Photo: MarleneWagner

Photo: MarleneWagner

Photo: Anna Weisbrod

Photo: Anna Weisbrod

The project bridgingMZAMBA starts with the local population’s desire for a safe crossing over the river MZAMBA in South Africa. The river now separates the inhabitants from necessary local infrastructure such as educational facilities, health care and general food supply. Each year several kids are drowning on their way to school and medical care can’t be reached in time. In the rainy season, when the water level of the Mzamba River is high, the whole community is cut off and inhabitants can’t reach the other side.

Due to the difficult accessibility on just one site of the valley all parts of the bridge needed to be carried to the site manually. Therefore the whole bridge is designed to arrive in parts and assembled together with mostly unskilled local inhabitants. The design itself started with a thoroughly survey of potential locations to find logical contact points like an ideal geological rock formation. That reduced the amount of concrete casted with local riversand. The precise positioning of the pylons have been carefully evaluated, because an increase of span results in higher forces and more material whereas the current situation leaves the section of the river undisturbed. The geometry of the pylons are designed in form of a frame-work consisting L-shaped angles, have been assembled on ground and put up with human power. Due to the most critical aspect of lightweight suspension bridges – oscillations – a system of prestressed cables is developed to increase the stiffness considerably, making the bridge as if it is made of heavier material. This process of prestressing piece by piece creates on one hand the arched walkway geometry and leads furthermore to a fascinating construction process: The whole bridge develops out of itself, all components that are necessary for construction are also part of the finished bridge.

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Project Data

Design
Carinthian University of Applied Sciences: Thomas
Harlander (Graduand) and Florian Anzenberger
(Graduand), Peter Nigst (Supervision, Former Dean
of Architecture) Wolfgang Steiner (Civil Engineer,
Supervision)

Location
Mzamba, Südafrika Mzamba, South Africa

Project Year
2015

Project Management, Site Management
buildCollective – NPO for Architecture and Development:
Marlene Wagner (Architect) and Elias Rubin (Architect)

Engineering Consultants
Dr. Luechinger + Meyer (Civil Engineer); Rudi Keudel- Schaeffer (Civil Engineer); Bruce Plumbly, (Geologist)

Client
Mzamba Community Steering Commitee

Spannweite gesamt Span in total 131 m
Pylon Nord Pylon north 13,2 m
Pylon Süd Pylon South 15 m
Spannweite zwischen den Pylonen Span between Pylons 66 m
Foundation South 19,5 m³ Beton of concrete
Foundation North 18,9 m³ Beton of concrete
4 ropes (Ø 24mm) in total 531,5 m
Trageseile Carrying ropes 2 × 133,85 m
Guy ropes 2 × 131,90 m
174 Hangers 635 m
96 Walkway elements 365,2 m
87 Binders 162,7 m
wooden planks 1 144 m
Screws 5250

Supporters
Mbizana Local Municipality
Eastern Cape Department of Economic Development
UNESCO