United States Department of Transportation
About
i
Vehicle track interaction safety standards
-
2014-04-02
[PDF-2.89 MB]
Details:
-
Alternative Title:Proceedings of the Joint Rail Conference, April 2-4, 2014, Colorado Springs, CO.
-
Creators:
-
Corporate Creators:
-
Subject/TRT Terms:
-
Publication/ Report Number:
-
Resource Type:
-
Geographical Coverage:
-
Corporate Publisher:
-
Abstract:Vehicle/Track Interaction (VTI) Safety Standards aim to
reduce the risk of derailments and other accidents attributable
to the dynamic interaction between moving vehicles and the
track over which they operate. On March 13, 2013, the Federal
Railroad Administration (FRA) published a final rule titled
“Vehicle/Track Interaction Safety Standards; High-Speed and
High Cant Deficiency Operations” which amended the Track
Safety Standards (49 CFR Part213) and the Passenger
Equipment Safety Standards (49 CFR Part 238) in order to
promote VTI safety under a variety of conditions at speeds up
to 220 mph. Among its main accomplishments, the final rule
revises standards for track geometry and enhances qualification
procedures for demonstrating vehicle trackworthiness to take
advantage of computer modeling.
The Track Safety Standards provide safety limits for
maximum allowable track geometry variations for all nine FRA
Track Classes — i.e., safety “minimums.” These limits serve to
identify conditions that require immediate attention because
they may pose or create a potential safety hazard. While these
conditions are generally infrequent, they define the worst
conditions that can exist before a vehicle is required to slow
down. To promote the safe interaction of rail vehicles with the
track over which they operate (i.e. wheels stay on track, and
vehicle dynamics do not overload the track structure, vehicle
itself, or cause injury to passengers), these conditions must be
considered in the design of suspension systems. In particular,
rail vehicle suspensions must be designed to control the
dynamic response such that wheel/rail forces and vehicle
accelerations remain within prescribed thresholds (VTI safety
limits) when traversing these more demanding track geometry
conditions at all allowable speeds associated with at particular
track class.
To help understand the differences in performance
requirements (design constraints) being placed on the design of
passenger equipment suspensions throughout the world,
comparisons have been made between FRA safety standards
and similar standards used internationally (Europe, Japan, and
China) in terms of both allowable track geometry deviations
and the criteria that define acceptable vehicle performance
(VTI safety limits). While the various factors that have
influenced the development of each of the standards are not
readily available or fully understood at this time (e.g.,
economic considerations, provide safety for unique operating
conditions, promote interoperability by providing a railway
infrastructure that supports a wide variety of rail vehicle types,
etc.), this comparative study helps to explain in part why, in
certain circumstances, equipment that has been designed for
operation in other parts of the world has performed poorly, and
in some cases had derailment problems when imported to the
U.S. Furthermore, for specific equipment that is not
specifically designed for operation in the U.S., it helps to
identify areas that may need to be addressed with other
appropriate action(s) to mitigate potential safety concerns, such
as by ensuring that the track over which the equipment is
operating is maintained to standards appropriate for the specific
equipment type, or by placing operational restrictions on the
equipment, or both.
In addition to these comparisons, an overview of the new
FRA qualification procedures which are used for demonstrating
vehicle trackworthiness is provided in this paper. These
procedures, which include use of simulations to demonstrate
dynamic performance, are intended to give guidance to vehicle
designers and provide a more comprehensive tool for safety
assessment and verification of the suitability of a particular
-
Format:
-
Collection(s):
-
Main Document Checksum:
-
File Type:
Supporting Files
-
No Additional Files
More +
