Archive for the ‘Electricity cable tunnels’ Category

An announcement in the press yesterday meant a big celebration for Skanska after they heard they had been successful in their bid for the tunnelling portion of the National Grid cable tunnels upgrade project. Costain were awarded the main contract worth £200 million last October by the National Grid electricity and gas company, but they have now awarded the tunnelling works to Skanska—this contract is worth £92 million and Skanska will help Costain to deliver a new electricity cabling network for the city of London.

The construction of cable tunnels is all part of a wider upgrade scheme designed to allow National Grid engineers to inspect and maintain the electricity network in conditions of safety.

There will be 33km of tunnelling constructed below London as part of the project: a tunnel 19.9km in length will be built between Willesden and Hackney and a 12.1km tunnel will be built between Kensal Green and Wimbledon. Each tunnel will be built between 20 and 60 metres below ground and the tunnels will be between 3 and 4 metres in diameter.

As well as the tunnelling works, Skanska will also be responsible for building access shafts for workers, head houses for electrical equipment, and all ventilation equipment works. Large tunnel boring machines (TBMs) will do the digging through ground conditions featuring London clay and the tunnels will have a segmental lining inside. In order to minimise potential disruption to the existing electricity supply, the new cable tunnels will be constructed alongside the existing tunnels. Residents and businesses should experience no interruption while the tunnelling work is ongoing below the city.

All tunnelling work is expected to reach completion by the end of 2014, but the rest of the works will not be completed until 2018.

It has just been announced in the press that National Grid has appointed Mott MacDonald as Project Manager following the recent appointment of Arup as Programme Managers on the forthcoming multi billion pound investment programme. This programme is being undertaken by the National Grid as part of their plans to upgrade and modernise the electricity infrastructure in London so that it will be able to cope with future demand as the population increases.

In the role of Project Manager, Mott MacDonald will be responsible for the provision of all Project Management services as the massive project to revamp London’s electricity transmission infrastructure progresses. As part of the works, another contractor, Costain, will be delivering two TBM driven tunnels, 33km long and 4m in diameter. Much of the work will be focussed on replacing electricity cabling first installed during the 1960’s. The planned cabling tunnels will help to ensure that future maintenance and repair access to cabling will be both easy and safe. It should also help to ensure that consumers living and working in the London area continue to enjoy a reliable electricity service that is free from disruption.

Mott MacDonald will have a number of crucial responsibilities in their role as Project Manager. The contractor will be responsible for overseeing all civil, electrical, and mechanical works on the project, plus it will be responsible for the supervision of risk management services, programme controls, environmental and health management, safety, change control, design checks and planning, construction and management advice. Sub contractor, Donaldson Associates, will be working alongside Mott MacDonald and providing assistance on the Willesden to Hackney section of the cable-tunnelling route.

During the course of the upgrade works, National Grid is intending to make good use of existing brown field sites and underground spaces beneath London. This should help to reduce the environmental effects of the planned works.

The National Grid energy company recently announced that Arup has been appointed as Programme Manager for the brand new investment programme designed to deliver two deep tunnel cable systems beneath London.

The work is part of an eight year programme of investment by the National Grid and is designed to ensure that the National Grid electricity infrastructure is able to meet the demands of future generations living and working in the heavily populated areas of London. Programme Management Director for Arup, David Twine, announced that Arup was delighted to have been given the opportunity to manage the programme on such an innovative and complex job.

The first works contract on the £200 million upgrade scheme has already been awarded to Costain and they will be required to design and construct two separate cable tunnels covering a total of 33 km. The first tunnel will run from east to west. It will connect the sub stations at Willesden and Hackney and will pass via St John’s Wood and Kensal Green. The second tunnel will run from north to south and will connect the sub stations at Kensal Green and Wimbledon.

Natioan Grid have designed the upgrade works to ensure that there will be the minimum of disruption and interruptions to electricity supplies as the work progress on the replacement of existing cable systems beneath the city of London. Once the tunnels have been built, engineers will be able to maintain and regularly inspect the cable circuits safely and easily.

National Grid’s UK Construction Manager, Michael Dyke, passed comment after the announcement that Arup would be managing the programme; he said that the National Grid was determined to continue providing a reliable electricity network for the millions of people who live and work in London and the UK.

It has been revealed in the press today that Costain have been awarded a very lucrative £200 million contract to build a 33km tunnel beneath London to house cabling for the National Grid. The project is part of a larger scheme of investment by the National Grid to upgrade and improve the electricity grid in the London area. The new tunnel will connect Hackney, Willesdon and Wimbledon, via Kensal Green.

The project is expected to take around four years from start to finish and construction work will begin later on this year. The tunnelling work will be completed at the end of 2014 and other associated works will be finished at the end of 2018.

The chief executive of Costain, Andrew Wylie, announced he was delighted that Costain had been awarded the National Grid contract. He commented that it showed Costain was capable of providing cost effective engineering and technology led solutions, plus he also revealed that Costain were looking forward to enjoying a mutually beneficial long term business partnership with the National Grid.

London currently accounts for 20% of electricity used in the UK and this demand is growing by 3-5% every year—compared to a 1% annual growth in electricity demand nationally. In order to meet the ever-increasing demand for electricity, the National Grid is investing huge amounts of money in an effort to improve the electricity infrastructure beneath the city of London to ensure the supply remains constant and reliable.

There are currently plans in the pipeline for several deep tunnels beneath London to house new 400,000-volt cables, one of which will connect Hurst to Eltham. Eventually, this section will extend another 10km as far as New Cross. When the work is complete, the new cabling will connect sub stations around London.