On the feasibility of life-saving locomotive bumpers. (April 2016) - Paden, Brad E.
Abstract : Highlights: Four abstract locomotive bumpers are proposed for pedestrian protection. A Head Injury Criterion (HIC) of less than 200 is achievable for all four bumpers. Life-saving bumper lengths as short as 2 m on a 22 m locomotive appear feasible. Abstract: Motivated by the thousands of pedestrians killed each year in train impacts, this paper investigates the life-saving capability of four high-level locomotive bumper concepts. The head motions produced by the four concepts are modeled as one or two square acceleration pulses and are analyzed using the Head Injury Criterion (HIC). Surprisingly, the analyses show that all four concepts can achieve HIC values of less than 200 for an impact with a locomotive traveling at 100 km/h. Two of the concepts eject the pedestrian trackside with at a velocity of roughly 40 km/h and the risk of ground-impact injury is discussed in the context of related automobile accident data. The computed bumper lengths are a fraction of the overall length of a locomotive and are thus feasible for practical implementation. One concept involves an oblique impact and the potential for rotational head injury is analyzed. This basic feasibility research motivates future investigations into the detailed design of bumper shapes, multi-body pedestrian simulations, and finite-element injury models.