How To Fix a Mysteriously Ruptured Undersea Cable

Illustration for article titled How To Fix a Mysteriously Ruptured Undersea Cable

Not a week after two massive undersea telecom cables were snapped—according to BBC News, most likely due not to Godzilla but a single tanker "dragging its anchor along the sea bed"—and the repairs are well underway. But how in the hell do you repair a nine-layer steel-reinforced cable located deep beneath the surface of the Mediterranean?


The first thing you're gonna need is an Optical Time Domain Reflectometer. Engineers on shore use it to send light pulses down the cable, which reflect back at the breakage point, providing a measurable delay that can translate to distance within "tens of meters."

Once you get your location guestimation, you posse up your team of about 50 people and pile them onto—what else?—a cable ship. This ship will need remotely operated vehicles ROVs (see James Cameron) that you drive down to the sea floor, roving around until you spot your breakage.

When the ROV finds the affected cable segment, it may snip off the nasty bits (just leaving them there to become part of somebody's new habitat) and bring up the two new ends. On board the ship, operators can splice a new segment between the cleanly trimmed ends of the cable break, and drop it back down.

Sometimes the ROV can't find the segment, or can't get the right grip on it. In these cases, the technicians send down a centuries-old device called a grapnel. The grapnel snags the cable wherever it can, and yanks it up to the boat for the end trimming and the repair job.

The cable itself is a tricky fix, because it is made up of nine layers, which you can see in the BBC's diagram below. If you are an experienced undersea-cable repairman who would like to add anything to this admittedly brief primer, I encourage you. And for the love of Pete, don't try any of this cable repair stuff at home! [BBC News]

Illustration for article titled How To Fix a Mysteriously Ruptured Undersea Cable



I can't find the story now, but sometime in the last couple of weeks there was an article showing a group of photos of things few people have seen. One photo showed two non-descript cables coming out of a floor and running up a wall. They were the landfall ends of two undersea cables. Anyone remember also seeing that and where it was? I'm thinking it might have been, but I can't find it now.