Hol-Mac Corporation

Hol-Mac Corporation

New Bumper Design meets Department of Transportation (DOT) Standards


Hol-Mac Corporation was founded in 1963 and produces Pac-Mac refuse and recycling equipment, Hammerhead Bumpers, hydraulic cylinders, and steel fabricated components in four modern facilities located in Bay Springs and Winona, MS. The facilities total over 600,000 square feet and employs over 800 workers.

The Challenge

The company realized that none of the existing vehicles in the market contained a rear bumper that met the current U.S. Department of Transportation (DOT) guidelines for preventing death and serious injuries from light duty vehicle impact to the rear of the truck. Therefore, a business opportunity existed to modify the current rear bumper and provide Hol-Mac with a distinct marketing advantage in the solid waste industry. The company approached engineers at the InnovateMEP Mississippi Center at Mississippi State University's Center for Advanced Vehicular Systems - Extension (CAVS-E) unit for assistance.

MEP Center's Role

InnovateMEP Center at CAVS-E partnered with the CAVS Research unit in Starkville. This was a challenging technical problem because the bumper had to be designed to minimize the effect of a rear end collision. The design problem was further complicated by the need for the bumper to automatically fold under the truck when the bed is tilted to empty its contents. Research engineers modified and analyzed the design in virtual space using advanced finite element analysis (FEA). The resulting design was physically tested at the CAVS laboratory to verify the bumper performance under actual loading conditions. This project was executed in a strongly collaborative manner involving university researchers, CAVS-E engineers, and Hol-Mac engineers. Several design change iterations were performed in order to achieve the new bumper design to meet DOT’s strength and energy absorption requirements. Detailed work included the design of testing fixtures by InnovateMEP Center at CAVS-E and fabrication of the fixtures and the prototype bumpers by Hol-Mac. The FEA based simulation outcomes were validated by the successful test results on the prototype bumpers.

This project was completed within a two month timeframe. Hol-Mac has incorporated the new bumper design into their product line and is the only company in its market with a bumper that meets D.O.T. rear impact standards. This has provided Hol-Mac with a significant competitive advantage.


• New bumper being installed on every vehicle
• Bumper performed as designed in a collision resulting in no serious injury or death to the driver of the car
• Winner of the Southern Growth Policies Board 2011 Innovator Award

“The new bumper design and testing has helped us continue to be an innovation leader with quality products for our industry. We value the InnovateMEP Mississippi affiliate Center at Mississippi State University's Center for Advanced Vehicular Systems - Extension (CAVS-E) unit and their resources, and consider them a partner in our success.”
Charles Holder, Founder & CEO