The announcement came as the International Olympic Committee (IOC) completed its visit to London to hear an update on preparations for 2012.

 

The tunnelling work has been underway since last April to create two 6km tunnels beneath the Olympic Park allowing the power needed for the Games and the community post-2012 to be carried underground.

 

This will allow 52 pylons which currently dominate the landscape to be removed, ‘unlocking’ the Olympic Park site for the start of construction of the main venues and infrastructure next year.

 

It is also a key part of the vision to regenerate east London and create an open and accessible Park in legacy.

 

The completion of tunnelling is the latest key milestone the ODA has hit this year and adds to the significant progress made on the project to date.

 

ODA chief executive David Higgins said: “Burying the powerlines underground is essential in unlocking the Olympic Park site for the start of construction next year and is a vital part of the long term regeneration of East London.

 

“The successful completion of this massive tunnelling project on time and on budget gives us real momentum as we set our sights on the challenge ahead.

 

"We have made a solid start in our delivery of the Olympic programme, hitting hit all of our milestones to date, but we recognise we are still at the foothills of the project and the mountain lies ahead of us.”

 

 

 

London 2012 chairman Sebastian Coe said:  "The Olympic Games and Paralympic Games can provide the inspiration to transform communities. 

 

"The completion of the tunnelling is an important first step in the transformation of the Lower Lea Valley. 

 

"The undergrounding of powerlines will provide an uncluttered landscape against which the Games can be staged. 

 

I am delighted we have been able to update the International Olympic Committee’s Coordination Commission on the significant progress we are making.”

 

Olympics Minister Tessa Jowell said: "The completion - on time and on budget - of the work on the powerlines tunnelling is a tremendous achievement.

 

"It is important not just for the creation of the Olympic park, but also as a crucial part of our ambitious regeneration plans.

 

"It demonstrates clearly the excellent progress being made to deliver a fantastic Olympics."

 

Mary Reilly, chair of the London Development Agency (LDA) which managed the powerlines project before the ODA became a statutory body, said: "The London Development Agency is delighted that the powerlines tunnels are complete.

 

"Getting these cables underground will be a major step toward the transformation of the Lower Lea Valley.

 

“It shows that the 2012 Olympics are already acting as a catalyst for the wider regeneration of East London which will create new homes, new jobs and a much improved local environment.”

 

Mayor of London, Ken Livingstone said: “This not only marks the completion of one of our first major projects on time and on budget but also the beginning of the transformation of east London.

 

"The area will benefit from new affordable homes delivered on a scale never seen before in the capital as well as thousands of new jobs that will come as we continue to regenerate the Lower Lea Valley in the coming decade.”

 

More than 350 workers and four 40 tonne tunnel boring machines have been working around the clock to complete the mammoth task in 424 days, one of the biggest tunnelling projects in the country.

 

The complex nature of the tunnelling process meant a series of obstacles and challenges were encountered during the project.

 

These included issues with soil contamination and encountering small ground movements and water ingresses beneath the surface of the Olympic Park.

 

But the project has been delivered on time, on budget and with an impressive health and safety record which is better than the industry average.

 

More than 200,000 cubic metres of spoil was created during the tunnelling process, enough to fill the new Wembley Stadium, the vast majority of which will be reused in the construction of the Olympic Park.

 

With the tunnelling work complete, work will now start to fit-out the tunnels allowing 200km of electrical cables, enough to stretch from London to Nottingham, to be laid next year which will manage the future electrical supply requirements of the Olympic Games and Paralympic Games and, in legacy, East London.

 

By the time the Beijing 2008 Games are underway the new underground cabling will be ready so that the power can be switched to the underground supply and the pylons dismantled towards the end of 2008.