Gold Coast Sand Bypass Jetty Upgrade

Bridge & Marine, Design & Construct

To support essential maintenance of critical coastal infrastructure, Alder delivered a major upgrade to an existing jetty, strengthening and widening key sections of the deck to improve access and operational safety for ongoing pump maintenance.

Gold Coast Waterways Authority

Main Beach QLD

2020

3.5M

Project value has been adjusted to reflect approximate current-day value as at 2025, based upon industry recognised construction indexation published by Rawlinson.

Project Highlights

Major upgrades to the Gold Coast Sand Bypass Jetty strengthened and widened critical pump platforms, improving access for ongoing maintenance works on a key piece of marine infrastructure.

Marine Infrastructure

Alder completed the largest upgrade to the jetty since its original construction in the 1980s, enhancing the functionality of this important coastal asset.

Complex Offshore Works

All works were undertaken over water, with the furthest work area located more than 490 metres offshore, requiring careful planning and specialised construction methodologies.

Scaffold Solution

A suspended scaffold and debris catchment system was designed to safely deliver the works within the jetty’s narrow footprint and restricted load limits.

Deck Upgrades

Fifty precast concrete deck planks were replaced with ten larger cast in-situ deck sections to improve crane stability for future maintenance operations.

Temporary Supports

A temporary support system was designed and implemented to minimise deflection on the cantilevered deck during concrete curing works.

Access Improvements

More than 200 lineal metres of existing aluminium handrails and gates were modified to suit the upgraded deck and pump platforms while meeting access requirements.

Structural Strengthening

Supply and installation of new steel sub-structural beams to enhance the jetty’s long-term structural performance.

Protective Treatments

Sand blasting and protective coating works were completed to improve the durability of marine-exposed structural elements.

Public Ramp Construction

A new public access ramp was delivered under a partial design and construct model, including piling, foundations, concrete works and high-strength composite decking.

Asset Preservation

Under-deck rust prevention works were undertaken to extend the service life of the existing marine structure.

Working over water and extending significant distances offshore, the project required innovative construction methodologies to manage logistical challenges and restricted load capacities. A suspended scaffold and catchment system was developed to enable safe construction and debris control, while new structural steel elements, temporary supports and in-situ deck construction enhanced the durability and stability of the upgraded structure.

Upgrades also included modifications to existing handrails and access platforms, protective coating systems and under-deck corrosion prevention works. A new public access ramp was designed and constructed, incorporating piling, foundations and high-strength composite decking, resulting in a resilient and future-ready marine asset.