Investigation into and design of an automatic restraint system for ROPS-equipped off-road vehicles

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Virginia Tech


Agriculture consistently ranks as one of the most dangerous occupations based on an overall work death rate. Tractor overturns, by far the single largest cause of death on farms, account for approximately 19% of all on-farm deaths. The concept of a Roll-over Protective Structure (ROPS) came into existence in 1971 and is designed to form a protection zone for the operator. However, the only way that the operator will stay in the zone is by using a seatbelt or other restraint system.

A survey on tractor seatbelt usage was undertaken. Results indicate that only 13% of operators wear seatbelts half or more of the time and 61% report never wearing one. The reasons for these practices are a combination of factors: too much inconvenience, time consuming, an old habit of not wearing one, and a feeling that there is no danger. However, even in the face of such negativity, the survey revealed that 65% of the operators were neutral or approved of the idea of an automatically closing seatbelt.

An automatically closing restraint system prototype was designed and built. The system was found to be costly ($560.00) and the potential for mass retrofitting was found to be very limited. However, an automatically closing seatbelt seems to be a viable solution to the problem of operators being unwilling to use the seatbelts provided.