Nothing romantic about data travel

by Janet Taylor

As we all know, internet messages move around the world from Brisbane to London, from Hong Kong to Melbourne, in the time it has taken you to read these words.
How does it get around?
“People think that data is in the cloud, but it’s not,” said Jayne Stowell, who oversees construction of Google’s undersea cable projects. “It’s in the ocean.”

In cables under the sea, lasers, using fibre-optic technology, propel data down tiny glass fibre threads at nearly the speed of light. After reaching land and connecting with a network, the data makes its way onto our devices. While new wireless and satellite technologies have been invented since the first undersea cable was laid in 1858, undersea cables remain the fastest, most efficient and least expensive way to send information across the world.

Nearly 750,000 miles of cable already connect the continents. In the past, telecommunications companies laid the cable, but now American tech giants have taken over. Google has backed at least 14 cables globally. Amazon, Facebook and Microsoft have invested in others.

Getting the cable under the sea is a time-intensive process. Google's cable, due to be completed by 2021, will be laid from a specially designed ship named Durable. The cable is assembled in a factory a few hundred yards away from the Durable's berth in the Piscataqua River, in Newington, New Hampshire, USA.

At least a year of planning goes into charting a cable route that avoids underwater hazards, but the cables still have to withstand heavy currents, rock slides, earthquakes and interference from fishing trawlers. Each cable is expected to last up to 25 years. In one case, a shark was filmed trying to bite a cable. It’s thought it was attracted to the electromagnetic pulses given off by the cable, as sharks also find prey that way.
The cables begin as a cluster of strands of tiny threads of glass fibres. These threads are wrapped in a copper casing that carries electricity across the line to keep the data moving. Depending on where the cable will be located, plastic, steel and tar are added to help it withstand unpredictable ocean environments.

A conveyor moves the assembled cable directly into the ship which will carry over 4,000 miles of cable weighing about 3,500 metric tons when fully loaded.

Workers inside the ship spool the cable into cavernous tanks in a similar way to coiling a massive garden hose. While one person walks and sets the cable, others lie down to hold it in place. Even with teams working around the clock, it takes about four weeks before a ship is loaded with enough cable to start work.
 
Picture of the workers holding down the cable while it is being loaded.

Laying the cable is slow –between 100 to 150 km per day. The ship, at sea for months at a time, moves at six miles per hour. Closer to shore, where there’s more hazards, the cables are buried in the sea floor.

Poor weather is inevitable. Swells can reach up to 20 feet, occasionally requiring the cable to be cut so the ship can seek safer waters. When conditions improve, the ship returns, retrieves the cut cable that has been left attached to a floating buoy and joins it back together before laying can continue.


Although the cloud allows us to rid ourselves of physical storage devices and other equipment, the cloud itself is wholly dependent on the highly vulnerable physical network of cables that crisscross the ocean floor.  Naturally, reliance on these cables bring security concerns, but that's another story…


If a cable is damaged, divers are dispatched to assess the problem. The cable is then brought to the surface and fixed.

After the Latin American project, Google plans to build a new cable running from Virginia to France, set to be completed by 2020. The company has 13 data centres open around the world, with eight more under construction — all are needed to power the trillions of Google searches made each year and the more than 400 hours of video uploaded to YouTube each minute.

Demand for undersea cables will only grow as more businesses rely on cloud computing services. And the technology being developed, such as artificial intelligence and driverless cars, will require fast data speeds as well. Areas that didn’t have internet are now getting access, with the United Nations reporting that for the first time more than half the global population is now online.

 

I thank Adam Satariano in the New York Times, one of the sources from which this article was produced:

https://www.nytimes.com/interactive/2019/03/10/.../internet-cables-oceans.html