The reconstruction of the technological tunnels of the National Theatre has been completed

Prague - The reconstruction of the technological tunnels of the Prague National Theatre has been completed. The work lasted 13 months and cost 127 million CZK. Journalists were informed of this today by representatives of the National Theatre and the company Metrostav, which carried out the reconstruction. The unique structure brings air and water for air conditioning and allows the transportation of materials from the riverbank level. The main investor was the Ministry of Culture.
"The original tunnels are even older than the Zítka building of the National Theatre itself. They were used to bring most of the materials for its construction. Thanks to the comprehensive repair, we can be sure that even floods like those ten years ago will not endanger this valuable historic building," commented the director of the Czech First Scene Ondřej Černý.
The reconstructed tunnels can bring up to 136,000 cubic meters of air per hour or pump up to 750,000 liters of cooling water in an hour. The main element of the flood protection is a steel, electronically controlled four-ton gate located in the embankment wall.
The condition of the tunnels under Masaryk Embankment had been very poor and even critical for a long time. Their structure was compromised by the heavy traffic of vehicles and especially heavy tram sets on the road. According to project manager Radovan Aulík from Metrostav, the work was not easy - for example, the builders had to create a twelve-meter opening in the outer wall of the "golden chapel" without causing cracks.
"The work took place on an extremely small construction site of about 800 square meters, all while the theatre remained in full operation. At the same time, the builders had to relocate thirty engineering networks," stated chief engineer Tomáš Míčka. "It complicated our work that we had to ensure the passage of public transport through the construction site throughout the reconstruction, as well as maintain temporary flood prevention measures," explained Aulík.
The construction, which was supervised by heritage protection officials, consumed nearly a thousand cubic meters of concrete, over 173 tons of reinforcement, and 18 tons of structural steel. It saw the involvement of 850 workers. According to the project by Pontex, the lifespan of the main load-bearing elements is at least 150 years.
Two tunnels located in close proximity were connected into one, and tracks were inserted into the ground contrary to the original plans. Černý sees their use in the repair of the lower stage of the National Theatre, which is to take place within ten years. "This will significantly reduce costs; otherwise, we would have to create alternative transport routes for the delivery of materials," he stated. During the reconstruction, the workers also encountered surprises. They discovered tunnels that no one knew about; once upon a time, they served as sewers.
In the longer term, the repaired tunnels could be used for the transport of decorations in large-volume containers without the need for trucks to enter the theatre.