Mere impact can be enough to wreck a cable, if it puts a leak in the insulation. Frequently, though, a net or anchor will snag a cable. If the ship is small and the cable is big, the cable may survive the encounter. There is a type of cable, used up until the advent of optical fiber, called 21-quad, which consists of 21 four-bundle pairs of cable and a coaxial line. It is 15 centimeters in diameter, and a single meter of it weighs 46 kilograms. If a passing ship should happen to catch such a cable with its anchor, it will follow a very simple procedure: abandon it and go buy a new anchor.
But modern cables are much smaller and lighter - a mere 0.85 kg per meter for the unarmored, deep-sea portions of the FLAG cable - and the ships most apt to snag them, trawlers, are getting bigger and more powerful. Now that fishermen have massacred most of the fish in shallower water, they are moving out deeper. Formerly, cable was plowed into the bottom in water shallower than 1,000 meters, which kept it away from the trawlers. Because of recent changes in fishing practices, the figure has been boosted to 2,000 meters. But this means that the old cables are still vulnerable.
When a trawler snags a cable, it will pull it up off the seafloor. How far it gets pulled depends on the weight of the cable, the amount of slack, and the size and horsepower of the ship. Even if the cable is not pulled all the way to the surface, it may get kinked - its minimum bending radius may be violated. If the trawler does succeed in hauling the cable all the way up out of the water, the only way out of the situation, or at least the simplest, is to cut the cable. Dave Handley once did a study of a cable that had been suddenly and mysteriously severed. Hauling up the cut end, he discovered that someone had sliced through it with a cutting torch.
There is also the obvious threat of sabotage by a hostile government, but, surprisingly, this almost never happens. When cypherpunk Doug Barnes was researching his Caribbean project, he spent some time looking into this, because it was exactly the kind of threat he was worried about in the case of a data haven. Somewhat to his own surprise and relief, he concluded that it simply wasn't going to happen. "Cutting a submarine cable," Barnes says, "is like starting a nuclear war. It's easy to do, the results are devastating, and as soon as one country does it, all of the others will retaliate.
"Bert Porter, a Cable & Wireless cable-laying veteran who is now a freelancer, was beachmaster for the Tong Fuk lay. He was on a ship that laid a cable from Hong Kong to Singapore during the late 1960s. Along the way they passed south of Lan Tao Island, and so the view from Tong Fuk Beach is a trip down memory lane for him. "The repeater spacing was about 18 miles," he says, "and so the first repeater went into the water right out there. Then, a few days later, the cable suddenly tested broken." In other words, the shore station in Hong Kong had lost contact with the equipment on board Porter's cable ship. In such cases it's easy to figure out roughly where the break occurred - by measuring the resistance in the cable's conductors - and they knew it had to be somewhere in the vicinity of the first repeater. "So we backtracked, pulling up cable, and when we got right out there," he waves his hand out over the bay, "we discovered that the repeater had simply been chopped out." He holds his hands up parallel, like twin blades. "Apparently the Chinese were curious about our repeaters, so they thought they'd come out and get one."
As the capacity of optical fibers climbs, so does the economic damage caused when the cable is severed. FLAG makes its money by selling capacity to long-distance carriers, who turn around and resell it to end users at rates that are increasingly determined by what the market will bear. If FLAG gets chopped, no calls get through. The carriers' phone calls get routed to FLAG's competitors (other cables or satellites), and FLAG loses the revenue represented by those calls until the cable is repaired. The amount of revenue it loses is a function of how many calls the cable is physically capable of carrying, how close to capacity the cable is running, and what prices the market will bear for calls on the broken cable segment. In other words, a break between Dubai and Bombay might cost FLAG more in revenue loss than a break between Korea and Japan if calls between Dubai and Bombay cost more.
The rule of thumb for calculating revenue loss works like this: for every penny per minute that the long distance market will bear on a particular route, the loss of revenue, should FLAG be severed on that route, is about $3,000 a minute. So if calls on that route are a dime a minute, the damage is $30,000 a minute, and if calls are a dollar a minute, the damage is almost a third of a million dollars for every minute the cable is down. Upcoming advances in fiber bandwidth may push this figure, for some cables, past the million-dollar-a-minute mark.
Clearly, submarine cable repair is a good business to be in. Cable repair ships are standing by in ports all over the world, on 24-hour call, waiting for a break to happen somewhere in their neighborhood. They are called agreement ships. Sometimes, when nothing else is going on, they will go out and pull up old abandoned cables. The stated reason for this is that the old cables present a hazard to other ships. However, if you do so much as raise an eyebrow at this explanation, any cable man will be happy to tell you the real reason: whenever a fisherman snags his net on anything - a rock, a wreck, or even a figment of his imagination - he will go out and sue whatever company happens to have a cable in that general vicinity. The cable companies are waiting eagerly for the day when a fisherman goes into court claiming to have snagged his nets on a cable, only to be informed that the cable was pulled up by an agreement ship years before.
In which the Hacker Tourist delights in Cairo, the Mother of the World. Alexandria, the former Hacker Headquarters of the planet.
The lighthouse, the libraries, and other haunts of ancient nerds and geeks. Profound significanceof intersections. Travels on the Desert Road. Libya's contact with the outside world rudely severed - then restored! Engineer Musalamand his planetary information nexus. The vitally important concept of Slack
31° 12.841' N, 29° 53.169' ESite of the Pharos lighthouse, Alexandria, Egypt
Having stood on the beach of Miura watching those miserable-but-plucky Japanese surfers, the hacker tourist had reached FLAG's easternmost extreme, and there was nothing to do except turn around and head west. Next stop: Egypt.
No visit to Egypt is complete without a stop in Cairo, but that city, the pinnacle of every normal tourist's traveling career, is strangely empty from a hacker tourist point of view. Its prime attraction, of course, is the pyramids. We visited them at five in the morning during a long and ultimately futile wait for the Egyptian military to give us permission to rendezvous with FLAG's cable-laying ship in the Gulf of Suez. To the hacker, the most interesting thing about the Pyramids is their business plan, which is the simplest and most effective ever devised:
(1) Put a rock on top of another rock.
(2) Repeat (1) until gawkers arrive.
(3) Separate them from their valuables by all conceivable means.
By contrast, normal tourist guidebooks have nothing good to say about Alexandria; it's as if the writers got so tired of marveling at Cairo and Upper Egypt that they had to vent their spleen somewhere. Though a town was here in ancient times, Alexandria per se was founded in 332 BC by Alexander the Great, which makes it a brand-new city by Egyptian standards. There is almost no really old stuff in Alexandria at all, but the mere memory of the landmarks that were here in its heyday suffice to make it much more important than Cairo from the weirdly distorted viewpoint of the hacker tourist. These landmarks are, or were, the lighthouse and the libraries.