103-535: The Penrhyn quarry is a slate quarry located near Bethesda , North Wales . At the end of the nineteenth century it was the world's largest slate quarry; the main pit is nearly 1 mile (1.6 km) long and 1,200 feet (370 metres) deep, and it was worked by nearly 3,000 quarrymen. It has since been superseded in size by slate quarries in China, Spain and the USA. Penrhyn is still Britain's largest slate quarry but its workforce
206-603: A pelite . Slate can be made into roofing slate, a type of roof tile which are installed by a slater . Slate has two lines of breakability—cleavage and grain—which make it possible to split the stone into thin sheets. When broken, slate retains a natural appearance while remaining relatively flat and easy to stack. A series of "slate booms" occurred in Europe from the 1870s until the First World War following improvements in railway, road and waterway transportation systems. Slate
309-578: A 20% tax on all slate carried coastwise, which put the Welsh producers at a disadvantage compared to inland producers who could use the canal network to distribute their product. There was no tax on slates sent overseas, and exports to the United States gradually increased. The Penrhyn Quarry continued to grow, and in 1799 Greenfield introduced the system of "galleries", huge terraces from 9 metres to 21 metres in depth. In 1798, Lord Penrhyn constructed
412-519: A large part of Hamburg in 1842 led to a demand for slate for rebuilding, and Germany became an important market, particularly for Ffestiniog slate. In 1843, the Padarn Railway became the first quarry railway to use steam locomotives, and the transport of slate by train rather than by ship was made easier when the London and North Western Railway built branches to connect Port Penrhyn and Port Dinorwic to
515-453: A light-green, spotted texture. These spheres are sometimes deformed by a subsequent applied stress field into ovoids, which appear as ellipses when viewed on a cleavage plane of the specimen. However, some evidence shows that reduced spots may also form after deformation and acquire an elliptical shape from preferential infiltration along the cleavage direction, so caution is required in using reduction ellipsoids to estimate deformation. Before
618-406: A long-lasting weathertight roof with a lifespan of around 60–125 years. Some mainland European slate suppliers suggest that using hook fixing means that: The metal hooks are, however, visible and may be unsuitable for historic properties. Slate tiles are often used for interior and exterior flooring, stairs, walkways and wall cladding. Tiles are installed and set on mortar and grouted along
721-410: A loss of up to 50% of the volume of the mudrock as it is compacted. Grains of platy minerals, such as clay minerals , are rotated to form parallel layers perpendicular to the direction of compaction, which begin to impart cleavage to the rock. Slaty cleavage is fully developed as the clay minerals begin to be converted to chlorite and mica. Organic carbon in the rock is converted to graphite . Slate
824-399: A lower poundage. The first Monday of every month was "bargain letting day" when these agreements were made between men and management. The men had to pay for their ropes and chains, for tools and for services such as sharpening and repairing. Subs (advances) were paid every week, everything being settled up on the "day of the big pay". If conditions had not been good, the men could end up owing
927-439: A property called fissility , forming smooth, flat sheets of stone which have long been used for roofing , floor tiles, and other purposes. Slate is frequently grey in color, especially when seen en masse covering roofs. However, slate occurs in a variety of colors even from a single locality; for example, slate from North Wales can be found in many shades of grey, from pale to dark, and may also be purple, green, or cyan. Slate
1030-569: A restored incline formerly used to carry slate waggons uphill and downhill. In Blaenau Ffestiniog, the Llechwedd Slate Caverns have been converted into a visitor attraction. Visitors can travel on the Miners' Tramway or descend into the Deep Mine, via the steepest cable railway in Europe, to explore this former slate mine and learn how slate was extracted and processed and about the lives of
1133-475: A rotary machine to dress the split slate. The splitting of the blocks to produce roofing slates proved resistant to mechanisation, and continued to be done with a mallet and chisel. An extra source of income from the 1860s was the production of "slab", thicker pieces of slate which were planed and used for many purposes, for example flooring, tombstones and billiard tables . The larger quarries could be highly profitable. The Mining Journal estimated in 1859 that
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#17328524409571236-570: A rudimentary damp-proof membrane . Small offcuts are used as shims to level floor joists. In areas where slate is plentiful it is also used in pieces of various sizes for building walls and hedges, sometimes combined with other kinds of stone. Because it is a good electrical insulator and fireproof, it was used to construct early-20th-century electric switchboards and relay controls for large electric motors . Because of its thermal stability and chemical inertness, slate has been used for laboratory bench tops and for billiard table tops. Slate
1339-456: A shipload of slates from Aberogwen, near Bangor, to Rhuddlan to roof a house at Henllan, near Denbigh . The wreck of a wooden ship carrying finished slates was discovered in the Menai Strait and is thought to date from the 16th century. By the second half of the 16th century, there was a small export trade of slates to Ireland from ports such as Beaumaris and Caernarfon. Slate exports from
1442-572: A single quarry. The first steam engine to be used in the slate industry was a pump installed at the Hafodlas quarry in the Nantlle Valley in 1807, but most quarries relied on hydropower to drive machinery. Wales was by now producing more than half the United Kingdom's output of slate, 26,000 tons out of a total UK production of 45,000 tons in 1793. In July 1794, the government imposed
1545-450: A slate mine as early as the 14th century. The earliest confirmed date of operating dates from the early 16th century when the local house Plas Aberllefenni was roofed in slates from this quarry. Transport problems meant that the slate was usually used fairly close to the quarries. There was some transport by sea. A poem by the 15th century poet Guto'r Glyn asks the Dean of Bangor to send him
1648-525: A slump in the home building trade had reduced domestic demand; finally French slate producers had increased their exports to the United Kingdom. All of this led to a prolonged decline in demand for Welsh slate. Eight Ffestiniog quarries closed between 1908 and 1913, and the Oakley dismissed 350 men in 1909. R. Merfyn Jones comments: The effects of this depression on the quarrying districts were deep and painful. Unemployment and emigration became constant features of
1751-484: A whole. The caban , the cabin where the quarrymen gathered for their lunch break, was often the scene of wide-ranging discussions, which were often formally minuted. A surviving set of minutes from a caban at the Llechwedd mine at Blaenau Ffestiniog for 1908–1910 records discussions on Church Disestablishment , tariff reform and other political topics. Eisteddfodau were held, poetry composed and discussed and most of
1854-512: A yearly rent of a few shillings and a royalty on the slates produced. The first landowner to take over the working of slates on his land was the owner of the Penrhyn estate, Richard Pennant , later Baron Penrhyn . In 1782, the men working quarries on the estate were bought out or ejected, and Pennant appointed James Greenfield as agent. The same year, Lord Penrhyn opened a new quarry at Caebraichycafn near Bethesda, which as Penrhyn Quarry would become
1957-422: Is a fine-grained, metamorphic rock that shows no obvious compositional layering but can easily be split into thin slabs and plates. It is usually formed by low-grade regional metamorphism of mudrock . This mild degree of metamorphism produces a rock in which the individual mineral crystals remain microscopic in size, producing a characteristic slaty cleavage in which fresh cleavage surfaces appear dull. This
2060-525: Is also fire resistant and energy efficient. Slate roof tiles are usually fixed (fastened) either with nails or with hooks (as is common with Spanish slate). In the UK, fixing is typically with double nails onto timber battens (England and Wales) or nailed directly onto timber sarking boards (Scotland and Northern Ireland). Nails were traditionally of copper, although there are modern alloy and stainless steel alternatives. Both these methods, if used properly, provide
2163-614: Is attested since the Roman period , when slate was used to roof the fort at Segontium , now Caernarfon . The slate industry grew slowly until the early 18th century, then rapidly during the Industrial Revolution in Wales until the late 19th century, at which time the most important slate producing areas were in northwest Wales . These sites included the Penrhyn Quarry near Bethesda ,
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#17328524409572266-442: Is in contrast to the silky cleaved surfaces of phyllite , which is the next-higher grade of metamorphic rock derived from mudstone. The direction of cleavage is independent of any sedimentary structures in the original mudrock, reflecting instead the direction of regional compression. Slaty cleavage is continuous, meaning that the individual cleavage planes are too closely spaced to be discernible in hand samples. The texture of
2369-462: Is mainly composed of the minerals quartz, illite , and chlorite, which account for up to 95% of its composition. The most important accessory minerals are iron oxides (such as hematite and magnetite ), iron sulfides (such as pyrite ), and carbonate minerals. Feldspar may be present as albite or, less commonly, orthoclase . Occasionally, as in the purple slates of North Wales , ferrous ( iron(II) ) reduction spheres form around iron nuclei, leaving
2472-486: Is not to be confused with shale, from which it may be formed, or schist . The word "slate" is also used for certain types of object made from slate rock. It may mean a single roofing tile made of slate, or a writing slate , which was traditionally a small, smooth piece of the rock, often framed in wood, used with chalk as a notepad or notice board, and especially for recording charges in pubs and inns. The phrases "clean slate" and " blank slate " come from this usage. Slate
2575-406: Is now nearer 200. The first reference to slate extraction at Penrhyn is from 1570, when the quarry is mentioned in a Welsh poem. The quarry was developed in the 1770s by Richard Pennant , later Baron Penrhyn . Much of his early working was for local use only as no large scale transport infrastructure was developed until Pennant's involvement. From then on, slates from the quarry were transported to
2678-505: Is particularly suitable as a roofing material as it has an extremely low water absorption index of less than 0.4%, making the material resistant to frost damage. Natural slate, which requires only minimal processing, has an embodied energy that compares favorably with other roofing materials. Natural slate is used by building professionals as a result of its beauty and durability. Slate is incredibly durable and can last several hundred years, often with little or no maintenance. Natural slate
2781-695: Is the owner and chairman of the Lagan Group) and renamed Welsh Slate Ltd. Kevin Lagan and his son Peter (MD of Lagan Building Solutions Ltd) are now directors of Welsh Slate Ltd which also includes Oakeley quarry and Cwt y Bugail quarry in Blaenau Ffestiniog , and Pen-yr-Orsedd quarry in the Nantlle Valley . The Lagan Group was itself acquired by the Leicestershire -based Breedon Group in 2018. A part of
2884-542: The Dee valley and around Machynlleth . The virtues of slate as a building and roofing material have been recognised since the Roman period. The Roman fort at Segontium, Caernarfon, was originally roofed with tiles, but the later levels contain numerous slates, used for both roofing and flooring. The nearest deposits are about five miles (8 km) away in the Cilgwyn area, indicating that
2987-562: The Dinorwic Quarry near Llanberis , the Nantlle Valley quarries, and Blaenau Ffestiniog , where the slate was mined rather than quarried . Penrhyn and Dinorwig were the two largest slate quarries in the world, and the Oakeley mine at Blaenau Ffestiniog was the largest slate mine in the world. Slate is mainly used for roofing, but is also produced as thicker slab for a variety of uses including flooring, worktops and headstones . Up to
3090-534: The Ffestiniog Railway , and Abergynolwyn and Bryn Eglwys quarry , including the Talyllyn Railway . The Welsh slate industry was essentially a Welsh-speaking industry. Most of the workforce in the main slate-producing areas of North Wales were drawn from the local area, with little immigration from outside Wales. The industry had a considerable influence on the culture of the area and on that of Wales as
3193-399: The First World War saw a great reduction in the number of men employed in the industry. The Great Depression and Second World War led to the closure of many smaller quarries, and competition from other roofing materials, particularly tiles , resulted in the closure of most of the larger quarries in the 1960s and 1970s. Slate production continues on a much reduced scale. On 28 July 2021,
Penrhyn quarry - Misplaced Pages Continue
3296-666: The Mid North at Mintaro and Spalding . Slate is abundant in Brazil , the world's second-largest producer of slate, around Papagaios in Minas Gerais , which extracts 95 percent of Brazil's slate. However, not all "slate" products from Brazil are entitled to bear the CE mark . Most slate in Europe today comes from Spain , the world's largest producer and exporter of natural slate, and 90 percent of Europe's natural slate used for roofing originates from
3399-623: The River Dwyryd to the estuary, where it was transferred to larger vessels. There was further expansion at Blaenau when John Whitehead Greaves , who had been running the Votty quarry since 1833, took a lease on the land between this quarry and the main Ffestiniog to Betws-y-Coed road. After years of digging he struck the famous Old Vein in 1846 in what became the Llechwedd quarry . A fire which destroyed
3502-435: The slate landscape of Northwest Wales , including Penrhyn quarry, was inscribed as a World Heritage Site by UNESCO . Slate Slate is a fine-grained, foliated , homogeneous, metamorphic rock derived from an original shale -type sedimentary rock composed of clay or volcanic ash through low-grade, regional metamorphism . It is the finest-grained foliated metamorphic rock. Foliation may not correspond to
3605-409: The "rubbish men" who cleared the waste rock from the galleries and built the tips of waste which surrounded the quarry. Only about a tenth, or less, of the rock extracted became finished product. The bad rockmen and rubbish men were usually paid by the ton of material removed, but the quarrymen were paid according to a more complicated system. Part of the payment was determined by the number of slates
3708-588: The Berwyn Quarry near Llangollen . The final large-scale underground working to close was Maenofferen, associated with the Llechwedd tourist mine, in 1999: part of this site, now effectively amalgamated with Votty / Bowydd, is still worked by untopping. The Wales Millennium Centre in Cardiff uses waste slate in many different colours in its design: purple slate from Penrhyn, blue from Cwt-y-Bugail, green from Nantlle, grey from Llechwedd, and black from Corris. Part of
3811-599: The Bethesda area, mainly from the Penrhyn Quarry. Blaenau Ffestiniog produced almost as much, and the Dinorwig Quarry alone produced 80,000 tons per year. The Nantlle Valley quarries produced 40,000 tons, while the remainder of Wales outside these areas produced only about 20,000 tons per year. By the late 1870s, Wales was producing 450,000 tons of slate per year, compared with just over 50,000 tons for
3914-792: The Breedon Group). It was previously owned by the Lagan Group, which also owned and carried out some operations at the Oakeley quarry at Blaenau Ffestiniog, the Pen yr Orsedd quarry in the Nantlle Vale, and the Cwt-y-Bugail quarry. In March 2010 the company announced its decision to mothball the Oakeley quarry because of subsidence at the site. The Greaves Welsh Slate Company produces roofing slates and other slate products from Llechwedd, and work also continues at
4017-471: The Dinorwig Quarry, with machinery powered by overhead shafting that in its turn was driven by the largest water-wheel in the United Kingdom, over 50 feet in diameter. There were several different categories of worker in the quarries. The quarrymen proper, who made up just over 50% of the workforce, worked the slate in partnerships of three, four, six or eight, known as "bargain gangs". A gang of four typically consisted of two "rockmen" who would blast
4120-575: The Dinorwig Slate Quarry is now within the Padarn Country Park, and the other part houses the Dinorwig power station in caverns under the old quarry workings. The National Slate Museum is located in some of the quarry workshops. The museum has displays including Victorian slate-workers' cottages that once stood at Tanygrisiau near Blaenau Ffestiniog. The museum has a working water wheel, and
4223-575: The Ordovician slate was less brittle than the Cambrian slate further north, and therefore easier to work by machine. The slate mill evolved between 1840 and 1860, powered by a single line shaft running along the building and bringing together operations such as sawing, planing and dressing. In 1859, John Whitehead Greaves invented the Greaves sawing table to produce blocks for the splitter, then in 1856 introduced
Penrhyn quarry - Misplaced Pages Continue
4326-405: The Penrhyn Quarry. Further mechanisation was introduced, with a computerised laser beam being used to aid the sawing of the slate blocks. As of 2022 , the Penrhyn Quarry is still producing slate, though at a much reduced capacity from its heyday at the end of the 19th century. In 1995, it accounted for almost 50% of UK production. It is currently owned and operated by Welsh Slate Ltd (part of
4429-551: The Penrhyn and Dinorwig quarries and in the Nantlle Valley. There are smaller outcrops elsewhere, for example on Anglesey . The Ordovician deposits run south-west from Betws-y-Coed to Porthmadog ; these were the deposits mined at Blaenau Ffestiniog. There is another band of Ordovician slate further south, running from Llangynnog to Aberdyfi , quarried mainly in the Corris area, with a few outcrops in south-west Wales, notably Pembrokeshire . The Silurian deposits are mainly further east in
4532-420: The Penrhyn estate are recorded from 1713 when 14 shipments totalling 415,000 slates were sent to Dublin . The slates were carried to the ports by pack-horses, and later by carts. This was sometimes done by women, the only female involvement in what was otherwise an exclusively male industry. Until the late 18th century, slate was extracted from many small pits by small partnerships of local men, who did not own
4635-453: The Penrhyn quarries produced an annual net profit of £ 100,000, and the Dinorwig Quarry £70,000 a year. From 1860 onwards slate prices rose steadily. Quarries expanded and the population of the quarrying districts increased, for example the population of Ffestiniog parish increased from 732 in 1801 to 11,274 in 1881. Total Welsh production reached 350,000 tons a year by the end of the 1860s. Of this total, over 100,000 tons came from
4738-418: The building of narrow gauge railways to transport the slates to the ports. The slate industry dominated the economy of north-west Wales during the second half of the 19th century, but was on a much smaller scale elsewhere. In 1898, a work force of 17,000 men produced half a million tons of slate. A bitter industrial dispute at the Penrhyn Quarry between 1900 and 1903 marked the beginning of its decline, and
4841-645: The calls of all four species of wild turkey in North America: eastern, Rio Grande, Osceola and Merriam's. Slate is found in the Arctic and was used by Inuit to make the blades for ulus . China has vast slate deposits; in recent years its export of finished and unfinished slate has increased. Deposits of slate exist throughout Australia, with large reserves quarried in the Adelaide Hills in Willunga , Kanmantoo , and
4944-456: The capital to expand further. The quarrymen usually had to pay a rent or royalty to the landlord, though the quarrymen at Cilgwyn did not. A letter from the agent of the Penrhyn estate, John Paynter, in 1738 complains that competition from Cilgwyn was affecting the sales of Penrhyn slates. The Cilgwyn slates could be extracted more cheaply and sold at a higher price. Penrhyn introduced larger sizes of slate between 1730 and 1740, and gave these sizes
5047-514: The coastal town of Porthmadog, where it was loaded onto ships. The railway was graded so that loaded slate waggons could be run by gravity downhill all the way from Blaenau Ffestiniog to the port. The empty waggons were hauled back up by horses, which travelled down in 'dandy' waggons . This helped expansion at the Blaenau Ffestiniog quarries, which had previously had to cart the slate to Maentwrog to be loaded onto small boats and taken down
5150-640: The death rate for underground workers in the slate mines was 3.23 per thousand, higher than the rate for coal miners . The outbreak of World War II in 1939 led to a severe drop in trade. Part of the Manod quarry at Blaenau Ffestiniog was used to store art treasures from the National Gallery and the Tate Gallery . The number of men employed in the slate industry in North Wales dropped from 7,589 in 1939 to 3,520 by
5253-634: The edges. Chemical sealants are often used on tiles to improve durability and appearance, increase stain resistance, reduce efflorescence , and increase or reduce surface smoothness. Tiles are often sold gauged, meaning that the back surface is ground for ease of installation. Slate flooring can be slippery when used in external locations subject to rain. Slate tiles were used in 19th century UK building construction (apart from roofs) and in slate quarrying areas such as Blaenau Ffestiniog and Bethesda , Wales there are still many buildings wholly constructed of slate. Slates can also be set into walls to provide
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#17328524409575356-407: The end of the 18th century, slate was extracted on a small scale by groups of quarrymen who paid a royalty to the landlord, carted slate to the ports, and then shipped it to England, Ireland and sometimes France. Towards the close of the century, the landowners began to operate the quarries themselves, on a larger scale. After the government abolished slate duty in 1831, rapid expansion was propelled by
5459-455: The end of the war. In 1945, total production was only 70,000 tons a year, and fewer than 20 quarries were still open compared with 40 before the war. The Nantlle Valley had been particularly hard hit, with only 350 workers employed in the entire district, compared with 1,000 in 1937. Demand for slate was dropping as tiles were increasingly used for roofing, and imports from countries such as Portugal , France and Italy were increasing. There
5562-450: The extension of a system of contracting out parts of the quarry. The quarrymen, instead of arranging their own bargains, would find themselves working for a contractor. The union's funds for strike pay were inadequate, and there was a great deal of hardship among the 2,800 workers. Lord Penrhyn reopened the quarry in June 1901, and about 500 men returned to work, to be castigated as "traitors" by
5665-425: The gang produced, but this could vary greatly according to the nature of the rock in the section allocated to them. The men would therefore be paid an extra sum of "poundage" per pound's worth of slate produced. "Bargains" were let by the setting steward, who would agree a price for a certain area of rock. If the rock in the bargain allocated to a gang was poor, they would be paid a higher poundage, while good rock meant
5768-570: The history of the British Labour Movement as the site of two prolonged strikes by workers demanding better pay and safer conditions. The first strike lasted eleven months in 1896. The second began on 22 November 1900 and lasted for three years. Known as "The Great Strike of Penrhyn", this was the longest dispute in British industrial history. During the strike, the community was divided between those who laid down their tools and those who crossed
5871-497: The horse-drawn Llandegai Tramway to transport slates from Penrhyn Quarry, and in 1801 this was replaced by the narrow gauge Penrhyn Quarry Railway , one of the earliest railway lines. The slates were transported to the sea at Port Penrhyn which had been constructed in the 1790s. The Padarn Railway was opened in 1824 as a tramway for the Dinorwig Quarry, and converted to a railway in 1843. It ran from Gilfach Ddu near Llanberis to Port Dinorwic at Y Felinheli . The Nantlle Railway
5974-405: The industry. This growth was mainly at Blaenau Ffestiniog and in the Nantlle Valley, where the workforce at Penyrorsedd reached 450. Slate production in Wales peaked at over half a million tons in 1898, with 17,000 men employed in the industry. A second lock-out or strike at the Penrhyn Quarry began on 22 November 1900 and lasted for three years. The causes of the dispute were complex, but included
6077-463: The larger quarries had their own band , with the Oakley band particularly famous. Burn calculates that there are around fifty men judged worthy of an entry in the Dictionary of Welsh Biography who started their working lives as slate quarrymen, compared to only four owners, though obviously there was also a distinct disparity in the numbers of the two groups. A number of Welsh writers have drawn on
6180-555: The largest quarries in mid Wales, employing 300 men and producing 30% of the total output of the Corris district. The Cardigan Railway was opened in 1873, partly to carry slate traffic, and enabled the Glogue quarry in Pembrokeshire to grow to employ 80 men. Mechanization was gradually introduced to make most aspects of the industry more efficient, particularly at Blaenau Ffestiniog where
6283-443: The largest slate quarry in the world. By 1792, this quarry was employing 500 men and producing 15,000 tons of slate per year. At Dinorwig, a single large partnership took over in 1787, and in 1809 the landowner, Thomas Assheton Smith of Vaynol , took the management of the quarry into his own hands. The Cilgwyn quarries were taken over by a company in 1800, and the scattered workings at all three locations were amalgamated into
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#17328524409576386-538: The late 19th and early 20th centuries, where the slate is usually dark purple to blackish, and many local structures are roofed with slate tiles. The roof of St. Patrick's Cathedral in New York City and the headstone of John F. Kennedy 's gravesite in Arlington National Cemetery are both made of Monson slate. Slate landscape of Northwest Wales The existence of a slate industry in Wales
6489-429: The lives of the quarrymen for their material, for example the novels of T. Rowland Hughes. Chwalfa , translated into English as Out of their night (1954), has the Penrhyn Quarry dispute as a background, while Y cychwyn , translated as The beginning (1969), follows the apprenticeship of a young quarryman. Several novels by Kate Roberts , the daughter of a quarryman, give a picture of the area around Rhosgadfan, where
6592-541: The main line in 1852. The Corris Railway opened as the horse-worked Corris, Machynlleth & River Dovey Tramroad in 1859, connecting the slate quarries around Corris and Aberllefenni with wharves on the estuary of the River Dyfi . The Ffestiniog Railway converted to steam in 1863, and the Talyllyn Railway was opened in 1866 to serve the Bryn Eglwys quarry above the village of Abergynolwyn . Bryn Eglwys grew to be one of
6695-460: The management money. This system was not finally abolished until after the Second World War. Because of this arrangement, the men tended to see themselves as independent contractors rather than employees on a wage, and trade unions were slow to develop. There were grievances however, including unfairness in setting bargains and disputes over days off. The North Wales Quarrymen's Union (NWQMU)
6798-446: The mid-19th century, the terms "slate", " shale ", and " schist " were not sharply distinguished. In the context of underground coal mining in the United States, the term slate was commonly used to refer to shale well into the 20th century. For example, roof slate referred to shale above a coal seam , and draw slate referred to shale that fell from the mine roof as the coal was removed. The British Geological Survey recommends that
6901-504: The miners. The Braichgoch slate mines at Corris have been converted into a tourist attraction named "King Arthur's Labyrinth" where visitors are taken underground by boat along a subterranean river and walk through the caverns to see audiovisual presentations of the Arthurian legends. The Llwyngwern quarry near Machynlleth is now the site of the Centre for Alternative Technology . A number of
7004-416: The morning, and the same distance home after six in the evening; to work hard from six to six; to dine on cold coffee, or a cup of buttermilk, and a slice of bread and butter; and to support (as some of them had to do) a family of perhaps five, eight or ten children on wages averaging from 12s to 16s a week. In 1879, a period of twenty years of almost uninterrupted growth came to an end, and the slate industry
7107-551: The names which became standard. These ranged from "Duchesses", the largest at 24 inches (610 mm) by 12 inches (300 mm), through "Countesses", "Ladies" and "Doubles" to the smallest "Singles". Methusalem Jones, previously a quarryman at Cilgwyn, began to work the Diffwys quarry at Blaenau Ffestiniog in the 1760s, which became the first large quarry in the area. The large landowners were initially content to issue "take notes", allowing individuals to quarry slates on their lands for
7210-410: The north side of the town. Historically, most accounts of the strike have mainly looked at its effects on male workers, owners, management, economy, and trade unions. However, modern historians are working to broaden this focus. They aim to shed light on the wider community's experiences during the strike, paying special attention to the often ignored roles and perspectives of women. In the longer term
7313-401: The oldest quarry in Wales, closed in 1914, though it later reopened. In 1917, slate quarrying was declared a non-essential industry and a number of quarries were closed for the remainder of the war. The demand for new houses after the end of the war brought back a measure of prosperity; in the slate mines of Blaenau Ffestiniog production was almost back to 1913 levels by 1927, but in the quarries
7416-417: The original sedimentary layering, but instead is in planes perpendicular to the direction of metamorphic compression. The foliation in slate, called " slaty cleavage ", is caused by strong compression in which fine-grained clay forms flakes to regrow in planes perpendicular to the compression. When expertly "cut" by striking parallel to the foliation with a specialized tool in the quarry, many slates display
7519-417: The output was still well below the pre-war level. The Great Depression in the 1930s led to cuts in production, with exports particularly hard hit. The quarries and mines made increasing use of mechanisation from the start of the 20th century, with electricity replacing steam and water as a power source. The Llechwedd quarry introduced its first electrical plant in 1891, and in 1906, a hydro-electric plant
7622-511: The picket line. Many locals wrote " Nid oes bradwr yn y tŷ hwn " or "There is no traitor in this house" in their front windows. William John Parry , one of the founders of the North Wales Quarrymen's Union, and an alderman in Bethesda, organised a co-operative to take over several other local quarries and employ locked-out Penrhyn quarrymen. He eventually included Pantdreiniog , Moel Faban and Tanybwlch quarries in his operation, all on
7725-479: The professions, and in Wales as a whole, its output value compared with that of coal. The prosperity of the slate industry led to the growth of a number of other associated industries. Shipbuilding increased at a number of coastal locations, particularly at Porthmadog, where 201 ships were built between 1836 and 1880. Engineering companies were set up to supply the quarries, notably De Winton at Caernarfon. In 1870, De Winton built and equipped an entire workshop for
7828-698: The railways which carried the slates to the ports have been restored as tourist attractions, for example the Ffestiniog Railway and the Talyllyn Railway. In July 2021, after development of a bid for over 10 years, the slate landscape of Northwest Wales was inscribed as a World Heritage Site by UNESCO . The areas included in the nomination include Penrhyn quarry and the Ogwen Valley , Dinorwic quarry , Nantlle Valley , Gorseddau and Prince of Wales quarries, Ffestiniog and Porthmadog , including
7931-514: The remainder. Eventually the workers were forced to return to work in November 1903 on terms laid down by Lord Penrhyn. Many of the men considered to have been prominent in the union were not re-employed, and many of those who had left the area to seek work elsewhere did not return. The dispute left a lasting legacy of bitterness in the Bethesda area. The loss of production at Penrhyn led to a temporary shortage of slates and kept prices high, but part of
8034-430: The rest of the United Kingdom, which then included Ireland. In 1882, 92% of the United Kingdom's production was from Wales with the quarries at Penrhyn and Dinorwig producing half of this between them. Alun Richards comments on the importance of the slate industry: It dominated the economy of the north-west of Wales, where, by the middle of the 19thC. it accounted for almost half the total revenues from trade, industry and
8137-409: The rock to produce blocks, a splitter, who would split the blocks with hammer and chisel, and a dresser. A rybelwr would usually be a boy learning his trade, who would wander around the galleries offering assistance to the gangs. Sometimes a gang would give him a block of slate to split. Other groups were the "bad rockmen" who usually worked in crews of three, removing unworkable rock from the face, and
8240-496: The sea at Port Penrhyn on the narrow gauge Penrhyn Quarry Railway built in 1798, one of the earliest railway lines. In the 19th century the Penrhyn Quarry, along with the Dinorwic quarry , dominated the Welsh slate industry . In 1868 eighty workers were sacked for failing to vote for George Douglas-Pennant , the son of the owner, in the general election. The quarry is significant in
8343-419: The shortfall was made up by imports. French exports of slate to the UK increased from 40,000 tons in 1898 to 105,000 tons in 1902. After 1903 there was a depression in the slate industry which led to reductions in pay and job losses. New techniques in tile manufacture had reduced costs, making tiles more competitive. In addition, several countries had placed tariffs on the import of British slate, while
8446-535: The site no longer in use for slate extraction is the site of a new adventure tourism facility operated by Zip World . The zip line Velocity 2 flies over an abandoned and partially flooded part of the quarry. Welsh slate such as that quarried at Penrhyn was designated by the International Union of Geological Sciences as a ' Global Heritage Stone Resource ' early in 2019 in recognition of its significant contribution to world architectural heritage. In July 2021
8549-547: The slate communities; distress was widespread. In the quarries there was short-time working, closures and reductions in earnings. Between 1906 and 1913 the number of men at work in the quarries of the Ffestiniog district shrank by 28 per cent, in Dyffryn Nantlle the number at work fell even more dramatically by 38 per cent. The First World War hit the slate industry badly, particularly in Blaenau Ffestiniog where exports to Germany had been an important source of income. Cilgwyn,
8652-720: The slate from Wales and Cumbria is colored slate (non-blue): purple and formerly green in Wales and green in Cumbria. In North America, slate is produced in Newfoundland , eastern Pennsylvania , Buckingham County, Virginia , and the Slate Valley region in Vermont and New York , where colored slate is mined in the Granville, New York , area. A major slating operation existed in Monson, Maine , during
8755-732: The slate industry there. Lesser slate-producing regions in present-day Europe include Wales (with UNESCO landscape status and a museum at Llanberis ), Cornwall (famously the village of Delabole ), Cumbria (see Burlington Slate Quarries , Honister Slate Mine and Skiddaw Slate ) and, formerly in the West Highlands of Scotland, around Ballachulish and the Slate Islands in the United Kingdom . Parts of France ( Anjou , Loire Valley , Ardennes , Brittany , Savoie ) and Belgium (Ardennes), Liguria in northern Italy , especially between
8858-544: The slate is totally dominated by these pervasive cleavage planes. Under a microscope, the slate is found to consist of very thin lenses of quartz and feldspar (QF-domains) separated by layers of mica (M-domains). These are typically less than 100 μm (micron) thick. Because slate was formed in low heat and pressure, compared to most other metamorphic rocks, some fossils can be found in slate; sometimes even microscopic remains of delicate organisms can be found in slate. The process of conversion of mudrock to slate involves
8961-450: The slate landscape of northwest Wales was awarded the status of a UNESCO World Heritage Site , whilst as early as 2018 Welsh slate was designated by the International Union of Geological Sciences as a Global Heritage Stone Resource . The slate deposits of Wales belong to three geological series: Cambrian , Ordovician and Silurian . The Cambrian deposits run south-west from Conwy to near Criccieth ; these deposits were quarried in
9064-554: The slates were not used merely because they were available on-site. During the mediaeval period, there was small-scale quarrying of slate in several areas. The Cilgwyn quarry in the Nantlle Valley dates from the 12th century, and is thought to be the oldest in Wales. The first record of slate quarrying in the neighbourhood of the later Penrhyn Quarry was in 1413, when a rent-roll of Gwilym ap Griffith records that several of his tenants were paid 10 pence each for working 5,000 slates. Aberllefenni Slate Quarry may have started operating as
9167-452: The strike lessened confidence in the Welsh slate industry, leading to declining orders and greater unemployment. In 2003, on the centenary of the strike, the Transport and General Workers' Union unveiled a plaque in memory of those who participated. From 1963 until 2007 the quarry was owned and operated by Alfred McAlpine . In 2007 it was purchased by Kevin Lagan (an Irish businessman who
9270-415: The term "slate" be used in scientific writings only when very little else is known about the rock that would allow a more definite classification. For example, if the characteristics of the rock show definitely that it was formed by metamorphosis of shale, it should be described in scientific writings as a metashale. If its origin is uncertain, but the rock is known to be rich in mica, it should be described as
9373-451: The town of Lavagna (whose name is inherited as the term for chalkboard in Italian ) and Fontanabuona valley; Portugal especially around Valongo in the north of the country. Germany 's Moselle River region, Hunsrück (with a former mine open as a museum at Fell ), Eifel , Westerwald , Thuringia and north Bavaria ; and Alta , Norway (actually schist , not a true slate). Some of
9476-410: The two sides usually involved the use of interpreters. In October 1885, there was a dispute at Dinorwig over the curtailing of holidays which led to a lock-out lasting until February 1886. At the Penrhyn Quarry, George Sholto Gordon Douglas-Pennant took over from his father Edward Gordon Douglas-Pennant in 1885, and in 1886 appointed E. A. Young as chief manager. A more stringent management regime
9579-430: Was built in 1828 and was operated using horse-power to carry slate from several slate quarries in the Nantlle Valley to the harbour at Caernarfon. In 1831 slate duty was abolished, and this helped to produce a rapid expansion in the industry, particularly since the duty on tiles was not abolished until 1833. The Ffestiniog Railway line was constructed between 1833 and 1836 to transport slate from Blaenau Ffestiniog to
9682-515: Was dependent upon slate quarrying and quarry closures led to a growth in unemployment in 1959. The nearby Votty and Bowydd quarries also closed in 1963 and in 1969, 300 quarrymen lost their jobs when the Dinorwic quarry closed. The following year the Dorothea quarry in the Nantlle Valley and the Braichgoch quarry near Corris announced their closure. Oakeley at Blaenau Ffestiniog closed in 1971, but
9785-506: Was formed in 1874, and the same year there were disputes at Dinorwig and then at Penrhyn. Both these disputes ended in victory for the workers, and by May 1878, the union had 8,368 members. One of the founders of the union, Morgan Richards, described in 1876 the conditions when he started work in the quarries forty years before: I well remember the time when I was myself a child of bondage; when my father and neighbours, as well as myself, had to rise early, to walk five miles (8 km) before six in
9888-404: Was harmless. In 1979, after a long struggle, the government recognised silicosis as an industrial disease meriting compensation. There was an increase in demand for slate in the 1980s, and although this came too late for many quarries there was still some production in the Blaenau Ffestiniog area at the Oakeley, Llechwedd and Cwt-y-Bugail quarries, though the bulk of roofing slate production was at
9991-464: Was hit by a recession which lasted until the 1890s. Management responded by tightening rules and making it more difficult for the men to take time off. Labour relations were worsened by differences in language, religion and politics between the two sides. The owners and top managers at most of the quarries were English-speaking, Anglican and Tory , while the quarrymen were Welsh-speaking and mainly Nonconformist and Liberal . Negotiations between
10094-557: Was introduced, and relations with the workforce deteriorated. This culminated in the suspension of 57 members of the union committee and 17 other men in September 1896, leading to a strike which lasted eleven months. The men were eventually obliged to go back to work, essentially on the management's terms, in August 1897. This strike became known as "The Penrhyn Lockout". There was an upturn in trade in 1892, heralding another period of growth in
10197-409: Was later reopened by another company. By 1972, fewer than 1,000 men were employed in the North Wales slate industry. For many years, the quarry owners had denied that slate dust was the cause of the high levels of silicosis suffered by quarrymen. From 1909, they had been responsible for all accidents and illnesses caused by the work, but had managed to persuade successive governments that slate dust
10300-538: Was opened in Cwm Dyli, on the lower slopes of Snowdon , which supplied electricity to the largest quarries in the area. The use of electric saws and other machinery reduced the hard manual labour involved in extracting the slate, but produced much more slate dust than the old manual methods, leading to an increased incidence of silicosis . The work was also dangerous in other ways, with the blasting operations responsible for many deaths. A government enquiry in 1893 found that
10403-421: Was some increased demand for slates to repair bombed buildings after the end of the war, but the use of slate for new buildings was banned, apart from the smallest sizes. This ban was lifted in 1949. Total production of slate in Wales declined from 54,000 tons in 1958 to 22,000 tons in 1970. The Diffwys quarry at Blaenau Ffestiniog closed in 1955 after almost two centuries of operation. North Wales
10506-460: Was used by earlier cultures as whetstone to hone knives, but whetstones are nowadays more typically made of quartz. In 18th- and 19th-century schools, slate was extensively used for blackboards and individual writing slates , for which slate or chalk pencils were used. In modern homes slate is often used as table coasters. In areas where it is available, high-quality slate is used for tombstones and commemorative tablets. In some cases slate
10609-478: Was used by the ancient Maya civilization to fashion stelae . Slate was the traditional material of choice for black Go stones in Japan, alongside clamshell for white stones. It is now considered to be a luxury. Pennsylvania slate is widely used in the manufacture of turkey calls used for hunting turkeys. The tones produced from the slate, when scratched with various species of wood striker, imitates almost exactly
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