Reflecting ages - New Danube bridge

All the bridges of Budapest represent special value. Their form, materials and structures reflect perfectly the age when they were constructed. The project of Szabolcs Király and Ákos Takács strives to preserve this tradition.

KKBK Kiemelt Kormányzati Beruházások Központja Nonprofit Zrt. as Contracting Authority published a restricted international architectural design tender with prequalification for the design of the new Danube bridge to be constructed with 2x3 traffic lines including track-based transport line in the axis of Galvani út. As our company has been successfully prequalified, we submitted a design project during the design phase. We are very proud of the designed bridge. The design period was fascinating; all the team members have taken up with enthusiasm this inspiring challenge, adding the best of their knowledge and a lot of work to the project.

Considering the extent of the task, we opened an in-house architectural design tender in order to find the version on the basis of which we can create the tender design. Within the framework of this in-house design tender, 4 architect teams have been formed and almost 20 drafts have been elaborated. We evaluated and re-evaluated several times the elaborated drafts, bearing in mind as a primordial aspect that the project should comply with all the tender requirements, considering the evaluating criteria defined in advance. Finally, departing from the symmetrical shapes of the bridges of Budapest, we opted for a single-pylon cable-stayed bridge, responding the requirement of the Contracting Authority to design a bridge structure not yet applied in Budapest. As for this aspect, the possibility of an arch bridge also emerged, but this idea had been rejected due to its less modern nature and the fact that it is more complicated to integrate in a city environment.

From aesthetic aspects, all the bridges of the Danube represent special value. Their form, materials and structures reflect perfectly the age when they were constructed. Our New Danube Bridge is designed to preserve this tradition. Regarding its design, cable-stayed bridges represent one of the state-of-the-art technologies, their materials and structural solutions are exemplary as environment and energy-conscious engineering structures.

The Northern area of Csepel Island is one of the most important development areas of Budapest. The sports centre and the recreational park to be constructed here, or the Campus to be installed near the Soroksár-Danube, emphasize more the importance of the new Danube bridge, forming a gate to Csepel and the new city centre.

Cityscape positioning also supports that the pylon of the designed bridge is closer to the Csepel side. The asymmetric form, and the most important support structure element constructed on the Csepel side are also justified by the fact that the pylon constructed here will be visible from the protected city centre areas of the capital, marking the Csepel Island developments within the cityscape.

We also examined the river piers, located far away from the streamline towards the Csepel Island, from the point of view of access to the free port of Csepel by watercraft. We determined that the access by barges to the free port, located at a distance of 1 kilometre from the crossing, is not at all affected by the pylon.

The interchanges related to the bridge, defined in the tender, cannot be constructed within the defined design limits in a way to satisfy all the necessary traffic requirements. Other areas shall be used around Budafoki út.

The new Danube bridge in the axis of Galvani út will significantly increase the value of the plots on Buda part. A zone reclassification is expected for the actually underused, more or less industrial buildings. The long term cityscaping plans of Budapest foresee an office or residential development area here, with a building height limit of 45 m.

We designed a two-level interchange near Budafoki út, as preferred by the Contracting Authority, minimizing the occupied area. As a possibility, we examined a single-level interchange of Budafoki út, but we rejected it as the Contracting Authority, in response of our question, opted clearly for the two-level interchange on the basis of the estimated traffic. Thus, considering the available area and the possibilities provided by the different levels, we opted for a semi-cloverleaf solution.

The pylon is a gate, a meeting point. The spatial restrictions due to tracks and the existing utility networks provides us new possibilities: at the designed bridge-head, a significant green area, a real recreational park can be created. The new park provides quality to the inhabitants of the capital / of Csepel to connect to the Danube. Due to the significance of this park, we designed a dedicated tramway stop and a P+R parking area near the bridge-head of Csepel.

According to the tender invitation, we designed bicycle lanes on both of the bridge sides matching the traffic direction, and a pedestrian side-walk respectively on both sides. At the bridge-head of Csepel, pedestrian and bicycle traffic will be separated from the motorized traffic. Pedestrian and bicycle traffic lanes will lead through the green area between the bridge and the wastewater treatment plant, on an alley lined with trees, toward Weiss Manfréd út. The axis of this alley, approaching the bridge, will point the bridge pylon in its appearance, and will lead the pedestrians and cyclists out to the pedestrian and bicycle alley to be constructed on Csepel quay. A multifunctional, paved “city space” can be created at the bridge-head with coffee shops and catering units for cyclists and visitors. This multifunctional social area can be an attractive destination as a southern counterpoint of the popular Római-part. The separated pedestrian and motorized traffic allow direct, undisturbed access to the Danube. A floating terrace will also be constructed on the water, creating a new quality in the relationship of the inhabitants and the Danube as a water surface.

The new Danube bridge, beyond functionally connecting two important potential development areas, two districts and two quarters of the two sides of the Danube, will also have an aesthetic importance in the view of Budapest.

The connection points on the two sides of the Danube are located in different river sections. We unanimously rejected the “S” shaped road track with an inflexion point in it. That solution would be definitely unfavourable from bridge structure construction complexity and cost effectiveness, as well as traffic safety aspects. Thus, we opted for the diagonal crossing, where the piers are oriented in the river flow direction.

The river piers are located as far from the waterways as necessary for ensuring undisturbed navigation. There was no reason for a larger span. Regarding the structure, the objective was to elaborate a visually generous, but, at the same time, an economic construction, using the lowest possible quantity of steel.

The pylon of the asymmetric cable-stayed bridge, a symbol-like, spectacularly high structure, visible from several renowned parts of the city, is located closer to Csepel. We definitely did not go for a double-pylon structure, as the span does not necessitate a second pylon, and the application of two pylons would decrease the pylon height, resulting that the unique design of the pylon loses its pronounced, spectacular appearance, becoming mediocre.

The form of the pylon includes multiple meanings: firstly it symbolizes the connection between the two sides, the two districts, and forms a gate to the new district of Csepel, and secondly the bifurcating silhouette with mild curves symbolizes the Danube, and its bifurcation at Csepel Island.

The bridge itself consists of characteristically curved lines, with some distinct, smooth and dynamic edges, as waves on the water, accelerating then mildly smoothening and spreading out.

The pylon legs enclose the road deck and approach each other in the upper section, but visually they do not merge. At their meeting point, a groove is formed, which emits light of different colours at night, as a part of the decorative lighting concept. The meeting point of the two pylon bases appears as two hands joined, with the light between them as the cohesion, the power of connection.

For those who approach the bridge on the bridge ramp, the form of the upper parts of the pylon will reveal the shape of two hands touching each other, with a coloured band between them pointing to the sky, or, by the light-line appearing in the night illumination, will symbolize a spiritual content for the spectators.

We attach an importance to the side and bottom views of the bridge too, visible partially from the quays, as well as from the vehicles navigating on the river. When creating the road track section (reinforcing supports) - similarly to the pylon - we applied smooth, curved silhouettes. Thanks to this section shape, the bridge seems more slender from the lateral sides. The fine curve over the river, and the curve of the pylon mutually emphasize themselves, and in this context, they match the well understandable, but sophisticated character of the modern architectural trends.

The side and bottom surfaces of the steel-structured bridge deck are covered by metal plates with hidden lighting, on which the lights reflecting from the Danube create a fascinating effect. The white-painted cover plates are locally perforated and transparent, as is the parapet rail along the pedestrian sidewalk. The luminaires flushed in the handrail will illuminate the sidewalk, the bicycle lane, but will also paint the external surface of the parapet with lights of different colours.

Around the pylons the pedestrian walkway is asymmetrically broadened, allowing the pedestrians crossing the bridge to have a rest and admire the Danube panorama. The viewing platform is protruded over the Danube on a cantilever structure. Between the two platforms, a lower “underpass” - a diagonal pedestrian walkway under the bridge deck - is available for those who wish to view the panorama from both sides.

The stairs leading to the “underpass” are integrated to a plant cassette combined with seats. The passage is very spectacular, as the side plates of the structure suspended under the bridge are made of transparent perforated plates. Here the pedestrians can have an unusual view of the Danube, and they can also see from close contact the base and the structure of the bridge pylon. This passage offers an insight to the mysterious world of bridgemasters by its unusual location and views.

We also assessed the view from the aspect of a car driver. The unique separating safety guard rail would be installed in a way to let the car passengers have a view above, without disturbing the panorama. The main speciality of the unique guard rail is the road lighting hidden in it. We did not design lighting column to the bridge span over the Danube, the high lighting points of which would cause flare, would cover the bridge structure and give the impression of a light source chain from a further distance, causing unnecessary light pollution. The lamps integrated in the guard rail provide uniform and excellent quality lighting, pointed exclusively to the road surface. Lighting sources are not visible from the cars, they will not “blind” the drivers. Public lighting on the bridge: perfectly lightened roads with “invisible” luminaires.