Historic slate mine re-opens in Northamptonshire

Collyweston slate is again being mined in Northamptonshire. Credit: ITV News Anglia

Mining is set to return to Northamptonshire with the revival of a very old slate mine.

For centuries Collyweston Slate was created by leaving lumps of limestone to split open in the frost but the changing climate made it an unreliable method and mining had to cease.

Now a way to artificially freeze the stone to crack it has been discovered which means they can re-open a mine that dates back hundreds of years.

They are digging their way towards a new source of historic Collyweston slate.

This mine at the Northamptonshire village has been closed for decades.

Nigel Smith, director of Claude N Smith roofers, has decided to re-open the tunnel on his land because a new method has been found for splitting the distinctive limestone into slates.

Click below to watch a report by ITV News Anglia's Stuart Leithes

For centuries, Collyweston slate was mined in the area and it can be seen on historic buildings like King's College in Cambridge and Rockingham Castle near Corby.

Some slates have been reclaimed from old buildings for reuse.

Traditionally the limestone was left outside to split naturally when there was a frost overnight. But production ended in the 1960s because frosts became too unreliable.

Now Natural England working with Sheffield Hallam University have shown that industrial freezers can replicate the process.

Production of Collyweston slate had to cease when the frost need to create it became unreliable. Credit: ITV News Anglia

In the new mine there are still signs of where stone was extracted hundreds of years ago.

King's College is hoping to use the first slates to do some roof repairs.

It is hoped that this new source of Collyweston limestone could prove to be a rich seam of business.

King's College, Cambridge is hoping to benefit from the new slate mining. Credit: ITV News Anglia
Collyweston slate has been used on a range of historic buildings. Credit: ITV News Anglia