Former hard coal ventilation shaft at Oer-Erkenschwick whose nearly complete 1940/44 surface plant survives as a listed monument, managed for cultural reuse by the civic association Blumenthal 7 e.V.
Zeche General Blumenthal - Schacht VII was a hard coal outer shaft sunk in 1939/40 and brought into operation in 1944, serving principally as a Wetterschacht and for Seilfahrt and materials transport for the northern field of the Zeche General Blumenthal colliery at Recklinghausen. Named after Generalfeldmarschall Leonhard Graf von Blumenthal, the parent colliery had been founded in 1873 and passed to the Hibernia AG in 1903; all Hibernia mines, including General Blumenthal, joined the Ruhrkohle AG in 1969. Schacht 7, located at the Westcharweg in what is now Oer-Erkenschwick, reached a final depth of 665 metres and was equipped with an unusually small two-storey Koepe headframe — its modest form a consequence of wartime material shortages — with a funnel-shaped Grubenlüfter beside it.
Coal production in the broader mine continued until 1999/2000; Schacht 7 was used for ventilation until 2001, when it was filled. The shaft, shaft hall, machine house with electric winding machine, entrance and Kauen building, and the Grubenlüfter with its ventilator building survive as a near-complete surface complex. The site was listed on the Denkmalliste of the city of Recklinghausen in 2006.
After more than a decade of inactivity, the civic association Blumenthal 7 e.V., founded in 2016, acquired the 24,000 m² site from RAG Montan Immobilien in March 2020, with plans to develop it as an open workshop and cultural venue.
The Zeche General Blumenthal takes its name from Leonhard Graf von Blumenthal, Generalstabschef of the 3rd Army in the Franco-Prussian War of 1870/71. The parent colliery had its origins in sinking works begun in 1873 south-east of the Recklinghausen Innenstadt. The Gewerkschaft General Blumenthal was a founding member of the Rheinisch-Westfälisches Kohlen-Syndikat. The shaft reached the Carboniferous in April 1877 at a depth of 347.25 metres, with the 1. Sohle established in 1878 at 408 metres; coal production was formally taken up in 1879, initially extracting the upper Flammkohle seams. A major Schlagwetterexplosion on 21 January 1884 killed 19 miners.
The Hibernia AG acquired the mine in 1903. Further Schlagwetterexplosionen in 1893 and 1896 had already killed 20 and 26 miners respectively. The mine's field expanded greatly over the following decades through the sinking of additional shafts and the acquisition of neighbouring fields. By 1920 the workforce approached 5,000. The mine's Grubenfeld, with its several striking Störungen running through the Horst-Recklinghauser Mulde, was geologically complex, and the northward extension of workings necessitated the provision of additional access and ventilation at progressively greater distances from the main 1/2/6 complex at Recklinghausen.
Schacht 7 was laid out as an Außenschacht belonging to the main 1/2/6 complex, which lay approximately 3.5 kilometres to the south-east at Recklinghausen. Teufarbeiten began on 6 June 1940. The shaft had a diameter of approximately 6 metres and reached a final depth of 665 metres. The decision to sink Schacht 7 arose because the northward advance of the working faces had lengthened underground haulage and travel distances to an extent that required a nearer point of surface access. The entire surface plant was designed and built under the material restrictions of the Second World War; the Koepe headframe is a small two-storey riveted steel structure whose unusually modest scale reflects the wartime shortage of materials. The installation came into operation in 1944. The trichterförmige (funnel-shaped) Grubenlüfter alongside the headframe was a primary function of the installation: together with the headframe, it is visible from a distance and serves as a landmark. Schacht 7 served primarily as a Wetterschacht, with Seilfahrt and materials transport as secondary functions.
All Hibernia AG mines, including General Blumenthal, were incorporated into the Ruhrkohle AG in 1969. In 1970 an underground breakthrough to Zeche Recklinghausen was completed; in 1975 a connection was driven to Zeche Ewald Fortsetzung at Oer-Erkenschwick. On 1 October 1992 Zeche General Blumenthal was merged with Bergwerk Haard (formerly Zeche Ewald Fortsetzung) to form the Verbundbergwerk Bergwerk Blumenthal/Haard, which at the time was the largest colliery in the Ruhr with a Grubenfeld of 194 km². Coal production in the main mine field continued until 1999/2000. Schacht 7 continued in service for ventilation following the end of production, and was finally filled in 2001 after the merger with Zeche Auguste Victoria in Marl to form Bergwerk Auguste Victoria/Blumenthal on 30 June 2001. The Grubengasabsauganlage of the firm Minegas GmbH was installed on part of the Schacht 7 site and continues to operate.
Denkmalwert was recognised for the Schacht 7 site immediately after closure in 2001. The site was entered on the Denkmalliste of the city of Recklinghausen in 2006. The listed ensemble includes the headframe with shaft hall, the machine house and its electric Koepe winding machine, the entrance and Kauen building — which has a distinctive three-bay window and door arrangement in worked stone surrounds with a Werkuhr — the Grubenlüfter, and the ventilator building; the surface buildings are predominantly in plain Backsteinarchitektur. The Bergaufsicht was declared ended on 19 December 2019. On 2 March 2020 the RAG Montan Immobilien transferred the 24,000 m² site, together with the Minegas tenancy, to the civic association Blumenthal 7 e.V. The association, founded in 2016 under the initiative of Stephan Widera, aims to establish an open workshop and space for art, culture, music, and community use on the site. At the time of the handover the Denkmalliste buildings were in need of conservation work, and in 2024 the roof of the administration building was reported to have been repaired with Heimatruhr funding from the state of North Rhine-Westphalia.