Google Helps Finance Latest Trans-Pacific Fiber Optic Cable Project

by Chris Preimesberger

This map shows the 15 current undersea cable lines stretching from the United States to the Far East. The PacNet-SubCom cable is only the latest. Company officials would not disclose the exact cost of the project, but conceded it was in excess of $100 million. PacNet laid half the cable, about 5,000 miles, from Los Angeles to the middle of the Pacific Ocean. Another company laid the remaining 4,500 miles from Japan. Total length: 9,500 miles.

SubCom’s Global Sentinel, a 19-year-old, custom-built ship that requires 55 crew people, is a sleek ship that has logged hundreds of thousands of nautical miles laying cable. It visited San Francisco’s Port 80 on March 12.

With the protective outside covering stripped away, the fiber optic cable appears almost too thin to handle the massive traffic it must carry as well the immense pressures of the ocean depths. Its only about 1 inch thick, yet billions of bits of data flow through it hourly. The larger section is a completed splice.

SubCom Vice President of Operations Frank Cuccio shows off a pile of spare “repeaters” in the upper hold of the ship. These repeaters power data up and move it along during its thousands-of-miles trip across the ocean. They are placed about every 75 kilometers on the ocean floor.

When the cable is “collected” for repair off the bottom, it comes through the specially designed bow port and is collected on this large, 15-foot spool.

As the cable comes in over the bow, it enters the ship over the top of the spooler. You can always tell a cable laying ship by the spooler on the front.

Here is a view over the top of the spooler, looking down into the water.

Cable tension controls keep the crew aware of how tight the cable is at all times. A control desk in the bridge also monitors this. Too much tension on the cable could be disastrous.

Crew members use these large, sharp-edge hooks to catch the cable at the ocean floor. It could be down as deep at 9,000 meters, although that depth is rare. Average depths for the ocean floor in the Pacific range from 3,000 to 6,000 meters.

Cuccio demonstrates fiber optic test equipment in the data center of the Global Sentinel. This shoots lasers down the cable to locate breakages or other problems, and prepares reports for the crew.

The ship has room for specific kinds of data center equipment, including racks of servers, in order to simulate a working data center and test it on the cable. Several racks can be attached to the yellow-and-black foundation shown.

Here are two large buoys—which are about 8 feet across and 15 feet high—that the Global Sentinel uses to mark its place along the cable, should it need to return to a specific location for a repair.

When the new cable is “paid out,” it travels from the lower hold of the ship through these tires, along a special track toward the stern of the ship.

This yellow machine at the stern of the Global Sentinel is a large, heavy plow that can dig a trench 1.5 meters deep and prepare for the burial of a cable line, should it be required to do so. As cable comes up to a continental shelf, it is required to be buried, so as not to interfere with the fishing industry—because of deep-water nets that are becoming more commonplace.

This custom-designed, remote-controlled vehicle can handle deep-water duties that divers cannot. Crew members never know what they’re going to face on a trans-ocean project, and this machine can do a lot of things underwater to help get the job done.

On the bridge, all the instruments required to monitor a cable-laying job are at the fingertips of specially trained personnel. Specialized software to do the job is essential.

Unfortunately, there are no more big pilots wheels on a ship like the Global Sentinel. To turn the 440-foot-long ship left or right, one simply needs to turn the black knob to the right or left.

Finally, on the bridge, the fine-tuning control for the ship (when docking, for example) is a joystick, with a graphical representation on a screen nearby.