Did you know that less than 1% of the global Internet traffic is transmitted via satellites? The actual workhorses are 1.1 million kilometers of submarine cables that lay on the bottom of the ocean floor. More than 400 of these cables connect the continents and make the Internet a really global thing. But how did they get there and how do they survive?
Modern cables use all fiber-optic technology and can carry up to 160 Tbps. While the actual filaments that carry the data are thin as a hair the cables are typically as wide as a garden hose for most of the journey across the ocean, protected by a few layers of insulation and protection. Cables laid nearer to shore use extra layers of armoring and are buried up to three meters into the ocean floor. But in the deep sea they are laid directly on the ocean floor.
All of submarine cables are visible on the interactive Submarine Cable Map, give it a try!
They also have a good Q&A on that webpage.
Meet the cable-laying ships
The technology behind these cables and the massive efforts to install these cables are amazing. James Hamilton has published an interesting blog post “CS Responder Trans-Oceanic Cable Layer” where he describes a tour of the CS Tyco Responder, a modern cable laying ship.
The article includes lot of photos of the ship itself and the cable infrastructure. A similar ship is featured in the Discovery Channels’s „Mighty Ship“ documentary series. The Episode is available on Amazon Prime (Season 5, episode 6, USA only) or on Youtube:
The first trans-Atlantic cable is from the 1860-ties
And finally, if you are into technology history, the book “A Thread Across the Ocean” from 1866 (!) describes how the first first trans-Atlantic cable was put into place.
In 1866, the Old and New Worlds were united by the successful laying of a cable across the Atlantic. John Steele Gordon’s book chronicles this extraordinary achievement — the brainchild of American businessman Cyrus Field and one of the greatest engineering feats of the nineteenth century. An epic struggle, it required a decade of effort, numerous failed attempts, millions of dollars in capital, a near disaster at sea, the overcoming of seemingly insurmountable technological problems, and uncommon physical, financial, and intellectual courage. Bringing to life an overlooked story in the annals of technology, John Steele Gordon sheds fascinating new light on this American saga that literally changed the world.