Mindener district
The Mindener Revier is a coal mining area in the northern Wiehengebirge foothills near Minden . Here, in the Schaumburger Mulde, coal seams emerge from the earth. During the Thirty Years War , Swedish soldiers discovered coal for the first time near Minden while working on digging at Bölhorst. As early as 1663 it was made a severe punishment for wild coal digging.
A number of pits reached ever greater depths. As in the Barsinghausen district in the Deister east of Minden, coal was mined in Minden until August 1, 1958. The last mining operation in this area was the Minden coal mine in Meißen .
geology
The Wealden near Minden is divided into the 150 m thick Lower Wealden Slate Clay and the 250 m thick Upper Wealden Slate Clay. The 200 m thick Wealden sandstone known east of the Weser is almost completely missing here. The layers of the Malm are located under the lower slate . The well-sealed shale caused a low water flow in the mountains, but a high outgassing rate of 90 m³ of mine gas (CH 4 ) per ton of coal.
The strata dip regularly at 20 ° –22 ° to the north. Two major faults became known through the coal mining: the Rösche jump (60 m) and the Porta fault (55 m). Two coal seams are embedded in the lower Wealden slate clay: the main seam with a thickness of 1.03 m (13 cm unclean coal, 60 cm tailings and 31 cm pure coal) and 32 cm below that the secondary seam with 31 cm pure coal.
The main seam has not been mined in recent years due to its impossibility to build. The coal of the secondary seam has 22% volatile components and is classified as low-gas fat coal . The calorific value is 31.8 MJ / kg with a sulfur content of 8 to 9% by beibrechenden pyrite .
Mines
Bölhorst colliery
The Bölhorst colliery was in production from around 1640 to 1806. Already in the early years it became clear to the miners that with advancing mining the extraction becomes more and more difficult due to the northern collapse of the seams. In 1743 100 miners and 4 climbers worked on the mine. The annual production was 90,000 bushels (Prussian). The neighboring salt mine in Rehme consumed most of the coal mined. The rest was delivered to blacksmiths and lime kilns in the region. A report from 1784 shows that mining had already reached a depth of 123 m (102 m deep shaft and a 21 m deep die ). Thus, in the 19th century, coal mining near Minden had reached the greatest depth of coal shafts in the German Empire. In 1801 the 37 cm thick side seam was opened up in a 174 m deep shaft. A hoisting machine and a dewatering machine , which were operated with steam, gave the shaft the name fire machine shaft. This was the second shaft in West German coal mining, the water drainage was a steam engine to promote even the first. Since this machine constantly caused problems and the tapped coal reserves were running low, the shaft was closed in 1806 after the remaining piers had been dismantled.
Prussian coal mine
The Prussian Klus colliery was operated from 1820 to 1847. Since only small amounts were mined from 1806 and not at all between 1812 and 1820, the mine was founded. This was created on the right bank of the Weser. The reason was a coal seam found in the quarry. A steam engine and a weather stove were procured. Coal was mined here until 1847, except under the village of Meißen where a safety pillar remained.
United Laura and Bölhorst mine
After the Preußische Klus colliery was closed, the company switched back to the left bank of the Weser. This is where the 60 m deep Aurora shaft was sunk. In order to expand sales, attempts were even made to burn the coal into coke. The fire engine shaft was opened up again, and with the unusual method of backfilling, it was sunk again and wider. It was gradually sunk from 182 m to 232 m and finally 272 m. In 1855 there were already 233 men working on the mine. The coke produced from coal purified in mine water from mountains turned out to be good, but was soon discontinued because of the excessive ash content. With him the blast furnace operation of the Porta mining company was stopped. After a production peak of 10,175 t in 1877, the mine was shut down in 1886.
Meissen colliery
After the supplies west of the Weser were exhausted, they went back to the right bank of the Weser. Between 1879 and 1879 the 189.5 m deep Meissen shaft was sunk. From this point on, only the secondary seam was dismantled. More than 10,000 tons of coal were mined annually. From 1910 to 1912 a coal washing plant , a coking plant and an electrical power station were built. In 1913, 192 men had already produced 17,348 t. The laundry throughput was 30 t / h. However, the coking plant was soon shut down again and was more of an experimental one.
Minden coal mine
In 1924 the shaft was sold to the Ilseder Hütte. In the same year they already mined 64,007 tons of coal with 748 men. In 1925 the 90 m deep weather shaft II was sunk. The plan to build a Fort C mine north of Minden was dropped because the seam here would only have been reached at a depth of 730 to 750 m. The Nothorn shaft was then sunk 800 m north of the Meißen shaft. The shaft was initially 420 m deep and in the first part was sunk by freezing due to a layer of alluvial sand. In 1930, the main production level 7 was completed at 380 m and a blind shaft with a smaller cross-section was sunk to the final depth of 480 m. In 1940/41 the 120 m deep Röcke shaft was sunk in the eastern field. Until 1956, coal was mined here, driven to the Notthorn shaft by truck and transported from here to the Meißen shaft by cable car. From 1928 a brickworks processed the resulting mountains and the existing dump into bricks. A blind shaft north of the Nothorn shaft reached a depth of 500 m and the 11th level before the shaft had to be closed in 1958 because of the poor coal quality and the insufficient seam thickness.
swell
- Hans Röhrs : ore and coal. Mining and ironworks between Ems and Weser . Ibbenbürener Vereinsdruckerei (IVD), Ibbenbüren 1992, ISBN 3-921290-62-7 .
- Thomas Krassmann: Materials on the geology and mining of the Schaumburger Land. 2010.
Web links
Coordinates: 52 ° 15 ′ 56.8 " N , 8 ° 52 ′ 46.6" E