Network Rail has released footage of work it carried out on the Thameslink line over Easter weekend.
The rail infrastructure operator carried out extensive works around the country over the four-day holiday period.
On the Thameslink line, which runs from Bedford to Brighton through the heart of London, a major part of the £6.5bn upgrade programme took place.
Track was relaid and moved, signals replaced and new equipment installed along several miles of railway stretching from Waterloo East to Bermondsey.
Thameslink programme director Simon Blanchflower said: “The work we completed over the Easter holiday was a crucial part of the plan to improve services through central London.
“There is no good time to do this disruptive work but by doing it over the holiday we were able to reduce the impact on the millions of passengers who use London Bridge, Charing Cross, Waterloo East and Cannon Street every week.
“By moving the track around, we’ve made the space for some more major work out at Bermondsey that will take place later this year. This will provide a new dive-under to separate Thameslink services from those travelling to Charing Cross and improve punctuality and reliability.”
After much criticism when some Christmas period engineering works overran, Network Rail largely finished its Easter programme on time. It was 44 minutes late at Bermondsey and New Cross when testing took longer than expected.