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CLS LITE Supports Thameslink

CLS LITE Supports Thameslink

by Unipart Dorman

Tags: Increased Safety Innovative Solutions Manufacturing Safety Signalling Unipart Dorman

Thameslink is the primary north/south rail route in London and work has been undertaken on a programme first raised in the 1990s to increase the capacity and efficiency of this vital commuter route.

As the project heads into its final phase prior to full operation in January 2018, Unipart Dorman is proud that its CLS LITE signal heads form a crucial part of increasing the safety of the railway and consequently the travelling public, by reducing the number of Signals Passed At Danger (SPADs), particularly at locations where some of the largest gantries in use on the UK network are fitted with signals controlling the approaches of up to 10 individual railway lines.

The unique optical arrangement of the LED modules used in the CLS LITE Signals means they can be specified in Medium Range Format with a narrow, 3 degree beam spread. This means drivers don’t suffer from the read through problems or cross-reading to the wrong signal difficulties often experienced with other manufacturer’s signals.

CLS LITE was initially developed as a one off solution at a particular gantry at London Bridge to incorporate the new optics in the Classic CLS frame to overcome a specific signal sighting problem in response to an urgent customer request. The new signal has since proved a very important addition to the Unipart Dorman range of mainline signals by giving projects the flexibility to specify the standard iLS in its usual GRP head and post in a reclining base format, or, as a CLS LITE for mounting on an existing gantry or structure, whilst maintaining continuity in the aspect’s presentation to the driver even at long range. 

Whilst the newest signals in the Unipart Dorman range have proved invaluable on Thameslink, the first mainline signals designed by Unipart Dorman back in the early 2000s are also delivering increased safety and efficiency. The entire Thameslink project has been designed and engineered around ensuring maximum reliability but it is inevitable that a route as busy as this will suffer occasional problems. Unipart Dorman Subsidiary Signals, comprising two 45 degree flashing white lights are being used to deliver Proceed on Sight Authority (PoSA) signalling. This permits the driver to move past a signal that has been placed at Danger. When the PoSA signal has been initiated by the signaller, it authorises the driver to proceed at caution to the next signal or buffer stop. This allows the route to keep moving (albeit at a much slower speed) based on the driver’s ability to recognise potential hazards early and bring the train to a safe halt. Unipart Dorman have also developed a Miniature Tunnel Signal variant of the PoSA signal which has a greatly reduced space envelope to cater for the reduced clearances in tunnels.

For full details of how the Thameslink project is counting down to its successful completion please see the article in Rail Engineer…       


About this author
Graham Scott

Technical Support Manager

I am the Technical Support Manager at Unipart Dorman providing technical and sales support across the Rail, Traffic and New Product Development areas of the business. In my spare time I write Flash Fiction and I also volunteer at a local community creative writing group and for various transport heritage groups.


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