Midland Mainline improvement programme

We've started the biggest programme of improvements to the Midland Mainline since its completion in 1870.

The Midland Mainline (MML) runs from London St Pancras to Sheffield, via Luton, Bedford, Corby, Leicester, East Midlands Parkway, Derby, Nottingham and Chesterfield. It serves a diverse set of markets ranging from long distance and commuter travel to leisure passengers visiting Derby, Leicester and Nottingham as well as London.

The line will be electrified from Bedford to Kettering and Corby, bridges and tunnels altered or rebuilt, and work will be carried out to remodel stations and carry out line speed improvements.

The benefits of electrification

Electrification of the MML north of Bedford to Kettering and Corby is scheduled to be completed by December 2019.

The work to electrify the MML is a vital aspect of our strategy to provide a safe, reliable and efficient railway fit for the 21st century and beyond.

Enabling electric trains to operate on the MML will mean:

  • more seats
  • less track maintenance
  • faster trains

Enabling electric trains to operate between Bedford to Kettering and Corby (the section between London St Pancras to Bedford was electrified in the 1980s) will deliver numerous benefits.

It will improve journey times and make services more comfortable and smoother for passengers, as well as cleaner and quieter for people living near the railway.

Preparing for electrification

In order to deliver the MML upgrade, a significant construction programme is required. To prepare for electrification we may need to make the following changes:

  • upgrade bridges and tunnels
  • carry out enhancement works to bridge parapets
  • strengthen railway embankments
  • assess footpaths/level crossings
  • clear overgrown vegetation
  • undertake piling work to install the foundations for structures that will carry overhead lines
  • install overhead line equipment.

Midland Mainline map

As we enhance our infrastructure we also work to minimise our impact on the natural environment. Before any work begins we carry out ecological surveys and environmental impact assessments where required to identify any protected species or nesting birds and relocate them where necessary.

Alongside our partners we try to make sure our sites are managed responsibly and to minimise the impact of works on people living close to the railway. We minimise noise and brief teams on working responsibly in the local community.

Keeping you informed

Under our licence conditions we have to work at times that cause the least disruption to train services. This means carrying out a lot of our improvements during the night, at weekends and bank holidays.

Work to structures such as bridges can require road closures and diversions. We understand this can cause inconvenience, however the safety of road users, pedestrians and our personnel remains paramount.

Clearing vegetation

Before electrification, we will address lineside vegetation along the route. This is to prevent interference with overhead line equipment and reduce the risk of short circuits to parts of the electrified system. Mature vegetation will usually be cleared to a distance of six metres from the railway – while a proportion of vegetation will be preserved for its ecological benefits.

Unmanaged, overgrown trees and plants can cause serious safety problems as well as train performance issues, such as:

  • covering up signals or falling onto tracks and overhead power lines
  • stopping our workers finding a safe refuge when trains are passing, and hampering their ability to see trains approaching
  • reduced visibility at level and footpath crossings
  • autumn leaves falling onto tracks – when railway traffic crushes them at 20 tonnes per square inch they form a hard, Teflon-like coating that reduces trains' ability to grip and affects acceleration/braking, leading to delays.

Overhead line equipment

The MML will be electrified using a 25kV overhead line equipment (OLE) design. This refers to the wires and supporting posts that distribute electricity at 25,000 volts to power trains.

Generally, most types of railway overhead line equipment have overhead conductors with a copper contact wire suspended from a catenary wire by 'droppers' or 'drop wires.'

Read more about how we electrify the railway

These conductors are suspended from trackside steel masts mounted upon concrete foundations spaced around 40m to 70m along the track (depending upon local terrain). The 'live' parts of the equipment are insulated from the structures by porcelain or polymeric insulators.

Electricity to power the MML will be drawn from the National Grid high voltage transmission network via four grid access points and distributed along its length through 24 substations. We will aim to place new equipment where it will cause the least visual impact. However, this infrastructure will change the appearance of the railway and surrounding area.

Minimising the impact of infrastructure

Network Rail respects the environment and aims to minimise its impact. The landscape is taken into account and, where practical, structures such as substations are sited in less visibly intrusive locations such as railway cuttings.

If we renew fencing we use fencing that is appropriate to the area.

Residential – Holly Green powder-coated palisade

Industrial – Existing chain fencing will not be replaced. New fencing will be galvanised palisade

Rural – Robust seven-strand wooden post and wire with stock netting

The MML is rich in heritage, and we've worked with specialist consultants to make sure sensitive historic structures are safeguarded. Over 1,500 structures have been assessed, resulting in over 100 new listings, upgrades or amendments by the Department of Culture, Media and Sport as a result of Historic England's advice. For example Ambergate Viaduct in Derbyshire has now been listed as grade 2* indicating its significance in historic and architectural terms. We therefore work closely with local authorities when designing new infrastructure in areas of architectural or cultural significance.

Contact us

If you have a question about our infrastructure, call our 24 hour helpline:

03457 11 41 41

or contact us online