The Beryl and Mount Piper Substations contain 132/66kV networks to supply the local townships. Due to the aging condition of the existing transformer bunds a new containment system was required to allow for the containment of water and oils should there ever be a fault with the transformer. Multiworks provided all upgrade works at the two substations to upgrade this existing oil containment system. This involved the construction of new primary spill oil tanks, upgrade of existing bunds, installation of new connecting pipework for both substations and flame traps for Mount Piper only.
Adding to the complexity of this scope was the proximity of the proposed containment systems to the adjacent high-voltage and in-service electrical equipment. Multiworks took over the design of this element to create a piling retention system adjacent to the structures and to ensure the site remained operational through the work.
The Narrabeen Substation Control building houses the live electrical switchgear and equipment that control the adjacent substation. As part of the upgrade of ageing assets, Multiworks was engaged directly by Ausgrid as Principal Contractor to replace the existing roof while maintaining the live operations of the substation and the electrical network. The works included: replacement of roof tiles with Colorbond sheets, installation of CFC sheets, replacement of gutters, installation of new downpipes, installation of earthing spires and installation of new anchor points.
Prior to commencement of the roof replacement works the Narrabeen Control Building was impacted by a storm causing leakage inside the Switch-rooms. Ausgrid engaged Multiworks to execute emergency works to stop the leakage. This required the roof replacement works to be brought forward and delivered within a significantly constrained time frame.
Multiworks effectively mobilised a skilled team including additional resources from interstate. Due to the poor condition of the existing roof, Multiworks made the entire control room building watertight through implementing anchor points and tarping. This provided a temporary shield around the whole building, eliminated any impacts due to poor weather and ensured the ongoing operation of the control room.
Multiworks delivered the project one month ahead of schedule, while also completing the Castle Cove Substation works.
Multiworks was responsible for the replacement of roof metal sheets with Colorbond sheets, replacement of gutters, installation of new downpipes, construction of stormwater inlets and installation of new anchor points. Multiworks delivered all scope while ensuring the ongoing operations of the live electrical substation.
A key challenge in the roof replacement works involved implementing appropriate physical protection over the existing Frequency Injection Units (FIUs). Due to the sensitivity of the assets and client requirement that only one FIU could be de-energised at a time, Multiworks developed and implemented a staged works program over the FIUs. Multiworks effectively planned and scheduled materials and resources to ensure protection over the unit while replacing the section of roof directly above. The protection was then stripped so that the FIUs could be re-energised.
Additionally, Multiworks developed an innovative ‘Rolling Scaffold’ within the substation that offered fall protection and acted as a physical barrier to ensure the substation equipment was not exposed to falling objects.
The Chullora Substation Control building houses the live electrical switchgear and equipment that controls the adjacent substation. As part of the upgrade of ageing assets, Multiworks was engaged as Principal Contractor directly by Ausgrid to replace the existing roof without any interruptions to the electricity network.
Works took place on the existing live control building, housing equipment for this 66kV Substation. Key scope involved ACM eave replacement, removal of roof tiles, installation of two layers of Compressed Fibre Cement sheets, installation of Colorbond sheets, reinstating existing gutters, installation of new downpipes and installation of new anchor points.
During the preliminary planning, it was noted that the height from the pitch of the roof to the soffit was greater than 0.8m. Due to the substantial height difference the existing anchor points could not be used as a means of fall arrest. As a result, Multiworks proposed and successfully implemented a construction methodology that provided a means of fall arrest utilising anchor wraps. The project achieved zero safety incidents.
The Victorian Government has mandated the rollout of Rapid Earth Fault Current Limiter (REFCL) installations across nominated Zone Substations in AusNet Services’ network, including at the Lilydale Zone Substation. Installation works included:
- Two new REFCL(s) units in bunds and footings
- Two new 22kV switched neutral bus kiosks onto new footings
- A new REFCL Room on to new pad footings to house associated inverters and control equipment
- A new modular Control Room onto new striped footings
- A new cable trench (600mm Wide x 600mm Deep) running north west to south east for associated control cables Conduits for control cables
- Associated reinstatement and surfacing
Replacement works involved:
- The existing NER with one new NER onto new pad footing
- Existing station service transformers (SSTx) with two new 750 kVA kiosk type units onto new pad footings and AC changeover boards
- Both existing Capacitor Banks with Metal enclosed Cap Banks with pad footings for REFCL compliance.
The Heywood Terminal Station (HYTS) 500 kV CB Replacement project includes establishment of two new 500 kV switch-bays to convert the incoming MOPS and TRTS line bays to a double-switched arrangement.
Multiworks was engaged by Zinfra to carry out all civil work associated with the project scope, including:
- Replacement of existing MOPS/TRTS line bay ROIs, CVTs and Surge Arresters
- Replacement of M1 and M2 transformer 500 kV Surge Arresters
- Decommissioning of 22 kV No.3 station services transformer
- Replacement of the 415 V station services infrastructure
- Installation of new 500kV Bus protection, new X & Y CBM scheme
As part of an ongoing maintenance program Citipower/Powercor is upgrading and structurally reinforcing many of its underground cable pits within Melbourne’s CBD.
Multiworks was engaged by Citipower/ Powercor to rectify the Exhibition Street pit following cracking and subsidence to its lid.
Upgrade works were complex due to the pit’s location within high density areas, their confined size and pre-existing structural issues.
The works were staged during shutdowns and involved crews operating 24 hours per day to access, reinforce and reinstall pit lids over a weekend period.
Multiworks’ effective collaboration with key stakeholders and Citipower/Powercor ensured the works were completed over the planned weekend shutdown period.
The security upgrade works at Bendigo Terminal Station included procurement, installation and commissioning of 1.2km of security fencing. The fence upgrade was complex due to the site’s multiple underground services beneath the boundary line.
Multiworks obtained all permits on time and ensured the works were executed without interruption to the electrical network. The project achieved zero safety incidents.
Multiworks was responsible for the design, procurement and installation of 700m of security fencing at the Mount Beauty Terminal Station. This involved the mobilisation of internal crews to undertake the installation of fencing and to establish the pit and pipework for future electrics. The fence upgrade works were complex due to the number of underground services beneath the substations’ boundary line. Multiworks obtained all permits in a timely manner and executed the works without interruption to the electrical network. The project achieved zero safety incidents.
Multiworks was engaged by Ausnet Services as Principal Contractor to replace non-compliant station security fences, signage and gates within zone substations at Moe, Ringwood, Warrigal, Sale, Nagambie and Watsonia.
Upgrade works involving these fences are inherently complex due to the existence of multiple underground services beneath the substation’s boundary line.
Multiworks obtained all permits in a timely manner to ensure the works were executed without interruption to the electrical network. Multiworks completed the works two months ahead of schedule and achieved zero safety incidents.
