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Art Symbolises Community

20 November 2017

You return home after a long journey. Imagine being greeted by a beautiful stainless steel sculpture surrounded by landscaped gardens on your return. One ASSDA Member has used stainless steel to symbolise everything we love about our communities: Security, comfort and home.

It’s easy to think of stainless steel in relation to tubes, panels and rolls in the construction industry, but Brisbane-based ASSDA member, Concept Stainless Design, has taken the product and crafted it into stunningly beautiful sculptures for developers Villa World at their new subdivision on the northern Gold Coast.

Located 70km south of Brisbane, Arundel Springs will provide 386 dwellings in a family-friendly environment adjacent to the Coombabah Lakelands Conservation Area and close to Griffith University and light rail services.

Villa World provided the concept design to reflect the organic growth of nature and symbolise the new families and children who will grow in the new suburb. 

The team at Concept Stainless Design adapted the design to match the size of available grade 316 stainless steel sheets. A small curve of 5mm radius was provided at the tip of the fronds to avoid sharp edges. Another small curve of 9mm was used at the gully between fronds to achieve a flawless polished finish.

The sculptures have been designed to withstand winds of up to 160km per hour, an important feature given Arundel Spring’s proximity to the ocean. An internal frame was built to secure the fronds in position, as well as a horizontal base beam hidden within the sculpture and two legs extending down from the base beam into a large buried concrete block. The structural design certification was completed by Concept Stainless Design’s in-house engineer.

The face of each sculpture was manufactured from grade 316 stainless steel sheet supplied by ASSDA Sponsor Dalsteel Metals.

The sculpture faces are joined along the centre line with an invisible polished butt weld, executed by Concept Stainless Design’s highly skilled tradesman at their Brisbane workshop. The faces were bonded to marine ply and “U” stiffeners were formed from grade 316 stainless steel strips then glued and screwed in. The second face was then placed over the stiffeners, glued and screwed to the ply-bonded face.

The entire project took eight weeks to construct and transported to their new home at Arundel Springs. The sculptures were secured in place by concrete blocks and steel bolts provided by Villa World’s civil contractor in under two hours.

Stainless steel was chosen for the sculptures because of its beautiful, smooth and highly polished finish, and for its low-maintenance properties. Surrounded by clear skies, new vegetation and lush grass, the sculptures welcome residents and visitors alike.

This article is featured in Australian Stainless Magazine Issue 60 (Summer 2017/18).

The Family of Duplex Stainless Steels

20 November 2017

The use of duplex stainless steels has grown globally based on their strength, corrosion resistance and a range of properties that improve equipment life.

The name duplex is sometimes used to describe Alloy 2205 (UNS S31803 or UNS S32205), however duplex is a family of alloys ranging from lean duplex and standard duplex to super duplex stainless steel.

HISTORY

Duplex stainless steel was first developed in France and Sweden in the 1930’s, with the early grades becoming a forerunner for AISI 329, but a lack of control over the chemistry and lack of adequate welding products and techniques impeded development of the product.

Cast versions eventually became available and were subsequently used successfully in many industries where some corrosion, wear and strength were required.  

Areas such as pump components saw a raft of duplex grades developed in standard and super duplex. It should be noted that further work or welding was not required with these particular forms.

In the 1970’s Swedish manufacturers produced and marketed what could be described as a lean duplex called 3RE60 (UNS S31500) with lower chromium, nickel and nitrogen than grade 2205.

3RE60 had success with tubing and displayed excellent resistance in replacing 304 and 316 tubes that had previously failed due to chloride-induced stress corrosion cracking.  The use of 3RE60 in vessels was less successful due to issues such as inter-granular corrosion (IGC) from early welding techniques. The issue was not with the grade but with fabrication, as well as the melting technique to enable control of alloying elements to provide a consistent structure and provide predictable strength and corrosion control.

In the late 1970’s grade 2205 arrived in the market, initially as a tube, then in flat-rolled and other products. The point-of-difference from earlier attempts was well-documented welding technique control, which lead to the increased usage of duplex.

The grades displayed higher strength than standard austenitic grades, excellent resistance to stress corrosion cracking and improved pitting resistance. The other driver was the rising price of nickel, which added a commercial advantage over using a lower nickel duplex product.

GRADES OF DUPLEX

The grades are listed in three groups; standard, lean and super.

The major difference between each grade is corrosion resistance.  This is based on a Pitting Equivalent Number: 

(PREN) = %Cr + 3.3 x %Mo + 16 x %N.

This is a comparative rating that relates to the critical pitting and crevice corrosion temperatures in hi chloride environments (CPT and CCT respectively).

DUPLEX TYPE PREN
Standard Approximately 35
Lean 25-30
Duplex Above 40

USES OF DUPLEX STAINLESS STEELS

Stress corrosion cracking (SCC) is a form of corrosion that occurs with a particular combination of factors:

  • Tensile stress;
  • Corrosive environment; 
  • Sufficiently high temperatures: Normally above 60°C but can occur at lower temperatures (around 30°C in specific environments, notably unwashed atmospheric exposures above indoor chlorinated swimming pools). 

Unfortunately, the standard austenitic steels like 304 (1.4301) and 316 (1.4401) are the most susceptible to SCC. The following materials are much less prone to SCC:

  • Ferritic stainless steels;
  • Duplex stainless steels;
  • High nickel austenitic stainless steels;

 The resistence to SCC makes duplex stainless steels suitable for many processes operating at higher temperatures. Examples of the successful use of duplex stainless steel are hot water tanks, brewing tanks and thermal desalination vessels.

WHERE CARE IS REQUIRED WITH DUPLEX STAINLESS STEELS

Duplex stainless steels can also form a number of unwanted phases if steel is not given the correct processing, notably in heat treatment. Phases like sigma phase leads to embrittlement, meaning the loss of impact toughness, but sigma phase also reduces corrosion resistance.

The formation of sigma phase is most likely to occur when the cooling rate during manufacture or welding is not fast enough. The more highly alloyed the steel, the higher the probability of sigma phase formation. Therefore, super duplex stainless steels are most prone to this problem. Another form of embrittlement occurs above 475°C, and it can still form at temperatures as low as 300°C. This leads to the design limitations on the maximum service temperature for duplex stainless steels.

SUMMARY: DUPLEX CHARACTERISTICS

Compared to the austenitic and ferritic stainless steels, duplex can give:

  • Up to double the design strength;
  • Good corrosion resistance depending on the level required;
  • Good toughness down to -50°C;
  • Excellent resistance to stress corrosion cracking;
  • Welding in thin and thick sections with care;
  • Additional effort required due to high mechanical strength;
  • Up to 300°C maximum in service.

  

Author: Trent Mackenzie is a metallurgist with more than 35 years experience in the industry and General Manager of ASSDA.

Photos courtesy of Outokumpu.

This article is featured in Australian Stainless Magazine Issue 60 (Summer 2017/18).

Wynyard Walk: Where Beauty Meets Function

New infrastructure in the heart of Sydney is set to transform the busy transport hub and provide a stylish new gateway to the Barangaroo development.

21 June 2017

A growing population in Australia's most populous city calls for innovative design, so when the NSW State Government commissioned construction of the Waynyard Walk, ASSDA Sponsor and Accredited Fabricator Stoddart stepped up to the challenge.

The Wynyard Walk forms one of several solutions to break congestion in the Sydney CBD, allowing pedestrians to move from the Wynyard transport hub to the new development at Barangaroo waterfront in six minutes, avoiding steep hills, busy intersections and inclement weather events.

With an estimated 75,000 commuters using the busy hub every day, traffic flow is expected to increase to 110,000 over the next seven years in what is traditionally Sydney's third busiest station.

The tunnel will become the main arterial connection between Barangaroo and the city's transport network and provides vital infrastructure into the future.

THE PROJECT

Alongside CPB Contractors, Stoddart incorporated over 1,600m2 of perforated and solid stainless steel sheeting fabricated into ceiling and fascia pannelling installed in the Clarence Street entrance facade and the tunnel lining. The new Clarance Street entry point is a multi-level portal descending to Wynyard Station via escalators and elevators.

ASSDA Sponsor Austral Wright Metals supplied the project with over 50 tonnes of 445M2 grade stainless steel sheet.

A major consideration for the design team was to ensure aesthetic value for commuters and visitors alike.

THE DESIGN

Inspired by nature and Sydney region geology, the design concept for Wynyard Station focused on flow, with all materials selected to create a sense of motion as part of a unified architectural expression.

The intricate patterns were all designed and executed within Stoddart's factory in Karawatha, Brisbane. The design work was completed wholly on CAD and Solidworks to ensure each panel fitted exactly into the patter and alongside adjacent panels. The Brisbane facility completed all aspects on the manufacture.

The external facade from Clarence Street to Wynyard Station was completed using perforated metal panels on the new access area via escalators and elevators down to the station several levels below.

The internal fitout, including the ceilings, walls and bulkheads, were all constructed from perforated stainless steel as well as solid stainless steel panels.

The complicated ceiling pattern proved challenging, but not insurmountable, resulting in a beautiful floating effect beckoning commuters along.

The project signalled the completion of Stage One of a $160 million upgrade to Wynyard Station.

 THE OUTCOME

The Ken Street level incorporates an extraordinary twenty-metre digital media screen which showcases flowing images of time, travel and places from all over Sydney throughout history, providing commuters with a far more entertaining commute than traditional toilet-block-tiled underground tunnels.

For tens of thousands of commuters who daily traverse the tunnel, Wynyard Walk is a time and energy saving alternative to the street level traffic roulette they once faced.

The added bonus is the stunning, aesthetically pleasing surrounds, the shiny panels and beautiful architecture, all of which was made possible by the use of stainless steel.

This article is featured in Australian Stainless Magazine Issue 59 (Winter 2017).

Stainless Steel Shines in Perth's Elizabeth Quay

12 December 2016

The successful collaboration of ASSDA members and their expertise in the extensive use of stainless steel has been integral to bringing Perth’s iconic and most complex bridge to life.

The Elizabeth Quay Pedestrian Bridge was constructed by DASSH, a joint venture between Decmil, Structural Systems and Hawkins Civil, and is a key feature of the Elizabeth Quay mixed-use development project core to revitalising Perth’s CBD.

Designed and engineered by Arup, the cable-stayed suspension bridge features a leaning double arch, is 22m high, 5m wide and is suspended over the inlet of the Swan River with a clearance of 5.2m from the water. The 110m long meandering pedestrian and cyclist bridge allows for continuous movement around the Quay, connecting the new promenades, an island and ferry terminal.

Stainless steel reinforcement plays a vital structural role in the bridge, with ASSDA Sponsor Valbruna Australia supplying approximately 89 tonnes of 2304 grade Reval® in 12, 20, 25 and 32mm reinforcement bar for the three concrete river piers. The reinforcement bar diameters originally specified were not available locally and so the design was modified to accommodate what was ex-stock in Australia to minimise construction downtime.

Installed exclusively in the splash zones of the concrete piers, stainless steel reinforcement was specified to resist corrosion attack and prevent concrete spalling. In addition, the overall mass of the concrete piers had to be minimised in order to support and achieve the sleek, sinuous design of the almost 200 tonne arches.

Reduction in concrete mass decreases the overall protection of the installed reinforcement bar, resulting in stainless steel as the material of choice to achieve the slimmer river piers and meet the demands of the architectural design.

During the grade selection process, grade 2304 lean duplex stainless steel was also deemed the most cost effective option to reduce ongoing maintenance costs and deliver the expected 100-year service life of the structure.

Visually, stainless steel is also featured in the key design elements of the bridge, including the handrails, balustrades, support posts, mesh barriers, kerbing, fascia panels and kick rail stations. Local jarrah timber decking and decorative feature lighting was used to complete the durable and low-maintenance walk and cycle way.

ASSDA Member Stirlings Australia supplied over 60 tonnes of stainless steel for the bridge project, including 111 wire mesh panels, over 300m of 50.8mm x 3mm round tube in a 320 grit finish to support the mesh panels, welded pipe for the handrails and balustrades, and 2205 and 316/316L grade plate in 6mm and 10mm. An additional 52 tonnes of 316/316L and 8 tonnes of 2205 grade stainless steel plate was supplied and laser cut in-house by Stirlings Australia using their 6000mm x 2000mm laser cutting machine for large-format materials.

Furthermore, Stirlings Australia supplied 7 tonnes of stainless steel channel and angle bar for the architectural elements and structural sections of the quay’s new ferry terminal.

ASSDA Sponsor Vulcan Stainless also supplied the project with over 50 tonnes of laser cut 2205, 316 and 316L grade stainless steel. Polished 2205 grade 3mm stainless steel plate was supplied via its Sydney service centre, cutting approximately 10 tonnes of coil to length, which was then laser cut to size and polished to the specified No. 4 finish prior to delivery. Upright and support pieces for the balustrading were also laser cut and supplied from Vulcan Stainless’ Sydney and Perth service centres using 316 grade 12mm and 316L grade 16mm stainless steel plate.

The 25mm thick pieces were cut using Vulcan Stainless’ in-house 8kw Trumpf Laser, the only machine in Western Australia able to laser cut at this thickness including holes.

Both Stirlings Australia and Vulcan Stainless also supplied laser cut 316/316L grade stainless steel plate for the planter beds that formed part of the landscaping around the Elizabeth Quay precinct.

ASSDA Member Unifab Welding was contracted to fabricate and install over 60 tonnes of stainless steel for the visual elements of the pedestrian bridge as supplied by Stirlings Australia and Vulcan Stainless.

Over 60 different individual balustrade sections each at 1800mm tall were fabricated to allow for the shape and movement of the bridge. Manufactured in compliance with AS/NZS 3992 and ASME 9, Unifab Welding used gas manual arc welding (GMAW) and gas tungsten arc welding (GTAW) techniques to fabricate the various sections.

To meet strict deadlines, all kerbing pieces were welded together using 8mm stainless steel flat bar to replicate the originally specified 300x100x8mm rectangular hollow sections (RHS), a product that was not locally available off-the-shelf. The kerbing pieces were also polished back to a 320 grit and No. 4 finish.

Aside from the wire mesh, all stainless steel components for the bridge were polished to Ra<0.5 and then electropolished prior to installation to provide maximum corrosion resistance in the salt-water environment.

A key architectural feature of Elizabeth Quay, the pedestrian footbridge was opened to the public in January 2016. It exudes in quality, aesthetic appeal and durability with its extensive use of stainless steel, and is certain to provide the structural and material performance required to stand the test of time.

Offering 360-degree views, the bridge is an exciting addition to Perth’s CBD and provides increased opportunity for locals and tourists to interact with the Swan River and reinvigorated waterfront destination.

This article in Australian Stainless Magazine Issue 58 (Summer 2016/17).

Innovative Urban Design

12 December 2016

Stunning stainless steel creations by ASSDA Member Draffin Street Furniture have delivered the contemporary edge required by the rising urban metropolis of Ringwood, Victoria.

Working in collaboration with a team of urban architects and designers, Draffin Street Furniture crafted a suite of custom urban street furniture for the Eastland Shopping Centre in Ringwood.

The Eastland Shopping Centre is located within a major transport network and services a large area of Melbourne’s eastern growth corridor. The integration of sustainable development within Ringwood is creating a sought after urban destination with a contemporary lifestyle. As such, its development is a consciously considered endeavour that is geared to meet the specific needs of its growing population.

Funded by Maroondah City Council, landscape architectural firm Urban Initiatives (UI) was commissioned to generate a design vocabulary that would establish a consistent suite of street furniture and treatments that relate to the proposed scale and vision for Ringwood. UI approached industrial furniture designer Andrew Gibbs to design a distinctive suite of street furniture and urban infrastructure that would meet his vision.

Australian Native Landscapes (ANL) who was commissioned by UI to construct the project, including acquiring and installing the furniture elements for the Ringwood development, contacted Draffin Street Furniture to bring Andrew’s design concepts to life.

Draffin Street Furniture worked in collaboration with Andrew to develop his unique furniture designs and generate physical manifestations that met the design brief. Draffin was able to produce an amazing result within a difficult timeframe, constructing an innovative and unique collection of urban infrastructure from his very complex and technical designs.

Comprised of a series of seat benches, both backed and backless, bicycle racks, tree surrounds and waste receptacle surrounds, the Ringwood furniture suite is constructed primarily of grade 316 stainless steel.

Using stainless steel plate ranging from 3mm to 6mm thick and 100x10mm flat bar supplied by ASSDA Sponsors Dalsteel Metals and Outokumpu, Draffin Street Furniture fabricated the custom-made furniture suite and performed the mechanical finishing in-house to Ra<0.5. The furniture was further pickled, passivated and electropolished by ASSDA Member MME Surface Finishing to ensure maximum protection against corrosion in a dense metropolis area.

Draffin Street Furniture’s Director Ian Draffin said the vast majority of street furniture and other public urban infrastructure going into the Melbourne CBD area is now trending towards stainless steel as a default specification. While there is a high capital cost initially, the benefits of using stainless steel is unmatched in its material performance and reduction in ongoing maintenance and life-cycle costs.

Ensuring sleek, modern aesthetics as well as durability, the choice of stainless steel ensures innovative urban infrastructure will remain functional and attractive for years to come.

This is an abridged version of a story that first appeared in Outdoor Design Source and later featured in Australian Stainless Magazine Issue 58 (Summer 2016/17).

 

Stylish Lines

12 December 2016

Stainless steel continues to deliver a strong and enduring reputation for visual appeal and structural performance in commercial applications.

Perth’s Cockburn Health and Community Facility features over 300m of internal and external stainless steel handrails and balustrades fabricated and installed by ASSDA Member and Accredited Fabricator, Balustrading WA.

The extensive use of stainless steel in the integrated medical and health centre complements the state-of-the-art building and quality services offered to the local community.

ASSDA Sponsors Austral Wright Metals and Vulcan Stainless supplied grade 316 stainlesss steel throughout including for the main vertical balusters, which measure 10mm thick, and are 150mm wide at the bottom tapering to 100mm wide at the top. Stainless steel brackets were custom made to support the balustrades and stainless steel spider fittings were bolted to carry the 13.5mm glass sheets. The handrails were manufactured from 50mm diameter stainless steel round tube.

All stainless steel components were specified with a 320 grit satin finish, and passivated by Balustrading WA prior to installation for maximum corrosion resistance.

The bespoke stainless steel balustrade and glass design offers stylish lines, spaciousness and unobtrusive views both in the facility’s internal voids and on the external balconies.

Stainless steel was specified not just for its aesthetic appeal, but also for its corrosion resistant properties. The facility’s exposure to a salt air environment being located less than 10km from the Western Australian coastline makes stainless steel the material of choice to resist tea staining and provide long-term durability and performance, particularly for the external applications.

Minimal maintenance is required, with a monthly wash down using soap or a mild detergent recommended to remove any deposits that can contribute to surface discolouration and ultimately corrosion.

Offering maximum durability, safety protection, visual appeal and style, the stainless steel architectural features of the Cockburn Health and Community Facility showcase an impressive everyday application of the material.

This article featured in Australian Stainless Magazine Issue 58 (Summer 2016/17).

 

Stainless Steel Supports Innovative and Engaging New Face for the Australian Museum

27 October 2016

The Australian Museum's 2015 facelift saw its new entrance made with a contemporary glass curtain wall feature supported by stainless steel.

The design brief for the architecturally stunning entrance hall feature was a structure that conveyed the image of a modern and transparent institution. Designers Neeson Murcutt Architects and Joseph Grech Architects drew inspiration from the museum’s collection of gemstones for the new façade, resulting in a double-glazed window set against coloured glass panes.

ASSDA Member SGM Fabrication & Construction fabricated the stainless steel frames to support the glass facade as part of the museum’s redevelopment plan. This transformation saw Australia’s oldest museum swing the orientation of its entrance from College Street to William Street.

Fifteen stainless steel framed glass panels stand 8.5m high by 1.6m wide to form a dramatic vertically pleated structure that runs parallel to and complements the existing sandstone wall. Behind the glass façade are 48 diamond-shaped coloured glass panes positioned to take advantage of the northern sun, diffusing and refracting the light to create a welcoming ambience into the museum.

Around 30 tonnes of specialty glass was imported from Luxembourg for the façade. Seven tonnes of 316L stainless steel was used for the frames, including rectangular hollow sections (RHS) supplied by ASSDA Sponsor Midway Metals and 8mm plate supplied and laser cut by ASSDA Sponsor Vulcan Stainless.

SGM Fabrication & Construction’s Managing Director Scott McHugh said welding the stainless steel frames was challenging due to the length and material, and all stainless steel plate had to be individually laser cut by Vulcan Stainless prior to being pressed. ‘Straightness was a big consideration due to the frames holding 30mm thick glass in place. The frames had to be straight and true to within 3mm over the entire length (0.4% tolerance) to support the double-glazed glass.’

The stainless steel frames were pickled and passivated by ASSDA Member Australian Pickling & Passivation Service (APAPS) to remove any heat-affected areas from the laser cuttings and to ensure there was no iron contamination from the pressing.

The frames were specified in stainless steel for its strength, visual appeal and similarity of low maintenance regimes with glass. It was installed by Kane Constructions and the entrance hall was officially opened in September 2015.

The museum’s grand entrance feature is a modern addition to the historically and culturally significant building, certain to maintain its visual appeal for decades to come.

This article is featured in Australian Stainless Issue 57 (Spring 2016).

Images courtesy of Kane Constructions.

Impressive Stainless Steel Ribbon Graces New Brisbane Food Gallery

27 October 2016

Stainless steel has brought life to a unique food precinct located in a recently opened premium office tower in Brisbane City's Golden Triangle.

Developed and constructed by Grocon, 480 Queen Street’s sustainable and eclectic design boasts a 6 Star Green Star and a 5 Star NABERS rating. The building’s food gallery, otherwise known as Room 480, is located on level 2 and capitalises on the stunning views of Brisbane River and Story Bridge to deliver a restaurant style experience and retreat for diners.

Complementing this space is a suspended stainless steel sculpture, designed by local architecture and interior design practice Arkhefield. Inspired by water flowing around rocks, the ‘stainless steel ribbon’ delicately hangs from the ceiling and weaves over the landscape of the room.

Grade 304 stainless steel was specified for the ribbon feature, using 100m of 0.9 x 600mm coil supplied by ASSDA Sponsor Dalsteel Metals. The 1 tonne of coil was supplied in a Bright Annealed (BA) finish and polyethylene coating on both sides for protection, with one side brighter than the other to fulfill the architectural effect and design requirements.

Arkhefield wanted the ribbon feature to be highly reflective on one side, with a brushed appearance on the other. As it curves and wraps through the space, the bright and flat sides of the stainless steel ribbon interact to reflect the surrounding colours and light, allowing movement and distortion throughout. Stainless steel proved the only material able to achieve this aesthetically appealing finish, whilst providing a high-quality, durable and lightweight structure.

The stainless steel ribbon spans 35m x 6m across Room 480’s ceiling and was installed by ASSDA Member and Accredited Fabricator Stainless Aesthetics.

Stainless Aesthetics Director Mike Mooney said the installation of the entire 1 tonne of stainless steel coil as a continuous ribbon was one of the more challenging aspects of the project. This was successfully achieved using their custom designed and fabricated turntable, which housed the coil and allowed it to unwind safely 3.5m above floor level, while protecting the ribbon’s surface finish.

The installation of the stainless steel ribbon around the light fixtures emphasised the visual appeal of the sculpture and its surface qualities. It is suspended using 3.2mm wire support cables and fixings in grade 316 stainless steel supplied by ASSDA Member Anzor Fasteners.

The stainless steel ribbon is an impressive and visually dynamic integrated element of Room 480, adding colour and movement to a traditionally formal space. In addition, the sculpture provides a level of intimacy to the space that could not be achieved with a standard flat suspended ceiling, providing a pleasant ambience for patrons to dine and relax.

This article is featured in Australian Stainless Issue 57 (Spring 2016).

Images courtesy of Stainless Aesthetics.

Stainless Steel Design Innovation

26 May 2016

Brisbane’s iconic Story Bridge is sporting increased safety measures with the application of innovative stainless steel products and laser-fusion technology.

 The 76-year old heritage-listed cantilever bridge now incorporates three-metre tall, stainless steel safety barriers on its pedestrian walkways, as a result of an outstanding collaboration between multiple project stakeholders. Completed in December 2015, the $8.4 million project was led by design and construct head contractor, Freyssinet.

The design brief was to develop an anti-climb structure that was both functional and aesthetically appealing, whilst ensuring the heritage values of the bridge were maintained.

This presented a number of engineering challenges, including the affixation of the barrier structure to the existing heritage-listed bridge without permanent methods of attachment, such as welding or other damaging techniques, whilst addressing the weight and wind load tolerances, ambient vibrations and noise potential.

Visually, there was also a key design requirement to ensure pedestrian views of the river, Brisbane city and surrounds, and of the Story Bridge itself, was preserved.

The initial reference design was specified in stainless steel (with an option for painted carbon steel) and required the fabrication of heavy box sections for over 1000 posts to support a tamper-resistant, horizontal balustrade cable system. The outrigging was specified in carbon steel, with isolation joints to support the upright posts. However, aesthetically, this design created a clutter of vertical elements.

Freyssinet developed an alternative design concept employing Carl Stahl X-TEND® stainless steel mesh, and engaged ASSDA Member Ronstan Tensile Architecture to assist in the design rationalisation. Ronstan Tensile Architecture conducted form-finding analysis to mimic increasing the mesh self-span between the posts. The findings resulted in a substantial reduction in the number of posts required and a more secure fall-restraint system than initially designed.

Replacing the original tension wire design with a mesh barrier significantly reduced the structural loading on the posts, allowing for a smaller number of lighter duty posts, and reducing the cost below the initial estimate.

The concept solution delivered was a dynamic structural design that met the exacting demands of the specification. The design evolved to using laser-fused stainless steel open section beams for the posts, positioned approximately three metres apart with a blackened Carl Stahl X-TEND® stainless steel mesh barrier.

This project is the largest to date in Australia using laser-fused stainless steel structural beams.

Low impact laser-fusion is a process that allows the welding together of pre-polished flat components to a special profile without damaging the visible surface. It provides an effective and economical alternative to extrusions or conventional welds, providing closer tolerances, superior joint integrity and more consistent finishes.

The introduction of laser-fused stainless steel structural beams into the Australian market allowed Freyssinet the flexibility to plan and design with stainless steel in an outcome that was unrivalled for the project scope. Developed and manufactured by Montanstahl (Switzerland) and its subsidiary Stainless Structurals Asia (Singapore), the laser-fused stainless steel structural beams were supplied by ASSDA Sponsor Atlas Steels, as the exclusive agent for the product in Australia.

To this end, Atlas Steels supplied over 30 tonnes of stainless steel for the project, including 316L grade 80x80x6mm I-beam sections for the 530 upright posts, 316 grade 65x65x6mm angle bars for the outrigging, and 316 grade 38.1x1.6mm 320 grit polished tube for the framing of the mesh.
The I-beams supplied were made from a pre-polished strip with a <0.5Ra finish. The I-beam components were laser cut, polished, and then laser-fused together.

Freyssinet rolled the I-beams using a local roll forming company in Eagle Farm to form a curve, following several prototypes to achieve the required design. The beams were then delivered to ASSDA Accredited Fabricator Stainless Engineering Services to cut the posts to the specified height, verify the dimensions, placement and drilling of the holes for the bolt connections, and passivate the posts to ASTM 380 prior to installation.

Stainless Engineering Services also used the offcuts from the I-beams to fabricate the brackets, ensuring no material wastage.

ASSDA Member Anzor Fasteners supplied 550 units of grade 316 stainless steel coupling cables in various lengths of up to 2.1 metres, in 4mm diameter and 1/19 configuration. Each cable was swaged to a threaded stud on one end and a u-shaped fork coupling on the other end. The coupling cables were used to affix the X-TEND mesh to the posts, providing an adjustable method of attachment.

Following the erection of the posts, Ronstan Tensile Architecture supplied and installed 3400m2 of Carl Stahl X-TEND® 316 grade stainless steel mesh constructed from coloured stainless steel wire rope. The stainless steel was blackened with an additional polyester amino resin, which was hardened to the wire under temperature.

The blackened Carl Stahl X-TEND® mesh was the key to achieving an unobtrusive composition and historical aesthetic, while providing the flexibility and tensile strength required for the structure’s design and use of the laser-fused posts.

The structure is a pivotal safety addition to the Story Bridge and exudes functionality in its excellent and unique engineered design. Stainless steel is unmatched in the materials selection for providing durability, structural performance, low maintenance, corrosion resistance and aesthetics.

This article is featured in Australian Stainless Issue 56 (Winter 2016).

Photography by Fullframe Photographics.

Stainless in Color

26 May 2016

A modern and innovative design using coloured and textured stainless steel has left an impressive statement on an Adelaide streetscape.

South Australia’s premier shopping district Rundle Mall underwent a full makeover from 2012-2014 as part of the Adelaide City Council’s initiative to revitalise the precinct.

Part of this redevelopment included a redesign of the facade of a commercial tower at 80 Grenfell Street, housing the Adelaide headquarters of the Bendigo and Adelaide Bank.

Design practice HASSELL delivered an iridescent façade design using coloured stainless steel cladding, supplied by ASSDA Member Steel Color Australia. The extent of the façade referred to as ‘the ribbon’ cascades over 10 storeys, connecting the office tower to the lobby entrance via the retail parapet. The ribbon was made up of over 100 panels that twist and bend over the full height of the building, creating an artistic ripple effect.

HASSELL and Arup’s façade engineering team tested this unique design with physical and virtual models, further refining the design detailing with extensive prototyping. This collaboration with the assistance of Steel Color Australia’s product and material knowledge ensured this remarkable design element was feasible.

Stainless steel was specified for this design as its inherent properties allowed for the level of manipulation required to construct the architect’s creative expression, as well as provide a high quality and aesthetically pleasing finish.

Over 1500m2 of grade 304 stainless steel in 4000x1250x1.2mm sheet in a Rosso colour (Italian for red) was supplied by Steel Color Australia, as the sole distributor in Australia and New Zealand for embossed, coloured, mirror finished and textured stainless steel manufactured by Steel Color S.p.a in Italy.

Steel Colour Australia owner Vince Araullo said that electro-colouring (INCO system) is the main technology in Steel Color Australia’s production. ‘The stainless steel sheet’s surface was directly altered, chemically stimulating the natural passivation of the material. No painting was involved in the process, increasing the pitting resistance of the stainless steel.’

In terms of manipulating the steel’s shape, Araullo said that colouring is an intrinsic part of the stainless steel. ‘This means the stainless does not lose colour during shaping, as opposed to aluminium for example which would need to be coloured after folding due to the fragility of the coloured anodic coating.’

Steel Color Australia facilitated the overseas production of some 270 sheets, weighing 10 tonnes and their shipment to the project site. Modular framework was constructed to bend the stainless sheets into shape for easy installation on site by crane.

The visually striking building façade integrates impressively into the Rundle Place precinct, and the outcome has resulted in a virtually maintenance-free and colour enduring structure.

This article is featured in Australian Stainless Issue 56 (Winter 2016).

Images courtesy of Steel Color Australia.

A Walk to Remember

12 June 2015

The spirit of the Anzacs is evoked in a new architecturally stunning, stainless steel walkway that unfolds around Newcastle’s cliffs and links Strzelecki Lookout to Bar Beach.

 The much-anticipated Newcastle Memorial Walk opened on 24 April 2015 on the eve of the Anzac centenary, and features spectacular 360-degree views of Newcastle city and coastline.

The 450m raised walkway forms part of Newcastle City Council’s ‘Bathers Way Project’, a $29 million foreshore development and revitalisation program to link Merewether Beach with Nobby Beach via a coastal walk. The total cost of the walkway was $4.5 million, $3 million of which was contributed by BHP Billiton to mark their 100-year anniversary since the commencement of steel making in the Hunter region.

In commemoration of the Anzacs the walkway features silhouettes of soldiers, laser cut from 10mm thick weathering steel, specified to withstand the coastal wind load. These silhouettes are engraved with 3,860 family names of almost 11,000 known Hunter Valley men and women who served in the Australian Imperial Force, Royal Australian Navy, Australian Army Nursing Service and British and Commonwealth forces during World War 1 from 1914-1918.

EJE Architecture carried out the detailed design work, and lead architect Barney Collins said the historical significance of the project site inspired the walkway’s sinusoidal design.

“During the design phase, we looked at the history of the site and build location next to Memorial Drive, which was originally constructed in 1922 to pay tribute to the soldiers who fought in World War I,” Collins said.

“The design concept of what is commonly known as ‘the wave effect’ was drawn on the fact that DNA was used to identify the human remains of soldiers, and this process stood as the connection between the soldiers and their families.”

Constructed by Waeger Constructions and engineered by Northrop Engineers, the walkway has a structural design life of 70 years, as required by Newcastle City Council. Grade 316L stainless steel was specified due to its sustainable, corrosion resistance and ductile properties. The cliff top location of the walkway overlooking the Pacific Ocean was also a determining factor given the high wind and salt exposure.

ASSDA Sponsor Atlas Steels supplied 64 tonnes of stainless steel for the walkway including DN150 x 10.7mm, DN125 x 6.5mm, and DN65 x 5.1mm wall pipe; 200mm x 100mm x 6mm rectangular hollow sections and 100mm x 100mm x 5mm square hollow sections for the bridge section frames; and 16mm diameter round bar and 50 x 2mm and 50 x 3mm round tube for the handrails and balustrades.

Good scheduling and planning ensured on-time delivery of the stainless steel over a period of 14 weeks, which was sourced from three overseas mills. Positive material identification (PMI) testing was performed by the mills on all stainless steel supplied to ensure the specified grade of 316L was delivered.

Fabricated and installed by ASSDA Member and Accredited Fabricator SGM Construction & Fabrication, the 160m of stainless steel bridge sections consist of eight, 20m single spans (four under trusses and four over trusses) each weighing 6.5 tonnes. The frame of each section is fabricated from 12 square hollow sections welded to two rectangular hollow   sections, and the walking surface is laid over the frame. On either side of the truss, the wave-like effect was created by bending and rolling wall pipe to sweep above the frame for the over trusses and below the frame for the under trusses.

Seven Y-shaped precast concrete pylons up to 8.8m high and 3.4m wide, and two abutments, support the bridge sections of the walkway that reach up to 9m above the ground.

The decking of the walkway was laid with fibre-reinforced plastic, and being a non-structural component, was specified with a 44-year design life. The safety aspects of the bridge are completed with hand railings, which are welded on to the bridge trusses inside the curved pipe sections.

Over 760m of handrails and 600m of vertical balustrades cover the length of the bridge, specified with a maximum Ra value of 0.5. ASSDA Member Australian Pickling & Passivation Service was contracted to electropolish the balustrades and pickle and passivate the completed bridge sections. A purpose-built electropolishing unit, consisting of six baths, was set up to handle and achieve the specified finish of the 1.5m high x 6m long balustrade panels each weighing 180kg.

With an allotted fabrication period of only four months, SGM Fabrication & Construction manufactured the bridge sections using its 2000m2 workshop to full capacity to meet the critical deadline for Anzac Day.

As the walkway runs parallel to Memorial Drive, the main thoroughfare from King Edward Park to Merewether Beach, the erection of the pylons and installation of the bridge sections took place only during a 10-hour window over two nights to avoid prolonged temporary road closures.

Coastal undermining was a challenge for the structural engineers, however good design and construction ensured environmental protection of the sensitive coastal site to minimise erosion.

Mr Collins said the key to the project’s cost control and overall success was the engagement of local contractors.

“The direct involvement of each contractor’s Directors ensured seamless communication and full control of each project phase. The walkway is already an icon for Newcastle, and everyone who has worked on the project is thrilled over its success,” Collins said.

More than two million people visit Newcastle’s beaches every year, and the Newcastle Memorial Walk is already one of Australia’s most remarkable coastal walkways and a significant World War I tribute.

  

This article is featured in Australian Stainless Issue 55 (Winter 2015).

Images courtesy of Bryce Thomas.

Riverwalk Reborn

21 October 2014

Brisbane's New Farm Riverwalk is one of the city's beloved icons. Originally constructed in 2003, the Riverwalk was used daily by over 3000 cyclists, pedestrians and runners before it was washed away during the 2011 floods.

After a construction period of nearly 18 months, Brisbane City Council’s re-imagined New Farm Riverwalk has now opened to the public, connecting New Farm to the Brisbane City via the Howard Smith Wharf Precinct.

Engineered by Arup, the Riverwalk has a design life of 100 years and sits 3.4m above mean sea level on robust piles.

Critical to its design and life expectancy is the extensive use of stainless steel for both structural and aesthetic purposes.

Brisbane City Council’s two key objectives of the project were to achieve a low maintenance, durable structure while achieving high aesthetic qualities. Stainless steel was deemed suitable to achieve both objectives while also providing the necessary strength required.

Key design elements featuring stainless steel include balustrades, skate stops, help point enclosures, light posts, signage, electrical enclosures, deck furniture and bins at the node structures. For additional durability, stainless steel reinforcement conforming to BS10088 and BS 6744:2001 was used in the soffit of the precast concrete girders where the structure could be subject to wetting and chloride contamination in the future.

Constructed by John Holland, the project involved a high level of collaboration between multiple suppliers and fabricators to meet the exacting demands of the specification.

John Holland Project Engineer Cameron Pahor said one challenge was programming works in accordance with project specifications to reduce contamination between carbon steel and stainless steel, both of which were used within the precast concrete girders incorporated into the Riverwalk.

Modelling of the reinforcing in 3D by Vectors Computer Aided Drafting also meant exact dimensions were ascertained, reducing waste of stainless steel reinforcing.

ASSDA Sponsor Valbruna Australia Pty Ltd’s Queensland construction division was contracted to supply 385 tonnes of stainless steel reinforcing bar, with The Australian Reinforcing Company (ARC) sub-contracted to schedule, cut and bend the rebar in a specifically prepared quarantine location to prevent processing and storage contamination issues.

Valbruna Special Products Manager Scott Ford said the majority of the rebar (in diameters ranging from 12mm to 40mm) was produced to precise precast tolerances predominantly using Reval® special Grade AISI 2304 (1.4362). Grades 2205, 316L and 304L were also used due to the unexpected increase in tonnage required: nearly 40% more than original project calculations was required, making the Riverwalk the largest use of stainless steel rebar in Australia to date.

Mr Ford said stainless steel rebar ensured the Riverwalk met the required 100 years life cycle, while minimising ongoing maintenance costs.

“Using stainless steel rebar ensures that a landmark structure such as the Riverwalk is kept open to the public rather than lengthy maintenance closures due to corrosion issues,” he said.

Down time was also minimised during construction, with Valbruna holding extensive stocks on the floor in both Italy and Australia of stainless Reval® rebar, enabling delivery to site within 48-72 hours of final approval of drawings. Manual templates were produced for many of the bars to ensure the accuracy of the bends and eliminate site down time.

Minimising maintenance for the visual elements of the Riverwalk was also a priority. To this end, ASSDA Sponsor Midway Metals supplied 275 tonnes of grade 316 stainless steel and two tonnes of welding consumables for the construction of around 1900m of balustrading. Midway also supplied 100 litres of Avesta pickling gel that was used to passivate all welds on the balustrades.

Midway Metals Brisbane Branch Manager Sean Lewsam said some of the specified handrail sizes were not available in Australia (e.g. 150x50x6mm rectangular hollow section or RHS) and had to be air freighted in to meet strict deadlines.

Midway supplied the project with 3,522 metres of RHS, 14,500 metres of round bar, 1,924 metres of HRAP (hot rolled, annealed, pickled) flat bar, 1,500 metres of flat bar from their slitting and flat bar machines, and 2,000 metres of mirror tube, storing the material in a dedicated holding area for the duration of the project.

Specific-sized Grade 316 plates were acquired (132 tonnes in total ranging from 10mm to 16mm) to minimise off cuts and wastage during the plasma cutting of stiffener plates, 1500 base plates and 1000 staunchions for the balustrades. Around 26 tonnes of laser cut profile plates ranging from 5mm to 20mm were also supplied.

ASSDA Member Southern Stainless was contracted to fabricate and install three different types of balustrading (solid uprights, mesh wire and glass infill), as well as the other visible stainless steel elements of the project using the stainless steel and welding consumables supplied by Midway Metals.

Southern Stainless General Manager Matthew Brown said all stainless steel components were manually polished to a 600 grit finish prior to assembly and welded in compliance with AS1554.6. After fabrication, the 960 balustrades panels (each weighing between 180 and 220kg) were electropolished in-house to Ra<0.5 and then hand polished with silicone-based polish prior to being wrapped and delivered to site for installation. The end product is both visually appealing and certain to stand the test of time.

Strength testing was undertaken for the balustrade/girder connections to ensure the stainless steel couplers, bolts and ferules (supplied by ASSDA Member Ancon Building Products) would not damage the cast-in items during a flood occurrence.

Riverwalk’s robust design makes it resilient to future flood events. The opening span has been relocated to reduce the likelihood of debris getting caught on the structure, and some elements have been designed to collapse in extreme events (rather than withstand the flood waters), reducing the force on the piles.

With the re-imagined Riverwalk now a fixture on the Brisbane’s riverscape once again, residents and visitors can look forward to enjoying the unique experience that Riverwalk offers well into the future.

This article is featured in Australian Stainless magazine issue 54, Spring 2014.

Grand Designs

21 October 2014

A grand ballroom demands high impact aesthetics combined with maximum functionality, both of which have been supplied in spades at the recently refurbished RACV Royal Pines on Queensland's Gold Coast

Central to Stage 1 of the award-winning refurbishment is a 55 metre long and 5 metre high floor-to-ceiling glass wall anchored and framed by nearly a tonne of stainless steel wire rope and fittings. The wall ensures an impressive visual impact, as well as enabling a flood of natural light, a stunning view, and flexible exhibition options.

Designed by Joseph Pang Design Consultants and project managed by Schiavello Constructions, ASSDA Member Structural Dynamics (Australia) Pty Ltd (Strudyna - an entity under the Arcus Wire Group) was contracted to work with Queensland Glass to meet the demanding needs of the wall’s design.

Strudyna Architectural Manager Ross Munro said the installation was extremely complex, as well as being the team’s first retrofit glass façade project involving engineering, supply and installation.

The client requested a vertical cable truss, internal glass façade and mirror polished fittings to ensure a high-end finish to compliment the refurbishment.

Mr Munro said the retrofit installation meant there were many challenges associated with working with an existing engineered structure.

“The suspended concrete floor had been built to a specific load capability and included post-tension cables within the concrete floor that had to be accommodated. This affected the loads that could be applied to the cable truss to keep the structure rigid, while considering slab deflection with loads from occupancy,” he said.

The cable truss façade featured frameless hinged doors that were also emergency exit doors, so there were no horizontal cable elements to stabilise the  trusses.

Around 926kg of grade 316 stainless steel were used in the job, including fittings/castings and 8mm and 12mm Hamma X-Strand. Hamma X-Strand is stainless steel wire strand with a high quality shine finish manufactured by KOS in South Korea to Arcus Wire Group’s specifications, including annealing, pre-forming of wires and finished lay length, which significantly improves performance.

Electro bath polishing was used on the wire rope and floor and head tension plate brackets, while the spyders, rotules and compression posts were hand mirror polished.

In addition to the glass wall fixtures, other elements of stainless steel in the refurbished space included a staircase and handrail constructed by Arden Architectural Staircases and around 60 metres of 38mm grade 316 curved handrail fabricated and installed on an existing staircase by ASSDA Accredited Fabricator and Member Stainless Aesthetics.

Stainless Aesthetics Director Mike Mooney said his team also installed grade 316 capping on about 50 metres of 20mm glass balustrade, as well as further handrail and mirror-finish capping in the refurbishment of the resort’s health and fitness centre, which formed Stage 2 of the project.

With just 10 weeks to meet the venue’s fixed re-opening date of Stage 1, this challenging project required a high level of co-operation between trades and resulted in a classic marriage of form and function.

In a nod to the outstanding work carried out by all those involved, the RACV Royal Pines refurbishment was recently awarded the 2014 Queensland Master Builders Association’s Gold Coast Construction Award for Refurbishment/Renovation costing $5-$10 million.

This article is featured in Australian Stainless magazine issue 54, Spring 2014.

Stainless Liquid Architecture

1 May 2013

Stainless steel has transformed Perth's historic Forrest Place with a modern, interactive water sculpture.

The ‘Water Labyrinth’ was designed by internationally renowned artist, Jeppe Hein, and is his first permanent installation in Australia.

Launched in mid-November 2012, the $1.3 million sculpture is a major part of the Forrest Place redevelopment initiated by the City of Perth to create a stimulating public space for hundreds of thousands of residents and tourists.

Designed in a grid of nine squares, jets of recycled storm water shoot up into the air, creating 2.3m high water walls that randomly rise and fall. These water walls create up to nine ‘rooms’ that appear and disappear in sequences of 10 seconds before changing configuration.

Visitors of all ages leap from room to room or simply have a splash. The Water Labyrinth enables the interaction of people and art while utilising an important public space flanked by the sandstone inter-war Beaux-Arts style General Post Office and Commonwealth Bank buildings designed by John Smith Murdoch.

Hein says interaction is a distinctive element of the artwork and people play a vital role. ‘The Water Labyrinth activates the space and invites the public to make use of the artwork, either as a space for seclusion and relaxation or the opposite, a place for pure joy and playfulness.’

An impressive feature of the 12m x 12m Water Labyrinth is the 179m of stainless steel grating and drainage. As one of Australia’s largest manufacturers of stainless steel wedge wire grating, ASSDA member and Accredited Fabricator Paige Stainless was chosen to fabricate the water sculpture.

The popular water sculpture features approximately 62m2 of PAIGE STAINLESS HEELGUARD® wedge wire and approximately 160m of 30x5mm flat bar in 304-grade stainless steel, supplied by ASSDA Sponsors Atlas Steels and Fagersta Steels.

PAIGE STAINLESS HEELGUARD® wedge wire is at the cutting edge of water drainage technology, overcoming inherent problems of drainage. The purpose-designed wedge shape in the stainless steel grates allows high volumes of water to shoot through the grates while trapping waste material for easy removal and cleaning.

The grating systems were custom made for the Water Labyrinth with a 5mm gap size and a 4mm wire head width, allowing a 50% open area for water flow. Pickling and passivation treatments were performed on the stainless steel grates prior to installation.

Paige Stainless senior design consultant Daniel Manning said a fine toothcomb approach was taken to ensure there were no safety issues in the final structure, as most visitors would be bare foot when experiencing the Water Labyrinth.

Having worked with stainless steel for over 15 years, Hein says stainless steel was the only material offering the required durability and compatibility for chemical treatment necessary for installation. Manning added that stainless steel’s aesthetic and corrosion resistant properties also made it an easy choice for materials specification in water technology.

Manning coordinated the production of the drainage system, which is an essential component of the Water Labyrinth’s design. All stainless steel components of the sculpture were 100% fabricated at Paige Stainless’s workshop in Caboolture, Queensland.

‘The collaboration with Paige Stainless flew smoothly and was very professional,’ says Hein. ‘They were able to produce and deliver quickly and the grids fabricated were of an extremely high quality.’

Main image above courtesy: Johann König, Berlin and 303 Gallery, New York. Photo credits: Jeppe Hein.
This article is featured in issue 53 of Australian Stainless magazine, Autumn 2013.

Quality Shines

1 May 2013

In the beleaguered Australian manufacturing sector, it's heartening to find ASSDA member Tasman Sinkware is a world-class leader in innovative design and manufacturing. Better still, in addition to supplying the domestic market, Tasman is exporting its products to Canada, the United States, New Zealand, Hong Kong and Singapore.

Tasman began operations in 1948 as a domestic metal fabricator in Adelaide. A move to sink manufacture saw its Oliveri brand pioneer the deep draw process in Australia and introduce precision manufacturing technology to produce high volume sinks.

Sixty-five years later, Tasman is now Australia’s only world-class, production line sink manufacturer, and its premium Oliveri brand is a market leader with a reputation for excellence in design, function and durability.

All Oliveri sinks are manufactured at Tasman Sinkware’s facility in Adelaide from 18/10 304-grade stainless steel supplied by various Australian distributors from reputable overseas mills. Significant capital expenditure over the years has enabled the company to introduce state-of-the-art processing equipment, including pressing, resistance welding, grinding, polishing, cleaning and product assembly equipment, most of which incorporate automation and/or robotic technology.

Tasman Sinkware employs a two-piece manufacturing process. The drainer and bowls are pressed separately then welded together to create bowls that are deep and have straight sides to ensure maximum capacity.

As a result, its stainless steel kitchen and laundry sinks are considered amongst the best in the world and the development of tapware and innovative accessories such as colanders and cutting boards has helped deepen domestic and international market penetration.

The superior design and function of the Oliveri sink range is led by Tasman’s in-house design team in Adelaide. Boasting more than 12 sink ranges and complementary accessories, the Oliveri brand has a strong presence in the building industry with the ability to influence trends.

Tasman Sinkware supplies leading Australian plumbing and electrical merchants and is developing inroads to commercial and residential real estate developments. Oliveri products are sold and distributed overseas through local agents and Tasman Sinkware also has staff on the ground in the USA.

Competition from cheaper Chinese imports is counteracted by Tasman Sinkware’s continued commitment to providing the highest quality products and excellent customer service. Manufucturing manager Steve Warnett says Tasman continues to innovate with new, leading-edge designs for the renovation and building markets. The Oliveri brand also enjoys high market recognition and loyalty amongst consumers and retail outlets.

Stainless steel continues to be the material of choice in laundries and kitchens due to durability, heat resistance, visual appeal and its 100% recyclability.

Grade 304 stainless steel has excellent corrosion properties, is resistant to most food processing environments and organic chemicals, and can be readily cleaned. It also has good oxidisation resistance in intermittent service to 870°C, and in continuous service to 925°C, making grade 304 the most ideal stainless steel grade and material for heat resistance in kitchen accessories.

Tasman Sinkware is Quality Accredited to ISO 9001. All Oliveri sinks are engineered to world standards and manufactured to AS 1756 and laundry tubs are manufactured to AS 1229.

www.oliverisinks.com

Images courtesy of Tasman Sinkware.
This article is featured in Australian Stainless magazine issue 53, Autumn 2013.

Stainless Steel Leads a Stellar Redevelopment

19 November 2012

When Sydney's Star City Casino emerged from the chrysalis of its construction scaffolding, its metamorphosis included a gleaming 340m2 stainless steel-and-glass canopy facing the harbour.

ASSDA member and Accredited Fabricator TripleNine Stainless fabricated and installed the canopy over the main entrance of ‘The Star’, as it is now known, as part of an $850 million redevelopment. This transformation saw Sydney’s only casino swing its orientation 180° from Pyrmont’s fish markets toward the city’s glittering Darling Harbour.

The Star’s façade was designed by Fitzpatrick + Partners and is comprised of 147 flags of clear, low-iron glass supported by two fingers of 20mm and 166mm plate stainless steel. The surfboard-shaped canopy is 40m x 8.5m and made of 300 nominal bore pipe with a lattice effect created by 100 x 50 rectangular hollow sections. All 18 tonnes of stainless steel is 316 grade and was supplied by ASSDA sponsor, Atlas Steels.

Peter Petro, the site architect for the project, says stainless steel was the obvious choice from both a practical and an aesthetic point of view. ‘From a practical perspective, we chose stainless steel because it’s so close to the water and we needed something that was resilient.’

In terms of aesthetics, Petro says they wanted a high-quality finish for the front of the building and stainless steel was a prime choice. ‘We also had a lot of lighting design so we wanted something that would bounce the light around. We were able to give the stainless steel a polish that also matched the glass façade upstairs. This gives it a playfulness at night and a high finish during the day.’

TripleNine’s Director, Justin Brooks, says electropolishing wasn’t an option because of the massive size of the canopy. ‘Instead, it was polished to 400 grit then passivated with an Avesta product.’

Brooks says the project's engineers and designers, Yuanda, employed a Feng Shui expert to sign off on the canopy before
it was built at TripleNine’s purpose-hired workshop. ‘The basic geometry came from the client but we did the design detailing because of all the different shapes and angles,‘ explains Brooks.

The $1.4 million canopy project commenced in August 2010 and was completed in January 2011 with about 15 people assigned to the project. The canopy was built in one piece and transported with a police escort in the dead of the night on the back of a truck with front and rear steering. Installation took only two days, says Brooks.

During the design-detailing phase, TripleNine employed 3-D modelling and Yuanda’s engineers gave careful consideration to expansion and
contraction. ‘Because [the canopy] was so big, we needed to include some bridge building technology,’ says Brooks. ‘We used expansion pads as the canopy was calculated to expand up to 50mm across the total length of it.’

‘The Star’ is a bright, light addition to the harbourside landscape. While the elements of Feng Shui can’t be guaranteed to produce financial fortune in The Star’s casinos, the stainless steel canopy is certain to maintain its appeal for decades to come.

Images courtesy of TripleNine Stainless.

This article is featured in Australian Stainless, issue 52.

Proven Strength in Stainless

19 November 2012

Stainless steel is the material of choice to specify for severe weather conditions.

The overhead netting of Perth Zoo's Australian Wetlands and Penguin Plunge Exhibit was badly damaged when a severe hailstorm and winds of up to 128km/h swept through Perth in March 2010.

During the storm, a tree collapsed onto the netting which was made from a nylon material.

The original concept for this major renovation project was to use stainless steel overhead netting and painted or galvanised steel for the cabling and the majority of other supporting infrastructure components.

However, when ASSDA members Structural Dynamics was awarded subcontractor for the supply and installation of the new overhead netting system, it proposed using stainless steel for all components of the structure, including the cable tension system.

Working closely with Slatter Constructions (head contractor), Thinc Projects (project manager) and Pritchard Francis (structural engineers), stainless steel became the clear choice to provide strength and the crucial ability to withstand severe weather conditions.

Structural Dynamics Managing Director Darren Wills said the team agreed that specifying stainless steel would improve performance, product life cycle and reduce the risk of galvanic reaction.

‘Stainless steel materials break down at a much slower rate than galvanised materials,’ Wills said.

In terms of longevity and durability, stainless steel was the better option given the conditions of the local environment and fresh-water animals.

Slatter Constructions’ Project Manager Rob Murrell added that, on top of providing an aesthetic finish and prolonging the life of the enclosure, using stainless steel for the cables negated the need to ensure separation of different metal types.

Perth Zoo was convinced that stainless steel was the better long-term option and proceeded with stainless steel as the majority materials specification. With a life span of up to 20 years when compared with only up to 10 years using galvanised steel, the increased cost of using stainless was outweighed by the longevity of the product.

The new 91m long x 33m wide x 10m high netting and support structure was completed in early 2012, using the following stainless steel materials:

Backstay column support cables

  • 440m of 16mm and 19mm HAMMA Pro Stand 1x19 AISI316
  • 48 units of 16mm and 19mm Strudyna P2H Adjusters AISI 316

Netting structural support cables

  • 720m of 8mm and 10mm HAMMA Pro Stand 1x19 AISI316
  • 56 units of 8mm and 10mm Strudyna AM Adjusters AISI316

Netting support cables

  • 3900m of 5mm HAMMA x wire rope 7x19 AISI316

Netting

  • 5,400sqm of ClearMesh zoological netting AISI316
  • 15,200m of 1.6mm seizing wire 1x7 AISI304

Rodent proof barrier

  • 300m of 5mm stainless steel angle AISI316 3000m x 150mm x 5mm

Miscellaneous

  • 2,400m of 10mm threaded rod AISI316
  • 600 units of 10mm eye bolts AISI316
  • 600 units of 5mm turnbuckles AISI316

It was pivotal that the new cable structure could cope with extreme one-in-a-hundred year Perth storms, and the high tensile stainless steel structural cable components were ideal for this design parameter. Meeting a range of cable tensions, the HAMMA stainless steel cables installed are rigid to deal with high tensile loads, but also allow for some give to counter the effect of high winds and other harsh weather conditions. Their grade 316 stainless steel construction provides excellent corrosion resistance.

ClearMesh - often used in zoological enclosures globally - was applied to the overhead netting and netting mesh wall that separates the Wetlands from the Penguin Plunge Exhibit within the enclosure. With mesh openings of 2mm, the lightweight and flexible characteristics
of the ClearMesh display a transparent look that complements the landscaped environment and allows for give in case birds fly into the mesh.

Wills said the structure was designed to retain wildlife inside the enclosure and provide a close-to-natural environment for the Australian wetlands wildlife and penguins to thrive in. This resulted in an extremely high level of detail being specified, with stainless steel seizing
wire used every 5mm on the seams of the stainless netting. Over 38,000 hand seizes were performed by the Structural Dynamics team.

As the enclosure was an established site prior to the storm, Perth Zoo required that construction had limited impact on the existing landscaping to assist with animals being reintroduced to their former habitat. Murrell said careful planning between Structural Dynamics and Slatter Constructions ensured the works were completed without harm to the existing vegetation and surrounding areas.

Further construction and landscaping works included a new timber deck walkway for visitors, a limestone block wall and vermin barrier to the perimeter of the wetlands area, an upgraded filtrations system and refurbishment of the existing penguin pool and surrounds.

The renovated enclosure has since survived the June 2012 storm with winds of up to 140km/h, and the cable netting structure and supporting infrastructure today remains as built.

Images courtesy of Structural Dynamics.

This article is featured in Australian Stainless magazine, issue 52.

Stainless Steel and Nickel - 100 Years of Working Together

19 November 2012

This is an abridged version of a story that first appeared under the same title in Stainless Steel Focus No. 07/2012.

The Nickel Institute's director of promotion, Peter Cutler, and consultant Gary Coates, reveal some of the reasons for the continuing popularity of nickel in stainless steels.

Stainless steel is everywhere in our world and contributes to all aspects of our lives. We find stainless steel in our homes, in our buildings and offices, in the vehicles we travel in and in every imaginable industrial sector. Yet the first patents for stainless steel were issued only 100 years ago.

How did this metal become so desirable over the past century that more than 32 million tonnes was produced in 2011? And how does nickel, a vital alloying element in most stainless steel alloys, contribute to the high demand for stainless steel?

THE 'CREATION' OF STAINLESS STEEL
By definition, a ‘stainless’ steel has a minimum level of about 10.5% chromium, so the discovery of chromium in 1799 by Nicolas Louis Vauquelin in France was the first key event in the creation of stainless steel. In 1821 another Frenchman, Pierre Berthier, published research that showed a correlation between increasing chromium content and increasing corrosion resistance, but the high carbon content of his alloys prevented them from showing a true ‘stainless’ behaviour.

Still in France, in 1904 Leon Guillet first published his metallographic work on alloys that today would be classified as ferritic and martensitic stainless steel. In 1906 Guillet published his work on the nickel-containing austenitic stainless steel family, but his studies did not include corrosion resistance. Albert Portevin then continued to build on Guillet’s work.

In 1911, a German scientist named Philip Monnartz reported that as the chromium content neared 12% in a steel with a relatively low carbon content, the alloy exhibited ‘stainless’ properties. Further developments then rapidly occurred in many other countries. In the United States, Elwood Haynes started working with martensitic alloys while Becket and Dantsizen were developing a ferritic stainless steel as lead-in wires for electric light bulbs. In 1912, Great Britain’s Harry Brearley worked on a 13% chromium martensitic alloy, initially for high temperature service in exhaust valves for aeroplane engines.

Meanwhile in Germany, Eduard Maurer and Benno Strauss were testing nickel-containingalloys and, in 1912, two patents were awarded. One of these grades, containing about 20% chromium and 7% nickel, was called V2A, and was found to have exceptional corrosion resistance in nitric acid. That grade had a relatively high carbon content compared to today’s stainless steel, and would be
similar to a Type 302 (EN 1.4317) stainless steel. 100 years later, the most commonly used alloy for nitric acid is 304L (EN 1.4307) with approximately 18.5% chromium and 8.5% nickel, quite similar to the V2A composition other than having a much lower carbon content.

Brearley’s martensitic stainless steel alloy would not rust when wet. He worked with Sheffield cutlery manufacturers to forge it into knife blades and then harden it, replacing the carbon steel blades they were then making. Stainless steel knives rapidly became a common household item. However, for forks and spoons, where high hardness was not so important, the 18-8 (302) composition became the most commonly used alloy.

300 SERIES
We normally think of the austenitic or 300 series family of stainless steels as the ‘nickel stainless steels’, but many other families contain nickel. One of the prime reasons for using nickel in the 300 series alloys is that nickel is an austenite former, but other reasons include:

  • Nickel adds corrosion resistance, especially in certain aqueous environments, and in certain high temperature environments.
  • Nickel can retard the formation of embrittling intermetallic phases at elevated temperatures, a major downfall of the non-austenitic families.
  • The austenitic structure can mean high toughness at cryogenic temperatures.
  • The advantages of the 300 series extend to welding and forming operations.

A fuller discussion of these topics can be found in 'The Nickel Advantage - Nickel in Stainless Steels', available on the Nickel Institute website.

200 SERIES
The 200 series stainless steels are also austenitic in structure. The standardised 200 series grades, which have chromium contents close to the level of a 304L alloy (about 18%), have an intermediate level of nickel. The ‘non-standardised’ 200 series not only have lower contents of nickel, but also lower contents of chromium, with the net effect of significantly reduced corrosion resistance, although still an improvement over the 11-13% chromium ferritic stainless steels.

DUPLEX
The duplex (austenitic-ferritic) family of alloys also need some nickel as well as nitrogen to ensure proper austenite formation. Most ‘matching’ duplex filler metals are actually over-alloyed with nickel to ensure that the welds have the required properties.

PRECIPITATION HARDENABLE
The precipitation hardenable (PH) stainless steel family contain nickel, which increases their corrosion resistance, ductility and weldability compared with hardenable non-nickel-containing stainless steel alloys. One of the other major advantages of the PH grades is that, unlike the martensitic grades, they do not need a quenching operation, which considerably reduces risk of distortion. Some of the martensitic grades also contain a small nickel addition. In the higher chromium types, the nickel is needed for the martensitic transition. In all nickel containing martensitic grades, nickel improves their corrosion resistance, ductility and weldability.

Some of the lower alloyed ferritic grades such as UNS S41003 (EN 1.4001) and S40975 contain a small intentional nickel alloying addition that allows for grain size control, which aids especially in welded constructions. A few of the higher alloyed ferritic grades also have a small nickel addition to increase toughness and ductility, which is beneficial during both hot rolling and in their end use.

Clearly, it is important for each specific application to select the appropriate alloy or alloys to give the desired properties.

GROWTH IN DEMAND FOR STAINLESS STEEL
According to the ISSF, 300 series stainless steel still dominates the worldwide production figures, as shown in Figure 1.

The properties of the various 300 series grades - created by the addition of nickel - are clearly valued by users, both in industry and the general public. Upwards of two thirds of all stainless steel produced in 2011 fell within the 300 series and close to three quarters of all stainless steel produced contains nickel.

The growth of worldwide production of stainless steel over the past 100 years has been steady, if not spectacular. This has meant that the demand for new nickel has steadily increased along with the demand for stainless steel, as shown in Figure 2. Recycled stainless steel is also a very important component in the alloy supply chain.

EFFICIENCY AND 'GREEN' CREDENTIALS
Resource efficiency is a recurring theme as the global economy faces economic challenges. Stainless steel not only contributes towards efficiency in many applications, it also shows continuous improvement in the resource efficiency related to stainless steel itself.

There are three important factors:

  1. Stainless steel’s long service life, which might average 15 to 20 years, although much longer in prestigious buildings.
  2. The extent of recycling: The percentage recovered and recycled at end-of-life - around 90% - is amongst the highest of all materials. Moreover, this recycling can be repeated many times without loss of quality. While the recycled content may appear to be relatively low, this is simply a result of stainless steel’s long service life (15 to 20 years) coupled with much lower global production 15 to 20 years ago.
  3. Continual production improvements for stainless steel and its raw materials. For example, whilst the ores being processed today are of lower grade than before, the extraction and recovery processes are more efficient.

THE FUTURE
The history of stainless steel would be incomplete without celebrating the extent to which it has enabled innovation not just in the area of improved performance, but also in the more intangible, aesthetic aspects. From chemical plants to medical equipment to iconic stainless steel-clad buildings, stainless steel has made - and will continue to make - a major contribution to almost every aspect of our lives.

With durability, recyclability, versatility and aesthetic appeal at the core of its appeal, stainless steel - with nickel as one of its trusted alloys - is well placed to continue to innovate and expand its applications.

STAINLESS STEEL IN USE

FOOD AND BEVERAGE INDUSTRY
The popularity of stainless steels in kitchens did not go unnoticed in the food and beverage industry.

If we take milk, we know of an early stainless steel bulk milk tank truck from 1927 in the USA. A paper entitled ‘The Corrosion of Metals by Milk’ from the January 1932 Journal of Dairy Science by Fink and Rohrman states: ‘It has long been known that milk in contact with iron and copper will not only acquire a metallic taste, but corrode these metals readily’. At that time, tin-coated metals were commonly used. It went on to say that ‘High chromium nickel (18-8) iron alloys … are very resistant to corrosion by milk and are satisfactory for dairy equipment …’. The modern milk processing industry is filled with stainless steel equipment, mostly of Type 304 (EN 1.4301) or 304L.

The report also went on to state that some materials that are otherwise suitable for processing of milk ‘…do not stand up well to the action of cleaning compounds that are commonly used in dairies’, but that the 18-8 alloy was suitable for those cleaning compounds. Today, the typical cleaning acids and hypochlorite sanitising compounds that are used not only in the dairy industry but also in most food and beverage plants worldwide, require that same 18-8 alloy as a minimum. A correctly chosen stainless steel alloy will not change the taste or appearance
of the food product. However, it is the ability to withstand repeated use of the sanitising chemicals over the lifetime of the equipment that has led to the widespread use of stainless steel in all sectors of the food and beverage industry. Producers are then able to guarantee the
safety of their food products.

ARCHITECTURE
Another area of quick acceptance was in architecture. The first recorded use for that purpose was in 1929 in London at the Savoy Hotel where a sidewalk canopy and a sign were erected with the 18-8 alloy. These were soon followed by two iconic skyscrapers in New York that used stainless steel as a dominant element on their exteriors: the Chrysler Building in 1930 and the Empire State Building in 1931.

Since then, many prestigious buildings around the world have used stainless steel, including the Petronas Tower in Kuala Lumpur, the Trump Tower in Chicago, and the Jin Mao Tower in Shanghai. Related to architecture is sculpture, and Isamu Noguchi convinced the Associated Press in 1940 to approve stainless steel instead of bronze for his sculpture above the entrance to its building in New York. Since then, artists around the world have been using stainless steel, mostly either 304L or 316L (EN 1.4404), in their works. The St Louis Arch in the USA, Frank Gehry’s Peis (Fish) in Barcelona, Spain, and more recently Genghis Khan in Mongolia are examples of what can be done with stainless steel.

TRANSPORTATION
During the Great Depression in the USA, Edward Budd realised the untapped potential for stainless steels. Although their use in aeroplanes was his first application, his legacy remains the building of more than 10,000 passenger railcars, some of them still in use today.

Around the world, stainless steel is used extensively for passenger rail cars for subways, commuter trains and long distance trains, ensuring safety plus long life and low maintenance costs. In addition, stainless steels are used to transport cargoes such as food products, petroleum products and corrosive chemicals by rail, road, water and even air, both domestically and internationally.

ENERGY
In the broad field of energy, stainless steels have been used to extract oil and gas containing hazardous substances as well as for use in the refining stages. For power plants, stainless steel is used extensively at both low and high temperatures, whether the fuel is coal, oil, gas, uranium or waste products. Hydroelectric stations use stainless steel for dam gates as well as turbines. Many of the established sustainable
energy technologies such as solar and geothermal are using stainless steel, as well as the present biofuels industry with corn or sugar cane as feed stock.

WATER
Fresh water is an essential commodity for mankind, and stainless steel is used extensively in treatment plants for potable water as well as for wastewater. Cost effectively producing fresh water from seawater or brackish water by desalination also requires the use of stainless steel. In some countries, underground stainless steel pipe is used to deliver potable water to homes to prevent leakage, or in other special cases to protect either the environment outside the pipe or the water inside the pipe. Stainless steel plumbing is also common in certain countries and offers a long lasting, low maintenance option.

SURGERY
The first recorded example of an austenitic stainless steel surgical implant is from 1926. Medical instruments are also known from that time period. The ability to easily and repeatedly sterilise components that come in contact with the human body or are used in hospitals and clinics contributed to the early acceptance of stainless steel. Today, there are well-established international specifications for materials used in this industry. For example, stainless steel alloys for implants must meet stringent metallurgical cleanliness requirements and be completely non-magnetic so that the patient can safely undergo diagnosis by Magnetic Resonance Imaging.

FUTURE USES OF STAINLESS STEEL
Strong growth in the use of stainless steel has continued in the past decades despite the rapid and diverse developments in other materials and the more recent economic turmoil. The nickel-containing alloys in the 300 series still account for nearly two thirds of current stainless steel production worldwide, and there is nickel in the 200 series, duplex and precipitation hardening families, as well as in some of the martensitic and ferritic alloys. The reason for this is the great value that is placed on the properties which nickel provides.

Society is rapidly evolving and facing challenges on a global scale. Population is increasing, expectations are growing and resources are limited. Therefore we must use those resources more efficiently. This is particularly apparent for energy where stainless steel, and especially the nickel-containing alloys, already plays a major role in the more difficult to extract fossil fuels. Stainless steel’s corrosion and heat resisting properties are key to more cost-efficient operations. This also applies to the renewable sources that are now being developed, such as wave power and biofuels from new organic sources.

The worldwide need for higher quality, safe food and beverages and water will only increase, especially as food products can come from anywhere in the world. Stainless steel has evolved as the material of choice in this industry, both industrially and domestically, and it is likely to continue to meet the demands of a global population that is predicted to increase to nine billion by 2050.

This growing population, combined with a rapid movement to urbanisation, requires an expanded and more efficient transport infrastructure. The characteristics of stainless steel enable it to deliver lightweight and durable designs, leading to more efficient performance, safety, lower energy requirements and reduced emissions while giving lower life-cycle costs.

Image of Trump Tower (Chicago, USA) pictured above courtesy of C.Houska.

This article is featured in Australian Stainless magazine, issue 52.


Posted 3 May 2012

Stainless is a key feature in the urban design and revamp of one of the Gold Coast's most iconic and vibrant tourist destinations.

The $25 million Surfers Foreshore Project was commissioned by the Gold Coast City Council (GCCC) to redevelop the beachfront area between Laycock Street and View Avenue in Surfers Paradise.

Aimed at improving infrastructure and visitor recreation, the new promenade features new lifeguard towers, amenity blocks, beach shelters, picnic areas with barbeques, and increased pedestrian and disability access to the beach.

Managing Contractor Abigroup Contractors Pty Ltd appointed ASSDA member and Accredited Fabricator J&T Mechanical Installation to fabricate and install the stainless steel architectural handrails and balustrades across stages 1, 2 and 3.

Trent Todd, J&T Mechanical Installation’s Director, said that with the handrails and balustrades being installed less than 30m from the shoreline, stainless steel was the only choice to withstand the harsh coastal environment to help resist tea staining and ensure long-term durability and performance.

A 2009 GCCC study in affiliation with Griffith University saw the GCCC adopt stainless steel as the default specification for structures with a design life of more than 19 years in foreshore zones.

This followed research results showing the material required lower maintenance and was the most effective in life cycle costs when compared with hot dipped galvanized (HDG) steel, paint systems and duplex systems using both HDG and paint.

At a total cost of approximately $80,000, the stainless steel handrails and balustrades span 1300m across the esplanade that fronts Surfers Paradise Beach.

Grade 316L stainless steel was specified for these elements of the project, which included 36 sheets of 10mm thick plate measuring 1500mm x 3000mm supplied by ASSDA member Allplates. ASSDA Sponsor STM Tube Mills Pty Ltd supplied 1300m of 50.8mm x 1.6mm thick tube. Another 3500m of 1/4” wire was also sourced for the balustrading.

All the flat and tube components including 124 stanchions were laser cut and folded by Allplates.

Stanchions and base plates were machine polished to 600 grit by ASSDA member and Accredited Fabricator Minnis & Samson to give the stainless steel an even polish and the stanchions a square edge. The stanchions were electropolished before being delivered back to J&T Mechanical Installation’s workshop for assembly.

J&T Mechanical Installation fabricated the top (50.8mm x 1.6mm tube) and bottom (folded channel, 4mm thick) rail frames with two vertical 16mm diameter solid round bar intermediate supports. Infill wires at 6.4mm diameter were positioned with swage fittings and lock nuts on each end to construct the vertical balustrades.

On site, J&T Mechanical Installation completed civil works prior to installation, including pre-drilling with the fasteners for the base plates to which the stanchions were then bolted. The rail frames were welded to the stanchions in 2.1m sections.

Following installation, a proprietary stainless steel cleaner was applied to remove any oxides, and a mild cleaner was followed to provide surface protection and inhibit corrosion.

Architectural feature lighting was installed to illuminate the pedestrian walkways at night.

The Surfers Foreshore Project was completed in April 2011 and today continues to thrive as the Gold Coast’s most popular entertainment precinct where city meets the surf.

Images courtesy of Allplates.

This article is featured in Australian Stainless magazine, issue 51.

Where Strength Meets Style


Posted 9 December 2011

Innovation in zoo enclosure design is a key feature of the recently completed $7.5 million makeover of the Chimpanzee Sanctuary at Sydney’s Taronga Zoo.

The project brief was to create a chimpanzee habitat akin to their native home that would encourage social interaction and allow the zoo’s primate keepers to manage animal husbandry and the group’s changing demographic. The enclosure’s transparency and the ability to withstand the chimpanzee’s remarkable strength and intelligence were essential.

ASSDA member Ronstan Tensile Architecture was contracted by the builder, the Lipman Group, to be the specialist contractor for the technical design and installation of a mesh enclosure and non-climbable wall. Ronstan’s unique capability in tensile architecture and their technical expertise were a natural fit for this challenging project designed by Jackson Teece Architects.

The Sanctuary features the mesh separation paddock (similar to an aviary), at one end of the main exhibit. A non-climbable wall with a removable curtain, allows both spaces to function as one large paddock. This enables introductions of new chimpanzees into the compound and helps manage the apes’ complex behaviour patterns.

Ronstan Tensile Architecture’s General Manager, Rowan Murray, said the non-climbable wall structure was one of the most the challenging design aspects.

“The architect’s greatest challenge was to separate the chimpanzees physically, but still have them all in view in the paddock. We had to build a wall that was transparent, had openings of no more than 5mm to avoid chimpanzees putting their fingers in and climbing, and could withstand the strength of chimpanzees.” Mr Murray said.

The structural complexity of the non-climbable wall required 3D modelling to analyse design configurations and ensure structural integrity. Test panels of the non-climbable wall were fabricated and assessed in the chimpanzees’ temporary enclosure to determine which would offer the safest containment of the site and minimise visibility.

Mr Murray said the primary structure for the wall consists of a Ronstan supplied tensile cable net that supports semi-transparent perforated stainless steel panels.

“Most materials can be damaged, but the durability of stainless steel panels of certain perforation proved to be the right solution and important in the development of the overall design,” he said.

“The non-climbable wall had been designed with wall panels clamped directly to the enclosure mesh face. In a collaborative effort, we changed this to an independent cable net structure to remove the risk of having the final wall shape differ from that modelled, and in doing so, avoided the risk of panel geometry differing from the complex 10 degree incline necessary for non-climbability. This also ensured uniform set out and fixing methods, more consistent panel shapes and allowed the panel geometry to drive the wall structure rather than this being determined by other elements.”

ASSDA member, Locker Group, supplied the grade 304 stainless steel panels, which were perforated to 50%. A black painted finish was applied before installation.

With stringent performance characteristics to adhere to, including long-term corrosion resistance and aesthetics, Carl Stahl X-Tend stainless steel mesh was specified for the separation enclosure and the removable curtain within the non-climbable wall. The stainless steel mesh was blackened using an electrolytic process to increase transparency of the enclosure.

Trevor Williams, Lead Consultant of Jackson Teece and Project Architect for the development, said materials selection was critical in delivering the aesthetic appeal and longevity of the enclosure.

“We spoke with Ronstan Tensile Architecture for technical design advice in the early stages of the project. There were various other types of meshes that were a possibility but, being a dynamic structure, alternate materials were far too rigid and not as flexible as the Carl Stahl X-Tend stainless steel mesh. I don’t think we could have achieved this outcome with any other mesh,” Mr Williams said.

“The stainless steel will have a longer life in the aggressive south-facing coastal environment. The blackened mesh has a fantastic form and from an architectural point of view, has achieved an organic appearance.”

Ronstan Tensile Architecture’s contribution to the project, including the tensile mesh enclosure and non-climbable wall, cost about $1.2 million and took 16 weeks to construct.

Mr Murray said the stainless steel demonstrates a great mix of strength and transparency, and the end tensile result is very forgiving.

“Achieving the architectural intent involved complex modelling and finite analysis of the mesh form to ensure the surrounding structures could be designed to support the enclosure loads. Ronstan is absolutely rapt with the state-of-the-art structure,” he said.

The paddock was completely re-landscaped and the impressive exhibit also now features several climbing platforms at varying heights of up to 12 metres, and a 180 kilogram hammock for the chimpanzees to enjoy.

The 17 lucky Taronga Zoo chimpanzees moved in to their renovated home in late September 2011.

QUANTITIES AND GRADES OF STAINLESS STEEL USED

›    Mesh enclosure 770m² of 3mm Ø x 60mm blackened stainless steel, grade 316 Carl Stahl X-Tend mesh.
›    Non-climbable wall facade 140m² of grade 304 stainless steel perforated to 50%, with a black painted finish.
›    Cables 1x19 construction 8mm, 12mm and 22mm diameter, grade 316 stainless steel cables. The stainless steel cable end fittings and  components were polished and passivated prior to installation.

Images courtesy of Ronstan Tensile Architecture.

This article features in Australian Stainless magazine - Issue 50, Summer 2011/12.