[3] In 1909, the quarry stopped working for two weeks due to a general depression in the price of slates.

In 1868, the LNWR opened their line to Betws-y-Coed and from that date onwards slate could be hauled there, which was still a distance of nearly 7 miles (11 km) over rough mountain roads.

During the later years of operation a Motor Rail Simplex locomotive was purchased to work the lower tramway.

Its height on the mountain meant it had a relatively restricted water supply, and on several occasions work stopped due to drought, including in 1891.

There were originally two pits, the upper working was known as Rhiw Fachno and the lower one was the main Cwm Machno quarry.

[8] The chair for the 2019 National Eisteddfod of Wales, held near Llanrwst, was made from slate from Penmachno quarry.