The influence of train type, car weight, and train length on passenger train crashworthiness

Crash energy management (CEM) is a type of equipment design that is intended to protect occupant space during a collision. Structures at the front and back of each car act as crumple zones that absorb the collision energy. CEM is intended to distribute the damage from a collision throughout a consist to unoccupied areas. This paper describes how factors that vary in the operation of passenger trains affect the crashworthiness performance of conventional and CEM trains. Crush and secondary impact velocity are introduced as measures of crashworthiness performance. The collision scenario selected for this study includes a standing locomotive-led freight train and a cab led passenger train with an initial velocity. The passenger train contains either all CEM or all conventional equipment, and is either a multiple unit (MU) train with no locomotive, or push-pull train. The influence of consist type (MU or push-pull,) car weight, and the number of cars in a train-to-train crashworthiness are explored. The crashworthy speed is that speed at which all of the passenger train occupants are predicted to survive in the selected collision scenario. For both conventional and CEM equipment, MU trains have slightly higher crashworthy speeds than push-pull trains. Trains with heavier cars have lower crashworthy speeds for both conventional and CEM equipment. Longer trains also have lower crashworthy speeds, although the decrease crashworthy speed is less for CEM trains than for conventional trains. In all cases evaluated, the CEM trains have significantly higher crashworthy speed than the conventional trains; the crashworthy speed of CEM trains is typically twice that of conventional trains, and in some cases is nearly three times greater.