NTL Record

Title Wheel Unloading of Rail Vehicles Due to Track Twist
Record ID 50575
Personal Name
Creator
Jeong, David; Weinstock, H.; Greif, R.
Source 58p. in various pagings
Corporate Creator John A. Volpe National Transportation Systems Center (U.S.)
Corporate
Contributor
United States. Department of Transportation. Federal Railroad Administration
Publisher United States. Department of Transportation. Federal Railroad Administration
Publication Date 19860201
Language English
Abstract An analysis is presented describing the effect that track twist has on the loads carried by the wheels of a rail car. Wheel unloading is determined as a function of the difference in crosslevel between the truck centers of the car. The different vehicle characteristics that affect a car's reaction to track twist are determined. It is found that light, torsionally stiff cars are the most susceptible to wheel unloading due to track twist. Using the results of a previous study where lateral wheel/rail force was determined as a function of curvature, the difference in crosslevel between truck centers that will cause Nadal's Limit for wheel climb to be exceeded is determined as a function of curvature. This difference in crosslevel between truck centers is normalized to 31 ft so that maximum track twist, as it is commonly defined, is determined as a function of curvature. It has been found that for less that 6 deg of curvature and at low speeds, most rail cars can withstand up to 1.5 in. of track twist in 31 ft. The amount of track twist that a car can withstand decreases with increasing curvature, and at 15 deg of curvature the amount of track twist that most railcars can withstand has dropped to 1.0 in.
Rosap ID dot:11952
Rosap URL https://rosap.ntl.bts.gov/view/dot/11952
TRT Terms Cross leveling; Curvature; Curved track; Deformation; Derailments; Railroad cars; Railroad tracks
Classification AGR - INFRASTRUCTURE - INFRASTRUCTURE;
AGR - INFRASTRUCTURE - Railroads;
NTL - RAIL TRANSPORTATION - RAIL TRANSPORTATION;
NTL - RAIL TRANSPORTATION - Rail Safety;
NTL - SAFETY AND SECURITY - Vehicle Design;
NTL - SAFETY AND SECURITY - SAFETY AND SECURITY;
NTL - SAFETY AND SECURITY - Rail Safety
Geographical
Coverage
United States
Contract Number RR519/R5305
Report Number DOT/FRA/ORD-85/14, DOT-TSC-FRA-84-7,
Resource type Tech Report
URL https://ntlrepository.blob.core.windows.net/lib/50000/50500/50575/DOT-TSC-FRA-84-7.pdf
Format PDF
Database NTL Digital Repository