Network Rail is warning passengers that it will have to carry out urgent late-night engineering work on the Fen Line in East Anglia next weekend.

The work will take place between the evening of Monday 28 July and the morning of Friday 1 August, and buses will replace Great Northern trains from 9pm.

Engineers will be working on improving the condition of the track, which has deteriorated as a result of the driest spring in more than fifty years. The lack of rainfall has caused the peat soil beneath the track to shrink, which has resulted in the track dropping in places and becoming uneven.

Network Rail has applied speed restrictions to keep train services running safely, but this has made journey times longer. With next weekend’s work, engineers aim to limit the effects of this, and will use tampers to lift the track and push ballast underneath to create a solid foundation.

While Network Rail was already planning to carry out work of this type on the line next week, with train services finishing earlier, it has now decided to extend the time for tamping by around an hour each night.

Over the last two years, Network Rail has added 25800 tonnes of ballast to this part of the line in order to minimise the effects of peat shrinkage. It had also carried out similar work prior to that.

Engineers will continue to monitor the Fen Line track closely over the coming weeks. Network Rail will advise passengers of any further changes to services.

The Fen Line runs between Cambridge and the Norfolk town of King’s Lynn, and two years ago, its growing popularity led to services being increased.

“We’re really sorry for the disruption at night next week, but we need the extra time to get the track in a better condition. Our teams are working hard to keep running the best possible service for Fen Line passengers, even with the significant challenges we face with peat soil following prolonged dry spells. Thank you to everyone for bearing with us.”

Simon Milburn, infrastructure director for Network Rail Anglia