How Submarine Cables Are Installed

In an era where everything tends to be wireless, the reality is that this apparent independence from cables falls apart as soon as you scratch the surface. You are likely reading this text thanks to a submarine communications cable, no matter where in the world you are. Of course, someone has to install that cable, and more importantly, someone has to repair it when something goes wrong...

Now, how often do these submarine cables get damaged? A 2008 report indicates that an average of fifty repairs are made each year in the Atlantic Ocean alone. A good example is the APCN 2 cable (19,000 kilometers), which connects China, Hong Kong, Japan, Malaysia, Singapore, the Philippines, and South Korea. In 2006, the Hengchun earthquake damaged the cable, disrupting Asian users' access to international portals. The cable was damaged again in 2009, 2010, and in March 2011, due to the Tōhoku earthquake and tsunami, which also affected four other cables.

How Submarine Cables Are Installed

Whether it's repair or installation, it's not a simple operation. The idea of "go and throw the cable" is completely absurd, because you have to consider irregularities in the ocean floor, seismic activity, and environmental impact. Between 1959 and 1996, less than nine percent of incidents were due to natural causes, which led to the process of burying cables. It all starts with moving one end of the cable to a shore station. Erbium-based optical repeaters, connected on board the ship (which, by the way, is specially designed and/or prepared for this task), have an interval of 40-80 kilometers between them. Depending on the ship, its plow equipment, the type of cable, and the region, up to 200 kilometers of cable per day can be installed. However, this data is insufficient to determine the duration of each project. The simple act of loading a ship with fiber optic cable can take between three weeks and a month.

As for the cost of the operation, the "average" I found for a transatlantic cable is around 500 million dollars. Despite this impressive number, installing submarine cables is still more viable than relying on satellite links, which have slower connections and higher latency. A submarine cable system can have more than a dozen "owners", including communications companies and other groups. And beyond the initial investment, cables are not eternal, as some become obsolete compared to other, more modern installations. If you want to learn more about the subject, see for yourself what's inside a submarine cable.