ASSDA Member and Accredited Fabricator Arcus Wire Group has delivered an innovative duplex stainless steel wire rope cable solution for a hydropower project in the Middle East.

The 344MW Kokhav Hayarden pumped storage hydropower plant is located 120km northeast of Tel Aviv. The project is the first and largest of its kind in Israel, as well as the lowest of its kind globally. The powerhouse lies 275m below sea level and features two 3.1 million m³ reservoirs at different heights. Expected to be operational in early 2023, the hydropower station is designed to provide flexible backup power and stability to the national electricity grid of Israel.

Arcus Wire Group was engaged by GE Renewable Energy to manufacture and supply the cables to form part of a guiding system for the draft tube gates and stop logs for the lower surge shaft of the power station.

The original project brief specified eight identical wire ropes approximately 110m in length with a diameter of 35mm constructed of a half-locked coil with an internal core of large diameter wire, capable of a permanently applied load of 100kN in an underwater application. A long working life was a critical requirement as maintenance of the cables was not an option once in place. 

The initial consideration of materials in order of preference was carbon steel (heavy zinc coating), austenitic stainless steel and duplex stainless steel. The water baseline data for the application during operating conditions were: 

• pH value: Min 6.50 pH, max 9.00 pH 

• Temperature: Min 2°C, max 33°C

• Total Dissolved Solids (TDS): Max 2,200mg/L

• Hardness: CaCO³ Max 960mg/L 

• Alkalinity: CaCO³ Max 436mg/L 

• Iron concentration: Max 320µg/L

• Chloride (CI^-) ) concentration: Max 1,000mg/L 

• Sodium (Na⁺) ) concentration: Max 504mg/L 

• Magnesium (Mg²⁺) ) concentration: Max 144mg/L

• Silica and other hard particles with hardness >5 Mhos: 

  • Particle diameter >_ 50µm: Maximum concentration = 20mg/L

  • Particle diameter >_ 1.5µm: Maximum concentration = 50mg/l

The cable guiding system required one part of the wire rope to be attached to an anchor embedded in concrete and permanently submerged in water exposed to highly corrosive conditions. The top part of the cable is connected to a post-tensioned wire located above ground and exposed to air, with temperatures at a maximum of 45°C and humidity of up to 75%. Post-installation, the wire rope cables will not be accessible for maintenance for up to 30 years.

ASSDA was consulted during the design phase, and as the specification evolved, the client identified stainless steel as a more suitable and sustainable option than carbon steel wire ropes for the submerged application. Considering the maximum temperature and minimum pH level, grade 316 stainless steel would be at its limits, particularly with the crevices that are characteristic of wire rope. 2205 duplex stainless steel was recommended and ultimately chosen as the material of construction to reduce the risk of pitting and crevice corrosion, in addition to its tensile strength, longevity, and life-cycle cost-effectiveness. 

The final design specification delivered alloy grades 1.4362, 1.4462 and 1.4501 duplex stainless steel wire rope cables, half-locked coil with an internal core of large diameter wires and a 30-year lifetime warranty.

The terminations proposed and subsequently selected for use were grade 2205 duplex stainless steel swage forks. They were designed specifically by the Arcus Wire Group team for the 26mm wire rope and a pin diameter of 40mm to allow connection to the anchor at the bottom and the post-tensioning system at the top.

Arcus Wire Group worked with its mill and manufacturing partners to produce and fabricate 970m of 26mm diameter 6x19 SL and IWRC construction 2205 duplex stainless steel wire rope and 20 units of 2205 duplex stainless steel fittings. Seale construction (SL) is a wire rope construction that offers excellent breaking load characteristics. It is used in a wide variety of applications and is resistant to wear and abrasion due to its larger outer wires. An independent wire rope core (IWRC) adds strength to the total length of the rope and reduces the amount of stretch during service.

Material testing was performed on the wire rope cables.
This included destruction testing of a 3m sample cable to measure the breaking strain (breaking at 456.061kN as tested on a horizontal tensile testing machine calibrated to AS 2193: Calibration and classification of force-measuring systems),
10 rounds of cyclic loading to 100kN and unloading to 1kN of an 11m sample cable and loading up to 1.8 times the maximum working load of 180kN to determine elongation under the various conditions. All cables delivered conformed to EN 12 385-4: Steel wire rope.; EN 13411-8 Terminations for steel wire ropes – Safety – Part 8: Swage terminals and swaging; and EN 10088-3: Stainless steels – Part 3: Technical delivery conditions for semi-finished products, bars, rods, wire, sections and bright products of corrosion resisting steels for general purposes.

The duplex stainless steel wire cables were assembled, swaged, tested, and quality certified at Arcus Wire Group’s facility on the Gold Coast, Australia, and shipped over 14,000km to the project site in Israel. The final delivery included 8 x hamma® 26mm diameter 2205 duplex stainless steel wire cables measuring 111.4m and weighing over 325kg each. 

Arcus Wire Group has delivered Australian stainless steel innovation and service delivery at its best with the supply of its wire rope cable solution meeting the exacting demands, life-cycle and performance expectations of Israel’s new hydropower station.

This article is featured in Australian Stainless Magazine Issue 76 (2022).

When you last snacked on some almonds, you may not have given much thought to how they were harvested and made ready for your consumption. However, like almost all food and beverages, on their journey to your snack bowl they encountered some stainless steel bearing equipment.

Australia is a dominant producer of almonds, with the Murray Darling region accounting for almost a third of production. Kooba, located a few kilometres south of Griffith in south-central New South Wales and off the Murrumbidgee River, is the site of a large almond orchard having received significant recent investment.

Irrigation is critical to growing almonds, and water usage can reach up to 14ML per hectare. ASSDA Member Custom Built Stainless, through their sister company and installer Irribiz, was commissioned to fabricate a range of dam water delivery systems for the efficient growth of these almonds. The scope of works included on-site valve banks, pump stations and fertigation (a process of delivering dissolved fertiliser through irrigation supply) systems, with stainless steel featuring heavily as a material of construction.

ICI Industries’ (parent company of Custom Built Stainless and Irribiz) Engineering Manager Vernon Green said, “A key element of supporting the business case for using stainless steel versus PVC and Poly Ethelene was the long-term value, with other factors taken into consideration including the aesthetic appearance and environmental sustainability”.

Around 7 tonnes of grade 304 and 316 stainless steel pipe in sizes ranging from 50mm to 600mm diameter was supplied by fellow ASSDA Member A&G Engineering. Welding was completed in accordance with AWS D18.1: Specification for Welding of Austenitic Stainless Steel Tube and Pipe Systems in Sanitary (Hygienic) Applications and AS 4041: Pressure Piping. Walkways were also manufactured from grade 316, with all stainless components pickled and passivated prior to installation. 

As the world continues to work through severe drought conditions and water supply issues, projects being designed to be as efficient as possible in water use will continue to rely on the longevity, durability and life-cycle benefits of stainless steel.

This article is featured in Australian Stainless Magazine Issue 76 (2022).

Stainless for the long run

Brisbane’s Kingsford Smith Drive upgrade saw Australia’s largest use of stainless steel reinforcement bar to date, transforming the structural performance of one of the city’s busiest roads.  

An initiative of Brisbane City Council and designed and constructed by Lendlease, the Kingsford Smith Drive upgrade involved widening the 7km road from four to six lanes between Theodore Street at Eagle Farm and Cooksley Street at Hamilton. This was achieved via a retaining wall built between 10m to 15m out into the Brisbane River. As a major road corridor, Kingsford Smith Drive links the Brisbane CBD to Brisbane Airport, the Port of Brisbane and residential and economic growth areas including Northshore Hamilton and the Australia TradeCoast region. Planning for future traffic volumes, construction commenced in 2016 to deliver increased road capacity and improved public transport, pedestrian and cycle facilities. 

Critical to the upgrade and structure was the extensive use of stainless steel. ASSDA Member Valbruna Australia supplied 800t of grade 2304/1.4362 Reval® stainless steel in 12mm, 16mm and 20mm stainless steel reinforcement bar (rebar), which was used in the tidal zone to 1m above the Highest Astronomical Tide (the splash zone) of the precast fascia panels and in the lowest of the precast cantilever panels that fell within the splash zone.

The Brisbane River is a tidal estuary, and duplex stainless steel reinforcement meets the service life demands of structures in a brackish water environment. Stainless steel reinforcing resists chloride attack and pitting corrosion, and when specified correctly, provides a minimum service life of 100 years in concrete, reducing life-cycle costs. Kingsford Smith Drive carries an average of 70,000 vehicles per day, and stainless steel rebar delivers confidence in the strength, durability and structural performance expected of critical public infrastructure. 

The scheduling, cutting and bending of the stainless steel rebar to tight precast tolerances was performed by Mesh & Bar. Furthermore, Valbruna supplied approximately 5,000 grade 2205 stainless steel terminator couplers, used to simplify rebar placement and create anchorage within the concrete. 

Stainless steel was also delivered in spades for various other components of the project, with ASSDA Member and Accredited Fabricator Stainless Engineering Services engaged for the fabrication and installation services. Forty-two road bridge expansion joints were fabricated in their workshop using 15t of grade 2205, 10mm and 16mm stainless steel plate, with material supplied by ASSDA Member Stirlings Performance Steels. The cantilever bridge deck was constructed in 40m long concrete sections, and the expansion joint fixings were countersunk and bolted insitu to deliver a continuous smooth surface. 

Additionally, Stainless Engineering Services delivered 1.5km of stainless steel top rails for the Lores Bonney Riverwalk, Kingsford Smith Drive’s riverside promenade. The riverwalk meanders from Bretts Wharf to Cameron Rocks Reserve and the top rail was specified to follow the flow of the river, presenting several challenges in its fabrication and installation. Furthermore, the top rail was specified to be delivered in 10m lengths. It was TIG-welded on-site using grade 316 stainless steel 150x50x5mm rectangular hollow sections (RHS) with a 600-grit finish supplied by Stirlings Performance Steels. Different methods were trialled to achieve the curve specified and conventional manual means were applied to bend the RHS in-between the posts.

Stainless Engineering Services fabricated the stainless steel spigots from 32mm plate to suspend and clamp the galvanised balustrade panels, as well as other various stainless steel components including planter boxes, rung ladders for sewer and drainage manhole access and cover plates at all expansion joints along the boardwalk.  

Stainless steel tube was also used for 300m of pedestrian and bike rails at Cameron Rocks Reserve, with material supplied by ASSDA Members Australian Stainless Distributors and Midway Metals.

With the Brisbane River at its doorstep, the use of stainless steel throughout the project has delivered several key benefits in ensuring the longevity of public infrastructure in a marine environment. Structural durability, corrosion resistance and visual appeal are just some benefits that stainless steel has contributed to the precinct’s improvement and development.  

Completed in 2020, the Kingsford Smith Drive upgrade has delivered up to 30% travel time savings for all vehicles, 7km of new and improved pedestrian and cycle paths, and enriched urban amenities and green spaces for locals and visitors.    

This article is featured in Australian Stainless Magazine issue 74, 2022. 

Water quality plays a crucial role in the decontamination and reprocessing of reusable medical devices, and stainless steel has helped facilitate the standard required for their sterilisation. 

The release of AS/NZS 4187:2014 Reprocessing of reusable medical devices in health service organisations requires hospitals across Australia to comply with a range of stringent new requirements consistent with European and global standards for sterilisation processes. Its aim is to ensure reusable medical devices are adequately cleaned, disinfected and sterilised to protect patients and prevent infection.

Water quality is critical for sterile processing, and one requirement of the revised standard includes the replacement of non-compliant cleaning, disinfecting and sterilising equipment. There are minimum water quality requirements for pre-cleaning, cleaning and the rinse(s) prior to final rinsing. These include water hardness no greater than 150 mg/L and chloride no greater than 120 mg/L. AS/NZS 4187:2014 also specifies water quality requirements for the final rinse stages of sterile processing across Tables 7.2, 7.3 and 7.4, including final rinse water for manual cleaning and washer-disinfectors, and feed water for a dedicated steam generator.

Despite the Australian water quality guidelines, water supplies are variable in chemical impurities and the microbiological purity may also be a challenge. Therefore, water used for the final rinse of the disinfection process and the generation of steam for sterilisation must undergo treatment to achieve the water quality requirements. Reverse osmosis technology delivers a solution to meet the physical, chemical and microbial water quality required for the final rinse.

Reverse osmosis (RO) is a water treatment process that uses a semi-permeable membrane and applied pressure as the final step to filter out ions, unwanted molecules and large particles. The process is effective for the removal of micro-organisms and both organic and inorganic chemical components. ASSDA Member and Accredited Fabricator J&T Mechanical Installation have delivered stainless steel bioprocessing equipment for over 25 hospitals across Queensland, New South Wales and Victoria to meet the new specification and requirements of AS/NZS 4187:2014. The ongoing work includes the fabrication and installation of new equipment and replacement of non-compliant ring mains, water distribution networks and RO water treatment systems.

The RO water treatment systems must accommodate the required regular thermal disinfection to mitigate bacterial endotoxins and deliver a high level of microbial water quality. The treated water is reticulated to central sterile services departments (CSSDs) where surgical instruments and other reusable medical devices are sterilised. Continuous bacteria control is critical to supplying the required microbial water quality and the use of ultraviolet (UV) light in the ring mains to treat return water delivers compliance with AS/NZS 4187:2014. UV sterilisation is 99.99% effective in killing microbiological substances, and  is a safe, chemical-free process.

Stainless steel is the standard material of construction in water treatment applications, offering hygienic properties, durability, and optimum long-term performance. With excellent corrosion resistance and hydraulic conductivity characteristics, stainless steel is the first-choice material for best overall water system design.  

In addition, plastic materials are not viable in high water purity applications due to potential leaching, and copper may also be an issue because of cupro-solvency in soft water. 

Grade 316 stainless steel material has been specified for works as per the standard, including the use of 51mm tube, 20mm three-piece ball valves,  and 45^o and 90^o bends as specified in AS 1528 and supplied by ASSDA Member Atlas Steels.

J&T Mechanical Installation’s expertise has ensured the highest quality of work continues to be delivered to meet the current and future requirements of water supply systems complying with AS/NZS 4187:2014. Orbital welding is used on site during installation, with bioprocessing equipment requiring high quality welds to ensure water supply remains free of bacteria, rust and other contaminants. Orbital welding ensures full penetration welds with no overheating occurring that could undermine the corrosion resistance of the final weld zone.

The J&T team also performs hydrostatic testing and weld traceability to confirm mechanical integrity, as part of AS/NZS 4187:2014’s requirement for all equipment to undergo installation qualification (IQ), operational qualification (OQ) and performance qualification (PQ) tests.

As the roll out of AS/NZS 4187:2014 continues across Australia, hospitals and other health organisations are required to have a documented plan for implementation in place by December 2021, with the deadline for full compliance by December 2022.  Critical hospital infrastructure demands long-term compliance, structural integrity and quality fabrication, all of which are being delivered using stainless steel and superior workmanship by J&T Mechanical Installation.

Photo credits: J & T Mechanical Installation

This article is featured in Australian Stainless Magazine issue 73, 2021. 

1934 marked the birth of the world’s first stainless steel passenger railcar in the United States, and today it represents over 80% of all passenger railcars in Australia. Stainless steels deliver a sustainable materials solution for the rail industry, offering excellent physical properties including formability and weldability, in addition to its high strength, durability and aesthetic appeal.

The typical lifespan of a passenger railcar is 30 to 35 years, however with a proper maintenance program, stainless steel railcars can last more than 50 years. While only requiring minimal maintenance, dirt and other surface contaminants from daily use can affect the appearance of stainless steel.

ASSDA Member Callington Haven was recently engaged in Sydney to rejuvenate 20-year-old stainless steel passenger railcars back to their original aesthetic using a pickling process.

Pickling is a chemical treatment process applied to the surface of stainless steel to remove contaminants and assist in the formation of a continuous  chromium-oxide, passive film. 

The process leaves a slight matt finish and provides a passive surface immediately upon rinsing, maximising the ongoing performance, durability and corrosion resistance of stainless steel.

With a controlled application and wash down process in place, the stainless steel passenger railcars’ transformation was performed using Callington Haven’s own S-Weld SPS Pickling Solution.

Following pre-cleaning of the surface with a detergent, the product was applied with a roller to prevent atomisation of the pickling product. After 25 minutes, the solution was soft water blasted and excess pickling agent was removed with a squeegee. A full water blast using clean potable water and dry down of the stainless steel passenger railcars completed the process.

S-Weld SPS Pickling Solution conforms to ASTM A380 (Standard Practice for Cleaning, Descaling and Passivation of Stainless Steel Parts, Equipment and Systems) and has a unique red colouring, allowing operators to know exactly where the product has been applied or if it has been washed down properly.

Pickling solutions usually employ dangerous acids, therefore personal protective equipment was worn by all personnel. For environmental reasons, measures to ensure prevention of run off onto the ground from the application and wash down of the railcars was implemented.

Maintenance is key to preserving public transport and using a pickling process that only took 1.5 hours to perform, Callington Haven delivered an ‘as good as new’ end result for Sydney’s stainless steel passenger railcars.

You can view this story’s pickling process in action at www.youtube.com/watch?v=CV64kea2pBE

 
Photo credits: Callington Haven

This article is featured in Australian Stainless Magazine issue 73, 2021.

The seaside town of Terrigal on the New South Wales’ Central Coast has welcomed a new addition to its foreshore with a scenic walkway using stainless steel.

The long-awaited Terrigal Boardwalk connects the existing pedestrian networks of the Terrigal Beach promenade and The Haven, providing a safe and accessible route around the headland. The new attraction provides social, health and economic benefits for the local community, allowing visitors and tourists to enjoy the public space and ocean front area.

The project was jointly funded by the Central Coast Council ($2.9M) and the NSW Government’s Restart NSW Regional Growth Environment and Tourism Fund ($2.98M). The Terrigal Boardwalk’s construction included a restoration of the adjacent rockpool, a new disability-access ramp and pathway to link the rockpool and boardwalk.

Engineered and designed by Arup, the boardwalk structure has a 50-year design life, demanding a robust design to ensure durability and longevity. The elevated boardwalk is 277m long and 3m wide, and complements the surrounding natural environment with its blackbutt timber decking and stainless steel balustrading.

The construction comprises of a reinforced concrete suspended deck structure, a suspended structural steel viewing platform with fibre-reinforced plastic open mesh, sandstone block revetment and a retaining wall ramp structure. For the bridge deck, 7.5m is the typical span of the precast deck planks between concrete headstocks on steel tubular piles. Solid concrete deck planks were chosen to protect the timber boardwalk above from wave damage and minimise overtopping for users. The boardwalk sits approximately 4.5m above sea level to be just clear of wave crests during strong weather events.

Materials selection was critical to meet the specified design life, with consideration given to the foreshore’s high level weather events and salt exposure. Grade 316L stainless steel was specified for the balustrading on both sides of the boardwalk, ramp handrailing and the rock platform staircase.

While aluminium was considered during the design phase, stainless steel was chosen due to the material’s proven performance, corrosion resistance and durability in a marine environment, and aesthetic benefits in conjunction with the timber decking and handrail specified. In addition, a costing exercise conducted by Arup presented the long-term benefits of using stainless steel outweighing its additional upfront cost over aluminium.

Constructed by Land and Marine Group, the project involved a high level of collaboration between multiple local suppliers and service providers to meet the exacting demands of the specification. 

ASSDA Member Synergy Engineering was engaged to fabricate and install the stainless steel handrails, balustrades and stairs, spotted gum timber railing and the structural steel viewing platform. The project involved the stainless steel fabrication of 247 balustrade panels, 119m of handrail balustrade and an 8-step 1200mm wide staircase with fibre-reinforced treads. TIG welding techniques were used throughout the fabrication and installation process to ensure precision and a clean aesthetic.

ASSDA Member Atlas Steels supplied over 15t of 316L stainless steel, including 3402m of 30x8mm flat bar and 1656m of 70x10mm flat bar. The project was undertaken in the midst of the COVID pandemic, presenting a number of challenges with the supply of imported stainless steel material and shipping lead delays. As a result, Atlas Steels took the initiative to laser cut stainless steel plate to size and engaged ASSDA Member Decoware Australia to polish the material to specification. Starting with a coarse 80 grit through to a 400 grit finish, a surface finish of Ra <0.5 µm was achieved. The resourcefulness of local service and skill assisted in meeting the project program, delivering a resolution for the unprecedented challenges.

A small proportion of material was sourced from ASSDA Member Viraj Profiles, and ASSDA Member Vulcan Stainless supplied an additional 11t of laser cut 5mm, 10mm, 16mm and 20mm 316L stainless steel plate for the project.

Following fabrication, all stainless steel balustrade panels and handrails were electropolished by ASSDA Member Australian Pickling & Passivation Service and delivered directly to site for installation by the Synergy Engineering team.

The beautiful coastal boardwalk features a viewing platform, integrated seating, LED lighting and access to the rock platform. Offering uninterrupted views of the Pacific Ocean and beyond, the Terrigal Boardwalk is certain to meet the performance requirements of its design with its quality construction and use of stainless steel. 

The Terrigal Boardwalk officially opened on 14 April 2021, with its first steps taken by local crowds alongside the New South Wales Premier Gladys Berejiklian, Parliamentary Secretary for the Central Coast, Adam Crouch, Central Coast Council Administrator, Dick Persson, and the Council’s new CEO, David Farmer.
 
    

This article is featured in Australian Stainless Magazine issue 72, 2021.

Stainless steel is playing an important role in delivering effective infrastructure to achieve water savings, securing a sustainable environment and future for irrigation communities in Australia.

Murray Irrigation's Private Irrigation Infrastructure Operator Program (PIIOP) Round 3 in New South Wales is a modernisation project focused on upgrading larger infrastructure within the main canals of its irrigation assets, including Mulwala and Wakool Canals.

Mulwala Canal is Australia’s largest irrigation canal, and together with Wakool Canal runs 157km long. It has the capacity to deliver more than 1,500,000ML of water per year to irrigators in the Southern Riverina, helping to generate more than $500 million of gross agriculture revenue per year for the region. 

ASSDA Member AWMA successfully delivered 91 stainless steel water control gates across the project’s irrigation system assets. This modernisation program has substantially increased water efficiencies, improved water flow, enabled ordering flexibility and significantly reduced water leakage through infrastructure upgrades.

The works included 21 Mulwala Canal Sites (65 LayFlat gates and 26 Undershot gates), Lawson Syphons (two Undershot gates), the Edward River Escape (two Bulkhead gates) and the Wakool Canal Offtake (three Undershot gates).

All gates were purpose-engineered, designed and manufactured by AWMA to meet exact site and operational requirements. The water control gates measure up to 5.5m wide and 3m high in size, fabricated from 230 tonnes of stainless steel. The stainless steel water control gates required 7.5km of weld, then pickled to improve corrosion resistance and tested in-house to international ISO 9001 quality standards. Dedicated tooling and handling equipment were also paramount in ensuring no cross contamination during all processes undertaken.

ASSDA Member Vulcan Stainless supplied grade 304 stainless steel plate material, whilst ASSDA member Valbruna Australia supplied grade 431 stainless steel shafts.  

ASSDA Member Akras Industries were also engaged in a semi-automated welding process in order to join the oversize gates back together post laser cutting and pre-pressing. Welding was carried out in line with AS1554.6 / ASME 9 /AS1210 - Class 1 classifications to ensure the highest weld integrity and compliance to quite rigid specifications as set out within the scope.

Another ASSDA Member Arcus Wire Group were engaged by AWMA to assist in the design and supply of 20mm, 7x19, grade 304 stainless steel wire rope cables for the purposes of raising and lowering the water control gates. 130 cables were supplied (two cables installed per LayFlat gate), with an individual Minimum Breaking Strength (MBS) of over 27,000kgf. Arcus Wire Group and AWMA collaboratively designed the bespoke cable end terminations to suit the specified MBS, and the manufacture of these products were completed in-house by Arcus Wire Group. 

Stainless steel was specified for its longevity and durability, particularly with the water control gates being submerged in irrigation water. In addition, stainless steel was chosen over aluminium in the materials specification to extend the nominated asset life from 25 years to 50 plus years. The gates have been integral to improving the efficiency and productivity of water delivery, and the use of stainless steel offers an economically maintainable and longer lasting infrastructure solution.

All new gates installed are stainless steel and telemetry-enabled for remote control, a capability that has radically changed the way Murray Irrigation manages water delivery to its customers. 

Photo banner at top of article courtesy of Ertech. 
Photo above (left) courtesy of Murray Irrigation. Photo above (right) courtesy of AWMA.

This article is featured in Australian Stainless Magazine issue 65, 2019.

What is the fire rating of stainless steel? This is a common enquiry from ASSDA Members and the construction industry, especially with the current concerns about flammable cladding. The three major branches to this question are covered in this article.

Will stainless steel burn, and if it does, will it give off fumes or facilitate the spread of fire?  

This question is readily answered because stainless steels are steels. It is recognised that steels do not burn and only start to melt at about 1400^oC. This means that stainless steels do not have a “fire rating” as such, so the tests of AS/NZS 1530.3 (or the equivalent tests in BS 476) are not required.

Heating in a fire will obviously have an appearance effect because, unlike the transparent nanometer-thick passive layer formed in moist air, stainless steels heated above about 300^oC in air discolour as they grow a less dense oxide layer. This develops from the rainbow colours seen beside welds to a dark and non-protective oxide layer whose thickness depends on the time of exposure and temperature reached. The street rubbish bin shown suffered from a fire but remained functional for almost a year (until the repair cycle reached it) with a decorative rainbow oxide. By way of comparison, powder coated bins would suffer from unsightly burn marks and corrosion. 

For austenitic alloys such as 304 and 316, the temperature limits for lifetime section loss due to oxidation is about 870^oC (with temperature cycling) so they are routinely used in high temperature furnaces and ductwork. The current trend to apply decorative coatings to stainless steels would require an assessment to determine the combustibility, potential fumes and flame spread of the coating. Tests to AS/NZS 1530.3 would be appropriate. 

Microstructural effects of a short-term heat cycle (less than a couple of hours of exposure, such as a fire) could include carbide precipitation (sensitisation) in an austenitic alloy which was not an L grade (i.e. carbon >0.03%). Duplex and weldable ferritic grades should not have sufficient carbon for sensitisation. Sensitisation would degrade the corrosion resistance but not affect mechanical properties. Both duplex and ferritic grades can suffer 475^oC embrittlement, however data produced by the International Molybdenum Association (IMOA) shows that this requires more than two hours in the 400^oC to 500^oC range for a 50% reduction in toughness. This duration is unlikely in most fires.

Will stainless steel provide a barrier to flames and if it does, how rapidly will the heat penetrate the barrier sufficiently to cause damage (usually a specific temperature rise) on the far side? 

A satisfactory demonstration is supplied by reference BS 647 Part 22 tests carried out for a British Stainless Steel Association (BSSA) member, Stewart Fraser, who manufacture 316 framed doors which include a cavity filled with non-combustable boards. The results are given at www.bssa.org.uk/topics.php?article=106.

It showed slight discolouration and distortion on the flame impingement side with the sheltered side of the door reaching only 98^oC after 60 minutes. The test was continued for another 80 minutes without the failure of flame containment or subsequent opening of the door in its frame. Similar testing was carried out on a 1.5mm thick 2304 duplex sheet fabricated into a simulated ship’s bulkhead with enclosed ceramic wool insulation. With a bright orange glow of an 1100^oC metal temperature on the flame side, the “safe” side reached 30^oC after 40 minutes and 110^oC after 60 minutes. The test was terminated after 120 minutes with containment still satisfying IMO resolution A518 (XIII).

What are the effects (both during and after an event) to the mechanical properties of stainless steel? How do these compare with structural carbon steels? 

There are tests as well as a theoretical basis which demonstrate that both austenitic and duplex stainless steels have superior high temperature properties compared to carbon steel. The table below shows the deflection and failure modes of three metre long commercial electrical cable trays loaded to simulate actual loadings. They were heated with 18 LPG burners to obtain an average temperature of 1000^oC  to 1050^oC for at least five minutes. [Nickel Institute publication No. 10042]

The publication also considers the life cycle costs (LCC) of the use of aluminium, galvanised steel or stainless steel for stairways, handrails, gratings and firewalls, as well as cladding for corridors and accommodation modules on North Sea platforms. Fire risk controls are obviously a major concern although corrosion resistance is also critical. On an LCC basis, stainless steel was most economical especially when its reduced requirement for maintenance periods were included. 

In addition to the above testing in cable tray applications, substantial research and application work has since been carried out and codified. Installations include 2205 duplex hangers suspending the slab which forms the floor of the emergency ventilation duct in the CLEM7 tunnel in Brisbane [ISSF].

In short term fires such as on balconies or stairways, the temperature rise exposed to an ISO 834 fire temperature profile depends on thickness and emissivity. Polished stainless steels typically have low emissivity of <0.1 and hence a slower temperature rise. Conservatively, after 30 minutes a 12mm sheet of stainless steel with 0.2 emissivity would reach 620^oC whereas steel (with no rust) and 0.4 emissivity would reach 750^oC.   

When considering strength and deflection, the metal temperatures in a conventional fire do not reach levels to anneal the material so any cold work strengthening will raise the temperature for a 50% strength reduction. In addition, as shown in the graph, the reduction in Young’s Modulus, i.e. deflection from a specific load, is less than that of carbon steel for temperatures above ~200^oC. By 600^oC the modulus retention for stainless steel is 0.75 compared to 0.3 for carbon steel, i.e. less than half the deflection for a given load.

In summary, stainless steel has substantial advantages in structural use when fire risk is considered, and these advantages continue into higher strength and lower deflections at elevated temperatures.

CLEM7 image above courtesy of Ancon.

This article is featured in Australian Stainless Magazine issue 65, 2019.

Stainless steel is the ultimate materials solution for electrical enclosures in safeguarding the network and communications technology invested in underground mining sites.

Olympic Dam is a large polymetallic underground mine located in South Australia, approximately 550km northwest of Adelaide.

Home to a major source of oxide copper gold deposit, Olympic Dam produces combined quantities of copper, gold, uranium and silver through an underground mining system integrated with a metallurgical processing plant. The large deposit was discovered in 1975 and in 1988, the mine was opened by WMC Resources. Today, Olympic Dam is owned and operated by BHP, following its acquisition of WMC Resources in 2005. 

ASSDA Member and Accredited Fabricator B&R Enclosures was contracted by MPS Building & Electrical to assist with finding a solution to a fibre enclosure hub capable of linking four mining shafts to the surface.

B&R’s design and engineering team worked closely with MPS Building & Electrical to design and fabricate an enclosure specific to BHP’s requirements. The customised solution was supplied through Auslec Electrical and Data located in Wingfield.

The outcome was a double door stainless steel field cabinet, 1000mm deep and capable of housing electrical and monitoring equipment. Due to the remote location of the project and the type of equipment installed, stainless steel sunshades and lockable handles were included to reduce heat within the enclosure and prevent vandalism.

Grade 316 stainless steel with a No. 4 surface finish was specified for the custom-designed enclosures, with material supplied by ASSDA Member Outokumpu in 1.5mm thick sheet. 

Underground communication networks are a critical link between operations below ground and at the surface to ensure efficiencies in production and personnel safety. Protecting the equipment that delivers these communication networks is vital and stainless steel offers the durability and longevity required to deliver a robust structure to ensure preservation of the internal hardware.

In addition, grade 316 stainless steel offers excellent corrosion resistance, particularly to pitting corrosion which can occur in inland Australia due to high salinity in the ground water. 

B&R have worked alongside BHP and MPS Building & Electrical on past projects, installing enclosure solutions into a variety of different applications. B&R’s ability to design custom solutions along with their reliable service meant MPS Building & Electrical could confidently deliver this project and supply an enclosure suitable for harsh mining environments and extreme weather conditions.

As a result of good collaboration and local technical expertise, the project’s stainless steel enclosure design is now a standard specification for future installations across Olympic Dam.

This article featured in Australian Stainless magazine - Issue 64, Summer 2018/19.

Mirror finished stainless steel sign blades can be found scattered along the central boulevard of Sydney’s revitalised Darling Harbour.

Through a recent $3.4 billion transformation, Darling Harbour has become Australia’s largest entertainment and events precinct boasting world class facilities, including over 40,000 square metres of exhibition space. This urban rejuvenation builds on the success of Darling Harbour and in turn, will generate $200 million annually in economic benefit for the NSW economy.

The Harbour is ringed by attractions, entertainment and extraordinary waterfront restaurants. The Boulevard creates an active north-south pedestrian connection between Central Station and Cockle Bay. Its prime location is within walking distance of most points in the Sydney CBD therefore wayfinding signage is pivotal in navigating people through and around the precinct.

ASSDA Member and Accredited Fabricator Stoddart were engaged by Lend Lease to manufacture and install 19 stainless steel wayfinding sign blades for Darling Harbour’s ‘once in a generation’ re-development. The sign blades are featured in groups of two and three, each standing seven metres tall and two metres wide.

258 panels of grade 316 stainless steel were used for the sign blades in order to provide housing for LED display screens throughout the precinct. The structural stainless steel frame also mounts speakers and power outlets. All stainless steel used in this project was supplied by ASSDA Member, Fagersta Steels. 

Featuring a mirror profile finish, the stainless steel signs create a stunning visual effect through the reflection of the countless city lights and surrounds of the bustling tourist and entertainment mecca.

Stainless steel was specified by landscape architects, Hassell, for its aesthetic appeal and high-quality attributes. The Harbour’s salt water environment and location was also a consideration in the materials specification, being adjacent to the city centre.

It is only fitting for quality material such as stainless steel to be showcased in one of the world’s most desirable entertainment and event destinations.

This article featured in Australian Stainless magazine - Issue 64, Summer 2018/19.

Stainless steel has delivered the confidence it will provide the structural performance and meet the 100-year life-cycle of a new marina development on the New South Wales’ South Coast.

The Waterfront, Shell Cove, is a joint residential and mixed-use development between Shellharbour City Council and Frasers Property Australia located 22km south of Wollongong.

Central to the development is its waterfront location and world-class marina that will offer pontoon berthing for approximately 270 vessels, direct access to the Pacific Ocean, charter boat operations, a public boat ramp and a variety of marina facilities and services.

Stainless steel reinforcement has played a significant role in the structural design and construction of the marina, with over 318 tonnes of grade 2304 lean duplex stainless steel reinforcement bar (rebar) supplied by ASSDA Member Valbruna Australia. Ranging in diameters from 8mm to 25mm, stainless steel rebar was used in all pre-cast elements to form the marina sea walls, marina steps and boat ramps and installed by Coastwide Civil.

The original project specification was for alternative materials and products with cathodic protection and sacrificial anodes that struggled to exceed a 50-year life-cycle guarantee. This specification was superseded by a requirement for a 100-year life span, and the use of stainless steel provided the best solution, as well substantial cost savings around constructability and man hours per tonne required.

Stainless steel rebar offers structural longevity in many environments with exceptional corrosion resistance in harsh marine developments. Its specification in this landmark waterfront development meets the expected minimum 100-year life and was also critical to minimising ongoing maintenance costs. This was an important consideration to avoid future maintenance closures due to corrosion issues and to ensure continued public accessibility to the waterfront promenade for all residents and tourists.

In addition, the use of stainless steel rebar significantly reduced the amount of concrete cover required, also minimising costs and resulting in a more lightweight and higher tensile strength structure.

Valbruna Australia’s commitment to stock large volumes of stainless steel rebar on the floor in Australia meant no delays were experienced during the project’s supply term, including meeting the 20% increase in supply quantity during installation. Coordinated supply was critical to the on-time completion of the project, which was further impacted by narrow site delivery windows and limited set down holding areas.

The scheduling, cutting and bending of the stainless steel rebar to tight precast tolerances was completed by Mesh & Bar, and performed at a dedicated stainless steel facility to prevent contamination risks.

All stainless steel welds were completed in a controlled environment, and pickled and passivated by Waeger Constructions.

Construction of the residential and mixed-use infrastructure will continue into next year, with the marina due to take water by the end of 2019. Once completed, Shell Cove will also boast a vibrant town centre and retail precinct, community centre and library, foreshore dining and waterfront tavern, and boutique accommodation.

This article featured in Australian Stainless magazine - Issue 63, Spring 2018.
 

Taking pride of place within Perth’s Optus Stadium Park is the Arbour featuring a stainless steel cable net canopy delivered by ASSDA Member Structural Dynamics.

The 60,000-capacity arena is the latest major development to hit Western Australia’s capital, boasting a world-class multi-purpose venue that combines innovative design with community infrastructure.

The impressive Arbour stands 10m tall and 20m wide, and stretches 450m around the south side of the Stadium. It connects a new six-platform railway station to the Swan River, over which the Matagarup Bridge is currently being constructed to provide pedestrian access to East Perth.

Over a thousand stainless steel cables were installed on the 43 arches that make up the Arbour to create a tensile structure in the form of a canopy. Suspended on the structure using bespoke fittings are 3,076 bronzed artwork panels reflecting Whadjuk and Noongar stories. 

Stadium Park was constructed on wetlands with cultural heritage significance to the Indigenous community, and its rich Aboriginal history was the inspiration behind the Arbour’s design.

More than 13 tonnes of grade 316 stainless steel was used, including in excess of 14km of 16mm and 8mm hamma^TM X 1x19 wire rope supplied by ASSDA Member Arcus Wire Group, 20,000 bespoke fittings and over 34,000 screws.

Stainless steel was specified for the cable net canopy for its strength and durability to withstand the harsh Western Australian weather conditions, including powerful coastal winds driven from the Indian Ocean. The 16mm edge cables on the structure were tensioned to forces up to 52kN, with the 8mm longitudinal and transversal cables tensioned up to maximum of 11kN.

In addition, the high quality and aesthetical value of stainless steel complemented the Arbour’s design in creating an eye-catching structure for patrons.

Structural Dynamics provided value engineering and practical advice to the project engineer Maffeis Engineering and project architect Hassell on how to best integrate stainless steel tensile systems into the design.

Their in-house team of engineers used structural and finite element analysis as components of the detailed analysis and modelling on how the cable design would behave and interact within a tensile architecture installation.

Structural Dynamics also worked with engineering firm Partridge to undertake the final design, review, slip testing of the bespoke cable clamps and final sign off for the project. Each of the eight different types of cable edge clamps were sent to the National Association of Testing Authorities’ (NATA) accredited laboratory for slip testing under wet and dry conditions to ensure their strength and adequacy.

The cable fittings were designed to the AS 1170 series: Structural Design Action, AS 4100: Steel Structures and AS 2759: Steel Wire Rope – Use, Operation and Maintenance.

Structural Dynamics’ Project Manager Shaun Salmon explained the logistics of the assembly of the Arbour whilst maintaining safe and continued access to the Stadium for more than 1,000 workers. ‘It was important during the installation process that our team of skilled and qualified tradesmen and riggers followed the approved construction sequencing and quality management system processes whilst not impeding access to the Stadium from the primary entry point on the southern concourse. Both temporary and permanent bracing measures were used throughout construction along with sequential tightening and regular cable tension testing to achieve the design intent drape and sag of the cable net canopy and not applying adverse force to any single point on the structure.’

Structural Dynamics’ collaboration with the multiple stakeholders involved in the Arbour design and construction ensured the successful delivery of a custom-designed stainless steel cable net canopy providing the flexibility, tensile strength and structural performance required.  

Optus Stadium officially opened on 21 January 2018 and is the new home game venue of local Australian Football League teams Fremantle Football Club and the West Coast Eagles.

Arbour photos courtesy of Structural Dynamics. Photography by Abigail Harman.

Aerial photo of Optus Stadium Park courtesy of MakMax.

This article is featured in Australian Stainless Magazine #61.

Stainless steel is playing a vital role in the structural integrity of a new state-of-the-art library at one of Brisbane’s most prestigious boys’ school.

The Centenary Library at Anglican Church Grammar School was designed by Brand + Slater Architects, and the ambitious project was part of the school’s master plan to provide a technology-rich, world-class centre for its 1800 students. Comprising four levels, the tertiary-inspired building features an extensive range of learning spaces including a 250-seat lecture theatre, teaching and meeting rooms and over 80 individual study areas.

The library stands 23.5m tall on a heritage-listed part of the school campus. Paying homage to the school’s history whilst appealing to a contemporary aesthetic, the library exterior features an intricate brick façade backed by a stainless steel support and restraint system custom-designed and manufactured by ASSDA Member and Accredited Fabricator, Ancon.

Grade 304 stainless steel was used and specified for its longevity, durability and performance properties to meet the building’s 50+ year design life.

Ancon’s specialist knowledge, manufacturing agility and project management service proved invaluable to the contractor when building the detailed façade of the decorative arches and corbelled brickwork with all structural steelwork now unseen.

Shelf Angle Brick Support

Ancon masonry support systems enabled the large-scale brick cladding installation on this impressive education facility to be completed to the highest safety standards, while showcasing its architectural brickwork features.

Ancon’s MDC and CFA continuous shelf angle support systems carry the intricate brick façade, consisting of freestanding archways and projected brickwork. The MDC stainless steel angles are fixed to the reinforced concrete frame, span a 40mm cavity, and create a horizontal shelf to provide the necessary support for up to 3 metres of brickwork.

Cast-In Channel

Ancon’s 30/20 cast-in horizontal channels were used to provide the fixing between the concrete frame and shelf angles. The channel enabled the necessary horizontal adjustment for the installer, and its compact size eliminated the issue of potential clashes with the reinforcement steel in floor slabs.

Nail holes aided the fixing of channels to timber framework and an infill prevented the ingress of concrete during casting. Cast-in fixings do not generate expansive forces in concrete. It can therefore be used at close centres and often used closer to the edges than expansion fittings.

Wall Ties and Restraint Fixings

To restrain the distinctive brickwork details to the reinforced concrete structure, stainless steel L-shaped SPB and SDB frame cramps were fixed into the reinforced concrete using 6mm FBN expansion bolts.

FBN single expansion bolts are a cost-effective anchor and fix into a hole similar to the diameter of the bolt. This allows the hole to be drilled through the hole in the item to be fixed.

Technical Expertise

As part of Ancon’s free design service, plans were produced illustrating the location and reference of all fixings required. Ancon’s early engagement with the project’s structural engineers, Bligh Tanner, enabled a workable and cost-effective design to be agreed upon prior to the build of the complex masonry features. Sharing their expertise with the clients at this stage of the project meant installation difficulties, site delays and unnecessary remedial measures were avoided.

Centenary Library photo (above); Copyright: Christopher Frederick Jones.

This article is featured in Australian Stainless Magazine #61.

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).

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).

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).

Water authorities tackle water shortages with stainless steel.

Water is a fundamental human need. It is central to our lives, from what we drink, to what we use in washing ourselves, our clothes and a multitude of other uses. Safe, clean and palatable water comes at a price though, and when leaks occur in distribution systems, additional costs are incurred as even more water must be found and treated. Security of water supply is a prerequisite for sustainable growth and dealing with leakage is a universal challenge. To combat the scourge of leaks, a number of water distribution authorities across the world have implemented affordable solutions utilising stainless steel, which not only saves money, but water, a precious resource.

Tokyo, Japan

Prior to the 1980’s, water shortages in Tokyo were chronic and rationing was occasionally required. When the city’s water provider, the Tokyo Metropolitan Government Waterworks Bureau (TMGWB), analysed leakage repairs, they determined that 97% were on the distribution pipes of 50mm diameter or less. In Tokyo, there are more than two million such connections that take the water from the mains to internal systems in buildings. Historically, lead pipe was the preferred material for distribution lines because it is soft, malleable and easy to work with, especially for the last few metres from the mains to buildings. Once lead pipe is in the ground, however, various forces can act on it. Vibrations from traffic and construction work as well as subsidence and earthquakes can cause the soft lead pipes to deform, become detached or even break.

In 1980, TMGWB started to actively replace all service connections with grade 316 (UNS S31600) stainless steel pipe. In 1998 corrugated grade 316 (S31600) stainless steel pipe was introduced for distribution lines that take water from the mains to final destinations in homes, offices and industrial plants. The pipe is corrugated at regular intervals to allow for it to be bent during installation, to accommodate changes in direction and the avoidance of obstacles without additional joints. It also allows for movement of the pipe during earth movement and seismic events. By supplying a single length of corrugated stainless steel pipe, the number of pipe joints was greatly reduced. In switching to stainless steel pipe, the reliability of the water supply has increased and the leakage rate has been reduced by 86% from 15.4% (1980) to 2.2% (2013). To put this into context, since 1994 Tokyo has reduced annual water leakage by nearly 142 million cubic metres - the equivalent of 155 Olympic-size swimming pools per day, with savings in excess of US$200 million per year. Also, annual leak repairs have decreased from 60,000 (1983) to 10,000 (2013). Due to the corrosion resistance of stainless steel, TMGWB expects service life in excess of 100 years.

Graph below: Correlation between repair cases, leakage rates and installation of stainless steel pipes in Tokyo.
Courtesy of the Bureau of Water Works, Tokyo Metropolitan Government.

Taipei, Taiwan

In 2002, a severe drought brought intermittent water supplies to the Taiwanese capital over a 49-day period. Of the 450 metering areas in the city, 40% were losing half of their water or more before it reached consumers.

Analysis of repair cases showed that while polybutylene pipe made up only 3% of the length of the system, it accounted for 28% of all leaks. Approximately 90% of all problems occurred in plastic pipes, with the vast majority (83%) caused by cracking.

In 2003, the Taipei Water Department began a similar program to Tokyo, replacing distribution lines with corrugated grade 316L (S31603) stainless steel pipe. Although the ongoing program has so far only replaced 35% of the lines, the result has been a reduction in water loss from 27% (2003) to 17% (2014). This adds up to an annual saving of 146 million cubic metres of water, the equivalent of 160 Olympic-size swimming pools per day.

In 2014, a drought occurred with even less rainfall than the 2002 event which precipitated the pipe replacement program. However this time, the improvement in leakage rates achieved since 2003 meant there was no interruption to the water supply.

The 2002 drought in Taipei caused severe water shortages.
Image courtesy of the Taipei Water Department.

Western Cape, South Africa

South Africa is by nature a semi-arid country; its annual rainfall is only half the global average. It has a population of 55 million and is facing freshwater scarcity. It is estimated that at least 37% of its clean drinkable water is lost due to leakage from old and unreliable infrastructure.

The Groot Drakenstein Valley is the cradle of the South African deciduous fruit and wine industries. Water is supplied to over 800 farms including 50 vineyards. Here, there are numerous examples of carbon steel and cast iron pipes that have failed in many areas after just one year due to the very aggressive acidic soils and high water table. “We started a project in 1992 in the Drakenstein Municipality to replace existing piping with stainless steel,” explains André Kowalewski, Senior Engineer - Water Services, Drakenstein Municipality. “We have reduced water loss to around 13% in comparison to the 37% national average. Ten years back only the Drakenstein Municipality used stainless steel. Now 80% of the Western Cape municipalities do.”

André and his team plan for a life expectancy in excess of 50 years. Stainless steel used in Drakenstein is primarily grade 316 and in some cases grade 304 (S30400) in visible locations. Projects are currently focussed around pumping, purification, storage, pipelines and sewage. One such project is a 500 mega-litre/day delivery system completely in grade 316 stainless steel.

Stainless steel pipe in the Western Cape resists aggressive acidic soil conditions.
Images courtesy of Johan Van Zyl.

Investing in the future

The experience of Tokyo, Taipei and the Western Cape gives water authorities the confidence to specify stainless steel for piping systems. While the initial cost compared to competing materials may be higher, stainless steel has been shown to be a good investment over its long life, paying back each year in reduced maintenance and cost per litre processed.

This article was originally printed in Nickel Magazine (August 2016, Vol. 31, No.2), published by ASSDA Sponsor Nickel Institute.

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

Banner image: Corrugated pipe installation. Image courtesy of Tokyo Suido Services/Showarasekan.

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 <0.5R_a 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.

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 R_a 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.

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 R_a<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.

ASSDA member Australian Pickling & Passivation Service (APAPS) and ASSDA sponsor Sandvik Mining & Construction have been central to the expansion of a coal export port in North Queensland.

With Queensland coal exports forecast to increase to 250mtpa by 2015, the strength and durability of the state’s expanding coal transport infrastructure and rail systems is critical to ensuring export capacity.

This recent expansion required the manufacture of 300 three-piece conveyor frames using 40 tonnes of 316 grade stainless steel, specified to foil the port’s exposure to wind, rain, salt spray and abrasive dust.

Sandvik Mining & Construction manufactured the conveyor frames for the project, and APAPS pickled the frames before delivery to the terminal.

Stainless steel can corrode in service if there is contamination of the surface. Pickling involves the removal by chemical means of any high-temperature scale and any adjacent low chromium layer of metal from the surface of stainless steel.

The client requested that the stainless steel conveyor frames were pickled to achieve a product that would not rust. According to APAPS’s Director Richard Raper, ‘Pickling stainless steel removes all traces of burnt chromium caused by heat from welding and any iron contamination caused by handling and processing during fabrication.’ He added that several variables must be considered when pickling stainless steel, including the grade, surface finish, the size and shape of the structure and bath temperature.

Transported by road on B-double trucks from Mackay to the APAPS workshop in Newcastle, the conveyor frames arrived a dull grey colour and heavily soiled from anti-spatter and other contaminants. Pre-cleaning of the stainless steel was required prior to pickling as contamination on the surface can reduce the effect of pickling. The frames were sprayed using an Avesta 401 Cleaner and Callington Haven Brite Wash and left for 30 minutes before being high-pressure washed with hot water.

The immersion pickling method was used to pickle the conveyor frames. They were immersed in a nitric and hydrofluoric acid bath for approximately 1.5 hours, which APAPS’s own pickling technician determined following a number of inspections. Avesta Pickling Bath 302 was used at a temperature between 25-30°C. The frames were lifted from the bath and allowed to drain for 15 minutes before being washed down using high-pressure water.

APAPS’s pickling of the stainless steel by was central to ensuring the performance and durability of the conveyor frames and maximising their corrosion resistance. The treatment also produced a consistent and smooth finish with aesthetic appeal.

After the pickling treatment, the conveyor frames were strapped together in batches of five, with timber placed between the stainless steel and strapping. They were then transferred and loaded using a forklift with stainless steel slippers [covers] to protect the frames from cross-contamination. Due to the physical nature of the conveyor frames, only one layer of frames at a time could be placed on the truck deck, and these were tied down with web straps. Transportation took an average of 3 days between Newcastle and Mackay.

The project was completed in 10 weeks and delivered back to Mackay in stages. The APAPS team worked two shifts a day to complete the work on time for Sandvik.

Richard Raper says the project was a testament to APAPS’s membership of ASSDA, as it was the Association’s referral that won him the job.

‘This is a good showcase of how ASSDA members and Accredited fabricators can achieve great outcomes and how clients get what they expect when specifying stainless steel.’

Images courtesy of Australian Pickling & Passivation Service Pty Ltd.
This article is featured in Australian Stainless magazine issue 53, Autumn 2013.