A new tunnel, able to carry a double set of tracks, was finally built over the 1914/1915 period, with the first air shaft connecting the two drives having been pierced in January 1915.
A new tunnel was finally built over the 1914/1915 period. This was with the first air shaft. This was able to carry a double set of tracks. This first air shaft was connecting the two drives. This first air shaft was having been pierced in January 1915.