Lanes Group drainage engineers have begun the task of carrying out a survey of tunnel drainage along the 7km-long Severn Tunnel.

The company has been commissioned by Amey, working for Network Rail, to carry out the surveys in the tunnel, which for over 100 years was the longest main line railway tunnel in the UK.

The work is one of a number of enabling projects preparing the way for the electrification of the Great Western Main Line between London Paddington and the west of England and South Wales.

In the first of yearly packages of examinations completing various sections, four teams of Lanes Group drainage engineers completed CCTV drainage surveys along 1,600m of track through the tunnel in 30 hours.