Construction will commence on the Molonglo River Bridge crossing – set to be the longest weathering steel bridge in Australia – early next year. The project could usher in a new era of improved road infrastructure.
Incorporating weathering steel into the Molonglo River Bridge crossing marks a significant step forward for the Australian bridge construction industry.
The project, encompassing the construction of an approximately 200 metre long steel girder bridge, along with 1.7 kilometres of new arterial roads and two new intersections, is key to enhancing connectivity between Molonglo and West Belconnen and the broader Canberra area, says Mark Gallagher, Construction Manager, BMD Constructions.
“The use of weathering steel provides long-term durability that reduces maintenance expenses, proving a practical investment for years to come. This is because weathering steel develops a protective patina over time, eliminating the need for additional coatings,” said Mark Gallagher, Construction Manager, BMD Constructions.
“It’s also set to improve transport in the region by prioritising safety and efficiency.
“The design caters to diverse modes of travel, including provisions for public transport and even future light rail considerations. Beyond its primary role in advancing transportation, the bridge provides invaluable flood immunity, guaranteeing a dependable and secure route for motorists.”
The project will foster vital service connectivity across regions.
“From electricity and communications to gas supply, this endeavour sets the stage for a more integrated and well-connected urban landscape.”
Harmonising with the environment
The project initially commenced in 2015 with extensive planning and concept design work completed along with significant environmental and planning approvals prior to BMD taking on the project in February 2023.
The ACT Government’s concept design integrated the Molonglo River Bridge into the Molonglo Valley’s natural landscape. This also involved designing the project in alignment with the ‘Family of Bridges’ vision endorsed by the Australian and ACT Governments for the region.
“Central to this concept is the creation of a consistent and harmonious architectural language across multiple bridges,” says Gallagher.
This involved careful collaboration with the ACT Government, design teams and Transport Canberra and City Services (TCCS) prior to the contract award.
“From the outset, BMD commissioned design teams from GHD, pitt&sherry and COWI to ensure our work progressed the design to integrate the Molonglo River Bridge into the Molonglo Valley’s existing distinctive visual landscape.” says Gallagher.
“BMD has a strong reputation of improving transport infrastructure through the construction of bridges across a range of challenging environments and we are leveraging this expertise to ensure the delivered project remains consistent with the ‘Family of Bridges’.
“The significance lies in enhancing the region’s overall aesthetics, fostering a sense of unity, and creating an iconic visual identity.”
To achieve this, BMD will be constructing the bridge using weathering steel elements to match the architectural attributes of the nearby Butters Bridge.
“This deliberate choice ensures not only visual congruence but also durability in challenging environmental conditions,” says Gallagher.
The Molonglo River Bridge will echo the design features of the neighbouring bridge by mirroring the diameter of the steel casing sleeve encasing the pier columns.
“By adhering to these principles, the Molonglo River Bridge becomes more than just a structure; it becomes a contributor to the cohesive narrative of the ‘Family of Bridges’.”
Designing the Molonglo River Bridge posed challenges that demanded creative solutions, says Gallagher.
“One pivotal hurdle was achieving a design that seamlessly integrated with the natural landscape, maintaining visual harmony without detracting from the area’s aesthetic appeal. Balancing structural integrity with landscape preservation was a complex task.”
Additionally, the design needed to incorporate provisions for temporary works to accommodate the construction phases.
“This called for careful planning and seamless coordination to ensure the safety and stability of the structure as it took shape.
“To address these challenges, we conducted several constructability workshops where we collaborated to identify and resolve potential issues.”
BMD’s focus on nurturing internal talent and culture of continuous learning has enabled the team to tackle a technically demanding project.
“As part of our forward-looking vision, we’re establishing an in-house specialty bridge and major structures delivery team,” says Gallagher.
“This strategic approach empowers us with a unique blend of skills to be innovative in our approach and poised to overcome challenges to ensure the project’s success.”
The adoption of weathering steel could open the doors for wider applications of weathering steel across major projects.
“The success of this endeavour holds the potential to spark a surge in the adoption of weathering steel within the construction landscape.
“This could further research, development, and refinement of construction methods, ultimately fostering a more resilient and sustainable bridge construction industry.”
BMD Group has grown from a small family-owned company in Brisbane’s bayside to become Australia’s largest privately-owned contractor. With a focus on long-term relationships and collaborative contracting, and through the support of its 1800 employees, BMD delivers infrastructure projects ranging in size from $1 million to over $1 billion.
For more information on BMD’s past and current projects or to explore current vacancies, head to the BMD website.