Engineers from electricity company National Grid and tunneling experts Morgan Est are celebrating the completion of tunneling on a new £80m cable link from Croydon to London. The 10-km tunnel broke through at the Beddington Substation site early on Tuesday morning, April 28, after almost two years of tunneling.

The tunnel is part of National Grid’s investment program to reinforce electricity transmission in the South East and will house a new 400-kV cable between existing substations at Beddington and Rowdown. The cable is required to meet the growing demand for electricity in London and the South East.

Leading UK infrastructure services specialist Morgan Est was selected by National Grid to design, build and commission the tunnel due to its world-leading tunneling expertise.

National Grid’s Scott Sadler said: “The breakthrough represents another major step towards the completion of this vital project. It is the culmination of many months of hard work by our workforce. I would like to thank everyone for their efforts and would also like to thank local residents and businesses for bearing with us throughout the tunneling process.”

George Jackson, Morgan Est Project Manager, said: “This is a significant tunnel breakthrough for us and a major step forward in our work on this project. It has been technically a very challenging process and I am pleased to say the consistent dedication and hard work of the team has paid off.”

Additional works on the tunnel – which cost £60 million to construct - included the construction of four shafts with surface buildings, two culverts and associated installation works. Work can now begin on the next phase of the project.

Sadler explained: “We can begin preparing the tunnel for the installation of the new electricity cables which will link our substations at Beddington and Rowdown and help meet electricity demand in the capital city of London and nationwide.”

The cable installation process will cost around £20million. The cable is due to go live in 2011.

Placing the cable in a tunnel removed the need to for major road works and minimized disruption for local people and road users. National Grid will be able to conduct routine checks and maintenance without the need for road excavations. Additionally should the need arise in the future a second cable can be installed with minimum inconvenience.