TEXTILES.ORG
Modular construction plus fabric cladding equal a dynamic showcase for events.
By Bruce Wright, AIA
A true collaboration between architect, engineer and fabricator, The Cloud is a vision of fabric, structure and showmanship. Unlike Internet-based data storage familiar to anyone who uses computers, this events venue anchored on the quayside of Queens Wharf in Auckland, New Zealand, is not composed of data bits and bytes but real materials like metal, glass and fabric.
Designed for a single event celebrating the Rugby World Cup hosted in 2011 by New Zealand, The Cloud has an afterlife as a popular events rental facility that draws attention, especially at night when it glows from inside and the translucent fabric that wraps the worm-like form lights up the waterfront of downtown Auckland. The temporary has become long term and the careful design and highly crafted construction that went into it have paid off in returns.
Despite the undulating sculptural quality of The Cloud, the internal frame-supported structure of the translucent and transparent building is based on a standardized truss shape that is jiggered up and down around a virtual centerline along its length. The variations in roof height are obtained by varying the support column heights at the sides, while the standardized curved truss frame that gives the structure its unusual look remains the same throughout.
Another factor that shaped the finished design form is Queens Wharf itself. Matching vertical loads on the structure with the wharf pilings dictated where the structure could touch down. Yet, the ultimate shape is the result of extensive modeling and formfinding.
Essentially a ribbed, segmented fabric and transparent membrane tube with glass curtainwall ends, The Cloud is 11 m high, 178.5 m long and 22 m wide (36 ft. by 585.6 ft. by 72 ft.) where it touches the wharf deck, expanding out to 29 m (95 ft.) wide at the mid-height.
As the client chose to ventilate the building naturally, designers added doors along both sides of the structure that can be opened to help cross ventilate, and vent slots at regular intervals along the length of the building, as well as mesh panels in the door recesses, are incorporated into the design to facilitate air flow.
The harbor end of the tube was designed for the media and VIPs during the Rugby World Cup and has a mezzanine-level exterior balcony and 500 sq. m (5,382 sq. ft.) interior party room at the same level with three sets of stairs, a fabric ceiling that conceals the truss beams and the structural steel, and is finished for entertainment service. Cladding of the exterior skin at this end is clear single-layer ETFE for the last two segments in order to give the mezzanine a more open atmosphere, while the rest of the structure is PVC-coated polyester in eight segments of approximately 23m by 35m.
“The project presented many challenges for us,” says Warwick Bell, director of Fabric Structure Systems, the New Zealand company that constructed the venue. “A very tight program meant that fabrication of steel had to start before the full design was completed. Over half the structure was standing by the time design of the mezzanine was concluded.”
A critical challenge for the designers was the age and stability of the wharf, its seismic movement contributing to the need for more steel added to the structure to stiffen the grid lines that hold the glass panels of the ends. This required careful engineering and detailing, including custom seismic aluminum channels developed to accommodate the higher than normal building movement due to the added weight of The Cloud. This extra weight, especially at the media balcony end, meant that placement of columns had to strictly line up with existing wharf pilings.
Inside, fabric plays a key role in creating a sophisticated environment. At the shore end, opposite the media/VIP suite, is a two-level public space forecourt where a white PVC-polyester ceiling liner covers all trusses and structural steel, creating a cloud-like quality with depth. To finish off the plush interior of the media/VIP suite, white fabric mesh liners are snug to the arched ceiling. The undulating shape and texture of the liners, along with carefully cut and fitted fabric around all the AC diffusers lends the space a sense of luxury found in more permanent hospitality venues.
After being pilloried by the media as “The Slug” during the design phase, The Cloud has rebuffed its detractors with a resounding success at the Rugby World Cup event, and has since been embraced warmly by the public.