The roof of the Olympic Stadium Munich: Floating and transparent
The Olympic Stadium in Munich was built for the Summer Olympics 1972; today it is one of the city’s landmarks. The roof made of PLEXIGLAS®, the branded acrylic from Röhm, is the most extraordinary part of the stadium.
At the time, the tent-like roof of the Munich Olympic Stadium was an architectural sensation the likes of which had never been seen before! The transparent roof was to symbolize airiness and openness, and thus provide a clear differentiation from the architecture of the 1936 Olympic Games in Germany and that of the Nazi regime. The transparency of the roof at the Munich Olympic Stadium also made it possible for the 1972 Summer Olympics to be televised in color, a technology which was still in its infancy at the time.
Built for the Summer Olympic Games 1972
When Munich won the bid in 1966 to host the Summer Olympics of 1972, it soon became clear that a new stadium was needed. The largest stadium in the city until then, the Städische Stadion an der Grünwalder Straße, was too small for the expected number of spectators. Therefore, the City of Munich organized an architecture competition for planning the construction of a new stadium. One requirement was that the roof of the Olympic Stadium had to be transparent. After all, the organizers of the Olympic Games wanted to broadcast the event on color television, which had just been launched at the time and required as much light as possible. A wooden or concrete construction was therefore out of the question.
The architects for the Munich Olympic Stadium had an unusual idea
The design of the stadium was submitted by the architecture firm Behnisch & Partner from Stuttgart. They presented a model which was based on the tent-like roof designed by architect Frei Otto for the German pavilion at the World’s Fair in Montreal in 1967. This type of roof was now to be constructed in Munich as well. However, the design by Behnisch & Partner was dismissed by the jury at first as the idea seemed too risky and unfeasible. After a long selection process and the intervention of one of the jury members, Behnisch & Partner was finally awarded the contract. The model won over the jury with the landscape architecture around the stadium in addition to the extraordinary tent-like roof.
Impressive material properties for the Olympic Stadium roof
Stadium façades made of PLEXIGLAS®
As was done in Munich in 1972, PLEXIGLAS® is now used in sports stadiums and other large buildings around the world. After all, its material properties of light weight, weather-resistance and safety make it the ideal material for public buildings.
The Olympic construction company conducted extensive tests to determine which material should be used for the roof panels. Glass-fiber reinforced polyester resin was out of question due to its unfavorable fire behavior. PVC-coated polyester tarpaulins, like the ones used at the World’s Fair in Montreal, did not convince either. They would have been cost-effective but were not transparent enough and would have been too difficult to install on the steel cable grid. Ultimately, the Olympic construction company chose transparent, four-millimeter-thick PLEXIGLAS® GS sheets for the Olympic Stadium roof. The brand acrylic glass won them over with its incomparable translucence. Some of the PLEXIGLAS® sheets were colored a light gray for better protection against the sun. In order to comply with the fire protection requirements of material class B1 as per DIN 4102 – “flame retardant” – sheet material was specially stretched for this construction and treated with a special fire retardant.
Identity-forming landmark
In the end, the Munich Olympic Stadium opened right on time for the Summer Olympic Games 1972. Since then, it has fascinated visitors with its extraordinary roof structure. Many soccer matches have taken place under the tent-like roof as well, including the final of the 1974 FIFA World Cup in which Germany beat the Netherlands. In addition, the Olympic Stadium was home to the Bayern Munich and 1860 Munich soccer teams for many years. Today, open air concerts and sporting events are the main events taking place under the roof made of PLEXIGLAS® sheets.
