The upgrade of the Sand Bypass System Jetty, a prominent land mark along the iconic Gold Coast coastline, has hit a significant milestone with the project now complete and reopened to the public.

 

Completed in 1986, the Gold Coast Sand Bypass System was the first of its kind in the world.  Playing a critical part in keeping the entrance to the Gold Coast Seaway safe and navigable, the system is designed to pump 500,000 cubic metres of sand northwards every year to ensure the entrance remains clear.  The Gold Coast’s multi billion-dollar tourism, recreational and marine industries depend on the safe access to the Seaway and the inland coastal waterways enabled by the Sand Bypass System.  The Sand Bypass System uses 10 jet pumps, each  (separated) 30 metres apart along the jetty and buried to a depth of 17 metres below the jetty deck, to pump sand under the Seaway across to South Stradbroke Island.

 

In 2006, Alder Constructions completed the first significant multi-million dollar upgrade to the Sand Bypass System Jetty, with the complete overhaul of the existing timber decking. Over the 6 month construction, our team:

• removed all existing deck components along the 490m jetty.
• reconditioned the top of existing support girders for the new precast concrete deck units.
• installed 245 precast concrete deck units.
• prepared and installed 1.4km of recycled plastic kerbing.
• fabricated and installed aluminium balustrades, security gate and sliding gates, including large support beams and all services via new suspended service ducts below the jetty platform.

 

Fast forward to 2019 – Gold Coast Waterways Authority successfully awarded Alder Constructions the tender for the latest multi-million dollar upgrade involving the strengthening and widening of the jetty deck at each pump to enable critical jet pump maintenance works to be carried out effectively and safely.

 

With all works carried out over water and the furthest section of the deck 490m out to sea,  our skilled and experienced team developed innovative construction methodologies to tackle this logistically challenging project.  Due to the narrow jetty and restricted load limits, we designed a suspended scaffold and catchment system to safely construct the works and capture debris and used specialised and light weight equipment to support the structure during works.

 

This allowed our team to successfully:

• replace 50 existing precast panels with cast in-situ decks over 10 spans.
• modify 200m of existing aluminium handrail and gate to suit the new decks.
• modify 10 existing pump platforms to meet access requirements for a 40t crane.
• install new steel sub-structural beams (approx 4t) at each platform.
• install a new disability compliant access ramp.

 

From our home base on the Gold Coast, Alder Constructions have expanded to other local council regions in South-East Queensland and Northern New South Wales, but it’s always a privilege to be involved in iconic local infrastructure projects like the Sand Bypass System Jetty.

 

Shane Pelczer, our Project Manager shares project insights on location at the Sand Bypass System Jetty.