The lifting system of the new Lourdes footbridge is now proving its worth against the bad weather currently raging in south-west France. The lifting bridge, designed by bureau greisch, was raised 4m in its safety position in order to allow the Gave de Pau to flow freely in flood.
The Gave de Pau is out of its bed again, with an air of déjà vu since in July 2013, a similar scenario caused many damages to the existing works. In order to provide an integrated response to this problem, the Sanctuaire de Lourdes then positioned itself by launching a Design and Build competition for three lifting bridges on the site.
To date, only the first bridge downstream from the Grotto of Marian apparitions has been completed. The construction of these mobile footbridges will allow the pilgrims to cross the Gave de Pau, and to put the works in safety in the event of flood.
The gangway is lifted by a system of hydraulic cylinders housed in pits at each abutment of the structure (4 m lifting). Built in duplex stainless steel for its aesthetic and mechanical qualities, it is characterized by its slenderness (40 cm thick for 38.5 meters span), like a metal ribbon connecting the two banks. The stainless steel is sanded to ensure a correct grip and make the texture matt, noble, and integrated. So there is no coating, no finish.
Bureau greisch, in joint venture with Eiffage Construction Midi Pyrénées (FR), Defol & Mousseigne (FR) and Beterem Ingénierie (FR), is responsible for the architecture and the structural stability of the three bridges.
Photos © Sanctuaire de Lourdes
© Patrick Mousseigne