Sealing a ski tower

Trelleborg - Case Study -Sealing a ski tower

Solutions by Trelleborg seal, damp and protect – even in unusual locations. Recently, for example, the D3630 casement seal, engineered for standardized sash rebates and overlaps, was used in the Heini Klopfer ski jumping tower in Oberstdorf in the Allgau region of Germany. This structure is one of the tallest of its kind and has recently been modernized. In the new glass facade – at the top of the hill – the Trelleborg seals defy the weather on a daily basis.

There are only five ski jumping towers in the world – and one of them rises above the landscape of the Stillachtal area in the Allgau region. From completion on the Heini Klopfer ski jumping tower has always been a venue for world cups and championships. It was built in wood in 1950 and restored in 1973, replacing the wooden- with a concrete structure. Named after the German architect and ski jumper Heini Klopfer, the ski jumping tower was modernised several times between 1997 and 2002. The current renovation and modernisation works began in 2016 – in accordance with the design of Renn Architekten based in Fischen im Allgau. These measures taken had become necessary due to further developments in ski sports and to changes in the FIS regulations.

Updated tower construction

A cantilevered prestressed concrete construction with an inrun tower height of 72 meters is the special architectural feature of the tower. The construction works carried out between 2016 and 2017 included the demolition of the old take-off platform, the construction of a new take-off platform, the enlargement of the outrun area and the construction of a barrier-free inclined passenger lift and a grandstand. The extension of the area at the top of the jump was also planned. As part of these works, the viewing platform was fitted with a wood and aluminium facade system.

Architecture with a bird’s view

The facade, constructed at airy heights, was styled on the appearance of an eagle's nest. The prefabricated elements, for example, were fitted with profiles running this way and that along the outside, making the vantage point look like a nest. The facade was manufactured and installed by Holzverarbeitung Bietsch from Ofterschwang. Trelleborg's D3630 seals were used to seal the wood-aluminium window elements. These seals are specially designed for use in wooden windows. A special feature: The D3630 profile can be used both as a rebate and overlap seal and fits into a groove three millimeters wide.

Sealed against the elements

Oberstdorf is one of the regions with the highest occurrence of precipitation in Germany, i.e. rain, snow, sleet, or hail that falls to or condenses on the ground. It also experiences cold periods with temperatures below minus 30 degrees Celsius and an above-average number of sunshine hours per year. In conditions such as these, the D3630 ensures a consistently high performance with a long service life. The high-quality sealing material TSP foam is based on a specially modified thermoplastic elastomer (TPE). Among other things, it has material properties such as high UV and water resistance and is compatible with specific coatings. In combination with the glazing and frame, the seal reliably protects against cold, wind, rain and snow.

“The Trelleborg profiles are produced to a high quality standard and could be inserted quickly and easily into the grooves of the window frames with the aid of a gasket roller,” explains Franz-Josef Bietsch, Managing Director of Bietsch. The installation work on site could also be carried out quickly. The installation company needed only three working days to install the basic facade and glazing. The ski jumping tower was reopened in February 2017. From the new tower head, visitors and sportspersons now enjoy a breath-taking view of the Freibergsee lake and the surrounding area.

Oberstdorf is one the regions with the highest occurrence of precipitation
in Germany, i.e. rain, snow, sleet, or hail that falls to or condenses on the