The precision of science and the art of design meet in Germany.
By Jake Kulju
Science has long relied on imagination to lure young people into the field. The Phänomenta Science Center in Lüdenscheid, Germany, is one of the world’s best examples of how powerful the relationship between science and imagination can be. The center entices visitors with practical demonstrations of imaginative physics, focusing largely on attracting youth to the fields of science and physics.
Phänomenta’s captivating demonstrations of the laws of physics have made it so popular that plans for expansion are underway. In 2015 the center will unveil a new exhibition space. To continue its tradition of fascination, the science center has turned to fabric architecture for the main component of the new 2,000-square-meter addition. The museum will expand by adding a steel tower with textile membrane construction designed by Werner Bauingenieure, Menden, Germany; KKW Architects, Altena, Germany; and formTL GmbH, Radolfzell, Germany.
Touching the sky
The highlight of the upcoming expansion is the 76-meter-high spiraling steel tower that will house a massive Foucault pendulum. A helix membrane will line the interior of the structural tower with approximately 1,000 square meters of fabric and three shape-giving ropes, which will harness the textile at nine different points to the steel tower.
Structural planning for the membrane was provided by formTL, and the membrane itself was designed by A. Arnegger GmbH of Leutkirch, Germany. The fabric helix has a height of 58 meters and a surface area of 990 square meters. Serge Ferrari, La Tour du Pin, France, provided the PVC/PES Ferrari Précontraint® 1202 S2 fabric for the project.
The perfect membrane
Précontraint 1202 S2 was chosen for both structural and optical reasons. “In a light test we learned about the different appearances of the materials in combination with artificial light; this built the base of the decision,” says Christian Würfl, formTL’s project leader for the Phänomenta membrane. “At night, translucent membrane skins appear as gigantic sculptures. They show a much clearer seam pattern than opaque membranes in most of the light situations. Opaque membrane envelopes often seem plasticky and lifeless. We prefer membranes with a high translucence since they not only cast shadows, but also soft shadows of trees are visible from the inside—such membrane envelopes appear alive.”
A membrane material with a minor translucence—so sufficient to light effects—was sought, due to the fact that the exhibitor wished for a subdued light in the pendulum room, says Würfl. Large membrane stockings of PTFE-fiberglass and of PES/PVC-fabric were hung up and illuminated with color-changing light from inside and outside in a test room at the ERCO Light Factory in Lüdenscheid.
Only light brown PTFE-fiberglass was available for the experiment. Because of this, the light characteristics could not precisely be determined and evaluated. However, the white PES/PVC-fabric could be, and compared to the PTFE-fiberglass, the PES/PVC-fabric showed a high homogeneity of the internal illumination, even where the spotlights had little distance to the membrane. Another reason for using PES/PVC-fabric is the fact that this texture can directly rest on the vertical cables, whereas PTFE-fiberglass needs a visible deflection protection, which would have needlessly emphasized the outer edge, says Würfl.
Précontraint 1202 S2 composite membrane material is designed and manufactured to provide uniform, high luminosity; dimensional stability; consistent flatness; and tear resistance; and employs a high-tenacity polyester yarn back cloth for strength. Surface treated on both sides with PVDF (polyvinylidine fluoride), Ferrari’s Formula S2 Weldable finish, Précontraint 1202 S2 is a lightweight (1050 gsm), UV-resistant option for tensile structures that resists pollution adherence and weathering over an approximate 30-year service life. In addition, the membrane material offers acoustic and visual comfort, making it a natural choice for a high traffic public center.
The fabric is specifically designed for use in a wide range of shapes and designs in permanent structures. Serge Ferrari designed the manufacturing process to hold the textile under tension in both warp and weft directions. This creates desirable dimensional stability and tensile strength in the textile without creating undesirable elongation. The fabric is also coated in a durable protective coating without an increase in overall thickness, reducing deformation under tension after installation.
French fabric meets
The helix shape of the membrane follows the architectural flow of the science center’s steel tower, rotating and tapering upward into the sky. The interior space of the helix will encompass approximately 5,200 cubic meters of space. Lit from within at night, the tower will form a luminous body visible from a great distance.
The membrane has not yet been installed, but will soon be ready for the 2015 unveiling. “We intend to bring the membrane in with a lifting bag, which will be positioned at the highest level [of the structure] and then gradually be lowered into place. In this process the membrane opens continuously,” says Würfl. “After opening and securing the membrane, we will insert the cables and attach the clamping.” He explains that the fabric was manufactured as a single piece and will be installed all at once. Aside from the steel elements of the tower, just three 26mm ropes will give shape to the fabric helix.
Form following function
Expansion of the science center is, in part, driven by the Lüdenscheid Regional 2013 project. Working within the parameters of the project, the science center developed the new exhibition concept for its expansion with the aim of increasing visitor engagement and enjoyment. The project’s specific goal is to convert the center into “modern education, research and service quarters” intended to halt the skills shortage in the science and engineering industry.
The science center’s goal is to enhance visitor enjoyment and draw more people to the museum. The tower was chosen in part for the impressively large Foucault pendulum it will house, but also for its striking physical appearance. “[This project] posed several different challenges from a design point of view,” says Würfl. “[We had to] find a shape which would be a real landmark. After that, we needed to find appropriate materials and details to guarantee functionality and to maintain the light appearance.” The finished project will actually be a tower within a tower, as the pendulum will swing from a 26-meter-high tripod set within the helix.
The luminous appearance and striking height of the structure are what the science center hopes will draw more visitors. Adjacent to the local public train station, part of the facility’s expansion includes a pedestrian bridge connecting the science center and the train platform. A 76-meter high steel and helix membrane tower is sure to turn a few heads in Lüdenscheid.