Cable Suspension Footbridge – Hallet Cove

Service Area: Galvanizing | Industry Type:

Project Overview

This project involved high stakes, high terrain, and the high level of capability delivered by J. Furphy & Sons Group. It required the galvanizing of two cable suspension footbridges at Grey Road Gully and Kurnabinna Gully along the Marion Coastal Park walkway at Hallet Cove SA. The bridges were designed to provide safe pedestrian access across steep coastal terrain and required a durable corrosion protection system suited to one of the harshest marine environment compliance levels. The result produced a long-life, low-maintenance solution that enhances connectivity, safety, and has enhanced the visitor experience along this popular coastal trail.

The Challenge

Terrain, environment, design life requirements, and structural component sizes all posed challenges throughout this project. The bridges are located in a highly corrosive coastal C5 environment, requiring maximum long-term protection against salt and humidity. Steep, rugged terrain and fractured rock created significant installation and access challenges for construction teams installing the large structural components that called for precise detailing to ensure effective venting and draining for safe galvanizing. The bridges also needed extremely reliable design life, including 100-year foundations and 50-year structural durability.

Our Solution

Full corrosion protection to meet C5 coastal environment and AS/NZS 4680 compliance was applied to 16.5 tonnes of structural steel, including towers, decking, balustrades, and bracing rods, using our signature hot dip galvanizing process. We collaborated early with the steel detailer which helped to ensure best-practice venting and drainage design, allowing safe, efficient processing and a high-quality finish to last the required lifespan. The modular bridge design enabled efficient fabrication, galvanizing, transport, and installation, supporting project timelines and constructability, and reducing costly delays.

Technical Specifications

Dimensions

40 metre span (each)

Weight

16.5 tonnes

Materials

Steel

Coating

Hot dip galvanized

Standards

AS/NZS 4680

Features

Suspension design
Design lifespan including 100-year foundations and 50-year structural durability

The Outcome

This highly successful project delivered:

A durable, corrosion-resistant structure designed for long-term coastal performance
Significant lifecycle cost savings, with galvanizing providing up to 55% savings compared to alternative coating systems.
A safe and accessible route for pedestrians, improving connectivity along a 7.2km coastal walkway
Enhanced visual appeal of the landscape, with the structures blending seamlessly into the natural environment
Supported sustainable infrastructure through reduced maintenance, recyclability, and long service life.