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The incredible length of submarine cables

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The incredible length of submarine cables

Did you know that submarine telecom cables can be longer than many marathons put together?

When you think of marathons, you probably imagine runners hurtling down the streets, crossing cities and pushing themselves beyond their physical limits. Yet, there is another type of “marathon” that is held underwater, in the depths of the oceans, and that involves huge submarine cables.

These cables — true arteries that connect continents and facilitate the exchange of data on a planetary scale — can extend to incredible lengths, far greater than many marathons put together. Behind submarine cables lies a fascinating, high-tech world, which is why they play a key role in the vast global telecommunications infrastructure sector.

The role of these underwater giants is often underestimated: surrounded as we are by augmented reality, artificial intelligence, robots and cryptocurrencies, we increasingly lose sight of the tangible dimension of the physical infrastructure that supports the infosphere we live in. However, it is crucial to remember that in our world digitalisation is still deeply rooted in real technologies and places, where data comes to life and travel, where data is processed and collected. These places do not float in space, as we are often mistakenly led to imagine: instead of looking up, we should look down, into the depths of the oceans.

When was the first submarine telecom cable developed?

Submarine telecom cables date back to the 19th century, when the first attempts were made to connect the continents via submarine telegraph cables. The first transoceanic cable — at the time used for the telegraph — was laid on the bottom of the Atlantic in 1857. The cable connected Canada to Ireland, a distance of around 3,200 kilometres. Unfortunately, due to problems of various kinds, the cable — which allowed to send a message between continents in about 17 hours — lasted only one month. Despite its brief existence, this attempt sent a clear message: the way had been paved for a new era of communications on a global scale.

Since then, submarine cable technology has leaped forward in giant bounds, allowing increasingly fast and reliable data transmission, down to our times: the first submarine telephone cable was laid in 1956 and the first Internet connection cable in 1988. Today, the Internet network is made up of over 400 submarine cables, extending for nearly 1.5 million kilometres overall.

The extraordinary length of submarine cables

But let us get back to our starting point: the length of submarine cables. Can you imagine how long a cable that connects two whole continents must be? The length of submarine cables is not fixed: of course, it depends on the route to be covered, ranging for instance from 131 kilometres for the Celtix Connect between England and Ireland to the over 20,000 kilometres of the Asia-America Gateway in the Pacific. These numbers make a marathon look like a child’s play indeed.

These thin, yet powerful cables extend across oceans, following intricate routes and overcoming natural obstacles such as submarine canyons and underwater mountains — all marine morphological features that are carefully studied before the cables are laid.

Submarine cables: the heart of global communications

Considering the enormous amount of data they handle each day, submarine telecom cables are much more than mere wires lying on the ocean bed. They are the backbone of modern communications, the connective tissue that holds our digital world together. Through their long, fascinating history of challenges and successes, these cables have grown to become today the beating heart of current communications infrastructure.