Entered in the LSAA 2016 Design Awards (Cat 6, 6425)
Entrant: John Wardle Architects (Architect / Designer)
Location: National Gallery of Victoria, Melbourne. Completed: 15 September 2015
Client: National Gallery of Victoria
Team: Matthew van Kooy, John Bahoric, Electrolight (lighting), 3D Structural Solutions (Shop Drawings), Light Project, Engineering Directions
Application
This outdoor installation is a steel structure with a canopy of brightly coloured polypropylene ‘blossoms’. It was a site for performance, retreat and reflection in the garden of the Gallery over Spring and Summer 2015/16. The grid shell structure spans 21 meters and stands 7.5 meters tall, the shading system involves 1650 die cut, hand folded pink, purple and orange polypropylene shade elements and utilized 6600 eyelets and 3300 laser cut cleats. The installation gave the gallery the chance to extend its offering and provide a buffer between the formal gallery and the outdoor spaces.
Inaugural Summer Architectural Commission Description
The Inaugural Summer Architectural Commission for the National Gallery of Victoria (NGV) was designed by John Wardle Architects, and opened in September 2015. This outdoor temporary installation was a steel structure with a canopy of brightly coloured polypropylene ‘blossoms’. It was a site for performance, retreat and reflection in the garden of the Gallery over the Spring and Summer period.
The pavilion was designed with a C.J. Dennis poem ‘I Dips Me Lid’ in mind. The poem commemorated the opening of the Sydney Harbour Bridge in 1932. A reference to another Sydney is made in the design which pays homage to a local piece of architecture, The Sidney Myer Music Bowl – a graceful, exuberant and innovative outdoor design of its era.
Another nod to local history was incorporated in the observation that Melbourne is a place where great civic spaces have been defined by magnificent ceilings. Walter Burley Griffin’s & Marion Mahony Griffin’s Capitol Theatre as well as Leonard French’s Great Hall at the NGV are two such ceilings. Both are set to strong repeated and inflected geometries.
As a structure that was to pronounce the Spring and only last until the end of Autumn, some of the colours of both seasons were utilized. The delicate shading elements echo the compelling, modulated ceiling forms and were applied to a grey structural armature. The grid shell structure spans 21 meters and stands 7.5 meters tall, the shading system involves some 1650 die cut, hand folded pink, purple and orange polypropylene shade elements and utilized 6600 eyelets and 3300 laser cut cleats.
The installation gave the gallery the chance to extend its offerings and provide a buffer between the formal gallery and the outdoor spaces. The 2015 Summer Architecture Commission was on exhibition in the Grollo Equiset Garden at NGV International until 1 May 2016.
Design Brief
Our primary brief was framed by the NGV as a loose fit ephemeral architecture commission; one which would invite audiences in, afford them shelter, host celebrations, invite relaxation and the enjoyment of a unique spatial environment within a garden setting.
Initially it was in imagined as a small bandstand and shade structure with a total existence of one month, to accompany a summer music program. The NGV came to us at that time with an implausible deadline of six weeks. After realising the greater complexity and possibilities of a project of this nature, the NGV wove it into a larger program and the project evolved over time. The pavilion stood for 9 months, it has now been demolished, its life from Spring to Autumn encapsulated in the changeful patterns of its autumnal blossoms.
Structural Systems
The structure started its life as a lightweight timber grid shell; it evolved into a steel grid shell due to time and cost constraints. The grid shell is a two way arched surface, and our choice of shape and materials allows the individual members to work together as a single system. A high level of engineering sophistication and material specificity is integral to the design in order to delicately balances the duality of span and strength. These properties come from both its form and materiality in equal balance.
The strength of the grid shell comes from its arching action (curvature), its rigid connections and member sizing and materiality. The design process involved tracking the shape of the structure as it was loaded to failure in the virtual environment. The shape at failure contains information that tells us a lot about its stiffness and strength, and we used this information to calculate the size of each member and to finalise its form. Our design checks also included measuring deflections and dynamic behaviours under wind loads (ie would wind cause the structure to flutter?).
Upon completion of design, the digital file was handed over to the fabricator to enable its speedy construction. This project was unique in so far as no traditional drawings were produced by the architect or engineer – all of our information was captured within the digital file. The builder worked closely with the engineer to resolve connection details and fixity details to the garden slab structure.
Adaptable and evocative, the structure merges the digital and the handmade. The design utilises 3D modelling and cutting edge engineering and fabrication systems to achieve the generous span of a lightweight steel structure. Beneath this outer high-tech layer of precision-engineered steel is a low-tech layer of timber, and a mass array of 1350 hand folded polypropylene elements. These 3-D textile elements are individually suspended to create a textural pink skin that provides colourful shade by day and a unique nocturnal glow.
The structure is open sided, lifting dramatically on high arches. It provides partial enclosure for visitors while also fostering conversations about the capacity of architecture to activate and enrich public spaces, and the role of the architect to work in collaboration with industry to devise new and progressive fabrication and construction systems that deliver technical, structural and ecological benefits.
The double curvature of the grid shell is the archetypal form of a sound shell which performs acoustically and has been used as a structural solution to achieve large spans with optimized structural members.
Materials
The project is entirely made in Victoria, a tour of the suburbs as it were; designed in Collingwood, steel fabricated in Laverton, painted in Dandenong, polypropylene manufactured in Bayswater, eyelets and assembly in Springvale all converging on the center of Melbourne.
Materials were chosen for their aesthetic, cost and material properties. The grid shell is steel, an obvious selection due to its material properties and off the shelf section availability and simple erection sequence.
Polypropylene was interesting to us because it is a relatively omnipresent and common material, which we’ve used in an innovative way. To us, it was about creating a repetitive system that we were able to make a three-dimensional surface out of from a flat plane. Megara worked with us to produce the tooling and custom dies to cut the 1650 custom sheets of polypropylene.
Similarly unconventional, the eyelet fixing system came out of a necessity to prefix the polypropylene and stainless steel cleats with an elegant and robust mechanism.
The NGV will repurpose the steel structure at the end of the installation; the polypropylene will be recycled back into everyday items such as book covers and the like. The lineage of reuse and repurpose is a good outcome.
Fabrication
Ours is a doubly curved grid shell which has become somewhat an expression of our time facilitated by developments in computing technology. However in the last few years there has been a lot of interest in this type of structure, primarily because we can now design, test and model the reactions very accurately. The fabrication has also developed and assisted by inline cutting technology and computer modeling. The grid shell was designed for complete disassembly and therefore has simple ridged bolted connections; the tolerances on these were reduced to 1mm in order to maximize the rigidity.
The use of eyelets as a fixing methodology is far from conventional as is the material that they secure to the frame. They are extraordinary strong as “ring” fixings and omnipresent in daily life. In the age of outsourcing, Eyelet Supply Company are the last remaining Victorian manufacturer and assembly workshop, from their factory in Springvale they provide a holistic manufacturing service, complete tooling, metal pressing and machining and assembly. The eyeleting was performed by hand with the latest pneumatic press machines, these are machines designed for the future; a future imagined in the 1960s when the machined were first made – it is an extraordinary last bastion of Australian manufacturing.
Collaboration, Construction and Maintenance
By its very nature the project was highly collaborative, we called on everyone we knew to help achieve this remarkable project in a short period of time. Engineer and architect worked closely in the development of a rational geometric shape, a seamless work flow, simplified by in house digital design tools. This process tested materiality and structural sizing to provide a solution that is remarkably efficient, easy to build and deconstruct, and visually dynamic.
The structure was temporary, having a life span of 9 months, it has now been demolished and no maintenance regime was in place. The durability of the polypropylene was always a question in our minds; it is not an external grade specific material so the use was experimental. UV stabilizers were added to the custom made pink, the material degraded very little with no visible fading, brittleness or cracking.
Costs
The total budget for the project was in the order of $250,000
Ref: sliders/DA2016/Cat6/6425 DP 234