Felsenufer play and climbing area in Heilbronn, Germany
Noise barrier as a vertical sports ground
published in sb 4/2020
Winding their way between industrial plants, new residential buildings and railway lines, parks and natural habitats have been created in the heart of the town of Heilbronn in connection with the 2019 Federal Garden Show. These greenedareas serve as public open spaces as well as performing ecological and technical functions. In their design, the architects at SINAI found inspiration in this“multi-coding”in sometimes very confined spaces, entirely in keeping with the principle of“formfollows function”.
The river landscape in the centre of Heilbronn was long fragmented and dotted with barriers and wastelands. With the impetus from the new district of the town in the bend of the river Neckar, the scars in interior of the town have begun to heal. An important element in this process is the Hafenberg, which shields the model quarter from the industrial town’s railway line and is at the same time an area for living, play and sport.
Location Heilbronn, Germany
Client/operator City of Heilbronn represented by BUGA Heilbronn 2019 GmbH
Gesellschaft von Landschaftsarchitekten mbH
DE – Berlin and Frankfurt www.sinai.de
Project partners Machleidt GmbH für Städtebau
Wald + Corbe GbR
BIB Kutz Ingenieurbüro
CDM Smith Consult GmbH
Photos Nikolai Benner
Official opening 2019
Construction costs Permanent facilities: EUR 30 million
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The Hafenberg with its up to 12 m high “river cliff” is a spectacular example of multifunctionalism. With its sculptural geometry, it is about 800 m long, but only 50 m wide at its narrowest point. It serves as an example of intelligent material recycling: the terrain was modelled with large volumes of in some cases contaminated local material, particularly in the creation of the two lakes and construction zones.
A large proportion of the excavated material has been re-used. On 6.5 ha of previously level, derelict land, 300,000 m² of soil was deposited to form a 9 to 12 m high embankment. The resulting earth sculpture is retained by gabion walls, while at the same time screening off and providing noise protection from the railway line behind it, creating an expressive landscape spine against the industrial backdrop of the Neckar Canal and accommodating a climbing wall and a vertical playground.
Inspired by the climbing rockfaces of sandstone and the vineyard terraces in Heilbronn’s surroundings, the Hafenberg recalls the cliffs of the river Neckar and makes a regional and atmospheric reference to the local countryside.
Climbing, hanging and sliding
photo: Nikolai Benner
The“Felsenufer”is the park’s central adventure playground with the overriding theme of climbing. The facility connects the“Skywalk”on the ridge of the earth sculpture with a viewing platform, lawns for picnics and open staircases to the Karlssee lake with play areas and boulder walls as well as the two climbing walls overlooking the lake. The play and climbing areas are spatially separated by the facility’s staggered arrangement created three free-standing sheet piling wall segments.
The play area is located between the walls. The theme of climbing has been realised in highly varied ways and for very different levels of difficulty. For example, it is possible to climb down from the top, Skywalk level to the ground via various rope configurations or a vertical climbing stack. The entry points are designed as so-called “toddler filters”, which bar access to the smallest children. At the northern end of the play area is the “via ferrata”, which offers a combination of climbing, hanging and sliding on a slope. Slides of different lengths, monkey bar courses and a pole path make it possible to overcome the various levels. The cushioned surfaces are made of EPDM and fall protection gravel.
The ground-level play equipment mainly consists of embankment slides and a children’s boulder area, which has been installed along the rear retaining wall with a maximum climbing height of 2.00 m and a maximum grab height of 3.00 m. Flights of steps have been placed between the via ferrata and the shotcrete wall so that the older generation can switch safely and directly between the different levels if necessary.
From an overhanging platform, it is possible to follow the action at close hand and enjoy a view of the entire site.
Modelling on site
The modelling of the climbing walls themselves was carried out in an elaborate shotcreting process. First of all, threaded rods were inserted horizontally into the sheet piling and the structurally necessary reinforcement mats were fastened to them. By applying expanded metal meshes, it was possible to roughly pre-model the surface with overhangs, recesses and offsets. Next, the volume was filled with a layer of grey C 25/30 shotcrete; the fine texture of the surface consists of a sandstone-coloured layer of mortar and was sprayed on in the final stage.
The aim was to create the best-possible surface texture that would meet both the architectural requirements of the overall site and the demands of climbing at different levels of proficiency. Various climbing features such as finger holds and cracks were modelled by hand in the still damp concrete.
The Hafenberg dominates the site as an identity-imparting element of the new swathes of greenery on the bend in the Neckar. The result is a spectacular structure with references to the region that satisfies the technical requirements of a noise barrier while serving as communal space and a vertical playground and sports ground.