Analytical Model of the Effect of Tangent Length between Vertical Curves on Train Derailments

Derailment is one of the most hazardous occurrences affecting the safety of railroad cars that must be prevented. The potential threat of derailment could be especiallysignificant when length of tangent between vertical curves isn't long enough. Although the length of tangent between vertical curves could be relevant to railway safety, no research had been conducted to study its effect on derailment risk. The primary objective of this paper was to investigate the effect of tangent length between vertical curves on derailment. This study consisted of three major components: (1) review of 1999-2008 derailment reports in Iran, (2) a regression analysis, and (3) recommendation model for estimating the probability of derailment, based on the tangent length between vertical curves and the number of cars derailing. The most important finding from this research is the statistical significance of tangent length between vertical curves on railway safety. Analysis confirmed that the shorter length of tangent between vertical curves results in more cars being derailed.