URGENT repair work on a busy railway line which carries thousands of commuters a week is set to cause severe disruption for passengers after a ‘worrying’ hole was found in the track bed by engineers.

Services will not operate between Barnsley and Wakefield for two weeks after Network Rail found that a hole had opened up in between ballast and the line near Darton station, leaving engineers concerned given the town’s ‘strong coal-mining heritage’.

Subsidence is set to be investigated by inspectors while the track is closed, while intrusive ground drilling will commence to rule out any underground voids.

The hole was quickly backfilled by track workers but trains have been kept to a restricted speed of 20mph when passing the affected area in recent days.

Equipment was also installed to maintain 24/7 monitoring of the site levels due to similar holes being responsible for derailments in worst-case scenarios.

However, Network Rail bosses confirmed that they are ready to carry out detailed investigations of the ground as they look towards finding a longer-term solution which will increase trains’ speed and quicken recently-delayed journey times due to the reduced limit.

The line will be closed from February 15 until March 2 to allow work to be carried out, which includes drilling into the ground.

Aaron Crawford, a route engineer for Network Rail, said: “We have worked hard to provide short-term measures and keep train services on the move, but we now need to establish the underlying cause of the loss of ballast seen in December.

“Our investigations so far have not identified a clear cause but, given Barnsley’s strong coal-mining heritage, it is crucial we explore if there have been any changes in the ground beneath the railway line.

“We’re sorry to passengers and residents affected while this work takes place, but it’s important this work is carried out as quickly and thoroughly as possible.”

Operator Northern will run a reduced service between Sheffield, Barnsley, Leeds and Wakefield as a result.

Replacement buses will operate between Barnsley and Wakefield’s Kirkgate and Westgate stations.

Coun Trevor Cave, who represents the Darton West ward, told the Chronicle he will support residents who have been affected.

He added: “This is clearly a worrying development but the safety of passengers must come first.

“I urge Network Rail to expedite both the investigation and repair as quickly as possible and ensure passengers are kept updated at every stage.”

Barnsley North MP Dan Jarvis said the works were essential for safety.

“Whilst these works will cause huge disruption to Barnsley residents relying on the train to get to Wakefield and Leeds, they’re urgently needed to keep passengers safe,” he said.

“I will be in close contact with Network Rail over the next few weeks to ensure the line is back up and running without delay.”