When using the Internet, it’s easy to ignore the infrastructure behind this so-called web of virtual connections. But as users clamor for fiber-direct connectivity like Google Fiber and nations plot the ever-growing hunger for more and faster global data transfer, there’s a new interest in some of the more obscure parts of today’s global network. One of these is the system of actual trans-Atlantic cables spanning across thousands of miles from the eurozone to North American shores.
In some ways, the idea of laying a trans-Atlantic cable structure boggles the mind. But these ambitious projects were first undertaken, incredibly, in the mid-1800s with the trans-Atlantic telegraph cable that predated all of the digital stuff we take for granted today.

Since that first cable was laid, a few others have followed; a 1954 Popular Mechanics story reveals the construction of a cable going nearly 2,000 miles between Newfoundland, Canada, and Oban in Scotland. But while you’d think that we’d be laying a whole lot of these types of cables these days to meet our growing demand for connectivity, you'd be wrong. While half a dozen cables were laid around the turn of the millennium, to date, the world has gone without a new trans-Atlantic cable for about 10 years. Media reports such as this one from PC World show how a glut in capacity has outpaced demand for a long time, and how, with a current combined capacity of more than 40 terabytes per second, there’s only just recently been a renewed interest in initiating one of these big projects again.

The Logistics of a Trans-Atlantic Cable

More than half a century after the above Popular Mechanics story, the magazine is still on the forefront of covering updates in trans-Atlantic cable. An October 2011 article covers plans by Hibernian Atlantic, now known as Hibernia Networks, to lay another line in order to speed up stock trading data - by five milliseconds. This represents the first trans-Atlantic cable laid since the 1990s, and although there's a big debate in the financial world about whether high-speed trading is a good thing, let's forget the whys of this type of project for a moment and focus on how. Because although we've been laying cable under the ocean for a very long time, it is still no easy process.

First, there are the fairly obvious challenges in physically delivering cables to the ocean floor. These cables sometimes dive as deep as 14,000 feet underwater, and in some cases are even laid below the ocean floor. Transmissions across these cables face ocean currents, deterioration and, increasingly, competition for space as a multitude of data transmissions are sent along it. According to an article in PreText Magazine called "Evolution of a Wired World," 70-80 percent of the TAT-1, copper wire cables under the ocean are in use, and capacity constraints have caused a return to laying underwater cable.

So what does it take to lay a trans-Atlantic cable? Well, it may be less intensive - and expensive - than satellite solutions, but that isn't saying much. For more on building today’s cables, I consulted Mike Saunders, Hibernia’s VP of business development, about some of the logistics of laying high-tech oceanic cable. First, there’s the planning: Saunders estimates a typical trans-oceanic project takes about three years to plan, considering aspects like route topography, testing, contracting with suppliers and squaring away finance details.

In addition, there’s the array of special protections placed around modern undersea cables to prevent the kinds of problems that have doomed earlier projects. This protection, says Saunders, starts with a steel tube containing the eight to twelve fibers in the core, which is wrapped in narrow-gauge steel wire. A copper layer carries power for amplifiers inside of a polyethylene shell, which is still the norm for undersea cable jacketing. Saunders adds that cable expected to weather tougher conditions may get a second layer of steel wire for an even larger diameter of just under two inches. Also, says Saunders, some parts of cables may be buried as deep as 2.2 yards under the ocean floor.

And while transmissions take mere milliseconds to traverse the Atlantic, installing the cables that make it possible is slow going. It involves a couple of ships, 24-ton plows and, in shallower waters, cutting a trench into the seabed in which to the lay the cable. The whole process happens, at best, at about one mile per hour. When something - such as another cable - gets in the way, a mechanical arm steps in to move the obstacle aside. Plus, you never know what obstacles will turn up on the sea bed.

All in all, it's not unlike the laying of the first trans-Atlantic cable in 1858, when two ships took their respective ends, met in the middle of the Atlantic ocean and attached them together. Now, of course, we lay fiber-optic cables, which have a much, much higher transmission rate than the few words per minute that could be managed in that first trans-Atlantic transmission over copper wire. And nowadays, speed is everything. Hibernia's submarine cable is projected to cost $300 million. All of this to save financial traders all of six milliseconds.

How Fast Is Too Fast?

Today’s high-speed trans-Atlantic cables may be built to last, but that still doesn’t satisfy concerns about whether people will actually need or use the additional bandwidth. However, in the financial industry, being just a little bit ahead of the game is worth a lot of money, and neither the finance world nor the overall business world is likely to reject new improvements in trans-oceanic bandwidth and signal speed. Instead, ISPs and other service providers on both sides of the Atlantic will likely work hard to match the capacity of the new lines, creating better global connections with new direct fiber and other technologies. In terms of other uses, there’s a concern that other bottlenecks will make new high-speed cable results moot for a lot of users.

And while we've long imagined that we'd be increasingly connected through space, it now seems more likely - at least for the foreseeable future - that we'll be connected across the ocean, much like we first were way back in the 1800s. One thing has changed, though: At hundreds of millions of dollars per connection, the stakes are much higher.