Ausgrid Substation Transformer Replacement Access Works
Scope of Works
Perfect Remediation was engaged to provide physical site access to a long-concealed Ausgrid substation hatch beneath the public laneway adjoining the Sofitel Sydney Wentworth. The purpose was to enable Ausgrid's scheduled replacement of three ageing transformers - originally installed in the 1970s. The scope of works was divided into three stages:
Stage 1: Investigation
- Removal of selected pavers near the presumed hatch location
- Scanning and investigation to identify slab structure, reinforcement, and live services
- Confirmation of the access hatch location and service routing
Stage 2: Hatch Exposure
- Construction of temporary hoardings (including removable barriers at Flynn Bar)
- Careful removal of concrete slab, tiling, and subgrade over the 2m x 1.8m steel/concrete access hatch
- Dust protection to VIP Gaming Lounge and adjacent grilles
- Installation of safety signage, temporary power, and emergency egress ramps
- Storage of removed fixtures (metal gates, door components) on site
- Coordination for staged access in sync with Ausgrid's transformer lift schedule
Stage 3: Reinstatement & Final Handover
- Reinstatement of concrete slab, substrates, and original paving
- Refitting of metal gates, overhead screen, and recessed door components
- Fabrication and installation of a custom identification plaque within the substation riser
- Progressive cleaning, final detailing, and client handover.
Challenges
- The substation access hatch had been concealed for decades beneath pedestrian infrastructure with no recent drawings available
- Working directly above a VIP gaming lounge and active hotel service zone, strict dust control and operational coordination were essential
- The works required flexible staging, with multiple partial removals and reinstalls of hoarding across weekends to align with Ausgrid's transformer lift program
- The team had to ensure high-finish reinstatement of stone pavers and metal gate assemblies, preserving the hotel's aesthetic standards.
How Perfect Remediation Overcame the Challenges
- Engaged service scanning and non-invasive investigation to verify the pit location and plan around live infrastructure
- Built a custom hoarding solution that was removable and reusable, enabling efficient transition between Ausgrid's staged visits
- Maintained open communication with the Sofitel, Charlotte Place Properties, and Flynn Bar to avoid disruption to guests or business operations
- Provided onsite storage and reuse of existing elements (gates, doors) and ensured like-for-like restoration wherever feasible
- Delivered a professional finish, including a clear plaque to mark the substation pit, supporting long-term future access by Ausgrid.
Perfect Remediation acknowledges the Aboriginal and Torres Strait Islander people as Traditional Custodians of the country on which we live and work. We pay our respects to the Traditional Custodians and Elders past, present and future, and honour their connection to the land and ongoing contribution to society.
