Cable-Membrane Roof for the Arena in Zaragoza, Spain

The city of Zaragoza in Northern Spain owns an open-air which, until 1988 was exclusively dedicated to traditional Spanish bull-fights. Since this left the arena unused for more than 350 days, the City decided to convert it, with its capacity of about 15,000 seats outside the central sand piste, into a multi-functional hall. This meant that the roof of the arena should satisfy several particular requirements: The roof should be retractable, at least within the inner circle above the sand piste, to allow for open air bull-fights; the roof should be as light as possible in order not to overload the old masonry structure upon which it would rest; and the roof should not interfere with the picturesque view of the 18th century arena's structure and preferably remain invisible from the outside. The partly retractable membrane roof provides optimum conditions for the 15,000 spectators in every sort of weather.