Zarembski, Allan M.2021-11-012021-11-011996-03Zarembski, A. M., “Development of Rail Gage Face Angle Standards to Prevent Wheel Climb Derailments”, American Railway Engineering Association Annual Technical Conference, Chicago, IL, March 1996.0096-0268https://udspace.udel.edu/handle/19716/29329Rail represents that part of the track structure that first "meets" the wheel and thus directly carries the wheel/rail loading imposed by the traffic operating over that track. As such it is subject to a significant level of dynamic loading; vertical, lateral, and longitudinal, and it must support these loads safely and economically. This requires an adequate level of strength of the rail, together with a proper support capability of the wheels. Traditional rail standards, and in particular rail wear standards, are generally strength based, so as to insure that the rail can adequately support this traffic without failure, e.g. fracture under traffic. By combining strength based wear standards with ongoing monitoring of fatigue failures (fatigue standards), railway maintenance officers define a zone of safety for the rail, beyond which the rail must be removed from track. In addition, rail represents a major cost area in the maintenance of the track structure, representing, for main line freight railroads, as much as 50% of the total variable cost of track maintenance. Thus, the decision as to when and where to replace the rail is an important one, not only from the point of view of safety, but also from the point of view of cost and economics. Leaving rail in track for too long can result in a service failure and the potential for a derailment. Removing a rail prematurely translates into significant costs for the railway. Thus maintenance officers must maintain a proper balance between safety and cost control. In the case of rail, this is done through the use of cost effective standards for the rail that maintains an adequate margin of safety for the track structure. To add to the complexity of maintaining these adequate standards, evolving operating conditions and maintenance practices have resulted in significant changes in the way railways determine when rail should be replaced in track. These changes stem directly from changes in maintenance of way practices and materials that have occurred during the past two decades, i.e. better higher strength rail, cleaner steel, improved lubrication and grinding practices, etc. as well as from changes in operating practices, i.e. heavier trains, increased axle loads, higher operating speeds, etc. The net result of these changing practices has been the extension of the service life of the rail, and often an overall reduction in rail maintenance costs over that life [1]. Thus, for example, the decreasing importance of rail joints, and the dramatic extensions of rail life through the use of effective lubrication, grinding, and improved steels [2]. While increasing axle loads have resulted in an increased emphasis of fatigue defects, rail wear remains a key replacement criterion for all rail systems to include freight, passenger, and transit systems. Thus, the importance of maintaining appropriate and adequate rail wear standards likewise remains. Recently, increased attention has been paid to the wheel/rail dynamic environment of the track structure, with major emphasis placed on the shape of the wheel and the rail [3]. This has led to a better understanding of several classes of derailments, to include those wheel climb derailments associated with excessive wear of the rail and/or the wheel [4]. This has become of even greater importance in recent years, as several classes of derailments have been associated with these levels of wear. It is the focus of this paper to examine those conditions, and to identify those rail wear criterion and standards that can reduce the potential for occurrence of these classes of wheel climb derailments.DerailmentWheel climb derailmentsArticle