With the development towards ever higher quality events, the aspect of weather safety became increasingly important. When the weather was bad, some concerts literally fell into the water, others did not take place at all due to the financial risk. Thus the idea was born to make as large a part of the fortress courtyard as possible weatherproof by means of a temporarily retractable protective roof. In doing so, strict requirements of monument protection had to be observed, which did not allow anchoring in the historical building fabric. The appearance of the fortress was also not to be impaired by the new construction.

In order to meet these boundary conditions in the best possible way, AR engineers developed a filigree, central cable structure, from the centre of which a membrane comparable to an oversized umbrella can be stretched. This convertible canopy makes it possible to cover a 2,000 m² area over the entire fortress courtyard and part of the casemates within 4 minutes in bad weather. In good weather, the membrane is retracted in the centre.

‍