New boreholes into old gallery
Version vom 9. Mai 2012, 10:50 Uhr von Backhaus (Diskussion | Beiträge) (Die Seite wurde neu angelegt: „In the old days was closed mine without degassing devices. Therefore, new access have to be created now in order to extract the gas in a controled way.“)
In the old days was closed mine without degassing devices. Therefore, new access have to be created now in order to extract the gas in a controled way.