Pfäfers - Fortress Furggels
The filter room for ventilation. Dehumidification, motor cooling and nuclear filters (f.l.t.r.). The fresh air conditioning is further back. The large fan on the left from the middle is for engine cooling. The air for this comes from the side wall from the air inlet number 2. The other air ducts are under the floor. The breathing air comes from the air inlet number 1 in the rock wall at observation post Prättigau. Two spare air intakes, number 3 and 4, are in the outside defenses 'Bild' and 'Tobel' above the main entrance. Switzerland, Oct 4, 2015.