Auñamendi Eusko EntziklopediaFund Bernardo Estornés Lasa

Charcoal, made from beech, chestnut, or oak, has been of great importance in past centuries for fueling forges. The charcoal burners [ ikazki ak ] worked in groups of eight or more, but were hired by another person. There were also individual charcoal burners who worked on their own. This work frequently took place in the spring and summer. Some groups remained in the mountains (beech forests) for up to six months, using cabins or shanties as shelter for ing and cooking. To forge 1,500 quintals of iron, 3,000 loads of coal weighing ten arrobas were used. Father Larramendi (18th century) points out that no coal was used in forges "because it produces very ugly, brittle, and easily broken iron."

It's no surprise that, given such a demand for charcoal, the Basque regional governments prohibited the extraction of charcoal outside their respective provinces. Charcoal was produced near a stream or from the woodpiles designated for that purpose. A chimney is built with crisscrossed poles, surrounded by vertical logs, and on top of the pile are several layers of firewood and logs until a pile 1.60 meters high is formed. The cone thus formed is covered with earth and moss, leaving the mouth of the chimney open in the center. Once the charcoal pit or txondorra is lit, the mouth of the chimney is covered with a few twigs and the fire is allowed to spread slowly until the entire pit is turned into charcoal. To do this, a few holes must be made on the sides so that the fire can breathe. The wood is not burned but cooked. The top of the pyre begins to char first, while the txondorra gradually shrinks in volume. The transformation into charcoal takes about ten days. The holes are then plugged and the fire is slowly extinguished over a period of about five days. About two thousand kilos of wood yield about a thousand kilos of charcoal.

Charcoal sales were made in loads, each equivalent to two sacks, each weighing three bushels and five bushels. A bushel of charcoal is equivalent to 45 kilos. The weight of charcoal also depends on the wood it comes from. A sack of chestnut charcoal weighs about 30 kilos, a beech 35, and an oak 38. The sack is closed with fern and crisscrossed string. In the forges, a type of vat with a capacity of one bushel was used to check the quantity of charcoal received. Manufacturing requires a series of utensils and sieves to sift the charcoal once it is made, utensils of solely ethnographic interest today.

Charcoal has been gradually replaced by other fuels and motive power, primarily coal, coke, gas, and electricity. At the beginning of the century, the charcoal industry was still important. In 1914, due to the European War, it gained renewed momentum. Locomotives ran on coal and wood until 1920. During the war, large quantities of coal were exported to France. A good example of this is Zeanuri, Bizkaia, which produced half a million and one million kilos annually, reaching a record figure of 2,000,000 kilos in 1914.

Lefebvre provides a detailed study of the Basque coal-producing areas, consumption centers, personnel employed in these operations, and prices. Coal mines were already being exploited in the first half of the 19th century, mainly in the Bilbao area. Transport to the interior was not viable. Lignite mining began in Etxalar, Hernani, and Zestoa, but the 12,000 tons produced by these deposits in 1865 were used to operate lime kilns and cement factories. The industrial use of coal required special equipment, which did not become available until 1865, when the first coke-fired blast furnaces were put into operation in Barakaldo.