A new method for checking the driving visibility on hydraulic excavators

A survey carried out by the ‘Caisse Nationale d'Assurance Maladie’ (French National Insurance Fund) on serious and fatal accidents in which earth-moving machines were implicated showed that one third of these accidents were due to insufficient driving visibility. A draft standard to define visual at the operator's position based on the projected shadows method was submitted to ISO. The ISO test method has been applied to 15 different hydraulic excavators. At the same time, INRS (National Institute of Research and Safety) worked out a novel approach based on photography of the visual field and applied it to the 15 hydraulic excavators in the same conditions. The purpose of this study is to compare the results and disadvantages of the two approaches for controlling applicability of the ISO Standard draft to hydraulic excavators. There is no correlation between the two techniques at all concerning front visibility, which indicates that the ISO draft is deficient. It only analyses one circular line rather than the full surface, which should be the more valid approach.