Fire in the Blücher seam

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The fire in the Blücher seam on the Neunkirchen (Saar) district between 1990 and 2012 was the largest fire in a seam in the Saar district and throughout Germany. It came into being after the federal road 41 was passed west of Neunkirchen in 1990 as a bypass road and the near-day coal seams were cut during the construction of the sunk route . In the 1990s, the carbon-bearing layer ignited due to the ingress of oxygen and the subsequent generation of heat. Extinguishing measures initially remained inactive or ineffective. The coal fire in the Blücher seam, one of the main seams of the Saar area, which was formerly exploited here on a daily basis , threatened to spread further and make the city center of Neunkirchen uninhabitable. The seam fire was fought by RAG Aktiengesellschaft with various measures from 2009 and was temporarily extinguished in October 2012.

Geological situation

Near Neunkirchen, the coal seams of the Upper Carboniferous in the Saar-Nahe Basin run close to the day or come to the surface and have been exploited first superficially and then by mining since prehistoric times. Since the 19th century, the König pit about 1 km further east, the Heinitz pit and the Reden pit, were built in the vicinity of the later fire source , and they produced coal on a large scale until the second half of the 20th century until the next Extraction of coal by exhaustion of the seams and by the competition of the world market could no longer be operated economically. After that, large amounts of unmounted coal and also the coal seams of small thickness remained in the ground , which could never be mined economically. The Blücher seam with a thickness of three to four meters was mined here around 1830 only at a height of two meters . The technology of the time did not allow more, as the miners could only work at body height.

The seam fire

It came into being after the federal road 41 was passed west of Neunkirchen in 1990 as a bypass road and the near-day coal seams were cut during the construction of the sunk route. In the 1990s, the carbon-bearing layer ignited due to the ingress of oxygen and the subsequent generation of heat. The seam does not burn with an open flame , but glows . In 1998 the seam had to be cleared for the first time. In 2009, steam leaked from the embankment of Bundesstraße 41. RAG Aktiengesellschaft explored the site in 2009 by drilling and discovered that the coal fire had already spread to a depth of up to 22 m. Starting in 2009, the area was sprayed with a total of 140,000 m 3 of water from lawn sprinklers in summer and winter , which fueled the fire, as the resulting water vapor caused cracks and crevices in the mountains that enabled better oxygen access.

Finally, the fire was fought expertly in 2011 and 2012. Starting in October 2011, a protective concrete cut-off wall was built facing federal highway 41 to prevent the fire from spreading to the street and to prevent oxygen from entering through the embankment. 197 piles with 3900 meters of drilling and a diameter of 90 centimeters were placed around the source of the fire. Then 2650 cubic meters of concrete in piles and spaces were used to separate the fire zone from the non-burning seam. The temperature in the mountain could be reduced from 300 degrees to below 60 degrees. From September 2012, hot material was dredged, cleared and reinstalled. For this, a partial excavation of the site of a maximum of three meters was necessary. The reinstalled material was compacted. The area devastated by the dredging work will later be modeled and reforested.

The entire project (28,000 m 3 of excavation was planned) cost RAG 1.5 to 2 million euros. The largest scenario to be assumed, the complete dredging of the earth fire (with a projected 87,000 m 3 excavation), could initially be avoided. The fire has been considered extinguished since the end of October 2012.

See also

literature

  • Maria Wimmer: Deleting the Blücher seam is difficult . Saarbrücker Zeitung from July 4, 2011. Online
  • Coal fire in the Blücher seam is now to be extinguished . Saarbrücker Zeitung from October 22, 2011. Online
  • Ulrike Otto: Extinguishing a coal fire on the B 41 takes at least a year . Saarbrücker Zeitung from November 26, 2011. Online
  • Get to grips with the source of the fire . Wochenspiegel Neunkirchen No. 48/2011 from November 30, 2011.
  • The danger in the ground below Neunkirchen has been averted . Saarbrücker Zeitung No. 247/2012 of October 23, 2012, p. B 1.
  • The fire on the B 41 is contained . Wochenspiegel Neunkirchen No. 44/2012 of October 31, 2012. Online with date October 23, 2012

Web links

  • Flöz Blücher: Concept for fire fighting presented . RAG Aktiengesellschaft dated March 25, 2009. Online
  • The earth glows in the Saarland . n-tv from January 1, 2012 online .
  • Successful renovation measure Flöz Blücher: fire on the B 41 near Neunkirchen contained . RAG-Montan-Immobilien from October 23, 2012. Online .
  • After a year of fire, RAG extinguishes the coal seam on the B 41 . Sol.de from October 23, 2012. Online

Coordinates: 49 ° 19 ′ 57.2 ″  N , 7 ° 9 ′ 36 ″  E