Life cycle cost-driven innovations for heavy haul turnouts

摘要

Life cycle cost (LCC) considerations are of increasing importance for all organizations making long-term investments. Developments for heavy haul applications were carried out in close cooperation with users identifying the key technical requirements and the overall cost situation. The design and material specifications of the components within a turnout have to be of the highest level with regards to axle load, dynamic forces, and accelerations to meet the demands for heavy haul. Aside from the price of a product, the supply-chain, installation, and maintenance costs coupled with the total life expectancy all have a significant impact on the LCC. Key influencing factors are: (a) initial track quality, (b) delivery logistics – track closing during installation, (c) inspection intervals, (d) time to maintain in track, (e) time for replacement of rails and components, (f) life expectancy of single components. LCC optimized turnout systems are influenced by the following features: (a) minimizing forces on rails, switches, and crossings by optimizing turnout curvature and contact/transition geometries, (b) providing ideal conditions for maintenance work (e.g. through automatic tamping throughout the whole turnout without dismantling of components), (c) using low-maintenance components in order to minimize costs for inspection and maintenance and to increase availability especially in the field of switching, detecting, and locking of the turnouts. The implementation of LCC philosophy in a state-of-the-art heavy haul turnout technology will be highlighted and demonstrated with examples.