The major Basslink undersea power and communications cable that connects Tasmania to the Australian mainland will be cut until mid-March, while the company investigates and fixes a failure in its electricity transmission capacity. That'll leave Tasmanians with severely reduced connectivity to the internet for nearly six weeks, although contingencies are in place.
Basslink doesn't disclose the capacity of the 300km-long undersea cable, although it's understood that several major ISPs including TPG, Internode and iiNet have ongoing deals to use the Basslink cable to service residential and commercial customers in Tasmania. According to Cablemap, the 640Gbps Basslink cable carries the vast majority of Tasmania's internet access to the outside world; the two competing Telstra cables have only 2.5Gbps capacity each.
The cable was damaged in December, and a repair crew on the specialist cable vessel Ile de Re will work to debury the cable from the sea floor and repair it at ground level, after identifying the fault region. The vessel itself required some modification to support the heavy electrical cable; that work was carried out in Geelong.
Basslink Telecom says that the internet service providers that use the dark fibre on its cable for backhaul and connection to the mainland have had to make alternative arrangements for their end user customers. A representative told Gizmodo: "Basslink has contingencies for issues with elements of the land based cable, however none is in place for the undersea component.
"Despite best efforts, a suitable commercial agreement could not be reached between Basslink and Telstra, the owner/operator of the other two subsea fibre optic cables [supporting Tasmania]. Rather, our customers have either put in place or are in the process of doing so, there own contingency arrangements."
Freelance journalist Jason Imms said that when he contacted Internode, his ISP, he was told that "probably... none" of its customers would be affected by the outage, with contigencies put in place. Those contingencies would almost certainly rely on Telstra, which operates two 240km-long Bass Strait 1 and Bass Straight 2 telecommunications cables to Inverloch and Yanakie on the Victorian coastline. iiNet's network map shows this as backup capacity.
Internode is supplying some of its customers affected by the outage with backup wireless solutions. According to the Internode customer support representative, "wireless isn't a great product, but there isn't much we can do about it." The company doesn't list any outages or imminent advisories on its network status website, and other ISPs are similarly quiet on the potential issue.
Whirlpool commenters in Tasmania are looking for answers from their ISPs, but no official comments have yet been made. At the moment, the cable repair crew is targeting a completion date of 19 March -- that'll be the time that Tasmania's internet connectivity to Australia and the rest of the world returns to normal. "Basslink’s anticipated return to service date remains unchanged at 19 March 2016.
"Contingencies have been built into this timeframe, and there is a possibility that the interconnector may be operational ahead of the indicative date. Despite confidence in our ability to meet the dates, there remain a number of aspects beyond Basslink’s control. We are using best endeavours to work with our partners in a tough environment to meet expectations."
The 4800km APX-Central cable that will be the fourth point of connection between Tasmania, Sydney, Melbourne, Adelaide and Perth is slated for completion in the third quarter of 2016.
Basslink also carries significant power to Tasmania, leaving the island to rely on its own hydroelectric, wind and gas power stations in the interim. The initial fault was with the electricity transmission cable, and the extra weight of that alongside the comms element is partially responsible for the delay.
Basslink does not yet know the cause of the electricity outage. "At this stage, it is too early to speculate." [Basslink]