The development of a test methodology for the determination of cricket batting helmet performance when subjected to ballistic impacts

The study presented in this paper was conducted in support of the development of a proposed revision to a cricket helmet certification test standard. Helmets were impacted between the peak and faceguard by ‘projecting’ balls at them at velocities up to 80 mph. The velocity at which the balls penetrated between the peak and the faceguard (or grille) for the various permissible peak‐grille gap settings for each helmet was recorded. The study progressed to compare these penetration velocities against the equivalent found when ‘game‐aligned’ alternate (drop) test methodologies were used. The results demonstrate that the penetration velocities are considerably lower than those that might be observed in play. As peak‐grille gap settings were reduced, penetration velocities increased as expected but, significantly, balls were able to penetrate despite gap settings, on occasion being considerably smaller than the ball diameter. The penetration velocity was also found, as expected, to vary with the stiffness of the ball with increased ball stiffness leading to reduced penetration velocities. When comparing penetration velocities against those found using the alternate methodologies, significant differences were found, suggesting that such methodologies cannot be used to reliably evaluate the performance of helmets to ball impacts occurring in this particular region.