WHITE PAPER: Wheel Chocks: Urethane vs. Rubber

Ongoing testing and side-by-side comparison demonstrate urethane chocks are more resistant to damage, are easier to carry and deploy and provide greater safety capabilities than similar rubber chocks.

Wheel chocks represent critical safety equipment in industrial, mining and aviation settings. Their proper and sustained use ensures that lives are protected, and such use is required by the DOT, NFPA, SAE and MSHA. There are multiple wheel chocks on the market, including those constructed of aluminum, wood, rubber and urethane. Federal guidelines do not generally specify the type of material that must be utilized for industrial applications; however, rubber and urethane are the two most commonly selected by safety managers.

There are multiple wheel chocks on the market, including those constructed of aluminum, wood, rubber and urethane. Federal guidelines do not generally specify the type of material that must be utilized for industrial applications; however, rubber and urethane are the two most commonly selected by safety managers.

Too often the final decision as to which chock to use is determined by chock cost. Unfortunately, this methodology is short-sighted when a long-term cost analysis is conducted as rubber has been shown to be less resistant to damage or breaking than urethane counterparts, thus requiring more frequent replacement and resulting in a higher cost.

 

 

A Comparison of Urethane Chocks versus Rubber Chocks

Checkers Industrial began developing and testing urethane chocks in the late 1980s with a significant investment that required extensive engineering and design. Testing initially included the comparison of the new urethane products against chocks made of various materials, including both metal and wood, as well as the more commonly utilized rubber.

 

Greater Strength and Flexibility: Initial independent testing showed “and repeated subsequent testing has confirmed” the urethane chocks consistently had a higher load-bearing capacity than their rubber counterparts and were better able to absorb high impacts from heavy machinery. While mimicking the flexibility of rubber, urethane chocks also showed significantly greater strength and resistance to abrasion. Over time, the urethane chocks also proved to better withstand harsh working conditions and extreme weather.

 

Improved Ease of Use: Because of the risk of human error in the placement of wheel chocks, ease of use was also considered and evaluated by Checkers in multiple testing environments. Urethane chocks have been shown to be 20 to 50 percent lighter in weight than similarly sized rubber chocks, providing ease of carrying and transport. Urethane construction also allowed the molding of ANSI-compliant chocking guidelines into the chocks themselves; an option not available in traditional rubber manufacturing. Molding of built-in carrying handles was also shown to be of benefit to workers in multiple industrial applications.

 

Superior On-Site Visibility: The use of urethane in chock manufacture has allowed other features to promote safety and protect both lives and assets. One of the most impactful is the ability to produce the chocks in high-visibility safety colors, which further aids in proper chock placement as well as raising awareness for those walking or driving around equipment secured by these components. This is in stark comparison to the rubber chocks, which have not successfully been manufactured to incorporate safety colors.

WHITE PAPER: Testing Cable Protector YJ2-400 in a Real-World Setting

While the technology surrounding modern mining and construction continues to evolve, there are some things that will always remain the same: the havoc wreaked on sites by trucks and heavy equipment. Of particular concern are the cables, lines, and hoses frequently crossing these sites and the expense required to purchase them initially and, when damaged, to replace them.

Current Status

For years, many mine sites have tried to protect their cables by building an overhead system that utilizes poles secured in old rubber tires filled with concrete. This make-shift system poses high safety risks to both people and equipment as trucks can easily get hung up on the cables. Over the last two decades, the market has introduced crossover pads and ramps in an effort to protect large cables and hoses at the ground level. While some have shown promise in the short-term, most have lacked the necessary durability needed for long-term use. As such, they eventually become a safety liability instead of a reliable piece of safety equipment.

In addition, past designs have proven inconvenient to use and difficult to transport. Overly heavy and awkward to move, they have also lacked expansion capabilities.

The most common weaknesses include:

  • inability to withstand extreme changes in temperature
  • cracking, warping or other damage caused by frequent, heavy loads
  • channel systems ill-suited to manage and protect multiple hoses or cable types and sizes
  • lack of adaptability to expand or reduce the size of the crossover units as needed

 

Testing cable protector YJ2-400

Yellow Jacket Heavy Duty Cable Protectors were introduced in 1991. As part of this line, the Yellow Jacket YJ2-400 extreme modular crossover system was created for industrial use, including construction sites and commercial environments. Constructed of all-weather polyurethane, the YJ2-400 had previously been shown to be significantly lighter than rubber protectors but rated to last up to 5 times as long. Since the company’s inception, testing of products in real-world settings has been critical in the formulation of new uses or in the refinement of existing designs. In 2012, for example, Checkers Industrial announced the recent testing of its wheel chocks used in the mining industry. That testing, supervised by multiple engineers and safety managers, proved the ability of the chocks to hold a 400-ton mining haul truck despite a 24 percent (24%) reduction in their weight. Given the results of that testing, the company opted to test the capabilities of the YJ2-400 under similar conditions.

On May 13, 2013, testing of the YJ2-400 was completed in an outdoor environment utilizing a Liebherr mining truck weighing 374 tons on a zero percent (0%) grade. Testing of the product was supervised by engineer Greg Widgery, who reported:

“The haul truck pulled across the cable protectors with the front left wheel and parked the left rear duals directly on top of the cable protectors and stayed parked for a count of one minute. The cable protector did not deform or break in any way. Test Results: Passed”

The May 2013 tests were also filmed and photographed, evidencing the ability of the YJ2-400 to withstand the repeated pressures placed on it. View Test Video

According to specs provided by Checkers, the YJ2-400 features two channels designed to protect cables and/or hoses up to 3.75″ in diameter. The system is modular, with each protector being 36″ in length and featuring dog-bone connectors for ease of expansion while maintaining portability.

The heavy duty protector features a thicker, reinforced version of the company’s standard hinged lid, which also features diamond-plate tread surface to improve traction for higher-volume traffic by even the largest vehicles. This aids in potential life-saving benefits of the system, as it reduces the likelihood of lid fracture, cable damage and electrical wiring exposure.

In the workplace, the primary benefits of the YJ2-400 were found to be:

  • Ease of installation
  • Ease of transport
  • Mobility
  • No chance of snagging overhead lines with vehicles
  • Unlimited linear installation, no center support needed to span long distances
  • Temporary solution (no need for semi-permanent installation)

Specifications

Operating temps range from 40 to 120 degrees Fahrenheit (-40 to 48 degrees Celsius). View more details such as: load capacities, size and other specs.

Summary

Testing conducted on the YJ2-400 in a real-world setting, as well as previous product development research evidences the product to be appropriate for use in industrial, mining and military environments. Its ability to repeatedly withstand even the harshest conditions, modular construction and capacity to house and protect multiple hoses or cables as large as 3.75″ in diameter further indicates the appropriateness of the use of the YJ2-400 in these environments, making it a cost-effective solution for safety managers, engineer, and supply chain managers.