With the potential for tremendous growth in the passenger rail

industry, providing for the safety of the train-riding public and

the crews who transport them becomes an ever-greater priority.

To provide for safety while making best use of its resources

and to facilitate passenger rail industry growth, the Federal

Railroad Administration (FRA), in consultation with the rail

industry, has developed alternative Criteria and Procedures for

assessing the crashworthiness and occupant protection

measures of rail passenger equipment. These Criteria and

Procedures are intended to be applicable to a wide range of

equipment designs, particularly equipment designs not

complying with current U.S. standards and regulations.

Because the latest technology in rail equipment

crashworthiness has been used to develop the Criteria and

Procedures, aspects of the resulting Criteria and Procedures are

fundamentally different from their corresponding regulations.

While technical results from sophisticated analyses and tests

have been necessary, judgment was also needed to develop the

Criteria and Procedures. This judgment was provided by the

Engineering Task Force (ETF), and ultimately accepted by

FRA. The ETF is a government/industry working group,

organized under the auspices of the Railroad Safety Advisory

Committee (RSAC).

The Criteria and Procedures are intended to provide an

engineering-based methodology for comparing the

crashworthiness of alternatively-designed equipment with that

of compliant designs. One particularly important aspect of

passenger car crashworthiness is occupied volume integrity

(OVI). It is essential that all passenger vehicles meet some

base minimum level of OVI. A primary goal of

crashworthiness is to maintain a volume for occupants to ride

out a collision. In the U.S., this base level has been

demonstrated through a vehicle’s ability to react a quasi-static

load of 800,000 pounds along its line of draft without

experiencing permanent deformation. This car-level

requirement has existed, in some form, since the early 20th

century. However, alternatively-designed vehicles may not be

able to demonstrate the ability to support this load, but may still

prove to be equivalently crashworthy. Based on analyses

performed on conventional and alternatively-designed

passenger equipment, three options have been developed to

demonstrate the OVI of alternatively-designed equipment.

These options consist of three load magnitudes placed along

the collision load path with a corresponding pass/fail criterion

for each load. OVI may be demonstrated by sustaining an

800,000 pound load with no permanent deformation, a

1,000,000 pound load with limited permanent deformation, or a

1,200,000 pound load without exceeding the crippling load of

the occupied volume.

This paper discusses the pass/fail criteria associated with each

option, the analysis and test procedures used in applying each

option, and the technical basis used in developing the Criteria

and Procedures for OVI evaluation. By applying such

techniques, the results of evaluations of alternatively-designed

equipment can be compared with the Criteria values for

compliant designs. In this manner, the crashworthiness

performance of alternatively-designed equipment can be

assessed relative to the performance of compliant designs. A

companion paper to this one discusses the development of the

train-level Criteria and Procedures.