Economics of Wayside Inspection Systems

The use of wayside load measurement sites to monitor vertical and/or lateral wheel/rail forces has been in active use in North America for many years. Recently interest has increased in establishing a network of such sites to allow for the monitoring of railway cars that generate excessive levels of vertical and/or lateral loads. This would potentially allow for the identification of these high load level vehicles and the ability to take them out of service to investigate the cause of these high levels of loading. This paper addresses the issue of the economics of such a site or series of sites. Specifically the benefits associated with both vertical and lateral load detection wayside sites are identified to include both safety related benefits (e.g. derailment reduction) and maintenance (non-safety) related benefits. These latter benefits include reduced track maintenance, reduced equipment maintenance, reduction in fuel consumption, reduction in lading damage, and reduced inspection costs. Likewise the costs to set up and operate these sites, to include capital and operating costs, as well as costs associated with “false alarms” and associated unnecessary removal and inspection of cars are defined and quantified. The resulting overall system economics, and the associated sensitivity of these costs and benefits to key operating parameters are presented and discussed.