Port Dinorwic

From Festipedia, hosted by the FR Heritage Group

Port Dinorwic was a private harbour on the Menai Straits used for shipping the products of Dinorwic Quarries, to which it was connected by a private railway. The whole operation was in direct competition with the Blaenau Ffestiniog quarry owners, who used the FR and Portmadoc Harbour.

Origins of the Port[edit]

At first Port Dinorwic was just a tidal creek on the mainland shore of the Menai Straits known as Aber-Pwll, Moel-y-Don or Felin Heli. The development of the dock system and associated buildings began in 1793 when the Assheton-Smith family of Vaynol built a small quay on a marshy inlet to ship the output of its Dinorwic quarries. It stood immediately downstream of a corn mill worked by the tide, which had given the area its Welsh name - Y Felinheli - and displaced an earlier arrangement whereby slate was lightered into the Menai Straits from 500m to the south-west. Slates from Dinorwic Quarries (after Penrhyn Quarry, the world's second largest slate quarry) near Llanberis were loaded onto lighters and taken out to ships anchored further out in the Menai Straits[1] until the quays were opened in 1809 allowing ships to be loaded directly. The name Port Dinorwic was being used by 1824, and in this year a tramroad from Dinorwic Quarries was opened.

Port Dinorwic was expressly included in the jurisdiction of Caernarfon Harbour Trust.[2]

The Dinorwic Quarries Railway[edit]

The tramroad was replaced by a steam-worked railway on a new alignment in 1848 which ran until 1961. This line was called variously the Dinorwic Quarries Railway or the Padarn Railway and was in the same ownership as the Quarry. It was laid to four-foot gauge but carried two-foot (nominal, centre-to centre) gauge slate wagons on transporter wagons from the quarry yard at Gilfach-ddu to Penscoins, at the top of the escarpment overlooking Port Dinorwic. Here they were unloaded from the transporters and lowered down a self-acting incline to the Port, where they were shunted by locomotives to the quays. These locos were similar but not identical to those used in the Quarry, but despite this locos were sometimes transferred between locations. The deep buffer beams on the Port locos caused particular difficulties when trying to get them up the inclines to the higher levels of the Quarry, but it was achieved.

The 4' line also carried quarrymen but did not offer a public passenger service. One of its 1848 locomotives (Fire Queen) is preserved at Penrhyn Castle. After closure part of its route from Gilfach-ddu alongside Llyn Padarn has been re-used for the Llanberis Lake Railway.


Fenton records the development as follows:

"Docks and quays built in 1809, lock gates added in 1828, dry dock and engineering facilities constructed in the 1830s,a new outer basin completed in 1854, an outer lock added in 1897 to make the whole inner harbour independent of the tides and a new sea wall erected in 1905 between harbour and basin to extend the quays. A standard gauge branch from the Chester & Holyhead Railway reached Port Dinorwic in 1852, but almost ninety percent of the slate still left by sea, all in chartered vessels." The dry dock was a facility rare in North Wales and hence of much worth to the coastal shipping while the vessels remained. The Dry Dock Co's engineering workshops also did boiler repairs for the quarry locomotives including complete new boilers. In 1933 when the FR was looking to have Merddin Emrys's boiler repaired with new copper fireboxes and retubing the FR Co. got estimates from Avonside Engine Company of Bristol and the Quarry Engineering Works at Port Dinorwic. The boiler was eventually sent to Bristol to get the work done. [3]

The End of Commercial Traffic[edit]

The first quarry owned steamship was acquired in 1892. Partly because it was in the same ownership as the Quarry and dedicated to its traffic, Port Dinorwic was never the complete nineteenth century maritime society that Porthmadog became. For instance it did not have a sizeable shipbuilding industry and the Port Dinorwic surveyor for ship insurance worked for Portmadoc Mutual Ship Insurance Society.[4] In Porthmadog the society employed no less than thirteen surveyors! After the First World War other visiting steamers not owned by the quarry were still very important. In a photograph taken in 1925 the Dinorwic Quarry owned ships were outnumbered by other coastal steamers.

The last quarry-owned steamer was disposed of in 1955. The railway from the Quarry closed in 1961. Port Dinorwic gradually became a yacht harbour and continues in that role. Tourism, not slate, is now the settlement's most important industry. The dry dock still remains and the port is well maintained. As the commercial port has gone the large village which once bore it name is now generally known as Felin Heli.


  1. ^ Fenton R S (1989) Cambrian Coasters, World Ship Society pp 92 - 103.
  2. ^ Lloyd Lewis (1989) The Port of Caernarfon 1793-1900, Lewis Lloyd, Caernarfon p 1.
  3. ^ Jones C and Dennis P (2018) Little Giants: a history of the Ffestiniog Railway's pre-revival locomotives, their mentors, manufacture and maintenance, Lightmoor Press, Lydney, Glos, GL15 4EJ, UK.
  4. ^ Hughes H & Eames A (1975) Porthmadog Ships, Gwynedd Archive Services, County Offices, Carnarfon p 36.