We started running the numbers on tires in the early 1990s — just taking stock of how many tires we have and how much they cost to replace," says Clay Jones, equipment manager with Austin Bridge & Road. "We found out pretty quick that there are big dollars tied up in tires. That's when we went to radials."
Jones wanted to investigate claims about the performance and durability of off-road radials, and recruited Michelin to help him discover the most cost-effective applications to test.
"As an employee-owned business, we all try to improve how the company does business a little each day," Jones says. Being a company owner also encourages him to carefully estimate the potential return of significant investments.
He says radials for the company's motor graders cost twice as much as the bias-ply tires they were using. The company had motor graders doing precise work on projects. Tire life was poor, and delays in graders' mission-critical work could stall an entire project.
The decision was made to switch graders to radials. At the same time, Jones and his maintenance department began revising tire-maintenance procedures. They plumbed an air hose with a valve-stem chuck to the brake-air compressor on each grader and gave every project supervisor a tire gauge. It became their responsibility to keep tires properly inflated.
Checking tire pressures is mostly delegated to operators, but project supers remain responsible for results — keeping tires at the correct pressure.
"We have a grader on most jobs, and since they have a compressor and air hose on them, the operators don't have to wait on the tire truck to air up," Jones says.
As operators began to take a more important role in tire maintenance, Jones invested some resources to train operators to avoid wheel slip and other strategies to get the most out of tires.
The change to radials and efforts to maintain them properly resulted in doubling of off-road tire life. They began to replace worn-out bias tires with radials on most machines, and now 95 percent of Austin Bridge & Road's off-road tires are radials.
"Project supervisors are employee owners, too," Jones says. "Any money they save on tires is their own money."
The investment in radials inspired an effort to retread as many tires as possible. With retread costs as low as half that of a new replacement tire, McGuire and his maintenance crews team up with the company's tire vendors to measure every tire's tread depth monthly. Careful monitoring of wear ensures that 80 to 85 percent of the off-road tire casings coming off the fleet are retreaded at least once.
They buy about 100 retreads per year and, because their cost is about half that of new replacement tires, retreads save Austin Bridge & Road a significant sum of money.
Accurately measuring the full value of a change in construction tires can be a problem because of flats. They happen fairly often and, if the tire can't be fixed, you never know how long it might have worked before it wore out. As it happens, though, the change to radials had the additional benefit of reducing the frequency of flats.
Frustrated by flats on backhoes and box blades, Jones and his maintenance supervisor, Harold McGuire, started counting tire service calls in 2003. The company uses about 40 two-wheel-drive box-blade tractors and backhoe-loaders to do cleanup work after projects.
"Flats are a significant problem, even with these box-blade tractors," Jones notes. "A flat every week wasn't unusual."
Radial rears were making a difference on the tractors but the company's records of experience with bias-ply tires were incomplete, so they didn't have the data necessary to make a clear comparison to radial performance.
At the end of 2003, McGuire and Jones identified a two-wheel-drive box-blade tractor with bias front tires that would make a good test case. The box-blade they picked was a typical machine on relatively new bias-ply front tires.
They replaced the front rubber with a set of Michelin XM27 radials (the machine has had XM37 radials on the rear since August 2002, which have never been flat).
Results of the front-tire comparison, within 12 months, were eye opening. McGuire's records showed that pair of bias-ply front tires suffering nine flats during calendar 2003. In 2004 — with virtually no change in working hours, operating conditions, applications, or operators — the radials sustained only two flats.
The cleanup tractors work, on average, about 800 hours per year. With all of the construction debris left behind a bridge or road project, it wasn't unusual for bias tires to go flat nine times in a year. But it was expensive.
The typical cleanup crew includes four people. On jobs that require a backhoe-loader, there's usually a truck on site during cleanup as well.
"We estimate that each flat results in two hours of downtime, which costs the company $100 per hour," says Jones. "Then you have the service call on top of that. Our average service call cost for fixing a flat is $57.45."
Simple math shows the costs for nine flats incurred by the bias ply tires in 2003 were $1,800 in downtime and $517.05 in service fees, or a total of $2,317.05. In comparison, the two flats in 2004 resulted in $400 in downtime and $114.90 in service fees, or a total of $514.90.
The difference — in downtime and service fees — between the box blade equipped with front-end bias-ply tires in 2003 and the same machine with radials in 2004 was $1,802.15.
This is just one example of how Jones and company have cut nearly 30 percent out of Austin Bridge & Road's tire budget.