Widespanned Retractable Roofs of Thermal Baths in Wörishofen and Erding

The present contribution describes two main structures of the Bavarian thermal baths in Bad Worishofen and Erding covered by retractable roofs. In both places 50m x 43m twolayer cylindrical grid shells are built which can be completely retracted in summer time. An additional structure in Erding is covered by a spherical grid shell with a span of 50m where only a 90 0 segment can be moved around a vertical axis allowing opening the interior at least partially. The contribution covers some related challenges associated with analysis, structural design and manufacturing. The stability and dynamics of these light weight structures as well as scenarios for the failure of local elements are briefly described.