Undersea cable repair via 19th century technology

An anonymous reader writes: Workers are relying on 19th century technology to fix a very 21st century problem — disruption of the Internet traffic that tech-savvy Asia relies on. "No electronics involved," said John Walters, general manager of Global Marine, one of the firms engaged in the repairs. "It's an old and traditional technique. After arriving at the scene they survey the ocean bottom to assess whether the contour has changed, and the degree of sediment movement. Then the traditional tools are brought out. A rope with a grapnel on the end is played out, down into the depths, and towed over the sea floor until tension registers on a graph on the ship, indicating contact has been made with the cable. Today's fibre optic cables are just 21 millimetres in diameter. The grapnel is a metal tool about 18 by 24 inches (46 by 61 centimetres) which includes a cutter, like a fine razor blade, and a grabbing tool. As tension increases and the cable is slowly pulled up, it is cut, grabbed, and half of it is hoisted to the surface. Dropping the grapnel, dragging the sea bed and recovering the cable can take about 16 hours, Walters said. "It is a tried and tested method." Once the severed half of the cable is on board the boat, debris is cleared from the damaged end, it is tested, sealed and the end boiled off. Then it is attached to a buoy on the water surface while the process is repeated for the second half of the cable before both halves are spliced together and dropped back to the ocean floor. Even before the Boxing Day earthquake, Global Marine had faced a busy year, with about 20 repairs after damage from fishermen or anchors. All those ruptures were fixed using the old grapnel method, he said.