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Severn Tunnel opens after electrification works

Severn Tunnel upgrade

The Severn Tunnel has reopened to rail passengers after completion of a six-week electrification upgrade.

The upgrade work involved preparing the tunnel for electrification, which Network Rail said would result in more seats and faster, more reliable journeys for passengers.

Network Rail engineers have installed over 12.9km of conductor rail that will eventually power a new fleet of electric trains through the 130-year-old tunnel.

Work to prepare the neighbouring Patchway Tunnels was also completed during the closure, which took place between 12 September and 21 October.

The works were carried out as part of Network Rail’s railway upgrade plan to provide a bigger and better railway for passengers.

“We are delighted to have delivered this vital milestone in the project to electrify the South Wales Mainline as part of our Railway Upgrade Plan to give passengers a bigger and better railway,” said Network Rail Wales route managing director Andy Thomas.

He said that without the six-week closure it would have taken engineers up to five years to complete this vital upgrade, delaying electrification of the route to South Wales.

“Electrification of the South Wales Mainline will transform the railway, bringing significant long-term benefits for passengers including faster, more frequent trains as well as a boost to economic growth for towns and cities across South Wales thanks to better connectivity to and from London,” added Thomas.

The work was carried out by the joint venture ABC Electrification, comprising contractors Alstom, Babcock and Costain, as well as numerous suppliers, designers and sub-contractors including Amco, Keltbray and Arup.

During the tunnel closure Great Western Railway (GWR) high-speed train services were diverted between Swindon and Newport, which increased journey times by approximately 35 minutes.

Tunnel facts and figures

  • More than 20 conductor rail anchors and 240m of conductor rail were installed in the Severn Tunnel per 10-hour shift
  • 7,000 anchors were installed to support the new electric equipment
  • 14km of overhead conductor rail was installed and supported by 1,648 drop tubes that are suspended from the tunnel crown
  • Over 3,500 people-hours of preparatory work was completed ahead of the six-week upgrade project
  • Over 40t of soot was removed from the tunnel during the preparatory work carried out prior to the six-week project
  • The Severn Tunnel is 6.4km long, with water sitting on top of a 3.6km stretch.

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