Two Lovat TBMs for Lower Lea Valley Cable Tunnel in LondonAt the Underground Construction 2005 conference and exhibition held 26th-27th October, 2005 in London, J Murphy & Sons signed a contract with Lovat for the purchase of two mixed-face 4.7 m-diameter EPB TBMs. The Greater London Authority, through the London Development Agency, awarded to Murphy 12 km of tunnel work to replace existing overhead power lines though the Lower Lea Valley as part of the 2012 London Olympics land redevelopment. Visit www.lovat.comThis is the first formal Olympic project. Development of these tunnels will free up approximately 40 hectares of land for the Olympic Park. For this phase of the project, two tunnels will be constructed at a depth ranging from 13 to 33 metres. These two machines will complete 5,800 metres of a tunnel lined with prefabricated reinforced concrete segments with an ID of 4.2 m and OD of 4.6 m. Grouting will occur through the segments. The tunnel will be driven from West Ham sub-station to Hackney sub-station. The finished tunnel will include its own monorail system. The first Lovat RMP185SE machine will bore 2,400 metres, while the second will complete 3,400 metres. Click uk/28.Tunnelling will occur below or close proximity to several significant structures including multiple railway and highway alignments, the Northern Relief Sewer, the Channel Tunnel Rail Link, several major river crossings and a number of multi-storey buildings. The tunnel alignment passes through two distinct geologic groupings. Surficial soils are of man-made fill (demolition rubble, landfill sites and sites of old heavy industries). The lower native soils are comprised of Thanet sands, silts and London clays, Thames gravel and Cretaceous chalks. Most of the tunnel alignment is through an upper and lower aquifer, with water levels of up to 14 metres above the tunnel invert. Expected EPB pressures are up to 1.5 bar. The Lovat RMP185SEs will be delivered, refurbished and modified to meet the current British standards. Previously these machines were instrumental in the construction of the 18.49 km East Central Interceptor Sewer (ECIS) project for the City of Los Angeles.Another separate 2.4 m-diameter tunnel will also be part of this project and is being constructed with two Lovat RME131SE TBMs already owned by Murphy. Lovat is providing engineering, components and technical support for the modification and refurbishment of these two machines. 46/05.