As part of an ongoing passenger rail crashworthiness effort,

a full-scale impact test of a train with crash energy management

(CEM) passenger cars was conducted on March 23, 2006. In

this test, a train made up of a CEM cab car, four CEM coach

cars, and a locomotive impacted a stationary train of similar

mass at 30.8 mph. This test included five occupant experiments

on the cab car and the first coach car to evaluate occupant

injury risk and seat/table performance during the collision

using anthropomorphic devices (ATDs).

Three occupant protection strategies were evaluated in these

occupant experiments. Forward-facing intercity seats were

modified to reduce the high head injury risk observed in a

previous test. Prototype commuter seats, included in both

forward-facing and rear-facing orientations, were designed to

mitigate the consequences of higher decelerations in the lead

two CEM cars. Improved workstation tables, tested with two

different advanced ATDs, were designed to compartmentalize

the occupants and reduce the upper abdominal injury risk to the

occupants.

Similar experiments were also conducted on the two-car

impact test of CEM equipment [1]. The experiments described

in this paper were conducted to evaluate the level of occupant

protection provided by seats and tables that were specifically

designed to improve crashworthiness. Pre-test analyses

indicated that the occupant environment would be more severe

for the CEM test than for the comparable test of conventional

equipment. The environment in the leading cab car was

predicted to be similar to a 12g, 250 millisecond triangular

crash pulse. The environment in the first coach was predicted to

be comparable to an 8g, 250 millisecond crash pulse.

To aid the design of the occupant experiments, occupant

response models were developed for each of the occupant

experiments using MADYMO. These models were developed

for the previous two-car CEM full-scale test and adapted to the

newly designed commuter seats and tables. Predictions of the

occupant response during the CEM train-to-train test were

developed before the test. The models were subsequently finetuned

to better agree with the test data, so that many different

collision scenarios may be simulated.

Most of the test results were similar to the pre-test

predictions. The modified intercity seats successfully

compartmentalized the occupants. The risk of both head and

neck injury, however, were above the respective injury

threshold values. In the forward-facing commuter seat

experiment the impacted seat experienced a partial failure of

the seat pedestal attachment, resulting in loss of

compartmentalization. The attachment failures occurred

because the seats weren't fabricated as designed. However, the

occupants were still compartmentalized, and the injury criteria

were within survivable levels. The rear-facing commuter seat

experiment experienced a more significant failure of the seat

pedestal attachment, resulting in a loss of

compartmentalization. The attachment failures likely occurred

because the seats were not fabricated as designed and the

collision was slightly more severe than predicted. To assure that

this failure mode is prevented in the future, a more robust

attachment is currently being developed. It will be tested quasistatically

and dynamically to demonstrate its effectiveness. The

improved workstation tables successfully compartmentalized

the occupants while limiting the injury risk to acceptable levels.