Located in the heart of Bibra Lake, Western Australia, a colossus of industry rises nearly half a football field into the sky—welcome to the Americold Spearwood Expansion. This isn’t just any warehouse; it’s a cutting-edge cold storage and logistics facility that has redefined the local horizon.
Crafted around a striking exoskeleton, Americold’s facility is a showcase of engineering and design, with 615 tonnes of structural steel intricately woven into a tapestry of strength and durability. The facility stretches an impressive 100m in length and 50m in height, making it seem a modern-day lighthouse.
Located four kilometres from the abrasive coastal elements, this facility had to be durable. Enter the hero of our story: hot dip galvanizing. More than just a surface treatment, galvanizing was readily able to outperform paint in the trilogy of cost-efficiency, longevity, and time to first maintenance. With every inch of Americold’s steel exoskeleton galvanized by DSI Underground, the Americold facility confidently meets—and exceeds—the requisite 50-year design life.
SHOWCASING THE POTENTIAL OF HOT DIP GALVANIZING
According to Jason Davies (Head of Infrastructure at DSI Underground), the impressive height of the facility gave the project its ‘wow factor’. He said, “It is quite prominent in the area. With the exoskeleton completely exposed, and galvanized, it really shines.”
Jason said, “The project is an exposed steel construction, located only 4km from the coast and was chasing a 50-year design life. The combination of all these factors together made galvanizing the best choice. The project couldn’t have been achieved economically by any of the alternatives: galvanizing and paint, or paint only. By the time you add up upfront and ongoing costs of all these options, galvanizing wins by far.”
The Americold Spearwood Expansion demonstrates the strength and resilience of galvanized-only surface treatment for fully exposed structural steel – more than just the usual awning steel on warehouse structures, but for the entire building. Jason said, “The project has potential to open that market up to specifying galvanizing only surface treatment more frequently, particularly on fully exposed steelwork, located this close to the ocean.”
Typically, at this distance from the coast, galvanizing would only be specified on internal steel cladded with sheeting. But the cooling afternoon sea breeze, known as the Fremantle Doctor, often picks up salt spray and blows it much further than the four kilometres where the building is located. “Galvanizing can stand up to these salt deposits on the steel for the intended design life, in the most economical way,” Jason explained.
What’s more, combining galvanized steel with an exoskeleton design allows optimisation of the internal floor area, providing greater value for the end user. Jason commented, “Being easily the tallest building in the area, it stands out anywhere in the surrounding area, which will keep galvanizing at the front of mind and therefore promote hot dip galvanizing for this application.”
A FEAT OF TECHNICAL AND ENGINEERING INNOVATION
To avoid having both insulated panels and exterior cladding, the building utilises exposed structural steel. Being higher than other buildings, it will endure the full force of the infamous ‘Fremantle Doctor’. This led to the engineers opting for galvanized steel so it could meet the desired design life.
“We have worked closely with the fabricator for this project—Fremantle Steel Group—on a number of jobs, so they were fully aware of our galvanizing capacity,” Jason said. “Having the biggest galvanizing kettle in the Southern Hemisphere, everything was single dip for us. We opened the plant about seven years ago now, so local industry is aware of our capacity and maximum sizes.”
The building features large truss columns throughout, which were custom-designed to fit into DSI Underground’s galvanizing facilities. This reduced the number of bolted connections required, while removing any requirements of welding after surface treatment.
While the initial design included minimum requirements for vent and drain holes, after the first truss column was galvanized, the galvanizer proposed larger holes. Consequently, all further truss columns were galvanized to a high-quality finish.
Jason said, “The only issue we encountered were on the large truss columns. They were initially fabricated with the minimum size drainage holes, which didn’t allow for the zinc to drain fast enough for a high-quality finish. So, after the first truss was dipped, we proposed that larger drainage holes were applied to the remaining columns for the project.”
REAPING THE ECONOMIC BENEFITS
Hot dip galvanizing provides key benefits to the end user, when compared with alternative surface treatment options such as inorganic zinc paint, two-coat paint, and three-coat paint.
Inorganic Zinc Paint System
Although the initial cost of an inorganic zinc paint system would be lower, the life to first maintenance is significantly reduced – meaning there would be additional maintenance costs within the first 10 years. In order to meet the 50-year design life, the structure would also need to be externally cladded, adding significant initial costs to the end user.
Two-Coat Paint System
The initial cost of a two-coat paint system would be either similar or slightly higher than galvanizing. However, the life to first maintenance would still be significantly reduced, resulting in a higher maintenance cost. If the second coat was a high-build epoxy, then this would not be UV-stable and would lose its colour to become chalky. Greater care would also need to be taken during installation of the steel, with any touch-ups adding to costs.
Three-Coat Paint System
The initial cost of a three-coat paint system is far higher than galvanizing. Ongoing maintenance would be required to achieve the design life, with installation and touch-up costs also a significant factor.
ENVIRONMENTAL AND SOCIAL RESPONSIBILITY
The Americold Spearwood Expansion project delivered key environmental benefits. Due to the selection of hot dip galvanizing, the building will require minimal maintenance throughout its design life. This drives down water usage, in lieu of regular washdown of painted steel, and the fuel needed for maintenance teams travelling to and from the site.
Jason said, “Galvanizing offers minimal maintenance compared to the alternatives. If the structure had been painted, it would have needed more frequent maintenance. Every few years, it would have needed a wash down with water, full inspections and touch ups applied if required. So, sustainability wise, there is much less water usage over the life of the project, as well as fuel consumption, and material usage.”
Being a cold storage facility that mainly handles food products, there is also a clear social benefit to this project: enabling fresh and frozen food to be distributed more efficiently to Western Australian companies and people. Because food is coming from a hub in the Perth metropolitan area, rather than the possible alternative of being transported from interstate in refrigerated transport, the end result is reduced emissions – creating an additional environmental benefit.
PROJECT TEAM
Architect: Bell Architecture
Engineer: Michael Bale & Associates
Head Building Contractor: Badge (D&C)
Steel Fabricator: Fremantle Steel Group
Steel Detailer: Xstruct Australia
Galvanizer: DSI Underground, Kewdale