Virtual buoys may stop ships from crashing in fog
Coast Guard tests electronic navigation aids that could help mariners navigate even the lowest-visibility conditions.
His view obscured by thick morning fog, the pilot of a container ship called the Cosco Busan slammed into the San Francisco-Oakland Bay Bridge the morning of Nov. 7, 2007. The accident gouged a 212-foot hole in the vessel's hull and spilled nearly 54 thousand gallons of toxic fuel into the water, soiling some 26 miles of shoreline and leaving at least 2,900 birds dead or injured.
San Francisco's famous fog often makes it nearly impossible for boat skippers to see, but though this was not the first local maritime collision, the US Coast Guard hopes the deployment of new technology could make it the last. A pilot program is now under way to test how well digital navigation tools can help ships and other maritime vessels navigate past hazardous obstacles even when everything outside looks like pea soup.
Known as electronic aids to navigation, or eATON, 25 virtual buoys have been deployed in and around the bay to complement existing radar beacons and other navigation tools.
The system, the first of its kind in the United States, was designed to help ships safely move around the bay in even the foggiest conditions. If successful, it could help avoid the kinds of accidents that over the years have led to repeated environmental disasters.
Here's how the system works. Many vessels now operate the Coast Guard's Nationwide Automatic Identification System (NAIS), a technology designed as a "standard for ship-to-ship, ship-to-shore, and shore-to-ship communications." Placed digitally on maritime electronic charting systems and radars, eATON is transmitted via NAIS, showing up on these charts as readily identifiable symbols, such as blue or purple diamonds or squares. The virtual buoys have been placed in "critical turn points" for maritime vessels in the bay, according to the Coast Guard, and five of them have also been "placed" on the bridge towers of the western span of the Bay Bridge.
For now, the new technology isn't going to replace any existing systems outright, said Coast Guard commander Jason Tama, but rather will be used to augment them. At the same time, the digital buoys can be used to mark locations "where it may have previously been impractical to do so," such as offshore locations where it's too deep to anchor a physical buoy. At the same time, he said, not all ships are outfitted with technology that can display eATON. Tama said the Coast Guard has no specific time frame for expanding the program. But because the NAIS system is available in other areas of the country, the potential exists to deploy eATON outside the San Francisco area.
Still, Tama added, the agency is looking forward to getting feedback from the local maritime community that will help it decide whether to expand the system.
The Cosco Busan's pilot was found guilty of operating the ship under the influence of as many as 19 prescription medications, according to the National Transportation Safety Board. He subsequently served 10 months in prison. But that accident wasn't a one-off. In 1971, two oil tankers owned by Standard Oil -- the Arizona Standard and the Oregon Standard -- collided a few hundred yards west of the Golden Gate Bridge in heavy fog. No one got injured, but 800,000 gallons of bunker fuel spilled into the waters, according to the Coast Guard, causing an environmental catastrophe.
More recently, another tanker, the 752-foot-long Overseas Reymar, hit the Bay Bridge, also in heavy fog. In that 2013 incident, the ship's pilot told investigators "that because of the reduced visibility and the absence of [adequate radar] information, he decided to change his path," leading to the accident.
Virtual buoys a big help
In the case of guiding vessels like giant container ships safely through narrow passages like those between the towers of the Bay Bridge, there are those who definitely think eATON could be a big help. "With the virtual [buoys], the pilot coming in and out of the open estuary [near the bridge] would be able to see where the bridge towers are," even in heavy fog, said Tom Dougherty, operations supervisor for the Blue and Gold Fleet, a local ferry company.
While the Coast Guard isn't claiming specifically that the new eATON system could have prevented any of San Francisco's big maritime accidents had it been in place in any of those cases, it's clear the technology is aimed at helping vessels avoid disaster. "We certainly don't think eATON is a panacea," Tama said, "but we hope this technology will provide an additional tool mariners can use to facilitate safe navigation. We are looking for feedback from early adopters of this technology on the efficacy of these aids."
It's too early to tell, of course, what that feedback will be. But to the Red and Gold Fleet's Dougherty, one big advantage of the system is that eATONs are immovable. "It's useful because we know that the mark is in the charted position, and it's stationary," said Dougherty. "One of the old-school [navigation] problems is that a fixed buoy is moored to the bottom of the bay by an anchor, and that mooring chain has some slack. So that buoy can move 100 feet in any direction."
That kind of variability in the location of essential warning symbols can lead to problems in low visibility. But with eATON, the "buoy" never moves. "With electronic, it stays put," Dougherty continued. "There's nothing going to move it. That accuracy is important."