APPLICATION OF PROJECT:
Playground Shade Structures
PROJECT DESCRIPTION:
Situated in East Perth, Wellington Square is one of the largest parks within the City of Perth and the star attraction is certainly the 3000m2 intergenerational playground Koolangka Koolangka Waabiny, one of the biggest playgrounds in greater Perth consisting of nature play, a skate park, parkour activities, a flying fox, embankment slides, a pump track, waterplay and climbing towers, as well as basketball courts. Large areas of the playground are covered by 3 large bespoke shade structures.
These shade structures consist of cantilever steelwork posts (by others) supporting complex hypar shaped sails constructed from Carl Stahl X-Tend Mesh with Ronstan cable borders. Decorative aluminium and perspex discs attached to the mesh with bespoke Ronstan clips to provide the shading effect.
Ronstan was initially involved in discussions with Playce Architects who were engaged by the City of Perth.
City of Perth was not keen on design and construct services and so Ronstan introduced Tensys Engineers to Playce to undertake the structural design of the shade structures independent of Ronstan and directly for the client.
Ronstan tendered on the works when the project was released for public tender.
Subsequently, the scope was tapered back and Ronstan was awarded the supply and installation of the cables, mesh and decorative shade elements by the successful main contractor, Advanteering Civil Engineers.
The Ronstan scope included the close coordination of our requirements with Adventeering who was supplying and installing the posts and foundations.
STRUCTURAL SYSTEMS
The mesh surface form is a non-planar hypar form so there was much attention to the mesh patterning to achieve the required outcome.
Due to the hypar form of the mesh panels there was extensive consultation with Carl Stahl’s project team in Germany along with Tensys around the mesh patterning and edge detailing to ensure that mesh forces could be transferred to the edge cables as assumed in structural modelling.
A key factor for coordination of the decorative shade discs and mesh was that the disks needed to fit the mesh grid attaching to specific mesh ferrules.
The mesh was therefore extensively analyzed and patterned to ensure that all mesh diamonds across the complete structure were of the same specific geometry. In this case the acute angle at the base of every diamond had to be installed within +/-2 degrees of a 60 degree planned aperture to ensure the positioning of the ferrules mated with the decorative panel connection locations.
From the patterns 12 bespoke X-Tend Mesh panels were fabricated by Carl Stahl in Germany and supplied to Ronstan for installation with no need for trimming or modification on site.
Shade disks of different colours and sizes needed to be located in accordance with a specific architectural design with locations pre-planned on 2d mesh panels by the design team. The correct identification of each disk connection location on the patterned and fabricated mesh panels became critical. This involved careful planning off-site including the creation of an algorithm to calculate and to identify the specific coordinates of each disk connection/ferrule location on a grid across the mesh surface. These coordinates were then overlayed and identified on the fabricated mesh panels offsite for easy of identification and assembly by our installers later leading to a seamless installation.
Close attention was paid to the disk connections themselves. These had to grip the disks holding them clear of the mesh. At the same time the design had to ensure a positive connection at the ferrule without creating a point of fatigue on the mesh cables. The connection development involved a process of modelling and 3d printing of prototypes for testing before being moulded in an engineered plastic comprised of glass reinforced nylon. This material provides strength and good UV resistance leading to long life.
MATERIALS
X-Tend Mesh D3mm wire 200mm nominal aperture was selected for the project by the design team.
X-Tend was selected for its strength, durability and flexibility.
The X-Tend Mesh panels provided an un-obtrusive canvas for the support of the decorative disc elements which at certain times of the day appear to float ethereally in space.
Decorative discs were fabricated from a combination of Alumimium with Fluoropolymer coatings and coloured Perpex with the combination of materials and coatings selected for optimal quality and durability.
Ronstan manufactured bespoke mouldings from engineered plastic for attachment of panels to mesh.
FABRICATION
X-Tend Mesh panels were made to order to predetermined patterns.
Unfortunately posts were not installed to the required tolerances by others so it meant some on-the run modifications to hypar shapes and mesh panels but this worked out surprising well.
The ultimate test was a perfect panel fit.
COLLABORATION, CONSTRUCTION AND MAINTENANCE
In particular there was close collaboration between Ronstan, Tensys and Carl Stahl Project team on mesh edge conditions and lacing techniques to ensure that forces in mesh were transferred into edge cables as modelled.
The mesh approached the edge cables at different orientations around the structures and so edge conditions varied along the boundary cables.
Ronstan undertook testing of different edge conditions and varied the lacing details across the structure to ensure adequate transfer of loads. This played a large role in achieving the “as-planned” uniform diamond apertures required to suit the decorative panels.
PROJECT CREDITS
Project ID Number 2004
Project Name Wellington Square (Moort-ak Waadiny) Playground Shade Structures
Project Location Cnr Wellington St and Wittenoom St
City / Suburb East Perth, WA 6004
Completion Date Feb-21
Preferred Category 2 or alt 7
Entrant Name Ronstan Tensile Architecture
Address 19 Park Way
City / Suburb Braeside, VIC 3185
Contact Phone Number 03 8586 2000
Email Address
Website Address www.ronstantensilearch.com
Entrant Type / Role Fabricator and Installer
Project Client City of Perth
Project Architect Playce Landscape Architects
Structural Engineer Tensys Engineers
Specialist Consultant & Role Tensys Eng - Patterning
Building Contractor Advanteering Civil Engineers
Fabricator(s) Cables and bespoke elements – Ronstan
X-Tend Mesh- Carl Stahl
