Network Rail has started the reconstruction of three bridges in Northamptonshire in the UK as part of a £70m programme to speed up journey times on the Midland Main Line between London and Sheffield.
The three bridges at Burton Latimer, Rushton and Kettering will be closed for up to 14 weeks while the work is carried out.
As part of the project, a fourth bridge close to Kettering Venture Park will also be demolished as it is no longer being used.
Following completion, the new bridges will provide extra headroom for trains travelling at high speeds, which tilt more as they pass through curved sections of railway track.
The rebuilt bridges on the line will also make room for the installation of overhead line equipment as part of the proposed electrification of the line between Bedford and Sheffield.
Network Rail is working with the Highways Agency, Northamptonshire County Council and Kettering Borough Council to reduce disruption and provide travel advice to those affected.
Network Rail acting route managing director Justin Page said that the reconstruction work will help to deliver quicker journeys for the growing number of passengers on the Midland Main Line.
"Our longer-term plans to upgrade and electrify the line will transform our diesel railway into one of the most modern in Europe providing more seats, even faster journeys, and cleaner and quieter trains," Page said.
Network Rail is planning to increase the line speeds on the Midland Main Line as it aims to reduce journey times between London and Sheffield by up to eight minutes.
The rail operator also intends to increase line speeds between Leicester and Trent South Junction, on the line to Kettering, around the Toton area, and between Nottingham and Sheffield.
Electrification work on the line between Bedford and Sheffield is expected to start in 2014, subject to approval from the Office of Rail Regulation in October 2013.
Network Rail plans to electrify the rail line to Corby by 2017, to Leicester, Derby and Nottingham by 2019 and to Sheffield by 2020.
Image: Three bridges at Burton Latimer, Rushton and Kettering will be rebuilt to speed up journey times on the Midland Main line between London and Sheffield. Photo: courtesy of Network Rail.