Wales Shale Industry

Manual crushing of shale blocks by quarry workers in Dynorwick, 1910. This work required great skill and was not mechanized until the second half of the 20th century.

The Wales shale industry is a branch of the Wales economy, which began to form back in the days of Roman rule in these territories, when slate made from mined shales was used for roof forts in Segontium (now Carnarvon). The shale industry developed slowly until the beginning of the 18th century, but then began to grow rapidly until the end of the 19th century. During this period of time, northwestern Wales became the most important oil shale mining area, including the Penrin quarry near Bedesda, the Dinorvik quarry near Llanberis , the Nantle Valley quarry and the oilfield near Blainay Festiniog , where shale was mined in underground mines rather than open pits quarries. Penrin and Dinorvig were the two largest shale quarries in the world, and the Okely mine at Blainai Festiniog was the largest shale mine in the world. Slate obtained from slates is mainly used for roofing, but thick slabs were also used, which were used to create various other objects, including floor coverings, countertops and tombstones.

Until the end of the 18th century, shale was mined on a small scale by groups of quarry workers (English quarrymen , rampart. Chwarelwyr ) who paid tax to landowner landowners for the right to mine shale in quarries. The extracted shales were then transported to the ports on the backs of horses or in carts, from where they were sent to England, Ireland and sometimes France. Towards the end of the 18th century, large landowners began to exploit quarries located on their lands on their own and on a much larger scale. After the British government abolished the shale tax in 1831, the industry began to expand rapidly, which was also due to the construction of narrow gauge railways to transport the shale mined to ports.

Shale industry dominated the economy of northwestern Wales in the second half of the 19th century, but existed on a much smaller scale in other areas of the region. In 1898, a workforce of 17,000 people produced half a million tons of oil shale. After a long and bitter strike in the career of Pernrin, which took place from 1900 to 1903, this industry began to decline, and after the outbreak of World War I, many career workers employed in it were forced to go to the front. The Great Depression and World War II led to the closure of many small quarries, and most of the large ones were closed in the 1960s and 1970s due to the beginning of the massive use of other materials, primarily tiles , instead of slate for roofing. A certain amount of shale is mined in Wales to this day, but on a much smaller scale.