Magician’s hat Knie | The story of the construction project
Facts and figures
Location: Rapperswil (SG)
Planning period: 2017 – 2018
Construction period: October 2019 – September 2020
Client: Gebr. Knie Schweizer National-Circus AG
Architecture: Carlos Martinez Architekten AG
General planning: Ghisleni Partner AG
Structural planning and statics: Primin Jung Schweiz AG
Timber construction, planning, assembly : Blumer-Lehmann AG
Wood: A total of 224 m3 of spruce/fir from Switzerland and Austria; of which 180 m3 for the supporting framework and 44 m3 for the interior cladding
«We generally like to work with timber. For scheduling reasons, but primarily for environmental reasons.»Carlos Martinez, Architect | Carlos Martinez Architekten
«I come into the magician’s hat every day. I love this building. Everyone who enters the building says wow!»Franco Knie Senior, Co-owner | Gebrüder KNIE, Schweizer National-Circus AG
«The biggest challenge was making the whole structure a reality within eight months.»Stefano Ghisleni, General planning | Ghisleni Partner AG
The timber supporting framework in detail: the shear forces on the ridge and collar beams – where the surface of the roof is folded – are absorbed by single-axis curved laminated timbers and are passed into the concrete supports in the lowest points of the roof valley via recesses at the top end. A concrete tension ring around the support heads holds them together.
Two pressure rings – fitted at a height of 11 metres and 18 metres respectively – stabilise the load-bearing diagonal cladding, which is only five centimetres thick. The detailed plan involved the peak of the hat being fully prefabricated when put in place. With a diameter of around seven metres and a weight of 18 tonnes, it was assembled with great precision.
The pavilion roof has a diameter of 32 metres. During the day, the arena is accessed via the south side. For evening events and deliveries, the north-west gateway is used. On the north side, the roof rests on top of the side rooms, which are situated underground. Terraced elements compensate for the difference in the ground levels.