The Llantysilio and Berwyn Mountains around the Dee and Ceiriog Valleys are good sources of slate, which has been used in local buildings for centuries. The coming of the canal opened new markets for the quarries, as far away as London. Canal boats could carry much heavier loads than carts into the booming industrial cities.
Quarries were linked to the canal by tramroads. These used wagons on rails, pulled by horses or just gravity on steep slopes, called inclines. Later, small steam engines were used on the Glyn Valley Tramway.
Cutting and trimming slate was usually done in the quarries, so only the useful stone had to be transported. However, the quarries near Llangollen transported the raw material to a slate mill at Pentrefelin. These works were large and included cottages for some of the workers’ families, a loading crane over the canal and eventually its own railway sidings.
In the late nineteenth century slate quarries and mills employed hundreds of workers. But the industry experienced economic boom and bust, and the dangerous work was not always a secure job. Today only one quarry still operates on Llantysilio Mountain, a much smaller operation than in the past.
1946 film from Penrhyn Quarry
This film, made in Penrhyn Quarry, Bethesda in 1946 shows working methods that were the same as those used at the Llangollen quarries and Pentrefelin. Click here to see the video.
1930s film from unnamed Welsh quarry
This film shows working methods that were the same as those used at the Llangollen quarries and Pentrefelin.
More Information About Slate
Minerals that form slate were originally mud at the bottom of an ancient sea. Over hundreds of millions of years, heat and pressure compressed the mud into hard layers. The alignment of crystals in these layers is what allows slate to be split into wide, flat surfaces of almost any thickness.
Clogau, now called Berwyn quarry, is the last in this area which still quarries fresh slate. The mill is now at the quarry, not Pentrefelin, but the slate is still mainly cut as slabs. These are used for kitchen worktops, floors and even for the clockface on Llangollen Church.
Moel y Faen was the largest quarry serving the slate works at Pentrefelin. In the 1880s it employed nearly 200 quarrymen. Today it is the enormous waste heaps that are quarried. This waste slate now has a use as aggregate in the building industry.
From the canal at Pentrefelin you can see the lower end of the Oernant tramroad, built in 1857. This horse-drawn railway brought the wagons of uncut slates to the mill at Pentrefelin. The tramroad connected with incline railways from the Moel y Faen, Oernant and Clogau quarries.
At the bottom of the Oernant tramroad, the wagons of slate were taken over the canal on a lift bridge. The bridge has gone now but today you can still see a narrowing of the canal where it used to stand.
The shed at Pentrefelin, where the slate was cut into slabs, is now the Llangollen Motor Museum. It used the fast-flowing river for power and the canal to transport its products. A railway link from the main line was built to the works in 1869, at the cost of £1,000.
There are cottages for slate mill workers on either side of the canal. The manager’s house is just above them on the hill. The manager for over twenty-five years was Captain John Paull. He founded the first English-language chapel in Llangollen. Before then, services were held in his house.
The Glyn Valley Tramway carried slate, granite and limestone from quarries in the Ceiriog valley to the canal. Originally it went to a wharf at Gledrid but after the railway was built, the tramway diverted to Chirk station and another wharf further along the canal, near the Afon Bradley feeder.
From 1874 the Glyn Valley Tramway carried passengers as well as quarry products. Originally drawn by horses, it converted to steam engines in 1888. As the quarries declined, so did the tramway traffic. Passenger services ended in 1933 and goods services in 1935.