Limiting Forces on Transit Trucks in Steady-State Curving

Volpe National Transportation Systems Center, Technical Reference Centerhttps://doi.org/10.21949/15270141981PDFTech ReportGreif, R.Weinstock, HerbertJohn A. Volpe National Transportation Systems Center (U.S.)United States. Urban Mass Transportation AdministrationUnited States. Urban Mass Transportation AdministrationUnited StatesCar trucks (Railroads)CurvatureFlangesForceMathematical modelsRail (Railroads)Rapid transitRapid transit carsRolling contactSteeringUndercarriagesVehicle designWearWheelsDOT-TSC-UMTA-81-69;UMTA-MA-06-0025-82-1MA-06-0025Interim report; Oct 1981-Sep 1981This study develops conservative bounds on wheel/rail forces and flange forces for several types of rigid and flexible trucks in steady-state curving conditions. The approximate analysis presented provides closed-form relations for estimating forces, truck angle of attack, creep force saturation and sliding conditions as a function of truck geometry and track parameters. The wheel profiles are modeled by conical wheel treads with vertical wheel flanges. Limiting case transit truck configurations are analyzed to provide comparison of the benefits achievable in curving performance from modification of truck geometry.138