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Hub piloted disc wheels courtesy of Milestone Equipment Holdings

Multi-Piece Rims Continue as Important Issue for Intermodal

Multi-piece rims on intermodal chassis tires continue to be an important — as well as complicated — topic for the intermodal community, driven by questions related to safety and cost.

Doug Hoehn, executive vice president, Milestone Equipment Holdings, summed up the differing views that intermodal equipment providers and other intermodal participants have on this issue in comments to Intermodal Insights, while also providing a historical perspective.

Safety standards for servicing multi-piece rim wheels were established by the Occupational Safety and Health Administration, and updated to also include single piece wheels. Hoehn explained that the standards only cover tire mounting within restraining devices or barriers to retain wheel components if there is an incident during tire inflation.

"While there are advantages that people cite for using 2-piece wheels, like being tougher and able to handle heavier weights, I think there are offsetting reasons that support our equipping our new chassis fleet with hub piloted disc wheels," he said.

The safety benefits are evident, in the form of OSHA statistics that since 1980 injuries have dropped by more than 70% while servicing wheel rims for multi-piece and single rim wheels alike, Hoehn said.

Still another factor is the difficulty in tire and rim mounting on two-piece wheels, which creates a disturbing appearance of wheels wobbling on the highway on some chassis.

"This improper mounting leads to excessive tire wear and premature tire failure that can be avoided with the use of one-piece wheels," he said.

The number of risks with multi-piece rims extends beyond mounting, said Rick Hawkins, Southeast area maintenance manager for P & B Intermodal.

He cited lock rings that are worn out, broken, or not matching the rims, a fact that’s critical because all the pieces must match the other and cannot be swapped out indiscriminately.

"If mismatched, they can come apart in an instant and without any kind of warning," he said. Water also can intrude between the tire flap and rim, leading to corrosion and weak welds, he added, creating still another difficulty

A particular risk, said Bernie Vaughan, EVP of administration and chief legal officer at FlexiVan, is corrosion-related failure — and possible separation — of mismatched lock rings and rims produced by different manufacturers.

Given the variety of potential risks tied particularly to multi-piece rims, several steps can be taken to lower the safety risk.

"We conduct thorough inspections of lock rings and rims to ensure they’re matched properly and have no corrosion damage," Vaughan said, in addition to conducting periodic audits of FllexiVan’s tire shops to ensure full compliance with the company’s proper handling procedures for bias ply tires mounted on two-piece rims. There also are monthly safety and educational meetings to make certain all staff is trained correctly by industry experts on the proper handling of tires, he added.

Jason Slegers, vice president of maintenance & repair and procurement for DCLI, also emphasized the importance of following proper OSHA procedures, including valuable information contained in a multi-piece rim matching chart produced by OSHA. IEPs can also address safety risks by requiring their contracted vendors to demonstrate how proper handling of multi-piece rims is being managed in their organizations, he said.

One of the most widely cited steps to enhance safety is converting to radial tires with single-piece rims.

The path of conversion from multi-piece to single-piece rims is taking various forms.

"DCLI continues to invest in radial tires, replacing multi-piece rims with single-piece rims throughout the U.S.," Slegers said, in part because price differences between new single and multi-piece rims are not a determining factor. However, converting to single-piece rims on existing chassis adds costs.

Vaughan said the issue of cost is critical for IEPs because tires are by far the single biggest expense for chassis owners.

"To reduce costs and meet market demand, FlexiVan has accelerated its program to convert its fleet to radial tires mounted on one piece rims," he said, with well over 50% of its chassis being converted, with plans for installation of single-piece rims on the entire chassis pool fleet by the end of 2020.

An important benefit, he said, is that radial tires offer both short and long-term cost benefits, therefore substantially reducing the cost of maintaining converted chassis overall.

P & B’s Hawkins elaborated on the differences between radial and bias ply tires with multi-piece rims, while noting the cost of fleet conversion has to be taken into consideration.

He noted that single-piece rims and tires have the advantage of longer life and lower repair expenses. He further elaborated on the costs related to multi-piece rims, including costly and time-consuming roadside repairs, out-of-service occurrences and inefficient driver usage resulting from downtime from those events, such as more repairs being needed from an operational standpoint. At the same time, multi-piece rims can cause significant safety risks, including accidents, injuries and fatalities caused by factors such wheel-end and hub failures, he added.

He recommended the automatic retirement of multi-piece rims after a certain number of years, and discarding any of those items with the slightest sign of wear or damaged parts. Also important are thorough examinations for rust, broken welds or bent parts and periodic inspections for those conditions.

Martin Summers, director of maintenance at Consolidated Chassis Management, said that as the chassis owners or contributors decide they want to convert to single-piece rims, that the equipment be installed whenever a wheel is replaced for damage. That process is being done through attrition, but that approach "doesn’t move the needle fast enough," Summers said.

An especially important fact in addressing tire handling and safety is training, Summers said.

"It is not as much the wheel as the individual mechanic working on it. If they follow the proper procedures, the likelihood of injury is far less. The largest risk is people taking short cuts when it comes to safety when airing up or removing tires," he said.

"It’s important to train every mechanic in proper procedures. Experienced guys may take a short cut and get injured. To a degree, you can’t do much about the short cuts — that’s human nature. You have to make sure that every mechanic understands that [the tire] can explode, because they may have the ‘it won’t happen to me’ mentality."

Whether the tire has single or multi-piece rims, it’s critical to take time to properly inflate and deflate tires and use a standoff device so they are not in the trajectory, thereby reducing the injury risk, Summers noted.

An important resource, Slegers and Vaughan noted, is the IANA Guide to Chassis Inspection and Repair, which provides detailed information on proper handling of multi-piece rims.

The annual IANA Business Meeting and EXPO provide opportunities for IEPs, vendors, facility operators, etc. to come together regularly to discuss and address this and other important issues, Slegers added.

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