Brisbane City Council is committed to providing safer, accessible, active transport routes. As part of this commitment, the $40 million Indooroopilly Riverwalk project was constructed. A separated two-way cyclist and pedestrian path, the new Riverwalk is 5m wide and 790m long (including adjoining pathways).
It links Twigg Street to the Jack Pesch Bridge and the Indooroopilly Rail Station, with additional connections to Radnor Street and Riverview Terrace. From the viewing platforms along the new Riverwalk, residents and visitors alike can enjoy gorgeous views of the Brisbane River and the iconic Walter Taylor Bridge.
The path is a critical part of the active transport corridor between the Western Freeway Bikeway and the University of Queensland.
DSI Underground delivered 1,580m of galvanized pedestrian balustrading for Indooroopilly Riverwalk, as well as lamp post brackets and cover plates. In total, DSI Underground galvanized over 100 tonnes of steel, including 690 posts, 690 panels and 350 lengths of handrail.
According to Drew Stainton (Senior Sales Representative, DSI Underground), the project was a career highlight. “The Riverwalk will be used by joggers, cyclists, pedestrians, tourists and locals—it’s a short-cut between the city, which will attract a lot of foot traffic. That means a lot of people throughout Brisbane will see our work. It really was an iconic project to work on.”
Why Galvanizing?
With the Riverwalk located in a C3 Corrosivity Category, the use of galvanized steelwork was the optimum means by which to ensure lower ongoing maintenance costs.
“Galvanizing was specified because of the durability it offers. Railings can be painted or coated, but for longevity of service life, galvanizing is the best option. It is also more affordable when compared to a material like stainless steel,” said Stainton.
DSI Underground was involved early on in the planning process, prior to construction commencement. This helped to ensure a seamless transition for the steelwork, from the fabricator to the galvanizer and onto the site.
It was during the planning process that DSI Underground confirmed the best possible design for the venting, draining and fabrication to achieve the best possible galvanized finish.
“We altered some of the venting holes on the original design. There were some different angles in the handrailing that required holes in the exact right positions for venting and draining, as well as handling points so that there weren’t any wire marks left on the surface of the handrails. Given the high visibility of the galvanized product and large volume of public traffic, it was important that a high quality galvanized finish was achieved on the handrail and balustrade system,” said Stainton.
To further increase service life in an area classified as a C3 Corrosivity Category, DSI recommended that all components were sandblasted prior to galvanizing. The sandblasting process lightly roughens the surface to create more surface area to react with.
“Sandblasting increased the coating thickness. This was particularly important when it came to the low silicon steel in the base plates—in order to achieve the requisite levels of coating thickness set out in Australian Standards, sandblasting was essential. Sandblasting the steelwork also afforded us rapid galvanizing turnaround times, which contributed to our early completion of the project,” said Stainton.
“In fact, DSI Underground completed the Riverwalk five months ahead of schedule. As a local Brisbane supplier, working on a local Brisbane project, our turnaround times were fast. Plus, regular onsite consultations with the other project stakeholders around any issues reduced delays and budget blow out.”
Galvanizing, Transportation and Delivery
The design of the Riverwalk featured changing elevations and directions. This meant that each post and panel was unique. To ensure efficient, effective installation, DSI Underground devised a custom process for the galvanizing and delivery of all these unique components.
“The marked steelwork was delivered to our workshop for galvanizing according to its installation sequence. After galvanizing, it then had to be delivered to site, in exactly the same order,” said Stainton.
“This meant that tracking of every item throughout the galvanizing process was crucial. Each post and panel had to be individually marked to ensure that it was installed into the correct position along the bridge. Every part was labelled with an ID number to ensure it could be correctly fitted onsite, and then our barcode scanning system provided the traceability required for the project.”
“Handling was also a challenge on this project. DSI galvanized a lot of small, loose components, like lamp post brackets and cover plates. All these components had to be packed carefully, so that during transportation and delivery they were not damaged,” said Stainton.
Economic, Environmental, Social and Engineering Innovation
DSI Underground’s work on the Indooroopilly Riverwalk produced a variety of beneficial outcomes across all areas, from economic and environmental, through to social and engineering innovation. The project paves the way to support the use of galvanized coatings in corrosive environments and, when marketed well, will lead to further opportunity for the Australian galvanizing industry.
“The use of galvanizing on the Indooroopilly Riverwalk will enable us to market the use of galvanizing to other government projects—and there are quite a few on the horizon,” said Stainton.
As a large, iconic, government project, Indooroopilly Riverwalk showcases the superior corrosive protection offered by galvanizing when compared to other coatings.
Project Team
- Builder: Georgiou and Brady Marine
- Architect: Brisbane City Council
- Engineer: Brisbane City Council
- Steel Supplier: Vulcan Steel and Steelforce
- Fabricator: Kenro Metal
- Galvanizer: DSI Underground (Queensland)