Highly Commended in the ASI’s 2025 Steel Sustainability Awards in the Small Projects category, the Queensland Rail Bridge Refurbishment shows how circular economy thinking can be applied to core transport assets—not just buildings. Completed in July 2023 across multiple South East Queensland sites, the program recovered, upgraded and returned historic steel girders to active rail duty, avoiding the impacts of new manufacture while improving network resilience.
The Queensland Rail Bridge Refurbishment – Stage 2 shows how smart reuse can deliver fast, verifiable wins for carbon, cost and continuity of service. The program refurbished 21 steel bridge girders for re-installation across South East Queensland, proving that century-old steel can meet today’s standards when governance and workmanship are rigorous
Circularity in action
Rather than specifying new girders, the team removed 100-year-old members, stripped coatings, conducted Magnetic Particle Testing to identify fatigue or stress cracking, then re-strengthened and re-braced the girders before applying protective coatings and returning them to service. By retaining the original steel, Queensland Rail avoided the emissions and resource draw associated with virgin production and heavy logistics, aligning the works program with circular economy principles while extending the useful life of existing assets.
Measurable carbon logic
The production of new steel from iron ore typically emits 1.8 to 2.0tCO2₂ per tonne; direct reuse of existing girders avoided those upfront emissions almost entirely, with only inspection, repair and coating required. The team estimated energy savings of up to 75% compared with fabricating new members, alongside reductions in mining, transport and manufacturing impacts—benefits that can be tracked and reported. The carbon rationale is clear and conservative, and sets a repeatable precedent for future rail renewals.
Governance and traceability
Fabrication and processing were delivered by Sun Engineering at its Carole Park facility under AS/NZS 5131 CC3 certification, backed by ISO 9001 and Transport and Main Raods approval—assurances that matter on safety-critical rail infrastructure. Material certificates were logged in Sun Engineering’s integrated management system; heat numbers and part numbers were tied to weld registers and welding procedure specification records, creating end-to-end traceability of who welded what, and to which procedure. A client-approved inspection and test plan governed hold and witness points to MRTS78, with non-compliance reports managed through workflows to close the loop.
Environmental and social dividends
Keeping steel in service is waste avoidance at its most effective: no melting, minimal reprocessing, and a clean path to further reuse when future refurbishments are due. The approach also engages local fabrication and coating supply chains, and supports jobs in deconstruction, testing, transport and re-installation. For a public owner, the outcome strengthens social licence, with visible sustainability in assets communities rely on every day.
Collaboration across the lifecycle
The program demanded tight coordination: engineers and inspectors to assess reclaimed steel; fabricators to adapt and strengthen members to today’s codes; and construction teams to plan storage, handling and safe sequencing back into service. That collaboration builds capability for design-for-disassembly and circular procurement, nudging the broader market toward traceable reuse rather than default replacement.
Queensland Rail’s bridge girder refurbishments demonstrate a pragmatic template for public infrastructure—auditably governed, circular by default, and eminently repeatable. When foundations like AS/NZS 5131 CC3 and ISO 9001 are in place, old steel can deliver new value—faster, cleaner and at lower risk—while keeping capital and carbon budgets on track.
PROJECT TEAM
- Architect: Queensland Rail
- Engineer: Queensland Rail
- Steel Fabricator: Sun Engineering
- Coatings: Fero Group
