Electronics Protection - Summer 2016 - (Page 18)

Feature Securing Electronics in Modern Railway Systems Hayden Harrington, Application Engineer Optima Stantron When the first trains started ambling down their tracks, excessive speed that could cause derailment was not a factor. Nor was there concern about the amount of traffic travelling the rails. But obviously throughout the years, the railway system has undergone significant evolutions that moved it from merely an efficient method of transportation to a vital means of economic development. This has significantly increased both the dependence on railroads for mass transportation of goods and people as well as the need for a more efficient system to manage the larger traffic network. Trains now travel at far higher speeds and at much greater frequency than when the railway infrastructure was built, and there are large elements of safety and reliability that need to be considered to accommodate the modern systems. Electronics are now an integral part of safe, reliable and functional railway operations. Unfortunately, recent crashes that have resulted in loss of life have shown the importance of high levels of offsite control, remote access and remote monitoring, which requires reliable, dense computing power to ensure safe operation across all channels. All of these critical functions are controlled by computing equipment, both inside the train and by the wayside that must be housed in an enclosure that can withstand the shock and, specifically on board the train, the enduring levels of vibration. (Figure 1) Some may say that railway electronics are subject to the same rigor as military and seismic environments, which require significant protection from extreme shock and vibration as well as other environmental factors. While the electronics may have ruggedization built inherently into their design, the added protection and stabilization comes from the enclosures that surround this sensitive equipment. No board or system is designed to fully take the brunt of any mobile or harsh environment, it's always the housing that provides the first line of defense. Ensuring Reliable Operation Figure 1. Rugged enclosure set up for vibration testing to meet rigorous industry specifications. The shock and vibration that the tracks, the wayside equipment and the car themselves have to endure in a railway environment is relentless. Fortunately, standards designed to incorporate key test requirements for shock and vibration have been developed for both North American as well as European railways. Unfortunately, these standards do not always account for the fact that much of the available space where these railway electronics need to be placed is a fixed dimension. Just as small form factor systems face challenges produced by Moore's Law, railway applications do not have the luxury of limitless space in which to place electronics. And although it may not be a compact environment, it is still an area where dense, heat-producing electronics are crammed into a defined area and expected to operate reliably. The rail specification standards that ensure electronics and enclosures can withstand the ongoing impact of a railway car barreling down the tracks are AREMA in North America and CENELEC for Europe. Both publish required practices for the design, construction and maintenance of railway infrastructure as well as define the degree of shock and vibration that can be safely endured in a railway environment. Typically, for an enclosure to pass these rigid test specifications, the use of resilient mounts or shock and vibration isolators is needed, but these seemingly innocuous components take up valuable real estate by increasing the footprint of the enclosure itself. 18 Summer 2016 * www.ElectronicsProtectionMagazine.com http://www.ElectronicsProtectionMagazine.com

Table of Contents for the Digital Edition of Electronics Protection - Summer 2016

Electronics Protection - Summer 2016
Contents
Editor's Choice
Common Coolant Types and Their Uses in Liquid Cooling Systems
The Benefits of Vertical Integration for Customized EMI Shielding Products and Services
Cool It Your Way: Versatile Cooling for Electronics Enclosure
Heat Pipes and Vapor Chambers – What’s the Difference?
Securing Electronics in Modern Railway Systems
Enclosures
Thermal
Power
Hardware
Industry News
Calendar of Events

Electronics Protection - Summer 2016