Channel Tunnel Rail Link

The project to extend the link from Ashford International to St Pancras has meant extensive building, track modernisation and track laying programme that has demanded the latest in surveillance techniques to ensure the security and reliability of the new track. With both money and prestige at stake, AMG was awarded the contract from communication system contractor, Optilan, for the CCTV solution.

CTRL is the UK’s first major new railway for over a century - a high speed line running for 109km (68 miles) between St Pancras in North London and the Channel Tunnel. Section 1 of the new line opened in September 2003, connecting the Channel Tunnel to Ebbsfleet in north Kent where it currently connects to the existing rail network. This first section also includes connections into the existing Ashford International Station and has already reduced journey times from Waterloo to the Channel Tunnel from 70 minutes to 55 minutes.

Section 2 opened in 2007. It brings the new line beneath the River Thames and through East London to its new terminus at St Pancras. The UK journey time will be halved to just 35 minutes, with non-stop times to Paris and Brussels of just 2 hours and 15 minutes and 2 hours respectively. The non-stop high speed running also fuelled the need for an efficient and resilient communication system that would ensure a first class surveillance network for the link’s operators.

AMG was approached by Optilan, the communication system contractors for the project, to devise a suitable video transmission network for the CCTV system that was being installed to monitor the new track between Ebbsfleet and St Pancras, a distance of approximately 40km. All this information would then have to be relayed a further 50km to the control room. In all there would be 50 cameras on a route that required maximum possible uptime. As well as the paramount importance placed on minimum system disruption, high levels of picture and data quality were required. AMG was charged with putting into place a full bandwidth, real time, digital video solution.

“We needed a system that would have excellent inherent resilience and the capability to withstand a high degree of interruption to the relay of information, such as damage to the fibre optic cables for example”, commented Richard Buckland, Managing Director, Optilan.

AMG installed the AMG2700 series multi-channel video transmission system to link the cameras on the new rail line in a dual redundant configuration, capable of ‘self-healing’ itself in the event of catastrophic fibre damage. This would provide a significantly improved performance compared with that of the legacy CCTV system. It would also be capable of transmitting high quality images over the long line lengths involved without video compression delivering real time, full bandwidth solution.

The AMG2700 series overcame four key design issues - video quality, latency, camera count and resilience. Designed for multi-channel video collection and distribution over singlemode fibre - together with associated data and audio signals – can carry up to 64 uncompressed video signals in a real time full bandwidth digital format. This ensures high quality transmission regardless of distance without compromising quality and without introducing latency to the video.

It will collect individual or multiple video signals in a ‘daisy chain’ along a rail track or road, and transmit them all back to one or multiple control rooms. Configured in dual redundant mode, the AMG2700 series automatically re-routes all video signals in the event of a fibre break between two nodes. This dual redundant option ensures no loss of signal during a catastrophic fibre failure and the system comes equipped with a self healing capability once the fibre breakage is spliced.

The flexibility of the AMG system allows for foreseeable future upgrades to be accommodated easily without significant disruption. For instance, the number of video cameras on the system can be increased by 100% without any disruption to the current network. A secondary control room could easily be created, with access to every camera on the network or, if necessary, the main control room could be moved entirely.

• Each of the 50 cameras is linked back to the control room, a total track distance of 90km
• The AMG 2700 series system allows images from all these cameras to be relayed with no deterioration in image quality and with zero latency
• The CTRL CCTV system is 100% scalable
• TheAMG 2700 series offers easy integration links to other networks
• Digital video recording is provided for each camera and 10 Ethernet channels provide a fast reliable communications medium for retrieving DVR data.