The Sydney Harbour Federation Trust (SHFT) is an Australian Government agency that was set up to conserve and preserve land in the Sydney Harbour region for the benefit of the general public. Cockatoo Island was a former naval dockyard located in Sydney Harbour with immense historic significance to Australia’s military and maritime history. After its closure, many buildings were demolished and the island was left idle for more than 10 years. SHFT is now undertaking the refurbishment of Cockatoo Island to become a public cultural centre. As part of this refurbishment project, the rehabilitation of the water, sewer and stormwater infrastructure was necessary to provide reliable operation of essential service underground services.

CLM Trenchless provides a broad range of world’s best practice technologies for the installation and renovation of pipelines and structures. Our diverse range of Trenchless Technologies are suited to pressure and non pressure applications, including potable water pipelines, sewer mains and storm water infrastructure. Besides the works for SHFT, CLM Trenchless also provides pipe refurbishment services to various water authorities, councils and industrial clients throughout Australia

SHFT advertised a tender to carry out the renewal of its underground assets, but the tender primarily was written around traditional open cut methodology. Seeing the potential for the application for Trenchless Technologies, CLM Trenchless submitted a tender which explained the technologies that were available for trenchless pipe renovation of the pipe network such as pipeline robotics, point-lining, cured in place lining, pipe bursting and open cut. SHFT realised the benefits of utilising Trenchless Technologies, and the contract was awarded.

There were many and varied challenges encountered in delivering this work, as the pipework had been dormant for a long period of time. Therefore, location of assets, CCTV, cleaning and de-silting was involved prior to undertaking any actual rehabilitation works. In addition, our work had to be coordinated around other contractors working on site and some major public events.

The scope was developed as the location and condition of assets became known. SHFT was presented rehabilitation options and the decisions on which technology to apply was done in a consultative manner which was made easier by the excellent client/contractor relationship that was established.

CLM Trenchless was able to dedicate a project manager and site supervisor to see the various rehabilitation activities delivered to our requirements. The works involved replacement of all valves in the watermain network, location, de-silting, leak testing and survey of the gravity pipelines, pipeline robotics to repair damaged pipelines, point-lining of localised pipeline defects, and cured in place lining of sewers that had multiple defects or structural failures. Due to the diversity of works that needed to be delivered, our delivery strategy involved using in-house and subcontract crews, with the majority of works being delivered by our own resources.

At time of writing, this project is still underway, with the stormwater pipeline now programmed for rehabilitation. It has been an interesting and rewarding project primarily due to the collaborative approach between client and contractor. It is an excellent example of how Trenchless Technologies can be applied on a ‘best for project’ approach with the end result being a rehabilitated underground pipe network, with minimal disturbance to the island operations.

With the experience gained from this project, we feel this approach could lead to significant client and community benefits on projects that have varying scope such as this. From our perspective, having a suite of rehabilitation options really paid dividends in terms of being able to provide a tailored rehabilitation plan with the client and community being the ultimate winners.