rate for radials than bias-ply tires when it comes to evaluating them for retreading.
"Primarily because the steel in the tire is subject to so much moisture when it gets cut," Mr. Walters said, "that it´s hard to deal with that amount of rust."
When retreading a giant OTR tire, the "green" (uncured) rubber is applied to it either in sheets or strips on machinery that has been customized by Walters Tire´s employees.
Molds, stands and cutters are purchased from manufacturers, "but, it´s pretty much a custom job to retread big tires," Mr. Walters said. "It´s challenging to develop the equipment and the methods to do it as efficiently as possible."
Large tires usually take between 6 and 12 hours to cure in a mold, he said, but very large tires or foam-filled tires used in metal scrap yards may need up to 24 hours of curing after new tread rubber is applied.
Curing molds for OTR tires are 8 to 10 feet in diameter. The top of the mold — which weighs up to 3 tons — is raised and lowered by an overhead crane system. A new mold for a large OTR tire may cost $100,000, Mr. Walters said.
Walters Tire also has a large curing chamber that is more than 15 feet high. It´s used for tires like the 36.00-51 tire from a rock or dirt hauler in a mine. This tire´s outside diameter is more than 10 feet.
Mr. Walters said most large OTR radials don´t fill circle molds adequately, so the tread is sculpted on the tire. After the green rubber is applied, a tech uses a "groover" manufactured by Salisbury Manufacturing Co. in North Carolina to form a tread on the tire.
"In that process we buff the tire to dimensions," Mr. Walters said. "We use a computerized machine to carve a tread pattern into the green rubber."
The depth and spacing of the grooves that form the tread can be manipulated to about one-tenth of an inch, he said, and the tire is cured in the large, open chamber.
He said the grooving machine also can "memorize" the tread pattern on a new tire and duplicate it when that size and type of tire is retreaded.
Mr. Walters´ father, Bud, founded the dealership in 1941 as a retailer and retreader of passenger and light truck tires. After World War II, construction of the Pennsylvania Turnpike, which passes near Somerset, created a new opportunity for the dealership.
"He (Bud Walters) was in the right place to try to do (repair and retread) larger tires," Mr. Walters said. "That´s when he first got involved with off-the-road tires."
Construction of the Interstate Highway System during the 1960s created a booming market for Walters Tire to serve road construction contractors in Pennsylvania and surrounding states.
Stagnant economic conditions during the ´70s and ´80s cooled highway construction and dried up the OTR market. Diminished profits caused the major tire manufacturers to get out of the retreading business. "The independents were finally able to get enough volume to stay in business," Mr. Walters said.
"The off-the-road retreading industry is somewhat of a niche business. It´s capital-intensive to get into," he said. "A lot of people have been in it a long time."
Mr. Walters said the strong economy of the last few years has spurred a lot of construction, leading to more tire service demand by aggregate mining and site grading companies. Business will be fairly stable the next few years, but there is a new source of competition.
"We do see additional competition from new tires. Michelin just opened their off-the-road plant (in 1998 in Lexington, S.C.)," he said, "and they´re getting very aggressive in pricing."
Mr. Walters said other manufacturers also are getting more aggressive in their marketing, which will put pressure on retreaders´ margins.
Walters Tire has modest expansion plans that involve serving its current customers better and expanding its dealer base. But limitations of distance will temper the dealership´s growth.
"There´s no sense in doubling my coverage (area)," Mr. Walters said, "and incurring traveling expenses that will erode profit margins."