Development and Evaluation of a Computer-Based ROPS Design Program

Tractor overturn is the leading cause of agricultural fatalities in the U.S. Most of these fatalities can be eliminated using a rollover protective structure (ROPS) and a seatbelt. Unfortunately, not all agricultural tractors designed to support ROPS have ROPS designs. A computer-based ROPS design program (CRDP) was developed and successfully tested to provide quick and simple two-post, rear axle-mounted ROPS designs based on SAE Standard J2194. The program uses the tractor dimensions and mass to calculate the dimensions needed for ROPS components. Excel was used as the framework to provide the input, calculation, and ROPS drawing worksheets. Three ROPS (for Massey Ferguson 265, Long 460, and Allis Chalmers 5040 tractors) were designed and constructed using the CRDP. Static rear, side, and vertical tests were conducted based on SAE J2194 on two of the ROPS. All ROPS performance deflection (RPD) tests were less than the ROPS allowable deflection (RAD), indicating that the ROPS passed the static tests. The third ROPS was successfully mounted on the tractor axle housing within one hour, demonstrating the ease of installation using a bolted corner bracket design. Although the CRDP provided quick and simple ROPS designs, this program does not eliminate the requirement to conduct and pass the performance tests for ROPS designs specified in OSHA and SAE standards.