Minimization of Impact Forces on Crossings by Railhead Profile Optimization

High vertical loads due to running over rail discontinuities, such as joints and turnouts, generate relevant mechanical vibrations, noise, and wear. This problem is also relevant for unworn crossings because they are not optimized to match the shape of the passing wheels. This study presents a new approach for the geometric railhead design of crossings installed in turnouts with tight curve radii, which are mainly travelled in the through direction, introducing the concept of conformal crossing for the most common wheel profile in Europe, S1002. Starting from the existing geometry of conventional crossings, a 3D model of a conformal crossing is developed, and sections are extrapolated to perform multibody simulations that include wheel-rail contact calculation with variable rail profiles. The results were then compared with those obtained for the conventional crossing. Results show that conformal crossing can prevent vertical dynamic loads in the through route. The resulting increase in the impact loads when running along the diverging route was mitigated by further simple and effective modifications of the crossing.