The photo shows our variable-section formwork system for the Carlberg Tunnel, a unique conical tunnel expanding from 13.8 m to 20.65 m in diameter. The system executed 78 pours of 12 m each, adapting precisely to the changing geometry with adjustable panels.

Its self-reactive structure absorbs lateral concrete pressure without ground anchors, while a crawler-based positioning system and hydraulic self-lifting mechanism allow safe, precise, and efficient assembly at ground level. A technical solution that delivered accurate construction, high-quality finishes, and optimized operational efficiency.