KARACHI, July 3: Engineers working on the snapped Internet link failed on Sunday to trace the fault in SEA-ME-WE-3, world’s longest fibre-optic cable. The engineers are aboard a ship sent by the 92-party consortium that runs the cable to the coast of Karachi.

The president of the Pakistan Telecommunication Company, Mr Junaid Khan, told Dawn that in a repair operation that involved scores of technical experts from various countries, the defective portion of the undersea SEA-ME-WE-3 had been narrowed down to around five kilometres.

“Frankly, the fault has not been traced. Previously, we had narrowed the defective portion down to 15 kilometres. At the moment engineers working aboard the ship sent in by a UAE-based company, E-Marine, were scanning five kilometres of the 39,000-kilometre-long fibre-optic link, which is believed to contain the defective portion,” he said.

Pakistan made an initial investment of $35 million in SEA-ME-WE-3. It pays around $2.5 million as maintenance cost, including repair cost, to the consortium annually.

The PTCL president said: “Apparently the undersea fibre-optic link is not damaged. If it had been damaged, it would have been easy to detect it. Besides, the rough weather has made the fault localization process, a tedious exercise in the best of times, even more cumbersome. Engineers are having a hard time differentiating between noise and signals sent back by the faulty portion of the cable in what is known as sonic testing.”