The Port of Melbourne Channel Deepening project involves deepening sections of the existing Great Ship Channel at the Entrance, parts of South channel, and the Port of Melbourne, Williamstown and Yarra channels to accommodate the world-wide need for larger container ships.
This requires major civil works in densely populated suburban areas and in highly environmentally-sensitive areas such as the Yarra River site, south of the West Gate Bridge.
As part of their project the Port of Melbourne authorities approached Telstra to relocate two cables crossing the Yarra River. As a result, Telstra’s Network Construction team was asked to project manage a major infrastructure relocation project (see fast facts for a summary of works undertaken).
Collaborating closely with Port of Melbourne authorities, the Network Construction team quickly developed an Environmental Management Plan which ensured Telstra’s Asset Relocation Project ticked all the environmental boxes.
The biggest challenge the team faced was the cleaning of four submarine steel pipes under the Yarra River, two of which housed Telstra’s cables.
The Telstra cables had to be removed from the pipes and rerouted via new, non-submarine routes. The four pipes then had to be thoroughly cleaned because they were previously used as bulk oil pipelines before being leased by Telstra over 20 years ago. Once this work was done, river dredging down the Yarra could continue without risk to the environment.
John Gibbs, Executive Director Telstra Network Construction said,
“This type of task has never previously been undertaken by the Network Construction team. But they quickly developed a solution which satisfied environmental concerns and exceeded the client’s accelerated deadline.”
How was this outcome achieved?
To begin, the team took samples from each of the four pipes to determine the level of residual oil contaminant in each pipe.
They then thoroughly investigated and implemented the most environmentally-friendly option to clean the ex-oil pipes. They used negative pressure (suction) rather than positive pressure (forcing air down the pipes) which would have risked blowing a hole in the pipe under the Yarra and leaking oil into the water.
By using negative pressure the team were able to remove most of the oil and water from the pipes and they followed this procedure by deploying foam pigs** for a more thorough clean.
The pipes were then filled with liquid expanding foam which had the chemical attributes to absorb the remaining hydrocarbons. This was a unique task for the foam pumping company subcontractor used as they had never pumped the foam through pipelines over the distance required to complete this job (430 metres).
Mr Gibbs explains how team work was a key part in the successful outcome of this project.
“Within Telstra, Network Construction worked to plans designed by Network and Technology, Service Delivery provided communication technicians to assist with fibre testing and commissioning and Telstra’s Global Operations Centre assisted with co-ordinating the migration of services required due to the cable relocation.
“Working closely with Port of Melbourne authorities also ensured work progressed well. In fact, when authorities requested an accelerated time frame to have the conduits under the Yarra River cleared 30 days ahead of the contract schedule, we exceeded client expectations by coming in 45 days ahead of schedule,” Mr Gibbs said.
David Salomon, Infrastructure Upgrade Manager for the Port of Melbourne Channel Deepening Project recognised the team’s efforts via email.
“I appreciate the effort that you and your team have put into getting the works done ahead of schedule and considering the tight timelines the Channel Deepening Project is working to, it makes our job a lot easier and your extra effort is much appreciated,” Mr Salomon said.
User: nowwearetalking, (24 June 2009). Channel deepening submarine cable relocation. Now we are talking[online] nowwearetalking.com.au. Available from: SOURCE [Accessed 12 July 2009].
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