Hanging bicycle bridge in Kadaň

The footbridge to the dam is a very important place on the route of the riverside promenade, where the promenade transitions into the open landscape towards Klášterec nad Ohří. The spot is significant both due to the termination of the promenade, as the next section of the original banks of the Ohře is submerged by the waters of the Kadaň dam, and because of the pronounced terrain configuration of the riverbanks with the dam, where adding a prominent element of an inclined ramp is not without pitfalls and must be very sensitive to support the configuration of the site rather than weaken it. The footbridge allowing cyclists and pedestrians to overcome the height difference between the top of the dam and the riverside promenade without the need to use the original steep and uncomfortable staircase along the dam is the only adequate solution to this problem.

The final design of the footbridge is the result of a long search for an appropriate solution and shape that would not fundamentally change the hierarchy of elements in this space while allowing safe movement for cyclists and pedestrians. The original design of a simple steel footbridge was adopted from the project of the cycling path Kadaň - Klášterec nad Ohří, in which the footbridges along the path were designed as a typical element with a continuous beam supported by a series of columns with a span of 10 m between the midfields; in variants, the element repeats along the entire path modified according to the altitude and directional progression of the route. For this reason, it was a structurally and visually simple element capable of minor changes according to its position in the landscape.
Concerns that the footbridge element would intrude too prominently into the area despite its structural simplicity led to the proposal of several possible design variants, in which a greater distance of the proposed footbridge from the rock massif was considered, as well as the cutting back of the rock and concealing the path from views along the riverside within the massif or other positioning of the bridge in a less prominent location or more delicate execution, which would, however, only be possible if the cycling path in this section were eliminated and replaced by a more subtle walking path structure. Ultimately, the interruption of the cycling path with a section where it would be necessary to push the bike along a narrow path was rejected for several reasons. The primary reason was the fact that it is not possible to interrupt the cycling path in a location that is difficult to address from various perspectives just to avoid difficulties in designing this section.

An important aspect of the design is the fact that any solution must overcome the height difference between the top of the dam and the riverside path with an allowable slope of only 9%, which represents a total length of the footbridge with adjacent ramps of around 100 m. This, however, means that such a structure is relatively difficult to conceal.

The final design attempts to diminish the visual impact and actual extent of the supporting structure of the footbridge by utilizing the configuration of the rock, even though it inevitably has closer contact with the rock. To partially conceal part of the footbridge from views both near and far, the configuration of the rock forming the left bank slope of the river valley is primarily utilized.

The shape of the rock massif in this location is quite rugged – a block extending towards the river adjoins the dam of the Kadaň step, behind which a sheer crack extends into the rock to a depth of up to 10 m with a width of up to 15 m. The described ravine is utilized in the design to conceal part of the structure and mass of the footbridge.

In addition to the simpler construction of the platform closely attached to the rock, another quality of this solution manifests itself in the fact that as one moves along the footbridge, they come into closer contact with the rock formations that are only passed at a certain distance while walking at its base. The vertical and directional routing of the footbridge was conducted very carefully, primarily aimed at utilizing the shape of the rock massif as much as possible and minimizing the extent of the steel structure of the footbridge.

The proposed footbridge thus descends at a slope of 8% from the dam around the rock spur, at its level it curves in the opposite direction parallel to the rock into the crevice, where it sharply bends again in an almost opposite arc along the rock massif. The side effect of the directional alignment following the shape of the rock is a reduction in the speed of cyclists on the path, contributing to increased safety of traffic. The shape of the rock in the further part of the footbridge is less dramatic, and the directional routing of the footbridge is only slightly undulating.

The path is led on a suspended steel structure along its entire length when in contact with the rock massif, to minimize the intervention into the rock. At the end of this section, the slope of the footbridge decreases to 4% so that it can be finished at a level from which it can smoothly continue over the natural terrain without the need to build more pronounced embankments or ramps.

The platform of the footbridge raised above the level of the terrain or rock is made of a galvanized steel grate that does not require subsequent maintenance and is resistant to traffic on the path, which is fastened to the steel supporting structure, whose elements are visually minimized. The partially transparent and permeable structure for rain and, to some degree, snow precipitation of the roadway is probably the most suitable solution in this place, which will concurrently compete the least with the mass of the rock, and the transparency of the grate in views in both directions will rather provide a fitting contrast to the mass of the rock. This solution pragmatically and poetically utilizes the characteristics of the location and, apart from sensitive treatment of the rock, also enriches the experiences when passing through or riding along the path.

Length: 83 m
Slope: 8% - 65 m of the length of the footbridge; 4% - 18 m of the length of the footbridge