By Jennigay Coetzer – Business Day, 29 July, 2011

Undersea cables have been in existence for many years, more recently for fibre optics and before that for telephone cables. There about 17 major transatlantic undersea cables linking Europe and the US, with three more serving sub-level routes.

There are also about 16 transpacific cables linking Asia with North America, and some six running up the east and west coasts of Africa, according to Thylan Chetty, West African Cable System (WACS) specialist at Infraco, which is a shareholder in the cable.  Chetty is also the procurement group chairman for WACS.

He says, traditionally, most of the data traffic carried by the Asia to US cables was bound for overseas destinations, but they are increasingly being used to carry data within Asia to support regional economic activity. “The same will happen in Africa.”

Chetty says one of the major challenges with undersea cables is the stringent environmental legislation that has been introduced in South Africa and many other African countries. “There are processes that have to be followed involving local authorities and communities in the relevant countries and sometimes a fee.”

He says landing an undersea cable involves digging a trench in the beach to a manhole, but it is a passive cable that does not contain any fluid. “But from an environmental perspective an undersea cable is classed in the same category as a nuclear power station.”

Telkom is a shareholder in SAT3/WASC/SAFE, the East African Submarine Cable System (EASSy), and the West African Cable System (WACS), which is expected go live in the first quarter of next year. Johan Meyer, Telkom’s executive for global capacity says having access to three undersea cables locally improves reliability and availability.

“It can take five days to three weeks to repair a break in a cable.” Further afield, Telkom also has stakes in The European India Gateway (EIG) cable, which links Europe, Middle East, North Africa and India, the Columbus III cable, which links Portugal and Spain with the US, and the SEA-ME-WE 3 or South-East Asia – Middle East – Western Europe 3 cable.

The 39,000 kilometre SEA-ME-WE 3 undersea cable is the longest in the world, stretching from north Germany to Australia to Japan. Meyer says undersea cables are robust and suppliers typically warrant for them not to have more than two technical failures during their lifespan.

When the depth of the water is less than 1.5 kilometres, undersea cables are vulnerable to fishing trawlers and at depths of 60 to 100 metres they are vulnerable to anchoring activity. “In the early days shark bites were also found in cables at 1.5 kilometre depths,” says Meyer.

He says it was thought that the sharks were attracted by the electro magnetic waves emitted by the cables. So the owners fitted screening over their cables at those depths. But this is now done during the manufacturing process because it is known at what point the cable will reach those depths, says Meyer.

He says other cable vulnerabilities include earthquakes. In 2006, an earthquake in the Pacific, close to Taiwan, damaged five undersea cables in 30 places and the last Japan earthquake took out four.

Meyer says a single undersea cable provides the equivalent capacity to that of all the satellites put together globally. “In this era of broadband communication, those countries without access to undersea cables will be left behind,” he says.

Today, most African countries have access to undersea cables or are in the advanced stages of accessing them through terrestrial links, says Meyer.

Jennigay Coetzer is a freelance business and technology journalist and she writes regularly for Business Day. She also runs media training and writing skills workshops, and is the author of A Perfect Press Release – or Not?, a guide to writing and distributing effective press releases, an electronic version of which can be downloaded free from her website: www.jennigay.co.za.

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