Tunnel boring machines ready for Northern Line extension

CONSTRUCTION of the Northern Line extension from Battersea to Kennington is set to get underway following delivery of two tunnel boring machines (TBMs).

The cutting head of TBM Helen is lowered into the launch tunnel at Battersea on February 12. From March, it and sister TBM Amy will start burrowing the twin bores of the Northern Line extension from here to Kennington. TFL

The TBMs were lowered underground at Battersea by a 750-tonne crane on February 12. They will now be fully assembled within two 77 metre-long launch tunnels before setting off in March to burrow the two-mile (3.2km) twin-tunnel route to Kennington.

Tunnelling tradition dictates that TBMs are given female names, and these two have been named Helen and Amy after the first British astronaut Helen Sharman and the first female pilot to fly solo from Britain to Australia Amy Johnson.

The work will take six months and include an intermediate station at Nine Elms, near the New Covent Garden market.

The 300,000 tonnes of spoil will be taken away on barges to Goshems Farm in East Tilbury, Essex, where it will be used to create arable farmland.

The extension is due to open in 2020, when Northern Line trains will run to Battersea from the Charing Cross branch only. This is because the extension will join to the Kennington loop, which is used to turn back trains off the Charing Cross line.

It will be the first major Tube line extension since the Jubilee Line in the late-1990s.

Read more News in the March issue of The RM – out now!

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