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DOROTHEA slate quarry - August 2011


Full Member
Aug 7, 2012
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The trip....Oldskool and Host, another epic fail turns good...

Arrived in Wales early morning (like we do ),took a short walk to find the pump house . I thought to myself this place we be a doddle being so remote , how wrong was i...

We spent a good hour and a half looking for a way in , even crawling under the boilers at the back and scaling old roofing beams ...this place is like fort knox .

The only place we could think of was to one side of the huge pipe running out of the pump house , alas on closer inspection it was back filled with scaffolding planks and lumps of cast iron and steel (epic fail)

Anyways no to be disheartened we set about the pretty big task of shooting the rest of the quarry ,after about two hours we arrived back at the top of a hill near the pump house this time Host had disappeared, i could hear voices round the corner so went to see what was going on , i came across Host talking to a man in shorts and a big black hat ( saved again by a dog walker )

Quote Host " This man knows were the engine's custodian lives , well kind off "..

Brief directions ...up the hill, he drives a four wheel drive and his name is John. So of we went ten minuets later we approached an elderly gentleman stood in his garden with his 3 dogs ....." hi could you tell us if john lives around here ? "

He replies im John..............NO WAY.........!!!!!

Ok onward, he takes us in his jeep and gives us a guided tour of the whole quarry and explains about every out building on there he even drove to the house he was born in and showed us his newly planted gardens, this went on for about a hour then we arrived at the pump house .....



Dorothea itself opened in 1820 and remained in production until 1970. The land the quarry stands on was owned by a Richard Garnons (1774 -1841) but the main driving force for quarrying in the valley was a Lancastrian - William Turner (1776 -1857). The original name for the quarry was Cloddfa Turner but it was renamed Dorothea after Gamona's wife. The workings grew out of a series of smaller workings with names such as Hen Dwll, Twll Bach, Twll y Weirglodd, Twll Coch and Twll Fire. Over the years these pits were deepened and amalgamated into the large flooded pit seen today. Turner gave up his interest in the quarry in 1848 and following a brief period of closure it was acquired by a family called Williams.

He married into the Rev John Jones of Talysarn's family & John Hughes Williams was from Llangernyw near Denbigh. bought shares in the Company set up by Jones & local Nantlle quarrymen (though half the money was raised outside the area). Williams gradually bought out most of the others by the 1860s, and his family continued in charge thereafter.


In 1828 the Nantlle Railway opened giving the quarries of the valley a route to the sea. The horse powered railway was of 3' 6" (105cm) gauge and ran originally to Caernarfon. From 1872 the tramway ran only as far as Talysarn where connection was made with the national rail network. The Nantlle Railway continued in use, as a part of British Railways, until 1963 and remained horse worked until a couple of years before closure. The final two horses in use were "Prince" and "Corwen". After the horses were retired a tractor was used for the diminishing amount of traffic. Over its lifetime the route of the railway was moved many times as the quarries expanded. Much of its route is traceable today as far as the easterly terminus at Penyrorsedd Quarry. Dorothea Quarry used the Nantlle Railway to dispatch slate from 1829 until 1959.

By the 1840's production at Dorothea had built up to about 5,000 tonnes per annum and had reached over 17,000 tonnes by the 1870's. The future looked good for Dorothea but serious flooding problems then befell the quarry. In 1884 several men were drowned when the pit was engulfed. In 1895 the Afon Llyfni which flowed through the valley was realigned and deepened to flow to the south of the slate workings. This cured the flooding problems to some extent but as the workings deepened, the need to continually pump out water became a constant drain on the quarry's profits. In 1904 the decision was taken to install a Cornish Beam Engine on site to replace the waterwheels.









The pump ....

At the beginning of the 20th Century, Dorothea quarry was urgently in need of a long term solution to the ongoing problem of keeping the workings, by then over 500 feet deep, free of water. It was decided to purchase a Cornish beam engine. An old but reliable technology. The engine was built by Holman Brothers and was the last but two ever built. It is also believed to be the newest Cornish beam engine still in existence. The engine was able to pump 10 gallons of water per second from a depth of over 500 feet. The engine started work in 1906 and served until 1951 when it was replaced by a 60hp electric pump. Apart from a brief period in 1956 the engine has been disused ever since.

Following closure of the quarry in 1969, the site has been owned by several companies, each with its own priorities and plans - none of which have included the engine. This has made the restoration and maintenance of this important artifact extremely difficult. In fact, grants have been made available towards its restoration but have subsequently been withdrawn because of the problems of access. The enginehouse is a Grade 1 listed structure which is the same as Caernarfon Castle. Despite this, and despite the valiant efforts of the engine's custodian, it continues in a state of limbo. What should be one of North Wales finest examples of industrial heritage is now a forgotten link to a golden age.

































Thanks for looking [email protected]@l.........

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Oblivion State Member
Jul 26, 2012
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spectacular pics chuck love it



O.S Friend AAA
Jan 7, 2011
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Wow, thats pretty different, what is that nutter doing in pic 2, I hope he's completed a risk assessment ;)