Taking a look back on a significant project we completed in 2022 alongside the team at Confluence Water and Addelec Power Services for Sydney Water – North Head Wastewater Treatment Plant.
This complex project involved gaining access to a 160m vertical service shaft at the North Head Plant in order to decommission and then replace several high voltage, low voltage and data cable bundles that travel deep beneath the surface. The critical hazards that needed to be addressed included working at heights/depths, confined spaces and working near HV and LV cables (11kV, 7.2kV & 415v).
Accessing this space required the design and engineering of an access solution comprising a high-strength Global Truss and SAYFA Group RAPTOR Rail structure constructed external to the shaft. Once the structure was in place, our rope access technicians could gain temporary access to the top of the shaft with a platform solution monitored by Broadweigh wireless load monitoring. This temporary access allowed RISE rope access technicians to install a SafetyLink X-Rail system to facilitate permanent access to the inside of the shaft. This allowed multiple technicians to traverse the significant vertical distance with our ActSafe ACX-powered rope ascenders.
With power and ventilation shut down for the works, the shaft and associated areas were treated as a confined space. This required the development of a Hazard Identification and Risk Assessment in consultation with all stakeholders and a confined space access and rescue plan including continuous atmospheric monitoring with MSA multi-head gas detectors. Due to the critical nature of the operation, RISE set up an onsite operations control centre to coordinate and manage the operation and communication with the team underground. This was facilitated over the 160m vertical space with a series of Riedel Bolero antennas which offered full duplex communication. The communication system was the backbone of the operation given the distance and number of workers interacting with the cables as they passed through the cable guides. This communications system was further integrated into the existing fleet of RISE Motorola radios for the remaining workers across the site.
With the complex nature of the works and a limited time frame to complete them it was imperative Confluence Water, Sydney Water and Addelec engineers and electricians could supervise and direct the works. In order to facilitate this RISE deployed a multi-camera CCTV system allowing the team to maintain both constant visual and audible links. This supported the live operation and the handover pack (HOP) to the client for QA.
A very successful & safe outcome for a challenging project.
