Scooped out of the side of the pocket mountain that gives the quarry it's name, Moel Tryfan (or Cloddfa'r Foel) is an impressive place. The tips are monumental as they rise five layers up, while the pit is spectacular enough to have been featured in several movies. It does have that "lost world" feel, although it must have been infinitely more spectacular when it went down to the full depth of the sinc.
At the top level, the pit joins the void of the Alexandra quarry, seperated only by a tooth of igneous rock. It's a wonderful site and well worth a day's exploration
As with most quarries, it has suffered a chequered history, not without drama. Unlike many in the area, it was successful, although plagued constantly by problems with falling rock and lack of investment.
The earliest mention of the quarry is back in 1745 when a lease was taken from the Crown estates although nothing significant seems to have been done until 1824, when a consortium of Caernarfon artisans took a lease on the sett. These men, two Jones Brothers and another unrelated Jones dug a small quarry near to the office building that still stands (just!) at mill level. They also started to dig further up the hill, which was later to become the twll mawr.
The quarry changed hands a few times, with problems due to the Crown's lax handling of the lease, incompetent management, thieving employees and of course, rockfalls. Several men were killed in a major rockfall in the main pit in the early 1840's. Five different lessees tried their hand at the quarry before 1876, all of whom invested heavily and came up against the same problems. While good rock was certainly to be had, sometimes the slate beds were elusive, sometimes they were gritty, had lacy veining (gwniadiau) or had "wild split", cleavage which shattered when split.
Eventually, the leasehold was sold in 1876 to local slate merchant Griff Williams, bankrolled by a band of adventurers who included ship owners, drapers and bankers. Williams built a new long incline and tramway to the Bryngwyn Drumhead of the NWNGR. In one move, the quarry was to become profitable; it was, in fact, one of the largest customers of the line, which closed shortly after Moel Tryfan's output went over to motor lorry. Immediately that the railhead became operational, the quarry's sales increased- £7,400 in 1886, then in 1903, £22,413. But this came at a cost. Rock fell regularly in to the pit and had to be manhandled out. In November 1909, 421,000 tons of rock slipped from the North face of the quarry, completely filling the pit.
Rail fans will know that the quarry was home to two curious "Quarry Hunslets", similar in specification to the Dinorwig "Alice" class, but with cut-down chimneys and cabs so that they could run through the very narrow tunnels connecting the mill to the pit.
Cliff Thomas, Quarry Hunslets of North Wales, Oakwood Press
Incredibly, worthwhile extraction of slate took place up to the late nineteen sixties- in 1962 there was a workforce of 35 men, but more serious rock falls in 1968 and in 1970 made things ever more difficult. Finally, in 1972, the Safety Inspectorate condemned the work face, and the end was signalled. Since then, there has been tip reclamation and extraction of hardcore by various concerns- the latest being a Caernarfon based road contractor.
"Cwm Gwyfrai - the Quarries of the North Wales Narrow Gauge and the Welsh Highland Railway" by Gwynfor Pierce Jones and Alun John Richards, Garreg Gwalch, ISBN: 0-86381-897-8
"Gazetteer of Slate Quarrying in Wales", by Alun John Richards, Llygad Gwalch, ISBN: 1-84524-074-X
"Quarry Hunslets of North Wales", by Cliff Thomas,Oakwood Press, ISBN: 0-85361-575-6