1. ITV Report

Traditional mining skills used to build tunnels on the Northern Line extension

By Katie Oakes, ITV London

Credit: PA

Miners are tunnelling part of the Northern Line extension by hand in an operation that's too dangerous and delicate for big machines.

The £1.2bn extension linking Kennington to Battersea is due to be completed in 2020.

Part of the work involves excavating around the 100-year-old casing of the existing Northern line while trains are still running.

They tunnel 24 hours a day, seven days a week but progress is slow. It takes a week so progress 2.4m, compared to giant boring machines which can tunnel 30m a day.

We can't put heavy machinery near it, it's too much of a risk, just in case they hit a tunnel ring or something happened. Therefore we have to do it all by hand.

Credit: PA

Many of the miners working on the new tunnels are using skills passed down through the generations from the men who built the Underground.

Most of the miners here tend to be multigeneration miners from Ireland. There are a few ex coal miners as well who make up the crews but the Irish miners tend to be the tradition in this kind of work.