Cwmorthin Quarry

View of Cwmorthin Quarry across Llyn Cwmothin

View of Cwmorthin Quarry from the south

Cwmorthin Quarry is a slate quarry west of the village of Tanygrisiau, north Wales. Quarrying on the site started in 1810. In 1860 it was connected to the Ffestiniog Railway. In 1900 it was acquired by the nearby Oakeley Quarry and the two were connected underground. In 1970 it closed along with Oakeley. There was small scale working in the 1980s and 1990s, the mine finally closed in 1997.

History

Slate extraction began at Cwmorthin in 1810, when a small quarry was opened on the site by the Casson family who later owned the Diphwys Casson Quarry. This early quarrying lasted for about twenty years.^[1] In 1861, the Cwmorthin Slate Company was formed and work began on underground mining.^[2] In the same year, the 2 ft (610 mm) Cwmorthin Tramway was constructed to connect the quarry with the nearby Ffestiniog Railway at Tanygrisiau.^[3] In 1876 the mine produced 12,500 tons of finished slate.^[1]

The quarry gained a reputation for poor working conditions and was known locally as "The Slaughterhouse".^[4] Between 1875 and 1886 there were 22 deaths in Cwmorthin out of a workforce of around 550.^[1]

A new company the New Cwmorthin Company was formed in 1876 following the collapse of the original company. By this time Cwmorthin's mining northwards had met Oakeley's mining heading southwards under Allt-fawr. Several disputes arose over the boundary between the mines. In 1884, the mine suffered a significant collapse which shut off many of the working chambers. This directly led to the winding up of the company in 1888.^[1]

Following the Great Fall at Oakeley in 1883, the Welsh Slate Company gave up their lease at Oakeley. In 1889, they set up the New Welsh Slate Company and purchased Cwmorthin. Their timing was unfortunate as the peak demand for slate had passed and the industry was descending into recession. By 1900 the new company had failed and went into liquidation. Oakeley purchased the quarry that year. With the fortunes of the industry continuing to decline, in 1902 Oakeley stripped Cwmorthin of its machinery and allowed the workings to flood.^[1]

After the First World War, Oakeley explored re-opening Cwmorthin. In 1925 they renewed the tramway connection to the Ffestiniog Railway and the mill and resumed working. In the 1930s, the flooded lower levels were drained via the Oakeley workings which by then were underneath the lower Cwmorthin chambers.^[1]

Oakeley continued to work Cwmorthin until it closed in 1970, though the slate was extracted via the Oakeley adits and was processed in Oakeley mills. The mine was worked again in the 1980s and early 1990s from the Cwmorthin side, but this was on a limited scale.^[2]

Description

References