40 Years Have Passed since the Prague Subway’s First Tunnel under the Vltava River Broke Through
Released: 18. 10. 2016
On October 18, 2016, exactly 40 years have passed since the first tunnel of the Prague subway system under the Vltava River broke through. Since it was not possible to perform any blasting work under the Vltava River or under the historical center of Prague, a prototype of the mechanical tunneling shield was used. The giant machine, which was the forerunner of today’s Adéla and Tonda machines, started from a giant cavern near the Mánes Bridge, reaching the Staroměstská Station on October 18, 1976.
The TSčB-3 mechanized complex was a machine prototype designed specifically for the hydrogeological conditions in Prague. Even today, tunneling shields are always designed for a particular type of subsoil. There were two machines, which could bore up to 60 – 70 meters per month. The state-of-the-art Tonda and Adéla tunnel boring machines advanced with a speed of more than 400 meters per month during the completion of the Prague subway.
So-called compressed concrete was used to construct the tunnel under the Vltava River, which was a very advanced method at that time. “Concrete was pumped into steel formwork, where it was pressed to achieve sufficient strength in order to support the rock. It filled up all of the spaces. Up to now, the tunnel has been in fairly good condition and leak-proof,” Jindřich Hess, the former General Manager of Metrostav, performing the position of Chief Site Manager of the driven tunnel at that time, commented on the anniversary.
At present, the Prague subway system includes four tunnels under the Vltava River. In addition to the abovementioned tunnel, there are tunnels between the Karlovo náměstí and Anděl Stations, the Florenc and Vltavská Stations, while the last tunnel connects the Holešovice and Troja Stations on the C line. The uniqueness of the latter tunnel lies in the fact that the tube was concreted on dry dock on the right bank of the Vltava River, and was subsequently slid beneath the river.
For more information contact:
Spokesperson Metrostav a.s.
Tel.: +420-266 019 715