Development of airbags for locomotive crew protection

The Federal Railroad Administration sponsored this work to examine the feasibility of protecting freight locomotive crew with restraint systems, such as airbags, optimized to specific conditions to which locomotive operators are exposed to. Finite element simulations and full-scale collision tests were conducted for injury mitigation evaluation of the crew with and without airbag protection. Computer simulations using MADYMO were utilized to optimize the airbag size, shape, fabric permeability, tethers and vent holes for adequate inflation duration. Based on previous collision tests and historical data, a trapezoidal crash pulse of 12 g over 0.25 seconds was used in this study. Full-scale tests simulating real world collisions were performed to study the performance of the designed airbags on locomotive operators. Dynamic loads and accelerations were measured on two identical anthropomorphic test devices (ATDs), one with the console mounted airbag and the other without an airbag, symmetrically placed in a freight locomotive at a speed of 30 mph in direct collision with a hopper car consist. The results showed that with no airbag present, the occupant experiences significant head, chest and lower abdomen injuries. When a console mounted airbag was used, the injuries were significantly reduced to well below the tolerance limits. The study also showed that the new technologies and methods developed in the design of airbags for the automobile industry can be adapted with minimum modifications for locomotive crew protection.