Former hard coal ventilation shaft in Saarbrücken-Klarenthal, with its 1908 Fachwerkgerüst headframe — the oldest surviving in the Saarland — the 1904 Rateau ventilators, and the brick machine house all preserved as listed monuments.
Delbrückschacht II, located in the Klarenthal district of Saarbrücken on the left bank of the Saar, was the second of a pair of Wetterschächte sunk to serve the Fettkohlenabbau of the Grube Luisenthal. The first Klarenthalschacht was begun on 1 April 1899 at the same time as the main Richardschacht I across the Saar; a second Frischwetterschacht was added alongside it from 1 April 1905; both were renamed the Delbrückschächte I and II in 1907 in honour of the visiting Prussian Minister Dr. Rudolf von Delbrück. The 34-metre steel Fachwerk-Strebengerüst over Schacht II was erected in 1908 by the Metz firm Charron, making it the oldest surviving headframe in the Saarland; it was reinforced in 1938/39 by B. Seibert of Saarbrücken.
The associated brick Fördermaschinenhaus, built over a high sandstone plinth with Rundbogenfenster and Lisenen, contains a 1949 Dingler-Werke Fördermaschine. The two Rateau ventilators of 1904 from Schüchtermann & Kremer (Dortmund) are the oldest surviving pit ventilators in the Saar mining district. The shaft continued in service until the final closure of Grube Luisenthal in 2005, and the listed ensemble survives as a monument to the Saar coal industry.
The origins of the Delbrückschacht II lie in the exploratory boreholes of 1897 and 1898, which revealed the presence of a 500 to 600-metre-thick Fettkohlengebirge beneath both banks of the Saar at Völklingen-Luisenthal. To exploit the seam, the Prussian Bergverwaltung authorised the sinking of two new shafts: the Richardschacht I at the Luisenthal works on the right bank, and a ventilation shaft on the left bank in the Klarenthal area. The Klarenthalschacht I was begun on 1 April 1899, coinciding with the commencement of the Richardschacht I. The shaft on the left bank was designated a Wetterschacht (later also named Delbrückschacht I, Clarenthalschacht I, or Beaunierschacht I in the French administrative period); it served to supply Frischwetter to the Fettkohlenbaue beneath the Saar valley.
On 1 April 1905, a second Frischwetterschacht was begun alongside the first at the Klarenthal site. This became the Klarenthalschacht II and was renamed in 1907, on the occasion of a visit by the Prussian Minister für Handel und Gewerbe Dr. Rudolf von Delbrück, first as Clarenthalschacht II and then definitively as Delbrückschacht II. Both shafts at the site were also known under the French administration (1920–1935) as the Beaunierschächte. In 1907 the 34-metre steel Fachwerk-Strebengerüst over Schacht II was erected by the firm Charron, Metz; this headframe, a German Strebengerüst in lattice construction, is regarded as the oldest surviving headframe in the Saarland. In 1938/39 the structure was reinforced by B. Seibert of Saarbrücken. The associated brick Fördermaschinenhaus, built over a high Sandsteinsockel and articulated with Lisenen and Rundbogenfriesen, is a substantial example of Historismus industrial architecture in the Saar region; it contains a Fördermaschine of the Dingler-Werke, Zweibrücken, dating from 1949. Alongside the Fördermaschinenhaus is the Maschinenzentrale, a brick hall housing the ventilation plant. Of particular historical significance are the two Rateau-Lüfter from the firm Schüchtermann & Kremer, Dortmund, built in 1904 — the oldest surviving Grubenlüfter in the entire Saarbergbau — and two Turbo-Kompressoren of 1937 and 1939 from AEG.
The mine to which the Delbrückschächte served as outer Wetterschächte — the Grube Luisenthal — was administered under the name Fettkohlenschachtanlage der Grube Gerhard by the Prussian Bergverwaltung, passed to French administration as Division Luisenthal from 1920, and reverted to German administration in 1935. The mine was badly damaged by a fire on 27 September 1914 and flooded until 1922; production resumed only in 1925. From the 1940s onward the Delbrückschacht II underwent successive extensions: by 1989 a substantial Umbau for improved Bewetterung of the Bergwerk Luisenthal was under way. The mine was progressively merged: in the early 1970s Luisenthal formed a Verbundbergwerk with Grube Camphausen; in the 1990s it was merged with the Grube Warndt; and on 1 January 2004 the combined Bergwerk Warndt/Luisenthal was united with Bergwerk Ensdorf to form the Bergwerk Saar. Coal winding at the Luisenthal surface complex ceased on 23 December 1994, though the Delbrückschacht II continued in ventilation service for the wider Bergwerk. The final closure of the Luisenthal component of the Bergwerk Saar took effect on 17 June 2005, ending over 185 years of coal production at the site.
Following closure, listed structures at the Delbrückschacht II complex were preserved: the 1908/1938 Fachwerk headframe, the brick machine house with its sandstone Sockel and Rundbögen, the Maschinenzentrale with 1904 Rateau ventilators, and the two AEG compressors. The ensemble is regarded as a heritage complex of Denkmalwert, noted for the completeness and age of its machine equipment in a singlesite context. The coordinate for this site corresponds to the Klarenthal district of Saarbrücken, where the two Delbrückschächte are located.