Atlantic crossing

It could be a scene out of old sailing days - men toiling in endless circles as mile upon mile of thick, black cable is loaded deep inside the C.S. Global Mariner for a new undersea link across the Atlantic. Nearly 9,000 miles of fiber will be coiled aboard a fleet of ships for the crossing, every last foot of it humped in place by hand, just as crews 200 years ago did with their own tarry cables and rigging.

As cold weather settled in the North Atlantic last October, Tyco Submarine Systems, Ltd. (TSSL) embarked from Long Island, N.Y. on its Atlantic Crossing (AC-1) project. The fiber's end currently is somewhere in the mid-Atlantic and the plan is to reach England by this May. A second line is to be finished in November and will complete a ring that includes Germany and Holland. With four fiber pairs carrying 10G bit/sec of traffic each, the system will double the existing capacity between the U.S. and Europe.

Visiting TSSL's operations on the banks of the Piscatagua River near Portsmouth, N.H., where the cable is manufactured and loaded onto ships, is a step into military/industrial protocol. Portsmouth locals aren't exactly sure what the place is about. "We see those big cable boats go by and wonder what they're up to," said a local brew pub master. "It's like Oz to us - no one knows what goes on behind that big curtain."

The scale of it

Our waters are spanned by nearly 200,000 miles of fiber optics, almost enough to reach the moon. TSSL put nearly all of that "wet plant" in the water. Accounting for roughly 85% percent of earth's installed base, the company has spun more fiber and built more undersea systems for carriers and the military than any telecommunications vendor in the world.

In April, TSSL acquired AT&T's undersea division, including a fleet of six cable-laying ships, making it both the world's largest builder of undersea cable systems and the only one that handles everything from cable design and production to installation and long-term management.

TSSL boasts to have laid enough fiber to circle Earth's equator six times, yet still there's not enough. Demand for undersea communications is growing at anywhere from 30% to 90% annually, depending on whom you ask. Data traffic from global internet service providers accounts for most of the new demand, especially on the heavily loaded transatlantic and transpacific routes leading to and from North America.

The 477-foot long Global Mariner is TSSL's newest ship, launched in 1992. Its two main cable tanks together hold up to 1,250 miles of cable, depending on the type. Three auxiliary tanks bring the total capacity to over 3,240 miles, not including odd lengths of ground rope - old, junk cable that comes in handy at sea.

Cables are spliced together in sections that vary from double armor near the coast to light wire in the deepest mid-ocean. In Portsmouth, Global Mariner was being loaded with 700 miles of cable, its maximum weight-load for this particular trip, comprising over a dozen different sections in each tank in order to accommodate the different seabed conditions along its route.

Altogether, AC-1 will involve five different ships making multiple trips. "We'll be loading cable literally non-stop for the next seven months for this project," says Norm Coltanovich, TSSL's director of cable operations.

Glass wars

You may wonder what doubling the transatlantic capacity will mean to the cost of international phone service.

"We'll see an enormous rate reduction," says Len Elfenbein, president of Lynx Technologies, a consultancy and publisher of a worldwide guide to telecommunications services, based in Little Falls, N.J. "I believe rates across the Atlantic will drop at least 30% to 40% over two or three years."

Global Telesystems, Ltd., the company that owns AC-1, already discounts the cost to carriers of bulk capacity on the new transatlantic link by at least that much, he says. "They're selling capacity on AC-1 for less than the carriers can sell to carriers."

"I think you have to say this is going to inevitably alter the factors of supply and demand," says Gene Shutler, Global Telesystems' executive director. "That is essentially the plan," although he says the time period over which the change will take place is hard to predict.

Transatlantic lines aren't exactly oversubscribed, but some carriers always wind up running out of capacity on different cables around the world. AC-1's largest demand has come from ISPs, both large, established players and start-ups jumping into the C-1 opportunity.

Cable cones

The Global Mariner's berth on the Piscatagua is connected to TSSL's fiber production plant on the river's high bank by a sloping cable shed several hundred feet long. Cable is drawn down a ramp and into the ship on rollers, then takes a bend onto the main deck and is fed down into the ship's tanks.

The main tanks are about 30 feet in diameter and several decks deep. At 38,400 cubic feet each they're like squat, shipboard silos. The walls are white and the "floor" is many layers of black cable already loaded aboard. From an overhead catwalk, the two men working below look like small action figures hiking in circles on a vinyl record.

A dull metal cone, roughly eight feet in diameter at its base, rises from the tank's bottom to a blunt top. Cable is fed in above the cone, and the men walk it around, packing the stuff in a tight spiral. The line comes aboard at 3 knots, which is close to a city walking pace of four miles per hour.

It's like mall-walking in an igloo. The men keep up with the cable and guide it by hand in circles, starting tight against the cone and widening outwards to the wall, then spiraling back in again, one layer at a time. It takes 10 days or more to pack the ship.

The loading is meticulous, tedious. Working day and night, the crew can handle about 50 miles of light cable per day. The heavier armored cable is more difficult to work with, averaging 25 miles per day.

Every 38 miles there is a sudden knot of action as the cable's optical amplifiers arrive. These repeaters boost fiber-optic laser signals at specific intervals along the cable.

Repeaters are the heart of a long cable system. They are beryllium-copper cylinders about three feet long and 18 inches in diameter. Flexible rubber boots at either end give them the flexibility to sink miles down to the ocean bottom without kinking the cable. They resist pressures of around 4.5 tons per square inch, and the occasional curious chomp of big critters.

Repeaters are installed on the cable at the factory but can't be coiled into the tanks aboard the ship. Instead, it takes more than 20 crew members to man-handle the repeaters onto special racks on the main deck. Lifting the repeaters isn't a problem, but bending armored cable back into the tanks without kinking it is, and the whole loading crew turns out for this careful maneuver.

Beach head

The obvious place to look for a cable would be on the beach where it comes ashore. AC-1 lands at the town of Shirley on Long Island.

Cable-laying begins with the ship idling a safe distance off the beach as the terminal end is towed ashore on a series of floats. A team of divers guides the cable into a trench leading to a manhole ashore, where a winch or bulldozer pulls it in. Once the end of the cable is secured on land, divers release the floats and the cable slips to the bottom of its trench.

The ship then heads off, towing a Sea Plow that furrows a three-foot deep trench to protect the cable. Off the continental shelf, in mid-ocean, the cable simply lays exposed on the bottom.

When the first ship lays all its cable, another ship comes along and splices on the next length. This is done in two ways. If conditions are reasonably calm and strong currents or approaching storms aren't an issue, the cable can be dropped and marked with a huge mid-ocean buoy. Several of these yellow buoys wait like enormous juggling props at the bottom of a round hole three decks deep in the Global Mariner's aft hold.

Topped with an array of radio transmitters and radar beacons, the bouys ought to be big enough to find anywhere. But Coltanovich doesn't like to use them. "Buoys will get moved in a storm and take the cable with them," he says. "Then either the cable or the buoy line breaks, and we have no idea where the cable is anymore."

Grappling is the preferred operation - just let the cable go, and later use a big hook to literally snag it up from some 20,000-odd feet down. Exact navigation is the key, using the Global Positioning Satellite (GPS) system to chart exactly where the cable was dropped. "We put a couple of kilometers of ground rope on the end of the cable, mark the spot, and then the next ship just grapples it up," Coltanovich says. "They generally snag it on the first try."

In the buoy hold is a collection of odd ropy things hanging down like long rubber spirals. They're cable stoppers that are used to deal with the end of a cable and hold it alongside the ship while attaching buoys and ground rope to it. They work like a Chinese finger trap, Coltanovich explains. Simply wrap a good length of cable stopper around a cable, and the harder you pull, the harder it holds.

Costs and risks

It used to be that carrier consortia built their own cable systems, dividing capacity among themselves. But over the past 18 months or so a trend has developed as new systems are privately funded and their capacity sold to the carriers. Global Telesystems is a major player in this new order of things.

Capitalized by investors that include the AFL-CIO pension fund and other large institutions, AC-1 is Global Telesystems' first major project.

Negotiations between Global Telesystems and TSSL started in late 1996. Less than a year later, cable was already in the water. About a month before installation began the system was reconfigured to add a shore drop in Holland. "It's a pretty good indication of the new business model overtaking this industry," Coltanovich says. "In the old days it would've taken a couple of years to hash things out, nevermind last-minute changes."

The underlying technology also is subtly changing. Wave-division multiplexing (WDM) is the key to upgradeable fiber capacity. "It used to be that repeaters limited your upgrade," Coltanovich says. "You had to go and change the wet plant to increase capacity, but now with optical amplifiers you can go from 2.5G to 5G to 10G by just changing the end stations."

This capacity doesn't come cheap. The AC-1 contract value has not been announced but can be estimated. A different consortium last year completed the most ambitious cable project ever built, the Fiber Link Around the Globe (FLAG) system. FLAG runs from Europe to the Mideast and around Asia and the Pacific. It spans over 17,000 miles and cost $1.5 billion to deploy.

Assuming an equivalent cost of roughly $86,400 per mile, AC-1's 8,750-mile pricetag should run about $756 million. Neither TSSL nor Global Telesystems would confirm the figure, although sources say the costs of building systems on such a scale are fairly similar across the industry.

Global Telesystems has funded some smaller projects around the world, and already is planning a Pacific Crossing similar to AC-1.

The Pacific is jammed, says Michael Hewitt, a submarine systems analyst at Information Gatekeepers Consulting, Inc., in Boston. "There's not as much total bandwidth demand across the Pacific, but the available capacity is pretty full. The carriers I've talked to are putting WDM on all their links to squeeze out whatever capacity they can."

Shutler says the company's plans for a Pacific crossing are based more on potential demand than current bottlenecks. "Cable projects still have long lead times; you have to be able to anticipate demand, not wait for it to show up."

At sea

Out in the Atlantic, the cable is fed out of its hold by Linear Cable Engines (LCE), the same contraption that helped feed it in. These pneumatically powered systems look like a convention of go-cart wheels all lined up in sets of six tires each, three on the top and three on the bottom. Forty-two wheels drive one LCE, gripping the cable and feeding it along without ever letting it slip. Articulated suspension lets the system handle thicker splices and repeaters without loosing its grip. If a cable ever slipped overboard out of control it would become an expensive pile tangled with pieces of the ship.

The cable-laying system also includes "dynamometers" that monitor tension on the cable, adjusting the strain so it doesn't snap from wave surge or the sagging of its own weight.

At sea, cable operations are planned almost to the minute. The ship's navigation has to account for the different sinking rates of each section of cable, which will land on the bottom according to its weight, water depth and the speed of the ship. The goal is to leave enough slack on the bottom when crossing undersea peaks and valleys so that the cable won't chafe or be drawn taut. Maximum cable-laying speed is 8 knots, and the LCE typically runs about 3% faster to ensure adequate slack.

Experienced crew down in the cable tanks shepherd the cable along as it whips up and away at about 800 feet per minute. It flashes out of the tank in a winding curtain, the men timing their step in and out of its orbit to retrieve pieces of wood and rubber dunnage that's used during tanking to smooth out lumps in the load. "It'll knock you out if it whacks you," Coltanovich says. "We don't send just anyone down there when the cable's moving."

Depending on water depth and other factors, the cable may touch bottom up to 20 miles behind the ship. So when changing course or adjusting speed, it can take half an hour before the change actually impacts what's happening behind on the ocean floor. These details are planned before the ship leaves port, and have to be orchestrated in real-time around changing wind and sea conditions.

Hostile ground

Planning cable routes is a meticulous affair. AC-1 is the 8th system to cross the Atlantic along basically the same U.S.-to-England route, separated from existing systems by just over a mile in places. The entire route is mapped anew by TSSL's deep-water surveying ships for any crossing. "We know the lay of the land pretty well, but you never know how it might've changed from one season to the next," Coltanovich says.

Underwater bottom-slides can wipe out existing terrain in a flash, and cables have to be laid in an exact path through rubble fields and underwater mountain passes. The mid-Atlantic rift is a geological challenge that only can be dealt with by careful mapping, precise navigation and cable placement accurate to within yards.

The day-to-day problems happen closer to shore. Continental shelves - the bottom terrain that slopes gradually from our beaches to the cliff-like edge where deep ocean begins - can extend 100 miles out to sea. Fishing trawlers drag their nets along the bottom on the continental shelves, and ships drop their anchors, accidentally snagging a cable and either snapping or damaging it internally. The most heavily-armored cable and fail-safe operations go into the "last mile" from the edge of the continental shelf onto the beach.

Hong Kong is the worst maritime shore for undersea cables. The surrounding approaches have a very soft seabed on which unregulated cargo ships drop anchor wherever they please. Their anchors weigh tons, and will carry down through the bottom to a depth of 20 feet. "In a storm these ships will drag anchor, snag your cable and yank it as far as it'll go until it breaks," Coltanovich says. The coast of Alaska has king crab pots about 10-feet square dropped to phenomenal depths 100 miles from shore, and also dragged around by winter storms. Off the Atlantic coast around New York, fishing trawlers drag the bottom as far as 90 miles out to sea, right up to the edge of the continental shelf.

In each case the only protection is to bury armored cable as deeply as possible under the seabed. TSSL's Sea Plows are towed behind the cable ships and use a contraption of water jets to bury cable about three feet into the muck. Sea Plows can be used in water up to about 5,000 feet deep. Around Hong Kong, TSSL rigged a barge with remote water jets to cut a trench 30 feet deep in the soft mud, and buried its cable within.

The bottom line

For all the invigorated competition, "It's a small universe of people who can actually drop these systems on the bottom of the sea," Coltanovich says.

"We actually built some of the FLAG system cable and loaded it for them, so we had a chance to see what they've got onboard and it's all the same basic stuff," he says. "The real differences between us are in how we handle the problems that come along."

Twenty thousand feet down, those are (not quite) problems of another world.