After the two collapses in 1995 (adit collapse next to the road above the hut shaft) and in 2003 (machine shaft collapse), a collapse of the shaft filling of the willow shaft occurred at the beginning of June 2016 as a result of heavy rainfall.
This shaft is called "Puits large ou grand Puits" in the plan of ODELIN (1787, 1. Riss), translated approximately "Wide Shaft" or "Large Shaft".
In the 2nd crack it is mentioned as "Willow Shaft" and as "Grand Puits", which can be interpreted as "Main Shaft". In the plan of ERDMENGER (1818) it is marked as "3rd light hole". The plans of DILLINGER HÜTTE (1824 to 1828 and 1914/15) name the shaft as "Shaft A".
The shaft stands directly above the adit roadway and, when it was reached in 1996, was obstructed in the roadway area by heavy timber lining (door frames made of round timber and beam distortion). Sinking of the old, backfilled shaft was not necessary either for the excavation work or for visitor operation, so that in 1996 only the former location of the shaft was marked above ground with the removal of the shaft head and a shaft roof.
The course of the water supply gallery (main gallery) can be imagined as coming from the main mining area at Linsenberg, along the machine shaft in an almost straight line to the willow shaft (location). Here the roadway swings slightly to the left, passes under the road at an angle of about 45°, then bends to the right and runs parallel to the opposite side of the road to the Hauzeur shaft. There, the adit bends to the right again and then, while crossing under the road once more, continues in an almost straight line to the Hütten shaft and from there finally to the mouth hole.