The results of analyses conducted to determine the effectiveness of structural and interior train
design strategies in protecting occupants during collisions are presented. Structural design
approaches considered include the conventional design approach of requiring a uniform minimum
longitudinal strength, and the crash-energy management design approach which provides for sacrificial
crush zones in the unoccupied areas of the train. Interior protection strategies considered include
occupant restraint and compartmentalization.
The analyses show that for typical train-to-train collisions at closing speeds above 70 mph, the
crash-energy management design is more effective than the conventional design in preserving the
occupant volume. For closing speeds below 70 mph, both strategies are equally effective in preserving
occupant volume. The crash-energy management design results in gentler secondary impacts for trainto-
train collisions than the conventional design for occupants in cars behind the first coach car, at
all speeds analyzed.
Estimates of the probability of fatality resulting from secondary impacts are presented for each of
the interior configurations and restraint systems modeled. These estimates are based upon the Head
Injury Criteria (HIC), chest deceleration and axial neck load criteria that are used in assessments of
automotive vehicle crashworthiness. The analysis results indicate that compartmentalization is as
effective as a lap belt in minimizing probability of fatality for the 50th percentile male simulated
when the seats are arranged in forward-facing rows.