Murturm

Mureck, Styria

In the selected area, the Mur riverbed has been renaturalized in sections. Near the center of the Mur renaturalization, the near-natural hydraulic engineering measure and the ecosystem of the riparian forest are made tangible. The fundamental idea of the Murturm, with its access and construction principle, follows a double helix, which structurally carries the idea of a continuous path upwards. The visitor's ascent becomes a landscape experience, as the path spiraling upwards leads through the so-called "forest floors" – the ecological altitude layers of the riparian forest – thus making the ecological order and microclimates in the riparian forest tangible. After 168 steps, at a height of 27 m, one finally reaches a deliberately small viewing platform, from which an atmospheric panoramic view unfolds. From up there, another flight of stairs leads downwards, so that ascending and descending visitors move on two different staircases in space. Here there is a surprising reference to the historic double spiral staircase in Graz Castle: this staircase, built around 1500, creates a unique sense of space, which inspired the architects of the Murturm. This "screwing together" of space and experienced path is the basis of the idea of the Murturm's spiral path. The supporting structure of the Murturm is a "hybrid structure", as the spatially rigid nodal connections in combination with a cabling system and compression struts form the load-bearing system. The main supporting structure is formed by load-bearing tubes and support tubes and ensures stability, while the cabling system limits vibration behavior and horizontal head deflection. An important concern of the structural design was to support the architectural concept of the double spiral of opposing ascent and descent with its geometric intersection points in its uniqueness. Thus, architectural design is combined with a static system. The cross-sections of the tubes of the supporting structure decrease – corresponding to a tree – towards the top of the tower. However, the seemingly free geometry of the supporting elements in perspective perception is an optical illusion - the supporting structure is based on a spatially clear symmetrical arrangement of the elements in the development of the supporting structure. Here, the uniform grid is revealed, with all nodes being in the same geometry to each other.