Graig Ddu quarry is a disused slate quarry near Blaenau Ffestiniog, in Gwynedd, North Wales. Although output was only about 3,000 tons a year, it reputedly has 36 saw tables and the same number of dressing machineson site. As with others in the area, the quarry suffered from a lack of water, resulting in the siting of the mill some distance away, at a lower level.
History
The quarry originally opened as Manod quarry in about 1800. In the 1840s, the Manod quarry moved northwards, and the new site was developed as Graig Ddu. From around 1868, a three-pitch cable-worked incline was built down to the main road. These first three inclines were renowned for the quarrymen's use of ceir gwyllt, a sort of skateboard which sat on one rail, with an arm reaching across to a parallel rail, an operation that was only possible at Graig ddu, of all the Blaenau quarries, because the exit incline from the mill level was both very long and of unusually shallow pitch—it ran across the face of the hillside to the east of Tanymanod, rather than directly up and down. This was one of the last quarries in the area to ship slatedown the River Dwyryd, as it did not link to the Festiniog Railway when that opened in 1836. Instead, Craig Ddu quarry continued to ship slate via a packhorse to the Dwyryd until 1868, when the Festiniog and Blaenau Railway opened. This railway connected with the quarry inclines; its vastly improving the method of transporting slate from the quarry. After 1883, when this railway was converted to standard gauge, wagons were carried to Blaenau Ffestiniog, where they could be transferred to the Festiniog Railway or into GWR wagons for onward shipment, using a piggy-back style similar to that used on the Padarn Railway at Dinorwig quarry.
Closure
Graig Ddu closed in 1939 at the outbreak of the Second World War. It re-opened briefly after the war to supply slates for rebuilding bomb-damaged cities. The quarry employed 86 men when it closed in 1946.
Modern operations
From the mid-1980s, modernquarrying operations at the site of the original Manod quarry extended over the summit of Manod Mawr and reached the derelict Graig Ddu quarry. Much of the quarry site has been obliterated by this untopping operation. Untopping at Graig Ddu ceased in 2007.
