Platform #2 at Carmarthen station was to be a relatively straightforward refurbishment project by Arriva Trains Wales. The platform required new passenger information boards, and the installation of constant surveillance and recording of CCTV images relayed to a remote monitoring centre operated by Arriva Trains Wales.
Traditional cable installation from remote camera locations is problematic and can be impossible if rail lines need to be crossed. This was the challenge at Carmarthen, where platform #2 is constructed as an island. With no existing bridge-over or under-track link, t the project would need additional construction within the station to accommodate cabling, taking into account the need to protect the vulnerable cables from damage.. The estimated costs began to climb, making the project prohibitively expensive.
Arriva Trains Wales turned to Fone-Alarm Installations Ltd to develop an alternative. They in turn commissioned Wood & Douglas to supply a high-performance wireless video and telemetry transmission system to support digital CCTV monitoring for security within the station, and data transport for the public information boards.
Wireless communication in such an environment is challenging because of the high levels of interference that can be caused by power supplies, overhead lines and engines. However, the wireless system designed and manufactured by Wood & Douglas is particularly robust and operates reliably where other systems may not.
Six cameras were installed on the platform, and a multipoint wireless system enabled camera images to be linked to the remote control room via a wide area network. As the station was well lit, conventional CCTV cameras were deployed, mounted onto pan and tilt platforms, with zoom capability. Cameras can automatically switch between colour images during the day, and monochrome for improved night-time visibility when used with infra-red lamps.
Using this modular system, video, audio, telemetry and alarms are carried over a single link. This is made possible by delivering high link capacity through efficient use of the available radio spectrum. The cameras deliver video via coaxial cable to an encoder/decoder box, which encrypts the signal before a transceiver with integrated antenna relays the signal to a second transceiver and decoder.
As the wireless link can also provide data communications, the system can control the camera’s pan, tilt and zoom functions, carry audio for public address to the camera locations, and support data services such as live feeds to the passenger information displays.
Installing a second wireless transceiver alongside the first provides a backup link as a failsafe. This also provides additional bandwidth should the system require expanding, for example to install more cameras for wider coverage, or more highly specified cameras with improved capture resolution. This helps to future-proof the installation.
At Carmarthen, securely bridging the railway line wirelessly cost as little as a quarter of the cost of the proposed cabled approach, and took just a month to install with minimal disruption to services or passengers. Secure, robust CCTV surveillance and passenger information over wireless Fast, easy, and cost-effective to install Scalable with options for additional functionality