Pyes Creek Swing Bridge | Fleetwood Urban

Pyes Creek Swing Bridge.


Client	Hornsby Shire Council
State	New South Wales

Preserving nature while connecting communities.

The Pyes Creek Swing Bridge was delivered for Hornsby Shire Council as part of the $250 million NSW Public Spaces Legacy Program. Located in a sensitive ecological corridor in northern Sydney, our brief was to design, manufacture and install a highly functional new pedestrian bridge across Pyes Creek, while causing minimal impact to the surrounding habitat and residents. The solution was a low-profile 50-metre swing bridge, connecting suburban Cherrybrook with Fallon Drive Reserve in neighbouring Dural.

The single span design was carefully chosen to eliminate the need for cranes and other heavy equipment, whilst also significantly reducing the bridge’s structural footprint. Featuring imported 30mm support cables, 32 galvanised steel cross beams and FRP mini-mesh decking, the entire structure was hand-assembled high above the creek before opening to the public in mid-2023.

Our involvement.

Fleetwood was appointed as lead contractor by Hornsby Shire Council. Guided by our proprietary project methodology, we oversaw every phase of the project from concepts and engineering to manufacturing and installation.

Our involvement began during the early design and costing stages, collaborating closely with Council to determine the most appropriate methodology for the new bridge, arriving on an innovative cable-based swing structure. The preferred design was then refined and detailed for final approval.

Moving into the delivery phase, the all-important 30mm galvanised steel support cables were custom-sourced from a specialist supplier in Europe while the cross beams and balustrades were manufactured locally at our Wetherill Park facility.

Groundwork began with the pouring of the footings at Pyes Creek, before final installation began by running a service line high across the creek and then securing the two main support cables with 10-metre-deep rock anchors at both ends. From there, the bridge structure was suspended from the support cables in sections, with 32 galvanised steel cross beams, enclosed wire mesh side panels, webnet balustrades, stainless steel handrails and FRP mini-mesh decking all assembled by hand.

How does this project inspire people to love the outdoors?

The Pyes Creek Swing Bridge makes the passage between Cherrybrook and Dural safer and easier than ever before. Public access is now more achievable for more members of the community – providing more reason for locals to get outdoors and enjoy the natural beauty of their own backyard. It also allows users to feel truly at one with nature, something not possible with larger and more intrusive bridge structures.

“What Fleetwood have delivered and the manner in which it has been delivered has been outstanding. On-site works have been managed with the utmost diligence and the action taken in regard to implementing environmental controls and being open to accommodate any concerns has been refreshing.”

David Green,

Project Officer,

Hornsby Shire Council

Design Challenge

The brief demanded an elegant ‘low touch’ bridge design that would blend seamlessly into the Pyes Creek habitat – and be delivered with minimum disruption to the local residents and surroundings. A pedestrian swing bridge was the ideal solution, but given the large 50-metre span, our design team needed to look beyond domestic bridge and walking track standards for guidance. The final structure was designed and engineered using a combination of AS 2156 and European bridge codes.
Construction Challenge

The design, location and height of the swing bridge required it to be installed mostly by hand with no cranes or heavy machinery, all while adhering to ISO 14001 (Environmental Management Systems). There was only a small excavator used to excavate a specific footing after identifying whether it was feasible to do so. To ensure the protection of the surrounding environment whilst manoeuvring the small excavator down towards the creek, ground protection mats were strategically placed to safeguard tree root zones. Additionally, tree trunks were delicately wrapped for further protection, exemplifying our commitment to minimising any environmental impact. These measures not only ensured the safety of the installation process but also expedited the timeline while reducing potential risks.

Over the course of five intensive days, our rigging crew assembled the structure, one cross beam at a time, working at heights ranging from 5-10 metres above the creek below. When on the ground, our crews also had to navigate steep and unstable embankments.
Innovations

The use of 10-metre-deep rock anchors at each end of the bridge removed the need for large concrete footings. This significantly reduced the overall footprint of the structure and allowed installation to be completed without the invasive impact of heavy machinery.
Features
- 2 x 30mm support cables, imported from Europe
- 4 x 10-metre rock anchors, each with a load rating of 48.5 tonnes
- 32 x galvanised steel cross beams
- 4 x 20mm cable/tension supports
Safety & Risk Considerations

To minimise sway and ensure maximum user comfort for years to come, the finished walkway was stabilised with four 20mm cable/tension supports anchored directly into the adjacent creek banks.

During installation, working at heights was an ever-present risk so a highly experience rigging team was engaged to ensure the safe assembly of the structure. Local residents were also very curious, so secure fencing was erected to keep the public at a safe distance from the worksite at all times.
Sustainability Considerations

Sustainability had a critical influence on the project from the very beginning. The quest to create a low touch bridge with the smallest possible environmental footprint, drove everything from design and material selection to the installation methodology.