Fitzroy Crossing Bridge

Fitzroy Bridge

Fitzroy Crossing Bridge

Client: Fitzroy Bridge Alliance

Location: Fitzroy Crossing, WA

Duration: 16 May 2023 – 24 May 2023

Structure Overview

Built in 1974, the Fitzroy River Bridge was a 180-metre, reinforced concrete deck over galvanised longitudinal steel I-beams. Ex-Tropical Cyclone Ellie tore through Australia’s north in January 2023 and the destruction included the Fitzroy Crossing Bridge, one of Australia’s major road freight connections.

Scope of Works

Mainline was engaged by Fitzroy Bridge Alliance to demolish the cyclone damaged bridge at Fitzroy Crossing. The demolition scope included:

• Complete demolition of the existing bridge structure
• Removal of piles
• Construction of causeway

Equipment Deployed

The Fitzroy River Bridge demolition involved expedited removal due to its critical access role, ensuring timely completion while prioritising safety, protecting temporary works, and preserving the environment.

Plant & Equipment:

• 35T & 50T Excavators
• 2 x Dump trucks
• 1 x Water trucks
• Front End Loader
• D7 Dozer
• Concrete pulverisers
• Concrete crackers suite 50t to 35t
• Rock breakers suite 35t to 50t machines
• 2 x Steel shears
• Grapples

Project Highlights

• Shortlisted – 2023 World Demolition Award
• Greater than 99% of materials recycled or repurposed
• Zero impact to environment
• Completed on time with zero HSE incidences

Operational Challenges and Solutions

• Flood-prone environment: The demolition and construction were planned with a large-rock fill causeway and temporary roadways to adapt to fluctuating river depths (0m to 12m).
• Limited site information: Demolition planning was based on minimal data due to lack of site access.
• Causeway design: A rock fill causeway extended to Pier 6, allowing water flow protection and access for demolition machinery with a below-waterline platform.
• Changing conditions: A subsequent flood event re-deposited silt, complicating pile removal after initial plans were made.
• Site access challenges: Many bridges and road surfaces on route to site were now considered possibly unsafe or unsuitable for overweight transportation without technical investigation. Government authority for roads (MRD) declared that they were not in favour of issuing transport permits for larger equipment. FB alliance and Mainline made the decision several days before official mobilisation to site that we must change to smaller equipment to achieve site access and maintain the emergency response programme to satisfy with MRD site access constraints.