On 22 July 1907 the construction, undertaken by
Philipp Holzmann, started to connect the quarters of
St. Pauli near the
Landungsbrücken and
Steinwerder. Work was done under pressure because the tunnel is below the
water table of the
Elbe. This type of building technique was used in the 19th century in large engineering excavations, such as the
piers of
bridges and
tunnels. The
caissons with high inside pressure were used to keep water from flooding the excavations, such as the foundations of the
Brooklyn Bridge in
New York City. At the construction of the St.-Pauli Elbtunnel they used normal vertical caisson for the entrance lift shafts. But for the horizontal tubuses they used special device, that was working horizontally; something like stamping shield under high atmospheric / caisson pressure. Workers who spent time in high atmospheric pressure conditions had to return to the lower pressure outside through special cabin of slowly pressure reducing. Despite that hundreds of workers had health problems (74 of them had lasting consequences) associated with
decompression sickness, and even three of them died. Total number of all workers at the tunnel was ca 4.400. The tunnel opened on 7 September 1911. ==Modern usage==