Basslink has refined the probable fault location of a subsea cable connecting George Town in Tasmania and Loy Yang in Victoria, and would proceed to the next phase which involves cutting the cables.
To identify fault location, Basslink’s sea and land repair teams have conducted more than 20 ROV (remote operated vehicle) dives, and collected more than 500 hours of visual imagery and data.
“While there remains some more days of work and analysis to be done before we can provide a more accurate estimate of return to service, it is an important milestone,” said Malcolm Eccles , CEO of Basslink.
He added, “We empathise with the community over the time that it has taken. However, the decision to cut the cables must be made with great care and consideration due to its complexities and challenges. The consequences of a hasty and ill-considered decision will be far-reaching. We have reached this milestone only after detailed analysis of the test results and close consultation with leading experts from around the world.”
Eccles also said that the exact cause of the fault would not be known for some time and will require a detailed analysis of the damaged cable point before any conclusions would be reached.
Due to the nature of the fault, including the lack of visible damage, the team may need to undertake additional cutting to narrow the location of the fault.
The probable fault location has been narrowed down to approximately 98 km from the Tasmanian coast. Subject to weather conditions, it is anticipated that the cables will be cut within the next week.
The entire process of “cut and cap” is estimated to take around two weeks, subject to weather and the cable tests.
Following the “cut and cap” process, it is expected the Ile De Re will return to Geelong, to load specialised jointing equipment, personnel and spare cables before returning to the cut location to insert new cables at the point of the cut, Basslink said.
Based on best estimates, and allowing some contingency for weather and other unforeseeable conditions, it is expected that the interconnector will be operational again in late May.