Engineers will be working on the track between London Bridge and West Hampstead this weekend (January 18 and 19).
This means that no Thameslink trains will run between London Bridge and London St Pancras or Finsbury Park.
Services will also be cancelled between London Blackfriars and Sutton in either direction, via Wimbledon or Mitcham Junction.
During the track closures, engineers will renew switches and crosses, which allow trains to change tracks, in Clerkenwell.
Additional work will also be carried out at Agar Grove bridge in Camden.
It comes less than a month after some Thameslink trains did not run for more than a week while the rail bridge’s deck was replaced.
This weekend’s closure will allow workers to reinstall trackside lighting, restore brickwork and install new drainage gutters at the bridge, Thameslink has said.
The track closure will also impact some East Midlands Railway (EMR) services.
Daniel Matthews, operations director for Network Rail’s east Midlands route, said: “We sincerely thank passengers for their patience and understanding while these improvements are carried out.
“We strongly encourage everyone to check before they travel via National Rail Enquiries or their train operator.”
Thameslink trains will continue running to an amended timetable on some routes.
These include:
- London St Pancras International and Luton/Bedford (trains will not call at Kentish Town)
- London Bridge and Three Bridges/Horsham/Brighton
- London Victoria and Sevenoaks (trains will not call at Elephant and Castle or London Blackfriars)
- Plumstead and Rainham (Saturday only)
- Plumstead and Gillingham (Sunday only)
EMR will run an amended service to and from London St Pancras as follows:
- One train per hour between Corby and London St Pancras International
- One train per hour between Nottingham and London St Pancras International
- One train per hour between Sheffield and London St Pancras International
