The £635 million Lee Tunnel will prevent 16 million tonnes of sewage entering the River Lee each year - a result of the capital’s Victorian sewers being too small to cope with heavy rainfall.

Lizzie is 8 m in diameter and 120 m long. The machine's 800 tonne cutter head was the first piece of the drill lowered.

Thames Water’s Lee Tunnel Project Manager Roger Mitchell said that lowering the cutter head was a four-hour operation, requiring a lot of precision. To lift it, the company used one of the biggest cranes in Europe, which was so large it had to be transported in 60 lorry loads.

Constructing the Lee Tunnel will be an engineering challenge, involving tunnelling through high groundwater pressures and passing through 4 miles of the most abrasive ground from the starting point at Beckton, to the destination at Abbey Mills.

Article continues below…

Lizzie has been custom-designed to suit London's ground conditions and will blend more than 100 tonnes of excavated chalk with water for every 1 m of tunnel, forming a white slurry before transporting it through a pipe the length of the tunnel, so it can be processed above ground.

Work started in September 2010 to build the 80 m deep entry shaft at Beckton sewage works. Tunnelling is due to begin in January 2012 and is likely to progress at a rate of 17 m a day, expecting to finish in late 2013.

MVB, made up of three civil engineering contractors - Morgan Sindall, VINCI Construction Grands Projects and Bachy Soletanche - is working with Thames Water to build the Lee Tunnel.

Thames Water will also be utilising No-Dig technology in Royal Wootton Bassett to replace a section of pipe under Minety at the crossroad of The Common and Station Road.

A spokesperson from Thames Water told Trenchless International that the works are part of a £2.083 million scheme in Wootton Basset to replace pipes prone to bursting.

The length of the pipeline to be laid is approximately 3 km, with variable size diameters.

The first 800 m in the road is to be 450 mm ductile iron, and the remainder that runs through fields is to be 560 mm of OD HPPE.

All work in Wootton Basset is due to be completed by December 2012.