Railway applications - External visible and audible warning devices - Part 3: Visible warning devices for urban rail

This document specifies technical requirements for visible signal devices located on the exterior of urban railway vehicles. It is part of a broader series addressing signaling systems for rolling stock, focusing specifically on visibility characteristics essential for operational safety in urban transit environments. The scope covers design parameters, performance criteria, and testing methodologies to ensure that signal devices remain effective under various lighting and weather conditions encountered during city operations. Key elements include color specifications, luminance levels, and placement guidelines to guarantee that signals are clearly distinguishable by train drivers and other relevant personnel. The content aligns with established European engineering practices for railway equipment, ensuring interoperability across different networks. Implementation of these technical provisions helps maintain consistent signal visibility, thereby supporting safe train movements within metropolitan rail systems. The document serves as a reference for manufacturers, testing laboratories, and railway operators regarding the technical specifications required for external visible signaling components on urban trains.