WHEN rail bosses needed to repair a 175-year-old hillside tunnel they turned to the sky to help them do the work.

They hired a specialist helicopter team to upgrade two historic ventilator shaft turrets protruding out of the moors above Darwen.

Network Rail spent £150,000 on the work on the Sough Tunnel which takes passenger trains between Clitheroe and Manchester through the hill.

The Great North Rail Project investment, which started in February and finished last month, was the latest stage in a long-running safety upgrade of the historic Victorian underground passageway.

Darwen East ward’s Cllr Roy Davies said: “Hiring a helicopter seems an enormous palaver for this work. It must have cost them a huge amount.”

The tunnel has two shaft turrets that protrude from the moors. They help release air pressure created inside by moving diesel trains, maintaining air quality for passengers and preventing damage to the walls inside.

Being unable to access the land surrounding the site on the ground, Network Rail hired a specialist helicopter team to transport five tonnes of bricks and materials to build a new 2.6metre diameter metallic grille on top of the shafts.

Mark E Smith, the scheme’s project manager, said: “As part of our putting passengers first programme, we’ve invested £150,000 to make Sough Tunnel safer and reliable for trains carrying East Lancashire residents between Clitheroe and Manchester via Blackburn and Darwen.

“While we were unable to access the site from the surrounding fields, we used a helicopter to help complete the safety repairs.

“It proved a cost-effective solution as we did not have to pay any landowner costs and, with the wet weather we have experienced, meant there was much less damage to the local area building access roads for heavy goods vehicles.”

The tunnel is approximately 1,842 metres long. Originally the shaft turrets were used as an outlet for steam trains. Today, they play a vital role releasing the air pressure caused by trains as they pass through.The new brickwork inside the shaft turret and grille will keep the structure safer from trespass and help keep trains punctual and reliable.

Cllr Davies said: “If people ask why are train fares so expensive, this could well be the answer.”