Media playback is unsupported on your device

Great Western Main Line electrification begins

13 August 2014 Last updated at 08:50 BST

Work to electrify the Great Western Main Line has begun.

Network Rail is using a specially-designed factory train called Brunel which works at night so trains can keep running during the day.

The train works up to five times faster than conventional gangs of track workers.

The team will work westwards at one mile a night, reaching Oxford, Newbury, Swindon and eventually Bristol and south Wales at the end of 2016.

BBC © 2014 The BBC is not responsible for the content of external sites. Read more.

This page is best viewed in an up-to-date web browser with style sheets (CSS) enabled. While you will be able to view the content of this page in your current browser, you will not be able to get the full visual experience. Please consider upgrading your browser software or enabling style sheets (CSS) if you are able to do so.