Work has started on the largest-ever scheme to modernise signalling on the Great Western railway line between Bristol and London.
When completed, the four-year £350m improvements to the 1960s signalling infrastructure could help cut delays by 50%.
The upgrade is vital to prepare for electrification of the line between London and the West and forms part of a wider 10-year, £5bn plan to expand services on the Great Western main to accommodate the increase in the demand for rail by the end of the decade.
Patrick Hallgate, Network Rail’s Western route managing director, said: “We are safeguarding the long-term future of a vital rail artery in the South West of England and Thames Valley. The Great Western main line is running out of room with nearly 30 million journeys and a growth rate of at least 5% each year. A robust and modernised signalling infrastructure is vital to cope with this burgeoning growth.
“In a few years’ time, the signalling infrastructure will be considered life-expired but we are ahead of the game by starting the improvements now.”
The work will be carried in five stages, starting from the Didcot area, to minimise disruption.
The biggest programme of work will be around Bristol – which is forecast to experience the highest growth in passenger numbers – and is designed to complement the capacity-boosting proposal to revamp the track around Temple Meads station.
The improvements will replace the outdated relay system of signalling to powerful computers allowing signallers to control the safe passage of trains from a state-of-the-art centralised hub using the latest digital technology.
Lightweight signals will be used trackside as part of this upgrade, which will reduce costs. These innovative signals have reliable LED powered lights, are quicker to install, last longer, are more environmentally friendly as they use less materials and power, and are safer for staff to maintain as there is no need to work at height.
Network Rail is also using innovative plug coupler technology to overcome complex wiring changes which means work can be carried out much quicker with less disruption to train services.
Timeline
* 2012: route between Didcot and Swindon and Didcot and Oxford
* 2014: route between Swindon and Chippenham, Swindon and Gloucester, Swindon and Hullavington (route to Bristol Parkway)
* 2015: route between Newbury and Reading
* 2015: Oxford area
* 2015: route between Bath and Parson Street via Bristol Temple Meads, Swindon and Bristol Parkway
The work
* Replace 1960s signalling control panels with modernised electronic control system
* Centralise signalling control, which manages the movement of trains, under one roof to improve communication and responsiveness during incidents
* Replace old signalling gantries and cantilevers with straight posts, where possible, to make room for overhead electric wires
* Improve signalling equipment, including points which allow trains to switch tracks to different paths, to become compatible with an electrified railway
* Replace filament signal heads with LED heads, which typically could last between 25,000 to 100,000 hours and are environmentally friendly
* New technologies and methodologies will be trialled with the aim of deterring cable theft and minimising the impact of any cable theft on the railway operation
