planned tunnel size:
60 000-75 000 m²

planned tunnel:
10 main tunnels (A-J)
23 crossways

completed tunnel:
1. level:
7 main tunnels (A-G)
15 crossways
2. level
1 main tunnel (H)
started crosscut

start of construction: spring 1944

concentration camp prisoners: about 15 000

alone in concentration camp Melk/Quartz B9 harrowing killed:
about 5 000 concentration camp prisoners

height of the tunnel:
1,5 m to 12 m
depending on the configuration