How Do You Fix an Undersea Cable?

Posted on January 9, 2007  Comments (3)

How Do You Fix an Undersea Cable?

A working fiber will transmit those pulses all the way across the ocean, but a broken one will bounce it back from the site of the damage. By measuring the time it takes for the reflections to come back, the engineers can figure out where along the cable they have a problem.

If the faulty part of the cable is less than about 6,500 feet down, the crew will send out a submersible tanklike robot that can move around on the sea floor. A signal can be sent through the cable to guide the robot toward the problem spot. When the robot finds the right place, it grabs ahold of the cable, cuts out the nonworking section, and pulls the loose ends back up to the ship.

A skilled technician or “jointer” splices the glass fibers and uses powerful adhesives to attach the new section of cable to each cut end of the original—a process that can take up to 16 hours. The repaired cable is then lowered back to the seabed on ropes.

Related: Underwater Fiber for the Internet

3 Responses to “How Do You Fix an Undersea Cable?”

  1. CuriousCat: Internet Undersea Cables
    February 3rd, 2008 @ 6:04 pm

    […] Early estimates suggested that half of India’s Internet capacity vanished after the first two cable lines were cut Wednesday. In other countries, such as Egypt, the figure was as high as 70 percent. […]

  2. CuriousCat: Unndersea Cables Cut Again - Reducing India’s Capacity by 65%
    December 20th, 2008 @ 9:18 am

    “Internet and phone communications between Europe, the Middle East, and Asia have been seriously disrupted after submarine cables were severed…”

  3. mike garner
    June 1st, 2017 @ 1:14 am

    I’ve worked on cable repair ships. Cables are damaged all of the time. I remember completing 8 repairs at 3 weeks each, before a cable lay was even completed. On two occasions in the same location in the Philippines, the damage was intentional, we even found the tools used laid on the seabed next to the cable. We fully expecte to fins a body, as the cut was only 1km from the station putting the tone on the cable. I guess they thought the cable had copper inside.

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