Rail operator to carry out test runs on train lines affected by heat

A section of train track buckled south of King's Lynn, the operator said

A train operator is to carry out test runs ahead of a return to a full timetable after two days of disruption due to the extreme heat.

Great Northern and Thameslink services were cancelled earlier and a rail track buckled near King's Lynn, Norfolk.

Managing director Tom Moran said the safety of passengers and staff was a priority.

"The heat has been completely unprecedented... and so has the impact," he said.

• Live updates: Tuesday's heatwave in the East of England

Tonight, engineers will begin repairs to the buckled track on the Fen Line at Watlington in Norfolk, a Great Northern spokeswoman said.

Jenny Saunders, customer services director for Thameslink and Great Northern, apologised for the disruption and said the firm was hoping to run trains between Cambridge and Downham Market on Wednesday.

A replacement bus service would run between Downham and King's Lynn.

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Mr Moran said the East Coast Mainline - and the Midland Mainline out of St Pancras in London - had shut all day after reviews were carried out on Monday night with operational and safety teams.

"The most important thing we need to do is to keep people safe; this is just one of those things," he said.

"We had similar disruption with Storm Eunice and Storm Franklin a few months ago. This will pass."

Record UK temperatures were recorded earlier on Tuesday - hitting 40C (104F) in Lincolnshire.

Most of the network could operate when track temperatures heat up to 46C (115F), Network Rail said.

However, Suffolk recorded the hottest rail track on record on Monday - with a temperature of 62C (144F).

Great Northern and Thameslink services out of London were cancelled on Tuesday

Mr Moran said overhead cables, used primarily on routes north of London, tended to be more affected by heat, causing sagging as the metal expands.

"We've had the hottest of the hot weather in this region," he said.

"This evening, when the main heatwave passes, we will run test trains without passengers to make sure the infrastructure is behaving itself.

"It should mean we will be up and running with a full timetable for the start of services tomorrow [Wednesday]."