MORE than 40 years of digging has created the longest cave system in Britain – allowing cavers to go underground in Cumbria, travel below Lancashire and emerge in Yorkshire.

Two teams of potholers made the breakthrough on Sunday, shaking hands in the dirt after tunnelling through the final 140m to complete the Three Counties Cave System.

The achievement is the culmination of decades of work to explore the huge network of caves beneath the moorlands near Kirkby Lonsdale.

The combined total of the new cave system is estimated to be around 100km.

The work to connect the system was done by a small group of dedicated cavers, including Tim Allen, from Ingleton, in the Yorkshire Dales.

He said: “That last 140m has been one of the hardest to complete, burrowing through a horrendous fault zone of broken rock.

“This sort of digging is not for the faint hearted – commercial miners would have nightmares.”

Mr Allen admitted the cavers had survived a few close shaves.

“I was trapped under a collapsed boulder the size of a piano and only saved by a swift move with my crowbar – we named that spot the Piano Bar after that incident,” said Mr Allen.

“There have been a few minor injuries over the years, bashes to the face and crushed and blackened fingers, but we work as carefully as we can.

“Normally, we have the lead diggers tunnelling at the face, supported by others moving scaffolding up, and rock and mud out.”

To ensure the two teams met up, the cavers used sophisticated surveying equipment including lasers and radio locators. Smoke tests were also conducted to detect draughts.

The existence of the megasystem was first proposed by Dave Brook, from the University of Leeds Speleological Association, in 1968.

Since then, different groups of cavers have worked to connect the known caves.

Finally, only one connection remained, which took the teams two years to complete.

Although the dream of connecting the three counties is complete, the next move could be to extend the network much further into Yorkshire.

The potholers warn that navigating the full network of passages should only be attempted by the very experienced caver.