Repairing submarine cables, a complex and tedious task

Published on: 03/20/2024 – 7:14 PM

4 minutes

then Internet disruptions that affected West African countries Like Côte d’Ivoire, which was the worst affected, Liberia, Burkina Faso, Guinea and Ghana, the situation has gradually returned to normal. Of the five submarine cables connecting this part of the continent Internet, four were damaged, including the two largest operators, Orange and MTN. In most cases, this type of incident is caused by a cable breaking through a ship’s anchor, fishing boat activity or underwater movement.

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The outage mainly concerns the West Africa Cable System, Africa to Europe, SAT-3 and MainOne cables, all thousands of kilometers long, serving several countries along the West African coast and connecting to Europe, notably Spain, the United Kingdom. and France.

Traffic was redirected to restore the network

Service providers reacted quickly to restore Internet access as quickly as possible. In the hours following the outage, South African operator MTN confirmed that “ performance » were in progress Redirect traffic through alternate routes on the network “Same thing for the orange who immediately said ” Dynamic to explore traffic rerouting solutions and connect countries separated by other routes “

By redirecting flows, Internet operators were able to quickly stabilize the situation and restore satisfactory network access for most of the countries affected by the outage. MTN, for example, confirmed this Monday March 19 that it has “ Successfully restored operations by recovering more than three terabits per second of capacity » over its entire coverage area. ” Throughout this period, we have prioritized service restoration by strengthening our network resilience, increasing interconnectivity and rapidly activating new cables to establish alternative routes. », welcomed the South African operator.

Find the incident for repair

Repairing them is now a priority for operators to avoid network saturation, but it is a complex and tedious task. “ You must start by precisely locating the cut, explains Stephane Lelux, president of Telecom company Tactis RFI on the microphone. After that, a special vessel must be sent to the site, which will precisely locate the position of the cables. It already takes a few days: three, four or five days maximum “

These particular ships are called cable ships. They are designed to install garden hose-sized cables on the sea floor, but also to repair them. Up to 2,000 meters deep, underwater robots are responsible for recovering each end of the damaged cable, but beyond 2,000 meters, the situation becomes complicated. In this regard, ” We do things the old fashioned way. We raise the cable to bring it back onto the board and once it’s up we can see if we hit it right. », Didier Dillard, CEO of Orange Marine, one of a dozen companies in the world capable of repairing submarine cables, explained to the newspaper. The New Republic In 2023.

An operation which It may take several weeks »

So the time it can take to repair varies greatly. Once the cable is reassembled, ” We cut them cleanly and we redo the welds on these cables which we attach to a waterproof sleeve that will then be placed back on the ocean floor. There we have four cables so four operations will be carried out. It may take several weeks », estimated by Stéphane Lelux. Because optical fibers are so fragile, resoldering the fibers together can take 15 to 20 hours for each joint. Work carried out by highly specialized personnel specially trained for this type of intervention.

About 99% of intercontinental internet traffic Supplied by submarine cables, its importance is particularly capital for Africa. There is a continent Heavily dependent on submarine cables including continental connections. I think the lessons to be learned from all these events will unfortunately continue, firstly to diversify the routes and strengthen the interconnections between the countries. », concludes Stéphane Lelux.

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