Llandegai Tramway (1798-1831)

Map of the Llandegai Tramway

The earliest predecessor to the Penrhyn Quarry Railway was the mile long 2 ft ½ in gauge Llandegai tramway which was built in 1798. The tramway was connected to a local flint mill that ground clay and chert into flints. These were transported to Porth Penrhyn on the coast by the tramway, which was one of the earliest overground railways in Britain. It included two balanced gravity inclines one from the floor of the Cegin valley near Llandegai to the hills above Bangor, the other dropping from there to the mill. Both inclines used vertically mounted winding drums.

Penrhyn Railway (1801-1878)

The success of the Llandegai Tramway encouraged the owners of the Penrhyn quarry to consider a similar tramway from their slate quarry to Porth Penrhyn.
The plan subsumed the existing tramway into a longer railway that connected Bethesda to the sea.

Construction started on 2nd. September 1800, relaying and extending the Llandegai Tramway, with the first slate train traveling on 25th. June 1801.
The new railway was also 2 ft ½ in gauge. The connection to the Llandegai flint mill continued to be used until 1831.
The railway was operated by horse power along with balanced inclines and gravity.

Penrhyn Quarry Railway (1878-1962)

By the early 1870s the Penrhyn Quarry Railway was no longer able to keep up with the output of the Penrhyn quarry.
By 1874 the decision had been made to replace the railway with a steam locomotive worked railway. Steam locomotives had already been introduced
with great success on the quarry's internal railway system and at the nearby Dinorwic Quarry.

At the end of 1875 the first "mainline" locomotive was delivered to Port Penrhyn and moved to the quarry workshops at Coed y Parc.
The railway was converted into the new railway in five stages from 1877 to 1878.