A Rail Vehicle Clearance Calculation Program

This paper explains and illustrates a computer program for calculating clearances between a rail vehicle and wayside objects and between a vehicle on one track and a vehicle on an adjacent track. The program includes a graphic animation illustrating the geometrical proximity of the subject vehicle to successive wayside objects and to a vehicle in successive relative locations along an adjacent track. The situations of minimum clearance for given vehicle and track geometry inputs are highlighted in a report. The main program is accompanied by an auxiliary program that uses independent logic to calculate clearances for idealized situations and that generates input files representing those situations for the main program. This provides an efficient means for verifying basic aspects of the logic of the main program.