Panorama from the summit, from the Rhinogs in the south west past Trawsfynydd and Porthmadog through to the Snowdon massif in the north west
| Date | 22 September 2012 | ||
| Location | Arenig, Snowdonia | SH 82700 36950; 52.91711°N, 3.74600°W | |
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Adit entrance
| Date | 2 July 2011 | ||
| Location | Cwm Croesor | SH 65701 45582; 52.99067°N, 4.00224°W | |
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Croesor Quarry is located on the Cwm Croesor side of the slopes of Moelwyn Mawr. Slate quarrying at the site dates back to 1846 and in 1864 a connection, via an incline down to the valley floor, was made to the Croesor Tramway, allowing produce to be transported to the port of Porthmadog. Virtually all the workings were below the surface and the relatively small amount of waste visible externally belies the volume of rock actually extracted, as much of the spoil was used to backfill completed excavations. Access to all the workings, on six floors, was via single adit. Unusually, forced, rather than natural, ventilation was employed in the mine and the remains of the fan house can still be seen amongst the surface structure ruins. In order to settle territorial disputes with the neighbouring Rhosydd Quarry, a tunnel was driven between the two quarries so that more accurate surveying could be undertaken. During the early 20th century a number of innovations were introduced at the quarry under the management of Cornish-born engineer Moses Kellow (1862-1943). Efficiency was improved first by getting the quarrymen to agree to certain changes in the traditional working practices and later by mechanisation. In 1904 Kellow built a hydroelectric power station at Blaencwm. This was fed by water from Llyn Cwm-y-foel and the electricity generated there powered both lighting and machinery at the quarry and also supplied power to the village of Croesor. (More recently the building was used as an outdoor pursuits centre, but, having been renovated by npower renewables, has now returned to its original function as a hydroelectric power station.) Elsewhere the slow process of drilling by hand was being replaced by the use of percussive pneumatic rock drills. Kellow, however, developed his own alternative: a hydraulic rotary drill. He made several improvements on his original design, with the final version being produced in 1915. Capable of drilling a 7 ft hole in about 90 seconds, the drill was driven by a turbine powered by high-pressure water and used a water-cooled twist drill bit. The drills were manufactured at the Keldril Works in the mill complex of the quarry itself. Despite its impressive power and efficiency, the Kellow Drill never gained wide acceptance, perhaps due to poor marketing. Slate production at the quarry came to an end in 1930, and it was later used as a storage facility by Cooke’s Explosives. In the 1920s that company had purchased a site in Penrhyndeudraeth — Gwaith Powdwr — where explosives had been manufactured since 1865. When Cook retired in 1958 the company was acquired by ICI and continued production until 1995. In 1949 Cooke applied for a licence to store explosives at Croesor Quarry, with ICI buying the quarry in 1964. The three floors below the adit level (‘A’) — ‘B down’, ‘C down’ and ‘D down’ — are all now flooded. Croesor Quarry (Wikipedia);
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Llyn Stwlan, the upper reservoir for Ffestiniog Power Station, from Craigysgafn (B). The concrete dam and intake towers can be seen on the right, with the lower reservoir at Tanygrisiau below.
| Date | 26 June 2011 | ||
| Location | Moelwynion |
(A) SH 65821 44862; 52.98423°N, 4.00016°W (B) SH 65991 44332; 52.97951°N, 3.99740°W (C) SH 66028 43754; 52.97433°N, 3.99661°W (D) SH 63574 43762; 52.97378°N, 4.03314°W |
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The Moelwynion group of mountains in Snowdonia are to be found roughly in an area with Porthmadog and Capel Curig at its south-west and north-east ends, respectively. The highest peak in the range is Moel Siabod (872 m) and the name of the group comes from Moelwyn Mawr (Big White Hill), 770 m, and Moelwyn Bach (Little White Hill), 710 m. A rocky ridge, Craigysgafn, separates these two mountains and overlooks Llyn Stwlan, the top reservoir of Ffestiniog Power Station at Tanygrisiau below. This 360 MW pumped-storage hyroelectric power station began service in 1963 and was the first major facility of its kind in the UK. Ffestiniog Power Station (First Hydro)
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Fron-boeth Quarry Tunnel
| Date | 26 June 2011 | ||
| Location | Cwm Croesor | SH 64361 45047; 52.98553°N, 4.02195°W | |
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The tunnel, approximately 450 m long, connected Fron-boeth slate quarry with an incline on the other side of a ridge on the western slopes of Moelwyn Mawr. The incline, 300 m north east of the tunnel exit, carried slate wagons down into Cwm Croesor and onto the Croesor Tramway. The tunnel is blocked about 30 m in from this end, although there is evidence of work being carried out to clear the collapsed material.
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Cornish boiler next to the ruins of the mill. The inscription on the front reads 'JAs. CARMICHAEL, & Co.'
| Date | 7 May 2011 | ||
| Location | Moelwyn Mawr | SH 64592 44648; 52.98200°N, 4.01836°W | |
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Fron-boeth is one of the Croesor group of slate quarries and is located on the lower slopes of Moelwyn Mawr on the other side of a ridge from Cwm Croesor. A processing mill was built here when quarrying moved down from the Pant Mawr quarry higher up on Moelwyn Mawr. A Cornish boiler can still be seen next to the ruins of this mill. (A Cornish boiler was a long horizonal cylinder with a single large internal flue for the furnace running along its length.) Fron-boeth was served by a tunnel running approximately NW for about 450 m. This joined a level section of tramway on the other side of the ridge, which then met an incline down into Cwm Croesor to join the Croesor Tramway. That incline also served Pant Mawr Quarry. There are two quarried chambers in the tunnel, and it is blocked by a collapse close to the Cwm Croesor end.
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Cnicht, Moelwyn Mawr and Moelwyn Bach from Beddgelert Forest
| Date | 24 April 2011 | ||
| Location | Beddgelert Forest | SH 56998 49513; 53.02373°N, 4.13353°W | |
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