Birk Heilmeyer und Frenzel Architekten

Visible from far away, the look-out tower Jüberg is prominently positioned at the end of a long flight of stairs, marking the end point of the city and the transition to landscape. The upwards expanding shape of the tower reacts immediately to the local circumstances; the forested hill Jüberg, the urban centre line and a 360-degrees view. The construction of the building is based on the principle of the hyperboloid, which had frequently been used for steel constructions by the engineer Vladimir G. Suchov (1853 – 1939). It consists of 240 straight timber members of Siberian larch (glued laminated timber) with a cross section of 8 x 8 centimetres. A large-mesh structure has been designed by inclining two reverse planes of members. Additional vertical members, such as steel columns or a centre mast, were consistently omitted.

The simplified static model of the tower resembles a clamped tube. Due to the horizontal wind forces, the maximal applied load develops at the clamping position. Steel needles anchor the construction up to six metres deep in the bedrock. Above the foundation, the rigidity of the tower is reduced gradually from the bottom to the top by decreasing the number of timber rods. According to the diminishing loads, the mesh structure expands towards the top. The supports in the lowest plane consist of six individual rods, which are reduced to five in the next level, then four, three, and finally two rods. This allows for an increasing panoramic view the higher you get to the observation deck. Each of the five landing platforms creates an individual atmosphere due to the diminishing rod system.

Corresponding to the forest aisle, the foot of the tower has been kept slim with its dimension of around 6 metres. Inside the structure, five flights of winding steel stairs with altogether 125 steps lead to the observation deck at a height of 23.5 metres. The observation deck, which has a diameter of 9 metres, offers a spectacular view.