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S7 Tunnel, Poland

Efficiency thanks to the flexibility of the MK System
Construction of Poland’s longest road tunnel with the MK Formwork Carriage.


The S7 Expressway crosses Poland from Lubień to Rabka Zdrój, north to south, passing through the Voividato Malopolskie region. There are three separate sections currently under construction.  One of these sections goes through Luboń Maly mountain, for which a tunnel with two separate tubes is being built, with a total length of over 4 km. This phase has proven to be the most time-consuming and costly of the entire Expressway project. There are two independent tubes, approximately 2 km each, designed for traffic to flow in a single direction. The tunnel will feature two emergency passageways between the tubes, a ventilation room, as well as technical and service installations. In order to build it, 1922.40 m have been perforated for the left-hand tunnel, and 1919.60 m for the right. 

Excavation began on the north side of the right-hand tube in March of 2017, and the entire tunnel is expected to be finished mid-2021.

ULMA Solution

ULMA’s Engineering Team designed an MK Formwork Carriage 15.50 m wide and 10.70 m long to pour the tunnel. With a single unit made from standard MK pieces, the carriage was able to adapt effortlessly to the tunnel’s complex geometry. For the roof, a special panel was designed to be load-bearing during the pour, and permit easy stripping without the need for hydraulic systems. TMK Formwork Panels provided an excellent finish. The carriage boasts a high load-bearing capacity, working platforms, access stairways, and other integrated safety features. 

For this project, ULMA provided the support of our Engineering Teams, as well as technical and assembly support. Due to the characteristics of the project and the variety of tasks that had to be carried out simultaneously, the carriage was assembled in sections inside the tunnel tubes. The flexibility of the MK System made it possible to match the assembly process to the excavation clearance, which prevented pre-assembly of the structure outside.

After pouring each 6.25m section, the carriage was easily advanced with a hydraulic system that facilitated formwork placement and stripping, lowering, and levelling, as well as advance. 

The success of this project demonstrates how collaboration with the client from the outset guarantees success, even in the face of demanding deadlines.