Award winning installation of two 2,700t bridge arches Torun, Poland
OVERVIEW: ALE was contracted to complete the skidding, assembly and float installation of two 2,700t arches to bridge the 500 metres wide river Wisla in Torun, a project which represented a major investment in the region.
SERVICES REQUIRED: ALE began by jacking up the two sections of the first arch from the fabrication supports using eight 500t capacity climbing jacks which were placed on skid beams; the sections were then skidded towards each other and connected with two centre hinges. A 55m high ALE gantry system was built up over the arch sections. The 1,350t capacity gantry utilized four 500t strand jacks connected with the anchor heads to the hinge point of the bridge. Four barges were used for supporting the bridge in sets of two; each contained a support structure to approximately 12m in height. On top of this support structure, the ALE jacking towers were installed, with a capacity of 1,600t per barge set.
Throughout the operation, careful monitoring was carried out as the river is well known for unpredictable water height and high water speed. Multiple hydraulic winches were used to rotate the bridge and float it to its jacking position. On the second day, ALE jacked-up the arch 14m to its final installation height of the abutments. The jacking operation was executed simultaneously with the jacking towers and all bracing strand jacks. From here ALE followed an identical process to install the second high bridge arch.