A “major milestone” was reached this week in the Northern Line Extension project when Amy and Helen, two giant tunnel boring machines, were lowered 20 metres below ground in the UK.
A Liebherr LR 1750 750-tonne crane rented from Weldex was needed to lower the two machines, which will create 3.2km underground tunnels extending the Charing Cross branch of the line from Kennington to Battersea Power Station.
Tunnelling will begin in March and take six months to complete.
Once lowered, Helen and Amy can be fully assembled within two 77 metre long launch tunnels and their final length will be a whopping 100 metres.
The earth- more than 300,000 tonnes- the machines dig out will be taken up to barges on the River Thames and be transported to Goshems Farm in East Tilbury, Essex, where it will be used to create arable farmland.
