OSTROJ supplied shuttering system with 30° incline movement for Prague Metro Line D escalator tunnel

OSTROJ has designed and manufactured a new mobile shuttering system for the escalator tunnel of Metro Line D on the Pankrác – Olbrachtova section. The equipment was designed to operate at an incline of up to 30°, which is an unconventional parameter for tunnel construction. The delivery took place in four phases, ranging from the base platform to the final concreting.

The project built on previous cooperation with STRABAG during the construction of Metro Line D. The new mobile shuttering system was custom-designed entirely from scratch, based on specific construction data and the requirements of the contractor.

"The design of the mobile shuttering for the escalator tunnel differed significantly from standard tunnel profiles. The solution for Metro Line D represented a specific structure that we developed from the ground up, tailored precisely to the given construction site and its conditions," says Martin Čmiel, Sales and Marketing Director at OSTROJ.

The equipment was deployed sequentially. First, the base platform with a material transport trolley was delivered, followed by an extension for the tunnel benches (banquettes). The third phase introduced the waterproofing and reinforcement platform, while the final stage enabled the actual concreting of the tunnel.

The mobile shuttering system had a total weight of 58 tonnes. The structure was 6 m long, 8.6 m wide, and 7.15 m high. The length of the concrete block was 6 meters. Incline movement was ensured by hydraulic struts that safely moved the equipment along rails in precisely controlled steps.

"The greatest challenge was the safe movement of the entire structure at a thirty-degree incline and securing it reliably in the working position. The specific requirements for reinforcing and concreting at this slope placed higher demands on stability, safety, and the precision of each movement," says Zdeněk Slavík, Sales Manager at OSTROJ.

The delivery also included an auxiliary material transport trolley. Throughout the project, it served as a supply platform and facilitated material handling within the confined space of the tunnel.