Former potash mine at Dietlas, Thuringia, whose shaft site later housed a mining machinery factory, now closed and cleared for a solar park.
Schacht Dietlas, known formally as Schacht Georg, was the primary shaft of the Gewerkschaft Großherzog von Sachsen, sunk between 1898 and 1905 to a depth of 560 metres in the Meiningen enclave of Dietlas, on the western edge of the Werra potash district. Preparatory borings began in January 1898, and full shaft-sinking commenced in February 1904 after a successful water seal was achieved. Potash extraction began on 3 February 1905, with crude salt transported to the Dorndorf chloropotassium factory by a 2,750-metre aerial ropeway opened in July 1906.
Ownership passed to the Wintershall concern before 1926, when technical difficulties forced the cessation of mining and the closure of the Dorndorf plant. During the Second World War, the Düsseldorf firm Hasenclever used the idle surface buildings for machine storage and production. In 1948 the site became the Mechanische Werkstatt Dietlas, later the VEB Bergwerksmaschinen Dietlas, which produced underground mining equipment for the East German and international mining industry until 1990, when it was privatised.
The firm closed definitively in October 2005. In 2013 construction of a solar park began on the former works site.
The Gewerkschaft Großherzog von Sachsen was constituted as a drilling company on 15 September 1894 and converted into a formal Gewerkschaft on 2 May 1896. The name honoured the Grand Duke of Saxony-Weimar-Eisenach, while the shaft itself bore the name Georg in recognition of Duke Georg II of Saxe-Meiningen, the territorial ruler of the Dietlas enclave. The site straddled the jurisdiction of two mining authorities: the Weimarisch Bergamt Dermbach and the Meiningen Bergamt Saalfeld.
Concession rights covered the fields 'Großherzog von Sachsen', 'Dietlas', and 'Dietlas 2'. Preparatory boring at the shaft location near Borehole IV began on 12 January 1898. By 15 March 1903 the boring was complete, and on 19 January 1904 a full water seal was achieved.
Shaft-sinking proper commenced on 22 February 1904. On 27 February the upper rock salt stratum was reached at 417.5 metres; on 12 June 1904 the upper potash bed was encountered at 539 metres depth. The shaft reached a final depth of 560 metres, and regular operations opened on 3 February 1905; the first salt was raised on 2 January 1905.
Development headings drove approximately 950 metres of new workings in the upper and lower seams during 1906. On 23 July 1906 the 2,750-metre raw salt aerial ropeway connecting the shaft to the Dorndorf chloropotassium factory was commissioned. The ropeway remained operational until the shaft's closure.
On 28 November 1908 a gas outburst occurred during blasting in the shaft. In 1912 the Gewerkschaft was converted into an Aktiengesellschaft, with the operational assets transferred to the new company with effect from 1 January 1912. The company was capitalised at approximately 5,996,000 Marks in share value.
In 1911 construction of a second double-shaft complex at Menzengraben was begun in the southern portion of the concession. A large chemical processing plant was built at the Menzengraben shafts and brought into operation in early 1923. The Gewerkschaft Glückauf-Sondershausen held a majority of shares in the Großherzog von Sachsen AG.
In 1924 the Kali Industrie reduced operations in summer months owing to poor markets. The Wintershall concern subsequently acquired the Großherzog von Sachsen works. Technical difficulties in the Dietlas workings forced a complete cessation of mining on 6 June 1926; this closure also ended operations at the older Dorndorf factory.
The shaft was designated a reserve mine. During the Second World War, the idle surface buildings at Dietlas were used from 1939 by the Düsseldorf firm Hasenclever for the storage and production of machine tools. Cultural property from the Goethe National Museum and the Thüringer Hauptstaatsarchiv, comprising at least 133 crates, was stored underground in the shaft during the war.
On 11 March 1948 the Soviet industrial organisation SAG KALI purchased the Dietlas site for one million Reichsmarks, establishing it as the Mechanische Werkstatt Dietlas. From the early 1960s the facility, by then the VEB Bergwerksmaschinen Dietlas, developed and manufactured mobile underground mining machinery for the East German potash industry and for export. By 1990 approximately 1,700 mobile underground machines had been produced there.
A smokestack on the former site was demolished in October 1965. In 1990 the VEB was converted into a GmbH and privatised in 1993. In 1997 bankruptcy proceedings led to the company continuing as Bohr-, Transport- und Zerkleinerungstechnik GmbH Dietlas with around 150 employees.
The facility closed definitively on 1 October 2005, with production transferred to Merkers. In October 2013 work began on a solar park on the former works site, following demolition of the remaining structures.