Makrolon®

Makrolon® lines up for the start of the Olympics

A polycarbonate roof tops the Olympic Stadium in Athens. The structure of the arena is itself Olympic, and is regarded as an architectural wonder. It is not only the biggest stadium roof in the world, it is also the largest transparent roof ever built.

When the first event of the Olympic Games gets under way in Athens on August 13, the "Spyridon Louis" stadium can be sure that half the world will be looking on. The roof of the arena in which the opening ceremony will take place is itself "Olympic", and is regarded as an architectural wonder. The imposing yet graceful structure, which was designed by the famous Spanish architect Santiago Calatrava, can already claim three world records. It is not only the biggest stadium roof in the world, it is also the largest transparent roof ever built. Thirdly, it is the biggest roof ever to have been placed on top of a stadium after the stadium was completed. The roof sections are made of solid, highly transparent plastic sheets of Makrolon® polycarbonate from Bayer MaterialScience AG. The bluish shining panels provide for a friendly, open and bright atmosphere in the arena, and make it possible for the spectators to gaze up into the Greek summer sky.
The roof is a dynamic suspension structure. Its main feature are the two metal arches, each 300 meters long, with their apex rising to a height of 78 meters. They span the stadium in the longitudinal direction and each carry a dome suspended on double-arch supports. In total, the roof structure weighs 17,000 tons, covers an area of nearly 25,000 m². and protects 75,000 spectators from direct sunshine and rain.
Wire cables are connected to the two large metal arches, and it is to these that the 12 mm thick, nearly 5 m long and 1 m wide polycarbonate sheets are fixed. "Makrolon® sheet was chosen not only because of its high transparency but also in particular because of its much lower weight than glass. It gave the architect far greater design scope because of the favorable statics," explains Dr. Peter Schwarz from Bayer MaterialScience's Business Development section. In fact, the sheets weigh just 14.4 kg/m². Had they been made of glass, the elements would have weighed more than twice as much.