Ponc Isaf Braich, Dinorwig slate quarry
Here the footpath across the old slate quarry crosses the level known as Ponc Isaf Braich. Please stay on the footpath and do not cross the fence.
South east of the path you can see the foundations of one of the quarry’s largest buildings, a mill where large volumes of slate were sawed and processed. When the mill opened in 1927, it had 108 sawing tables – more than any other mill at Dinorwig at the time.
Two of the quarry’s many smithies were at Ponc Isaf Braich. Quarrymen paid the blacksmiths for tool repairs. The smiths were self-employed, paying the quarry company rent and for coal.
The gallery’s name contains a clue to how this side of the quarry, known as Braich, developed. Ponc means gallery. Isaf means lowest. In the early decades, slate was removed from the quarry through Allt Ddu, on the far side of the quarry (north west of here). Ponc Isaf Braich was at approximately the same elevation, c.300m (1,000ft) above sea level. Slate from the higher galleries reached here on gravity inclines.
Quarrying the slate from lower levels was inefficient because the rock had to be hauled up to this level for dispatch. When Lord Newborough sold his land alongside Llyn Padarn, Dinorwig quarry owner Thomas Assheton Smith was at last able to build his Padarn Railway along the shore which opened in January 1843. Slate from below Ponc Isaf Braich could then be transported efficiently downhill and onwards to his dock at Y Felinheli.
West of the footpath stands the ruin of a winding house built onto the side of its predecessor. This structure controlled the descent of wagons on the C3 incline. The inclines from here downwards were rerouted between the world wars. The original C3 winding house wasn’t angled correctly for the new incline so another one was built alongside. The brakesman’s hut was placed inside the original winding house.
Leading upwards to the north from here was the C4 incline, one of the quarry’s longest.