By mid-December, ÖBB-Infrastruktur AG will renew the entire infrastructure of the Gailtalbahn railway line. The 124-year-old Gail Bridge near Arnoldstein will be replaced by a new structure as part of the electrification of the Gailtalbahn. A 750 tonne crawler crane will swap the old structure for the new one.
On August 30, 2019, the technically complex lifting operations will be carried out with the old and new preassembled structure. The crane, which can lift loads weighing up to 750 tonnes, is currently being assembled on site. The construction site area may not be entered during the lifting operations for safety reasons; apart from that, parking on the B 111, the Gailtalbundesstraße, is not permitted.
“The old steel truss bridge over the Gail river, whose girders and gusset plates are connected with forged rivets dating back to 1895, weighs 151 tonnes,” says Siegfried Moser, Regional Manager ÖBB-Infrastruktur AG. A crucial factor for the construction is the hydrology of Carinthia’s second longest river, the Gail, which does not permit auxiliary structures in the riverbed.
The old bridge has a span of 61.60 m in length and has a width of 5 m. It offered neither enough space for the overhead line nor for a necessary bypath. The new bridge is 50 meters long, 7 meters wide and weighs around 235 tonnes. It should not only enable a modern railway operation, but thanks to the bypath offers optimal conditions for the maintenance work. To allow undisturbed drainage, a special method of construction was chosen:
On an area of 110 x 23.5 m, which was partially poured into the existing river bed and secured with stonewalls from floods, the pre-assembly of the new bridge structure was carried out. A crawler crane was also positioned there, which can remove the old structure in one piece at the end of August and lift the new one.
Also the construction and dismantling of the crane is demanding. The individual crane components were delivered with a convoy of special transports. Just for the construction and dismantling of the crane, another 110 tonne mobile crane is required. WHat is particularly favorable is the immediate vicinity of the construction site to the motorway exit. Due to the tight time window, only 3 weeks remain for the actual bridge exchange.
The new steel truss construction was made by the ÖBB bridge construction experts from the Wörth bridge near St. Pölten. ÖBB is investing around EUR 60 million into the modernisation of the Gailtalbahn as a whole, which started in the previous year and will be completed this year in December. This year, ÖBB is investing about EUR 250 million into the renovation and new construction of the infrastructure in Carinthia.