A crucial stage of the £6bn Thameslink project connecting trains from the South East to the north of London is reaching its conclusion.
New tunnels at St Pancras will link rail service through London to the north, allowing 24 trains an hour to London and beyond. It will mean for the first time passengers will not need to change trains in London.
It's expected to ease overcrowding and provide better services.
Improvements include major improvements at London Bridge and more than 1,000 new train carriages.
Trains will run every 2-3 minutes in each direction through central London at the busiest times. Many of the trains will be longer with more space for passengers.
It will also involve untangling the track on the approaches to and around London Bridge station to reduce the time trains wait for platforms to clear and cut delays.
There will be direct links to Crossrail at Farringdon, the Eurostar and High Speed services at St Pancras International as well as direct links to Gatwick and Luton Airports. This will increase travel options across London and relieve congestion in places like the central sections of the Northern Line.
The first two new platforms open at London Bridge (14 & 15) with new longer and wider canopies to protect passengers from the rain.
As the two new platforms open, other platforms (12 & 13) close for redevelopment.
23 - 31 August 2014
No Southern services will call at London Bridge. Some Thameslink route services will be retimed and some Southeastern services may be altered. This includes four working days after the late August bank holiday.
20 December 2014 to 4 January 2015
No Southern or Thameslink route services will call at London Bridge for 16 days. This includes three working days before and after Christmas.
December 2014 to January 2018
Thameslink services between Bedford and Brighton through central London will be diverted away from London Bridge and will run via Herne Hill instead. There are plans to maintain an off-peak service between London Bridge station, Gatwick Airport and Brighton.
January 2015 to August 2016
Southeastern services to and from Charing Cross will not to call at London Bridge as Network Rail redevelop platforms and work on the associated track and signalling.
Southeastern services to and from Cannon Street will still call at London Bridge. Some diversions will take place between Charing Cross, Cannon Street and Blackfriars.
January 2015 onwards
Greenwich line, New Cross and St. John's station services are diverted to Cannon Street from January 2015 onwards.
The first new Thameslink trains will be used on the Thameslink route.
The station redevelopment work reaches half way with the redeveloped platforms 10-15 complete.
August 2016 to early 2018
Southeastern services to and from Charing Cross services resume calling at the station.
Southeastern services to and from Cannon Street services will not call at London Bridge as Network Rail redevelop platforms and work on the associated track and signalling. Some diversions will place between Charing Cross and Cannon Street.
Half of the new street level concourse opens at London Bridge station with direct access to St Thomas’ Street.
Cannon Street services resume calling at the station.
Completion of track, signalling and major bridges work around London Bridge station. New bigger and brighter station opens.
The East Coast Mainline Great Northern route, from Peterborough and Cambridge and stations in between are connected to the Thameslink route via tunnels at St Pancras International.
Crossrail is complete and starts running east-west across London connecting with the Thameslink route at Farringdon.
Further details on the scheme can be found here.