on
Commuter Car Safety
Regarding:
Wheel Running Surface
Manufacture And Reprofiling Contour
Prepared by the Wheel/Rail Interface Working Group of the
Passenger Rail Equipment Safety Standards (PRESS) Task Force
November 3, 1998
I. Introduction:
This bulletin provides background information on interim actions that should be
applicable to all APTA commuter rail operators. This document is intended to aid in the
understanding and use of technical information deemed of an urgent nature by APTA members.
The specific information in this bulletin addresses assurances that minimum wheel
flange angle is present on wheel profiles intended for use on passenger vehicles.
The intended audience includes the following:
- Individuals or organizations that specify profiles for new wheel procurement used on
passenger rail vehicles
- Individuals or organizations that specify or control maintenance practices that
affect wheel profiles on passenger rail vehicles
- Suppliers interested in providing wheels for passenger rail vehicles
- Suppliers interested in providing wheel maintenance equipment service and tools for
passenger rail vehicles
This bulletin is intended to assist individuals and organizations in procurement and
maintenance of wheels to ensure that the running surface profile consistently minimizes
the potential of wheel climb derailment without compromising other aspects of track
worthiness.
The PRESS Task Force recognizes that this bulletin is not enforceable by APTA or any
government agency. This document is provided to the North American Passenger rail
community in the spirit of self-regulation and self-policing.
II. Participants
This bulletin represents a consensus opinion of the PRESS Task Force, Mechanical
Subgroup, Wheel/Rail Interface Task Group. At this writing the group consisted of the
following full APTA members:
NAME / ORGANIZATION / TITLE
Mark Campbell / Metro North Railroad / Task Leader - Director, Trng
Dave Carter / New Jersey Transit / Director, Capital Projects
George Chipko / New Jersey Transit / Mechanical Engineer
Dave Warner / Amtrak / Sr. Engineer
Mike Trosino / Amtrak / Engineer - Track
Jim Dwyer / Port Authority of Allegheny Cty. / Mgr., Technical Support
Frank Maldari / Long Island Railroad / Mechanical Engineer
The following suppliers, consultants and government agencies were also represented:
NAME / ORGANIZATION / TITLE
John Leary* / TTCI / Manager-Bus Development
Gary Carr / U.S. DOT, Volpe Center / Mechanical Engineer
Chris Holliday / STV, Incorporated / Project Manager
Magdy El-Sibaie / U.S. DOT, FRA / Asst. Program Mgr.
Ken Hesser / LTK Engineering Services / Mechanical Engineer
Kevin Kessler / ENSCO Dep. / Division Mgr.
Tom Peacock / APTA / PRESS Task Force Coord.
John Pearson, Jr. / LTK Engineering Services / Sr. Mechanical Engineer
Alan Zarembski / Zeta-Tech Associates / President
*Principal Author-Telephone 719-584-0572, Internet john_leary@ttci.aar.com
III. Issues
The most beneficial wheel profile for any particular operating environment must
optimize several parameters so that the resulting service performance provides:
1. safety from derailment under adverse but realistic operating conditions
2. maximized wheel and rail life
3. stable vehicle performance over the range of normal train speeds; and
4. smooth negotiation of special track work
This bulletin encourages the presence of a minimum flange angle on wheel profiles for
use on passenger vehicles. Maintaining a specified minimum flange angle will assure
maximum compliance with issue number 1 above while not compromising other wheel
characteristics or performance parameters.
In the continuing pursuit of maximizing passenger and operator safety, and minimizing
risk of personal injury and property damage, the following details are offered as interim
guidelines until definitive wheel profile standards and practices are developed and
approved by the APTA PRESS Task Force voting membership.
This Technical Bulletin provides guidance to organizations on reducing the probability
of wheel climb derailments by suggesting a minimum wheel flange angle of 72° (suggested tolerances are +3.0° and -2.0° ). This is the nominal angle
achievable with the commonly used AAR 1:20 Narrow Flange Profile. Figure 1. illustrates
the baseline for the flange angle reference.
Figure 1.
The Wheel Rail Interface Task Group recognizes that within the specified tolerances,
lower angles may be present, however it is the opinion of this group that a nominal angle
of 72° is practically obtainable during manufacture and
recontouring. This has been confirmed through communication with wheel manufacturers and
recontouring equipment suppliers as well as measurements carried out on a representative
cross-section of commuter rail properties. In addition to the need for a minimum of 72°, it is recommended that this angle be achieved at the gage point,
3/8 inch above the standard base line, to assure that it will come into rolling contact
with the rail should the wheel flange begin to climb the rail.
Go to
part 2
Some of these pages may include links to documents in the Adobe PDF format. Please download the Adobe PDF reader if you have not already done so.
