connecting link wien

starting point
the mouth of the wienfluss into the donaukanal represents one of the most historically and urbanistically valuable areas of vienna. here is located the largest water surface within the inner-city area. at the same time, however, it also represents a barrier for cyclists and pedestrians in the 17km long path network along the donaukanal. the architectural office gaupenraub addressed this missing connection with their study missing link schwimmsteg and thus provided the idea for bridging the wienfluss mouth and thereby closing this gap in the path network.

route alignment
the location of the pedestrian and bicycle path on the so-called hermannpark side is determined by the current use of this area as a popular beach bar, the hermannbar, with generous lounging areas and boule courts. the arrangement of the associated extensive toilet and service rooms directly on the north wall of the quay prevents a free-flowing route of the pedestrian and bicycle path south of the hermannbar. for this reason, we propose to guide the pedestrian and bicycle path on the hermannpark side free of intersections along the water side directly on the donaukanal. this also corresponds to the general routing along the entire donaukanal directly at the water’s edge. the wienfluss flows from the radetzkybrücke into the donaukanal in a funnel-shaped expansion. the larger the distance of the new bridge from the radetzkybrücke, the larger its span must be. on the urania side, the underground structures of the vorkai adjacent to the radetzkybrücke define the bearing possibilities of the bridge and prevent too close an approach to the radetzkybrücke and thus a minimization of the span. in addition to the smaller span, a location of the bridge as close as possible to the radetzkybrücke would have the advantage that smaller ships have more space to turn and thus fewer lifting operations are necessary. based on these considerations and in the effort to achieve a harmonized route for cyclists without abrupt changes in direction, the optimal plan form of a curved bridge geometry results.

bridge elevation
gentle ramps with a 4 percent slope lead on both sides to the level of the new bridge, which is raised by about one meter compared to the vorkai level. this has the advantage that the vorkai wall, including the curb to the donaukanal, can remain completely unchanged, as part of the bridge bearing can cantilever over the vorkai wall. all necessary foundation measures for the bridge begin only behind the curb. the ramps leading to the bridge gently make users aware of the change from the vorkai path to the bridge. this is supported by the change of surface, the transition from ramp railing to bridge parapet, and in the evening by the special lighting situation on the bridge. the slightly elevated bridge also offers less resistance to floodborne debris.

appearance
based on the importance of the appearance of the radetzkybrücke, a slim bridge was targeted. like a thin line, it should disturb the radetzkybrücke as little as possible. no tall elements such as pylons or other cable or truss constructions. a thin, closed visible surface, reduced design, restrained, simple, clear, in a light appearance referring to the colors of the quay walls and the urania.

lifting process
two hydraulic telescopic arms lift the entire bridge arch at the third points by about 31 degrees into the height until the required clearance profile is reached. all necessary mechanisms such as hydraulics, pumps, oil pans, etc. are integrated into the bridge parapet. this has the enormous advantage that in case of flood only the ends of the extended telescopes are in the water and all sensitive systems remain suspended in dry air. there are no installations to protect from floods for lifting mechanisms, counterweights, or similar in the vorkai. the unusual tipping of the curved bridge construction to a large air-standing arch emphasizes the fascination of the lifting process and becomes a unique attraction.

lighting concept
light strips cut into the bridge parapets illuminate the bridge deck and, through the angled position of the parapet walls, also illuminate the bridge users. in addition, handrail lights illuminate these parapet walls. as a result, the light gray coated bridge deck and parapet surfaces become a brightly shining and reflective interior of the bridge, creating a friendly and fearless atmosphere. lights on the underside of the bridge shine into the water and create, via reflection on the bridge exteriors, a flickering typical for water. in the raised position, the telescopes are additionally illuminated to highlight their importance. before the lifting process, the light color of the entire bridge lighting can switch to red and blink to indicate that the bridge must be cleared.