Rollover stability of tank trucks, test and calculation requirements based on ECE 111 regulation

This paper describes our experience in the application of Regulation UN-ECE No. 111, regarding the rollover stability of tank vehicle categories N and O, describing the difficulties encountered in applying the test and calculation methods and presenting some proposals to enhance the precision of the calculation method. The first part is a statistical analysis of accidents of hazardous cargo tank trucks in Spain. The second part is a categorisation of vehicle types and their stability determination based on R111 requirements. Many parameters are considered, like filling level, height of the lateral supports for the wheels during tests, and some modifications in the calculation method. Finally, in order to reduce the difference between test and theoretical results regarding the rollover threshold, two approaches are described: one calculates the effective track width and the other represents an alternative detailed model, based on planar 5-degree of freedom sections representing the axles of the vehicles, c...