Three brothers shaft

Three brothers shaft
General information about the mine
View of the building complex of the Drei-Brüder-Schacht.
Mining technology	Underground mining
Information about the mining company
Employees	~ 200 (19th century)
Start of operation	1818 (completion of the shaft) 1914 (commissioning of the cavern power plant)
End of operation	1898 (cessation of mining) July 10, 1972 (decommissioning of the cavern power station)
Successor use	technical monument / exhibition
Funded raw materials
Degradation of	Silver, lead, zinc
Geographical location
Coordinates	50 ° 53 '12.5 "  N , 13 ° 19' 55"  E Coordinates: 50 ° 53 '12.5 "  N , 13 ° 19' 55"  E
Location Drei-Brüder-Schacht
Location	train
local community	Freiberg
District ( NUTS3 )	Central Saxony
country	Free State of Saxony
Country	Germany
District	Freiberg district

The Drei-Brüder-Schacht is a shaft sunk between 1791 and 1818 in the Freiberg district . Originally built as part of a drainage project, among other things, it developed into the main shaft of the pit “ Blessing God Duke August” . After mining ceased in 1914, one of the world's first cavern power plants was built in the Drei-Brüder-Schacht .

Geographical location

The Drei-Brüder-Schacht is located on the western edge of Zug near the city of Freiberg in the district of central Saxony . It is not far from the federal highway 101 between Freiberg and Brand-Erbisdorf , along which the Silberstraße runs in this area .

The shaft is to be assigned to the southern Freiberg mountain area near the Brander area (pit field "Beschert Glück" ). The heap that extends around the shaft is larger than average for the mining industry in the 18th and 19th centuries in the region.

history

Mining

Generator (left) and turbine in the substation of the Drei-Brüder-Schacht

Generator around 1920 with exciter (left edge of the picture, later removed)

In 1791, the mines Beschert Glück und Segen Gottes Duke August decided to find a joint solution for the drainage of these mine fields in order to develop deeper veins . As a result, the mine water should be discharged through the Moritzstolln system . In the course of this, the Three Brothers Shaft was also sunk.

After completion in 1818 and the connection to the Moritzstolln at a depth of 143 m , a sweeper and an artificial bike were installed in the Drei-Brüder-Schacht in 1823/24 with the help of Christian Friedrich Brendel . A foreground was built above ground for the Wassergöpelanlage .

After the pit water was no longer a problem, ore mining could be continued at greater depths. With the extensive hydropower plants , the Three Brothers Shaft was also very well developed and thus became the main shaft of the Pit Blessing God Duke August. Up to the middle of the 19th century it experienced an upswing and good yield , up to 200 miners worked here. As a witness of the mechanical conveyor operation at that time, there is still an ore roll above the ground , one of the oldest still preserved loading facilities in the Freiberg district.

With increasing depth, however, there were no more ore deposits that were hoped for. When attempts to a depth of 388 m did not promise success, the mine was shut down in 1898. The decline in the price of silver marked the end of all mining in the Freiberg area and after the last mine was closed in 1913, the question arose of how the extensive surface and underground water systems of the Revierwasserlaufanstalt should be maintained and used. In order not to let the water run off unused after the end of mining, it was decided to use the run-off water for energy generation. In this way, funds for the maintenance of the plants could be generated at the same time.

Cavern power plant

Schematic functional representation of the power plant operation with storage space

The idea of ​​using the water from the Revierwasserlaufanstalt to generate electrical energy , which flows off over great gradients and is brought up above ground through artificial ditches , was born at the end of the 19th century. As early as 1899, work began on the expansion of an underground engine room in the nearby Constantin Shaft, which, however, initially came to a standstill due to an overall concept that was still missing and legal issues that had not yet been clarified.

From 1904 onwards Oscar Reinhold Lange , head of the Himmelsfürst Fundgrube , dealt with this idea. By 1911 he worked out a concept in which the three brothers shaft was given a decisive role in the construction of a cavern power plant. The legal basis was created in 1912 with a law that permitted the use of mine water for purposes other than mining. Work on the district power station began under the direction of Lange .

On December 24, 1914, the substation in the Three Brothers Shaft was put into operation. From January 26, 1915, the power plant initially delivered 2.4 MW of electrical power in continuous operation, which was transferred to the communities of Brand-Erbisdorf , Muldenhütten , St. Michaelis , Langenau and Großhartmannsdorf via a network specially built for the district power station . In 1921, a high-voltage line was also built to Freiberg.

When it was commissioned in 1914, the Drei-Brüder-Schacht was one of the first cavern power plants in the world. Power plants of this type that had already been commissioned are known from Snoqualmie ( USA , commissioned 1898) and the Samson mine in the Upper Harz Mountains (commissioned 1912). Until then, however, the use of the large underground storage space in the Three Brothers Shaft is unique. By including the existing shafts , routes and excavations , a storage volume of 1.5 million m³ could be achieved.

After delays as a result of the First World War , the upper works in Constantinschacht was completed in 1922 . From 1924, an additional 2 MW were fed into the grid. After being used in the upper plant, the water now reached the lower-lying storage space and could be used a second time in the lower plant together with additional groundwater. Then it flowed over the Rothschönberger Stolln towards the Triebisch .

Through further improvement measures, which were financed by the inexpensive electricity generated, the output could be increased to 6 MW by 1943. The Drei-Brüder-Schacht thus represented the most powerful hydropower plant in Saxony at the time.

Situation after 1945

Schematic functional representation of the power plant operation without storage space between 1953 and 1969.

After the Second World War , the SAG Wismut carried out explorations for uranium ore in the area of ​​the Drei-Brüder-Schacht as in all Ore Mountains deposits . After the bismuth left the mine field after two years in 1949, operations were started in 1951 by the lead ore mine "Albert Funk" . With the resumption of active mining, the underground storage facilities could no longer be used, so that the substation had to be shut down in 1948. The upper works in Constantinschacht could initially be operated until 1951.

By changing the water flow, the power plant was able to be put back into operation in December 1953, although the large storage space between the upper and lower plant was no longer required. Instead, the water after the upper works was directed to the lower works via a newly excavated section and a die . In the operational management it was now necessary to ensure that there was always sufficient water in the die, which now only holds 7000 m³, above the substation. In addition, only the water flowing over the surface could be used to generate energy, the pit water flowed away unused. Disputes after the separation of the power plant from the district water run-off facility over the provision and price of water also led to a decline in performance.

The assessment by the energy industry that the power plant was unprofitable , especially compared to the lignite-fired power plants preferred in the GDR at the time, and had no historical value, led to the decision to close the plant in 1968. Just one year later, the upper works in the Constantin shaft went offline. The substation continued to operate until July 10, 1972, after the Albert Funk lead ore mine was closed in 1969, even using the underground storage space again.

Attempts to maintain the power plant continued to fail due to the re-commissioning being judged to be economically unacceptable. However, the underground machinery of the substation was not completely removed, but preserved. The surface facilities were damaged by neglecting to divert the pit weather .

Drop tests to prove the earth's rotation

In August and September 1831, the physics professor Ferdinand Reich from the Freiberg Bergakademie carried out one of the most important fall experiments to prove the earth's rotation in the Drei-Brüder-Schacht . The upper part of the shaft runs vertically, so that a drop height of 158.5 m could be achieved. In numerous experiments, Reich initially dropped tin balls attached to threads, which he released using a pair of tongs, into the shaft. After suspecting that the movement of the tongs was too much of an influence on the balls with this method, he let the balls cool down over a precisely fitting hole in the starting device after a bath in boiling water, so that they fell into the shaft without any external influence. By measuring the deviation of the point of impact of the balls from the vertical , which resulted in an average value of 27.5 mm in Reich's experiments and thus came very close to the theoretical value, he was able to prove the rotation of the earth.

Todays situation

View of the greenhouse of the Drei-Brüder-Schacht

The renovated Scheidebank building, built around 1820

A hunt in front of the three brothers shaft

Old control room in the three brothers shaft

View of the control room in the Drei-Brüder-Schacht around 1920

In 1992 the Friends of the Drei-Brüder-Schacht eV was founded with the aim of preserving the technical monument Drei-Brüder-Schacht. In addition, the aim is to one day generate electricity again in the cavern power station. With donations and contributions, large parts of the surface facilities could be renovated. Steps to maintain the system could also be taken through the sale of Kuxen , symbolic shaft share certificates, with which a sponsorship for a section of the shaft tube can be taken. However, the underground facilities are no longer suitable for future power plant operation because they have been damaged and corroded despite their conservation .

The exhibition WassErleben has been located on the Drei-Brüder-Schacht since November 2008 . Funded by the German Federal Environment Foundation and the Saxon State Ministry for Environment and Agriculture , it illustrates the interaction of the Revierwasserlaufanstalt with the idea of ​​the cavern power plant.

The steam model meeting , which takes place every year in May, has established itself as a magnet for visitors, where exhibitors from all over Germany come together to exhibit and demonstrate steam models of all kinds.

Flood in 2002 and renovation of the shaft system

Since the shaft installations in the Three Brothers shaft were removed after the closure, access to the underground facilities was only possible for a long time by entering the shaft of the teaching and research mine “Reiche Zeche” of the TU Bergakademie Freiberg . The former substation with the preserved turbines could be reached in about 12 hours of driving through the Rothschönberger Stolln .

During the August floods in 2002 , the Rothschönberger Stolln was also affected. Due to an eruption , masses of water backed up to the Drei-Brüder-Schacht and put parts of the underground facilities under water for a long time. The water level in the shafts reached a height of 16 m above normal level, the engine room of the cavern power plant was flooded about 6 m. The underground facilities that were still in existence, which had been in relatively good condition until then, were rendered unusable.

After this flood event, renovation work was carried out on many essential water-dissolving tunnels in all of Saxony to ensure the water removal capacity - i.e. for flood protection, including the Rothschönberger Adit. Since the Drei-Brüder-Schacht represents the southernmost access point to the Rothschönberger Stolln, the shaft is an important point to be able to drive, control and maintain the tunnel. Between December 2013 and October 2016, renovation work was therefore carried out on the Drei-Brüder-Schacht on behalf of the Saxon Mining Authority to make the access mechanically accessible again. On October 27, 2016, in the presence of representatives of the Saxon State Ministry for Economics, Labor and Transport , the Saxon Mining Authority, the City of Freiberg and the Friends of the Drei-Brüder-Schacht eV, the shaft was reopened for inspection and maintenance purposes. Since then, the Rothschönberger Stolln can be reached again via the Drei-Brüder-Schacht.

See also

• Freiberg Gangerz deposit

literature

• Gunther Galinsky , Jürgen Leistner, Gernot Scheuermann: Three Brothers Shaft Cavern Power Plant . History and considerations for reconstruction. Ed .: Saxonia location development and administration company mbH. 2nd Edition. Freiberg 2001, ISBN 3-934409-12-1 .
• Birgit Seidel: The Three Brothers Shaft: Past, Present - Future? In: ACAMONTA . Journal for friends and sponsors of the Technical University Bergakademie Freiberg. 19th year 2012, ISSN  2193-309X , pp. 175–178.

Web links

Commons : Drei-Brüder-Schacht  - collection of pictures, videos and audio files

• Homepage of the Friends of the Drei-Brüder-Schacht eV

Individual evidence

1. ^ Otfried Wagenbreth , Eberhard Wächtler (ed.): The Freiberg mining industry . Technical monuments and history. 1st edition. VEB German publishing house for basic industry, Leipzig 1986, ISBN 3-342-00117-8 . P. 153
2. ↑ Gunther Galinsky, Jürgen Leistner, Gernot Scheuermann: Cavern power station Drei-Brüder-Schacht . History and considerations for reconstruction. Ed .: Saxonia location development and administration company mbH. 2nd Edition. Freiberg 2001, ISBN 3-934409-12-1 . P. 5
3. ↑ Gunther Galinsky, Jürgen Leistner, Gernot Scheuermann: Cavern power station Drei-Brüder-Schacht . History and considerations for reconstruction. Ed .: Saxonia location development and administration company mbH. 2nd Edition. Freiberg 2001, ISBN 3-934409-12-1 . P. 41
4. ↑ Ferdinand Reich: Drop tests over the rotation of the earth made on high order by the Mining Authority in the Drei Brüderschachte near Freiberg . Freiberg 1832.
5. ↑ Question marks about power plant plans. Inspection of the underground facilities - the club continues to fight. In: Free Press. March 10, 2004
6. ↑ Birgit Seidel: The Three Brothers Shaft: Past, Present - Future? In: ACAMONTA . Journal for friends and sponsors of the Technical University Bergakademie Freiberg. 19th year 2012