EoW May 2008

english corporate news

Keeping the trains on the right track!

ClearFill ‘Line’, part of an innovative suite of end-to-end wireless indoor solutions (WINS) from leading wireless technology group, Radio Frequency Systems (RFS), has been successfully installed in the stage two development of the UK end of the channel tunnel rail link (CTRL Section 2). RFS Radiaflex radiating cables, Cellflex coaxial feeder cables and accessories form a key component of the wireless communications system for the high-speed rail upgrade. The new link runs between the centre of London and Southfleet Junction, approximately 40km to the south-east. Courtesy of the upgrade, trains can now travel at 230km/h from Folkstone, on England’s coast, right through to London’s St Pancras station. The entire journey from Paris to London now takes only 2 hours and 15 minutes. The RFS ClearFill Line solution was selected by infrastructure specialist Thales UK, the company with responsibility for the entire communications system of CTRL Section 2. Senior principal design engineer with Thales UK, Kevin Moxsom, said that the low longitudinal and coupling losses of RFS’s RADIAFLEX radiating cable – an important element of the ClearFill suite – was a key consideration. The new link includes three tunnels with a combined length of 21km. The RFS Radiaflex radiating cable was installed in close proximity to the tunnels’ high-voltage catenary cables. To prevent power surges in the communications cables, RFS’s ‘DC blocks’ – which protect both the inner and outer conductors – were installed every 500 metres. An important system requirement was to concurrently support all four tunnel communications systems. At the heart of the system is the 900MHz Global System for Mobile communications-Railway (GSM-R). Emergency services use a separate

Courtesy of a channel tunnel rail link upgrade incorporating RFS’s ClearFill ‘Line’ solution, trains can now travel at ▲ ▲ 230km/h from England’s coast right through to London

terrestrial trunked radio (TETRA) system operating at 380MHz, with the London Fire Brigade operating an additional 462MHz system. Communication to the locomotive is presently via cab-secure radio (CSR) operating at 448MHz. According to Moxsom, the GSM-R system will ultimately replace the CSR and also the trackside signalling. All signal and control information will be transmitted directly to the locomotive, and the familiar sight of railway signals alongside the track will be a thing of the past. In such systems, a fail-safe mechanism stops the train if the GSM-R communications are lost for more than three seconds. For built-in system redundancy, every component of the CTRL Section 2 communications system has been

duplicated. The RFS Radiaflex cable was the only exception, as in single-cable format it exceeded the ‘mean-time- between-failure’ (MTBF) reliability specifications. This was achieved, not only because of the quality of the cable, but also by careful system design: the dual-redundant communications signals are fed simultaneously into the cable, from opposite ends of the tunnel. In the event of accidental cable damage, communications can continue on both sides of the break. The emerging use of GSM-R for train control in CTRL Section 2 and other links opens the way for harmonised communications systems throughout the entire pan-European rail network. Radio Frequency Systems – Germany Fax : +49 511 676 3750 Email : rfs.germany@rfsworld.com Website www.rfsworld.com

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EuroWire – May 2008