Preparation of the Reconstruction of the Old Bridge over the Danube in Bratislava

The Old Bridge over the Danube in Bratislava was built in years 1889 - 1890. At the end of the WWII steel structure of the bridge was destroyed.In 1945 new road part of the bridge (Roth-Waagner system) was built as a replacement for an original structure. It had 7 spans.In later time a railway bridge was laid on common pillars beside the road bridge. The railway bridge consisted of simple supported trussed beams. In 1985 the railway bridge was set out of order. In 2010 the road part of the bridge with main girders with Roth - Waagner system fell into disrepair. Consequently several expertises were made and based on their results it was decided to immediately stop traffic and to close the bridge. In June 2010 employees of Ingsteel, spol. s r.o. for Alfa 04, a.s. worked out a proposal of reconstruction of the railway part of the bridge to the stage of construction permit. Considerations were given to using the original riveted main girders of the railway bridge. During the reconstruction of the bridge with the original width of 5.0 m had to be widened to 11.0 m and it had to be complemented with a new orthotropic deck, footpaths on both sides and new upper and lower longitudinal bracings. Due to change of the concept of core network corridors system of public transport in Bratislava axle loads of trams were increased (change to tram-train system). Also the width of footpaths was increased from 3.0 m to 4.5 m. Analysis proved that original main girders do not have enough capacity to bear this increased loads and the reasonable strengthening of the structure is not possible. Later, in February 2012 Ingsteel submitted to customer unfinished project for construction permit with proposal of new bridge with continuous beams shaped similarly to the railway part of the Old Bridge.