Abstract
This paper describes tests conducted in the North River tunnel of the Pennsylvania Railroad to determine a practical means for communicating with moving locomotives and trains in tunnels. It is shown that frequencies between about 25 and 1500 megacycles per second are not suitable for such communication over any substantial distance when employing conventional radio techniques. Tests are described utilizing other means of transmission, including the use of a series of antennas bridged onto a transmission line extending through the tunnel, and a closely-spaced two-wire line without antennas acting as a radiating and pick-up device. It is concluded that satisfactory transmission in tunnels can be obtained for a distance up to approximately 6,000 feet using the frequencies and equipment ordinarily employed in railroad mobile systems and twin-lead cable such as RG-86/U suitably located within the tunnel.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
