Tonga's domestic cable may take a year to replace [1]
Thursday, July 7, 2022 - 22:16. Updated on Thursday, September 8, 2022 - 14:44.
By Linny Folau
It may take a year to fix Tonga's domestic fibre optic telecommunications cable, which was torn apart and deeply buried under volcanic debris on the ocean floor, on 15 January. The cable was caught in the pyroclastic flows from the Hunga eruptions. The cable connects the outer islands centers with Tongatapu.
Tonga Cable Ltd CEO James Panuve in his latest update, told Matangi Tonga that although there had been delays there are promising signs for the work ahead.
He said a geological survey showed the seabed around the volcano and along our cable path (near the volcano) is very smooth and as such provides a pretty good surface for laying the new cable over.
“Although, NIWA did not do a survey of the full length of our domestic cable system as we had hoped for, their findings were sufficient for SubCom to make a recommendation on the amount of cable that we needed to order to make the repair,” he said.
In June, Tonga Cable placed its order for the cable with Alcatel Submarine Networks (ASN) based in France.
"So depending, on the schedule and whereabouts of the [cable repair ship ] Reliance at that time, we would probably be looking at 2-4 weeks for the ship to mobilize, pick up the cable and bring it to Tonga to do the repair job. So in total we are probably looking at about 11-months from today, or roughly April/May 2023."
Delays
Panuve said one of the delays was not finding a similar cable type around the world.
“There was one operator in Africa who had similar cable spare in their storage. However, they only had 10km and we did not pursue it,” he said.
The other delay they had was that Sub-Com (the company running the cable repair ship, the Reliance) recommended that they have the domestic cable path surveyed to confirm the state of the seafloor, he said.
"They were concerned that the seafloor has become unstable or too dangerous to re-lay the new cable over."
Tonga Cable then approached EGS, a survey company, but they were not able to fit them into their schedule until later in the year. EGS did the initial survey of Tonga's international and domestic cable systems several-years ago.
However, the visit by the NIWA vessel (RV Tangaroa) managed to provide Tonga Cable with a glimpse as to the state of the seafloor around the volcano, and in particular, the area where our domestic cable passes by the volcano.
This research vessel completed its survey, which was conducted through NIWA’s ship RV Tangaroa, during the month of April-May.
“NIWA shared with us some of their findings in late May and this information was relayed to Sub-Com.
"The findings give us great comfort as it shows that there actually was not much structural damage or collapsing of underwater mounds or slopes in the area. In fact, the seabed has a very smooth finish to it from all the sediment and ash that has been deposited there by the volcanic eruption.
“As such, the seabed around the volcano and along our cable path (near the volcano) is very smooth and as such provides a pretty good surface for laying the new cable over."
“In addition, the NIWA findings also shed a lot of light on why we could not find our cable and the probable cause for its destruction,” said Panuve.
"Their findings show several channels (60-90m deep) emanating from the edges of the volcano, likely formed by powerful ash-laden flows (pyroclastic flows) triggered by the eruption. These flows are most likely what damaged and covered up most of our international and domestic cables."
Repair timeframe
In June, Tonga Cable placed its order for the cable with Alcatel Submarine Networks (ASN) based in France.
“They confirmed their lead-time for manufacturing would be six-months and then estimate a delivery time of the cables to the Apia, Samoa depot of about 14 weeks (3.5 months).
“This is also the original company that designed and made our domestic cable system,” he said.