Basslink has announced the completion of its third and final cable jointing repair on the subsea cable providing energy and wholesale high-speed telecommunications services to Tasmania, with the company to conduct tests ahead of a relaunch of services late this month.
"The Basslink team will shortly commence a range of land-based tests of both the electricity interconnector as well as the fibre-optic telecommunications cable, and all associated equipment on either side of Bass Strait," Basslink said in an update.
The cable bight is now lying on the seabed, with the repair vessel to return to the site and bury it after testing the telecommunications and electricity services over the next week. Services should be back by the end of June.
"There has been well over one hundred people working incredibly hard at sea and on land to rectify the fault," Basslink CEO Malcolm Eccles said.
"Subject to some final testing and satisfactory weather conditions, we will rebury the cable in the next few days, and recommission our converter stations at George Town and Loy Yang with a view to return both the electricity interconnector and the telecommunications cable to service as soon as possible."
The cable repairs have been hit with months-long delays: In March, Basslink revealed that excess water damage into its cable would result in repairs not being completed until mid-June. Prior to this, Basslink had said repairs would be done by late May .
This was followed in April by Basslink saying it would require six days of consecutive clear weather to repair each of the three joints in order to complete repairs on its subsea cable.
In May, it then said it had lost more than 20 days to inclement weather since completing the first joint, with the repair timeframe pushed out to late June.
"As the jointing works take place on the deck of the vessel and are highly susceptible to weather conditions, each joint will require a window of relatively calm sea conditions and clear weather for six continuous days to allow such works to be completed safely," Basslink said.
"Bad weather or rough sea state can damage the cable, result in abortive jointing works, or pose unnecessary occupational, health, and safety risks for the repair crew. The jointing works are highly complex, and will see the three lengths of new cables (ie, the high-voltage cable, the metallic return cable and the fibre optic cable) joined to the existing cables and bundled together, before being laid on the seabed."
The Basslink Interconnector, the world's second-longest subsea cable, has been down since December, leaving many Tasmanians without energy and internet services.
The fault in the cable was discovered 90.5km from the Tasmanian coastline and removed and capped on Easter Sunday, three months after going down.
The outage has lasted so long that the Tasmanian government got involved.
Tasmanian Minister for Information Technology and Innovation Michael Ferguson in March said the state government was "very disappointed" that TPG's group of internet service providers (ISPs) had still not made provisions for the Basslink outage, "urging them to buy more capacity on the remaining Telstra cables" in order to provide customers with services.
"Our understanding is that customers of TPG, which includes iiNet, Internode, and Netspace brands, have been affected, while customers of other non-Telstra ISPs are provided for," Ferguson said at the time.
"I have spoken to TPG senior management to put forward the concerns of Tasmanian customers. I have been assured that TPG are aware of the issues and will continue to expand their use of the ample Telstra capability.
"As I stated some time ago, Telstra advised there was sufficient capacity to cater for all Tasmanian retail and wholesale customers on the two fibre bundles it owns and operates across Bass Strait."
Ferguson added that he had also "reminded" Telstra Wholesale "of the importance of constructively receiving requests for more capacity from TPG".
Telstra itself had commented that it is the duty of telcos to provide continued services for their customers despite outages, with Telstra offering capacity to allow this.
TPG thereafter negotiated for extra bandwidth over Telstra's fibre-optic cable.