Other Reports

Technical Documentation: 2, 3, & 4 Axle Rigid Truck Curve Negotiation Model

  • 01
  • Jan
  • 1976
AUTHOR: K. R. Smith, R. D. MacMillan, G. C. Martin
SUBJECT: Track/Train Interactions
KEYWORDS: Friction Creep, Curving Modes, External Loads, Reaction Forces
ABSTRACT: [From the Introduction] An understanding of curve negotiation mechanics is vital from the standpoint of learning of the design and operating parameters that result in decreases and increases in the lateral reaction occurring between the wheel flange and rail, for it is this lateral load that results in wear on the wheel and rail, determines if a wheel will climb the rail during curving or if the entire track structure will shift. Aside from the more obvious considerations of tracking, lies, the importance of an understanding of curving from the design standpoint. It must be known how much clearance should exist in a rigid framed truck to allow negotiation of sharp curves and what loads may be expected, so that proper design for strength can be accomplished. The objective, then, of this study is to develop a technique by which the wheel/rail interaction associated with the negotiation of a section of curved track by a rigid framed locomotive truck may be predicted for various arbitrary operating conditions, such as: any combinations of individual axle loads; any combinations of individual wheel loads; operation at over or under balance speed; development of a tractive or braking effort; and train operation forces which may result in buff or drag force components at the truck center bearing. Section 2 discusses the friction-creep phenomenon and its solution, while Section 3 gives an explanation of the various possible curving constraint modes. In Section 4, the external loads to be considered are outlined, and Section 5 discusses the physical model to which they will be applied. Sections 6 and 7 describe the method of solution and the results of that solution, respectively.