Mayor of London Boris Johnson kicked off the official start of work on the Northern line extension that will see two new stations built at Nine Elms and Battersea Power Station.

The new additions will be funded entirely through the private sector, cutting journey times from Battersea to the City and West End to an estimated 15 minutes.

Wandsworth Times:

The project also promises to increase the frequency of trains to a minimum of 30 per hour.

November 19: Plans for 300 homes above Nine Elms tube station as Battersea development expands

From 2014: Unlocking Wandsworth: Nine Elms and the impact on the infrastructure

From 2014: Unlocking Wandsworth: Nine Elms project to transform forgotten area​

On Monday, Mayor Johnson and Wandsworth council leader Councillor Ravi Govindia visited the site and started up a specially designed 300m conveyor belt to transfer excavated earth from the site. 

Waste generated by the construction of the station and the two 3.2km tunnels will be taken by barges and unloaded to Goshems Farm in East Tilbury in Essex. 

Transporting this excavated material will reportedly remove more than 40,000 lorry journeys, reducing traffic congestion and saving the site's carbon footprint by 2,000 tonnes of CO2.

Wandsworth Times:

Mayor Johnson said: "The whirring into action of this fantastic machine marks a key moment in the delivery of the Northern line extension.

"This gigantic conveyor belt will enable a staggering 600,000 tonnes of material to be excavated from beneath south London and transported safely by barge on the Thames."

Nine Elms and its regeneration on the South Bank has seen huge economic growth and has provided over 25,000 new jobs and 20,000 new homes.

Leader Coun Govindia said: "This Tube extension is transforming the fortunes of north Battersea.

"Around these new underground stations we're building more than 6 million square feet of new commercial and cultural space which will make Nine Elms a lively and exciting new addition to London's South Bank.

"The regeneration programme is one of the greatest sources of new jobs and homes in the country and this would not be possible without the Tube link."

The extension is due to begin early 2017 and will take an estimated six months to complete.