Construction of the River Tunnels

When the colliery was working the River Rhymney was diverted from it's original course to run through the colliery to be used to clean the coal.

As part of the reclamation a stretch of the river was to be tunnelled over. It had to be an exact amount of tunnel due to the fact that fish would not swim up through the tunnel to breed in the upper reaches of the river.

The walls for the new river course were constucted with hexegon slabs then faced with stone and massive concrete arches were constructed on site for the tunnels.

The river was then diverted back to run through the new course.

As I mentioned earlier in the blog the Rhymney River was in a terrible state when it was used to clean the coal from the colliery.

Nature is wonderful though, less than a decade later and you can see how clear the river is in the picture below

Here is a close up of the same photo and you can see to the bootom of the river.