Mines de Gardanne — Puits Z Gardanne · Provence-Alpes-Côte d'Azur · France

Lignite extraction in the area around Gardanne is documented from the sixteenth century, with the commodity initially supplying local dyeworks, sugar refineries, glassworks, and soap factories. In 1805, 51 active descenderies were recorded in the vicinity, worked by 92 miners and approximately a hundred children. The first title minier dates from the eighteenth century, and by 1811 many early workings had been exhausted, flooded, or destroyed by fire. The first vertical shaft in the basin, sunk to 70 metres, dates from 1820. Thirty-five shafts were sunk between 1839 and 1945, accompanied by numerous inclined galleries. The persistent problem of underground water was central to the development of the basin. In 1855 the Société anonyme des Charbonnages des Bouches-du-Rhône was founded, bringing the previously anarchic extraction under organised management. The company received authorisation on 21 March 1889 for the construction of the Galerie de la Mer, a drainage gallery of 15 kilometres linking the mines to the sea at La Madrague near Marseille, conceived originally in 1859 by Ernest Biver. Excavation began at the Marseille end in 1889 and a second attack was opened from the puits Biver in 1894; the gallery was completed in 1905. It was equipped in 1906 and 1907 with a narrow-gauge railway carrying lignite and spoil to a screen at La Madrague, its deposits progressively extending the shoreline by several tens of metres. The gallery also served as a drainage conduit for the mines throughout their operational life.

By the end of the nineteenth century the company had evolved into the Société nouvelle de Charbonnages des Bouches-du-Rhône. Production at the basin grew from 45,000 tonnes in 1856 to 402,000 tonnes in 1892 and 694,000 tonnes in 1913. The puits Hély d'Oissel was sunk from 1912 to 1916, reaching 456 metres; its 25.5-metre metal headframe was built by Dérobert. Accidental flooding prevented it from entering service until 1923, when it became the principal extraction shaft of the Grande Concession until 1961. During the Second World War the Compagnie d'Hydrocarbures et de Synthèse acquired 20 hectares for a projected synthetic fuel plant using local coal, but the project was abandoned at the liberation. Production in 1940 reached 1 million tonnes. The puits Gérard was sunk between 1942 and 1945 by the Société nouvelle de Charbonnages des Bouches-du-Rhône, reaching 615 metres; its metal headframe was supplied by the manufacturer Vénot. It entered full exploitation in 1950.

Nationalisation in 1946 created the Houillères du Bassin de Provence (HBP), unifying the four remaining private mining companies. In 1946 the workforce stood at 6,142. Under the HBP, the coal supplied a new thermal power station constructed at Meyreuil under the Marshall Plan. In 1957 a second 50-megawatt unit was added; in 1958 a third; and in 1967 a fourth unit of 250 megawatts was commissioned. From 1960, puits Courau at Meyreuil became the principal extraction shaft, with all coal destined for the power station passing through it from 1970. In 1969 the seven central and southern French coalfields were unified as the Houillères du Bassin du Centre et du Midi (HBCM). The workforce was cut sharply through mechanisation: from 6,142 in 1946 it fell to approximately 1,900 by the 1970s, while output per underground worker rose fourfold. The basin won national and European productivity awards in 1952, 1963, 1971, and 1974. A reconversion programme began in 1961, establishing the Zone industrielle de Rousset for workers seeking professional retraining.

In the mid-1970s research campaigns revealed approximately 60 million tonnes of lignite reserves in the area of Gardanne and Meyreuil. In 1980 the HBCM launched the Grand Ensemble de Provence programme, which required the sinking of two new deep shafts. Puits Z was sunk between 1982 and 1984 to a depth of 878.80 metres and a diameter of 6.50 metres; it was designed for extraction and return air, and entered service in January 1986. Its headframe, at 66 metres height, was built by the Société F.C.B. Puits Yvon Morandat (puits Y) was sunk from 1981 to 1983 by the German firm Deilmann-Haniel using explosives, reaching 1,109 metres depth and 10 metres diameter; it entered service on 16 January 1989, serving for personnel and materials transport, exhaure, and supply of compressed air, water, and electricity to the underground workings. At the same time new embauches accelerated from the end of 1981. The sole outlet for the lignite was the central thermique de Provence at Gardanne. The annual output reached approximately 1.5 million tonnes and records of productivity were set regularly.

From the late 1980s production declined. The Pacte charbonnier was signed in October 1994 by all trade unions except the CGT, providing for the cessation of all French coal extraction by 2005 and incentivising retirement at 45 years for miners with 25 years of underground service. In December 1986 the Plan Gandois had announced the closure of the La Barasse site, which closed in 1988. In 2003 the Raffarin government advanced the closure date by two years. The last extraction at puits Yvon Morandat took place on 31 January 2003, the entire operation ceasing at that date, approximately two years earlier than planned, due to technical difficulties linked to depth and the cost of underground support, as well as a workforce of fewer than 340. A total of approximately 130 million tonnes of lignite had been extracted from the basin over its operational life, representing 2 to 3 per cent of total French national production. The DREAL records 17 titres miniers granted across the basin, the first in the eighteenth century and the last on 28 January 1981.

Demolition of most surface installations followed in 2004. The two concrete headframes of puits Courau and Boyer at Meyreuil were demolished on 5 February 2004. The city of Gardanne purchased the puits Z carreau, retaining the 66-metre headframe and the winding engine building, though the winding engine was subsequently heavily vandalised. At the puits Yvon Morandat site, the winding tower was purchased by the city; the remaining installations were demolished in 2004 and the site was redeveloped as a business incubator housing approximately twelve start-up companies by 2014. The Galerie de la Mer continues to drain water from the flooded former underground workings; since 2003 the abandoned galleries have gradually filled, creating one of the largest underground water reserves in the Provençal subsoil.