Locomotive Occupant Safety
The FRA crashworthiness research program has a long history (See: Mayville, R.A., Stringfellow, R G., Rancatore, R.J., Hosmer, T.P., 1995, "Locomotive Crashworthiness Research, Volumes 1 through 5," DOT/FRA/ORD-95/8.1-8.5). Initially, the program focus was on passenger equipment but a February 1996 accident in Silver Spring, Maryland that resulted in several fatalities brought a powerful impetus to address the problems of train collisions and their consequences.
Freight railroads also took notice of the FRA crashworthiness initiative, studying the number of injuries and fatalities associated with rail collisions. As a result of this appraisal, the Association of American Railroads (AAR) developed a simple, one-page Locomotive Cab Standard for a short-hood wide-nose cab, (S-580-1989) that was partially motivated by a need to address an FRA regulation on the subject.
In 1996, the Rail Safety Advisory Committee (RSAC), a joint industry-labor railroad group, requested that an RSAC group re-examine the effectiveness of the simple AAR standard and in 1997 the Locomotive Crashworthiness Working Group was formed. After a protracted period of time, the group agreed to a new regulation (Federal Register / Vol. 71, No. 124 / Wednesday, June 28, 2006 / Rules and Regulations) which was approved in 2006 and would be effective only for new locomotives built after January 1, 2009. FRA supported the technical work of the RSAC group through the Volpe National Transportation Service Center.
Following these studies, accidents of significance were studied in depth by the RSAC committee where five major collision types were identified. Three years of collision data were catalogued and two collision scenarios were analyzed and the impact of proposed changes were assessed.
In 1998, it was recognized that additional research was needed to specifically test full-scale locomotive structures and to simulate the various collision scenarios in a manner that allowed for managing their outcomes to mitigate the severity of the resulting injuries and fatalities.
Technical Approach for Locomotive Crashworthiness Research Program
The technical approach used in this effort consists of four essential parts:
- Identify likely train collision scenarios and collision scenario assessment to explore alternate effective means of surviving these scenarios
- Static testing of locomotive crashworthiness components in a full-scale test machine
- Modeling of the collision scenarios so as to reasonably predict outcomes of accidents and to conduct parametric evaluations of designs and at alternate speeds
- Full-scale testing of locomotive and car structures to verify accident outcome projections
Much work in each of these areas has been accomplished and additional work remains to be done. A brief description of each area is given further on this page.
The Locomotive Crashworthiness Research Program analysis focus waso n developing a LS DYNA-based simulation capability and a full-scale locomotive cab structure static testing capability. With the excellent co-operation of the two major locomotive manufacturers, Electro-Motive Division and General Electric Comapny, both goals have been achieved. The locomotive test facility in Fitchburg, MA is shown in photo at left.
The simulation capability is also in place, samples of which can be seen below.
Typical locomotives available for train collision simulations
Typical freight car and vehicle models available for train collision simulations
Testing Areas of Locomotive Crashworthiness Research
- Static component strength and design evaluations
- Full-scale dynamic testing and simulations
- Crew injury mitigation
Full-scale tests for ten scenarios have been completed. All of the elements shown above were part of the program. For example, collision posts were instrumented with strain gauges for static tests in the test fixture. The same locations were used in full-scale dynamic testing.