Some dynamic considerations for agricultural tractor rollover

The potential for tractor rollover exists in some applications within agriculture. To help minimise the danger to the tractor driver Roll-Over Protective Structures (ROPS) were introduced some time ago along with corresponding international testing procedures. Some deaths and serious injuries resulting from failure of ROPS however still occur. This has led to recent renewed interest in tractor rollover research to gain an understanding of the processes involved. The impact that could potentially be experienced by the ROPS is a function of the energy available at the start of rollover. This paper presents some of the initial work on rollover by considering different initial conditions; in particular, the theoretical difference in available energy for lateral rollover on different planes together with the inclusion of forward velocity. Measured data pertaining to 102 narrow type tractors fitted with front ROPS, with mass variation between 700 and 2700 kg, was used to calculate the available energy. Some addition considerations complicate the analysis, for example, the coupling of forward momentum and lateral roll when forward velocity is included.