Multi-function movable scotch block: application of an analytical-experimental methodology for the design of the innovative component

In recent years, the need to mitigate situations of potential risk due to human error that can occur inside a railway station has emerged, such as the failure to remove scotch block or the their undue allocation. These devices are generally positioned on the rail to prevent any movement of rolling stock parking in in the railway stations/depots. In the aforementioned error situations, the wheel of the moving vehicle can overcome the scotch block and derail with consequent damage to both the rolling stock and the infrastructure, with disruption of railway traffic. Therefore, it was decided to design a multifunction device, starting from a standard component already in use in RFI, which could guarantee both vehicle's parking (main requirement) and collapse (additional requirement) in case it was not removed before vehicle's starting or accidentally left on the rail. The present research describes a methodology for testing and designing of innovative component that allows compliance with design requirements illustrated above. For the scope, a component already used by RFI was modified by means of simple mechanical processing, finding the right compromise between the following requirements: • static requirement: the primary function of stationary parking. • dynamic requirement: minimizing the probability of derailment of vehicle in the event of an impact of the wheel with the component due to failure to remove it after use. This requirement is realized with the collapse of the component without causing an excessive raising of the wheel with respect to the rail level. Above design requirements are antithetical to each other and represent the challenge of research. To verify compliance with static and dynamic requirements, an extensive campaign of simulations and tests was carried out both in the laboratory and trial sites in real use conditions.