Application of New Lubricant and Modifier Formulations for the Reduction of Wheel Squeal Noise Under Freight and Passenger Service
Date
1999-09
Journal Title
Journal ISSN
Volume Title
Publisher
American Railway Engineering Association
Abstract
Wheel sequel noise on curved track is a serious problem in residential areas where the
tracks are near or adjacent to homes and residences. This was the case in a Southern California
community that was adjacent to a Southern Pacific Railroad mainline that carried both freight
and passenger traffic. The specific wheel squeal problem was associated with the negotiation of
the moderate curved track by the mix of traffic at a range of speeds and operating conditions.
While significant noise levels were recorded by all of the traffic, to include commuter
and inter-urban passenger traffic, the highest levels of noise were recorded by intermodal freight
equipment, both trailer and container carrying. These n0ise levels were of significant magnitude
and resulted in numerous complaints as well a'$ follow up lawsuits from the residents.
In order to address this noise problem, the dynamics of the wheel/rail interaction
mechanism was examined and a two part solution applied. The solution consisted of using a low
coefficient of friction modifiers on the gage face of the high rail of the curve(s) in conjunction
with a high positive coefficient of friction modifiers on the top of the rail head on both the high
and low rails. In this configuration, lateral slip of the wheel tread across the rail head was
significantly reduced, together with the more traditional flanging effects 011 the gage face of the
high rail. The result was a significant reduction in the level of noise generated by all of the
traffic types. In order to achieve this dual application at specific locations on the rail head, a high rail
vehicle mounted application system was developed and utilized. The hi-rail based system
allowed for a uniform and accurate application of the friction modifiers onto the rail. However,
the friction modifiers deteriorated with time and traffic (as a function of the number of axle
passes), and as such had to be reapplied on a regular and ongoing basis.
This paper describes the development and application of this combination of friction
modifiers to the high noise curve(s) as well as the determination of the rate of degradation of the
friction modifiers under traffic. The testing of the Friction Modifiers (Lubricants) performance
led to the development of a well defined friction modifier effectiveness degradation curve which
served as the basis for an ongoing program of friction modifiers aimed at keeping the level of
noise below a defined threshold. In addition, the need for a "reasonably long" interval between
friction modifier applications led to the development of an extended life version of the friction
modifiers that made them appropriate for use in an ongoing maintenance application.
Description
Keywords
Wheel squeal noise, Passenger Service, Gage face
Citation
Zarembski, A.M. Chiddick, A.S. “Application of New Lubricant Formulations For The Reduction of Wheel Squeal Noise Under Freight and Passenger Service”, American Society of Mechanical Engineers Joint Technical Conference with AREMA, September 1999