Moving forward: new ATON technology saves CG time and money

Thousands of years ago, Phoenician mariners used fires blazing on towers to find their way into port. But times have changed for contemporary mariners around the world as they find their way into port at night. The same concept of a bright light guiding the way still exists, but it has evolved into something safer, reliable and approximately the size of a thumbnail.

Evolution in this case refers to light emitting diodes, or LEDs, which are found in places like remote controls, traffic lights, and even toys. They use about half the energy it takes to light an incandescent lamp, like a light bulb, partly because they don't need to heat a filament before they produce light. These new technological advancements are now being put into service atop ice-hull buoys and save the Coast Guard valuable time and money spent maintaining and responding to the conventional systems' chronic failures and discrepancies.

Ice buoys in the U.S. are found in navigable waterways prone to freezing. When a waterway freezes it can pull a buoy under water. A warm spell can release large masses of ice, some the size and weight of a pool table or larger, spelling out a possible doom from collision. For that reason ice hulls and their lanterns are shaped to deflect loose ice floes and to sustain prolonged periods of time submerged below an icy waterway and emerge still providing a signal to the mariner. A conventional buoy in the same situation would be severely damaged.

Crews working on Coast Guard buoy tenders and Aids to Navigation Teams have been switching conventional buoys with ice hulls for years. There are as many as 306 ice-hull buoys replaced annually, but some are only changed out if endangered by ice.

The LED ice buoy lanterns were first tested in 2002 as prototypes in the Chesapeake and Delaware Bays, installed on a limited basis late in the ice season of 2003 and then completed as a full conversion this winter.

"These lights will probably appear brighter than the legacy systems because we chose to provide a better signal (brighter light) to the mariner. The LED technology allows us to do it without paying a penalty for a larger power system," said Jon Grasson, who is the Team Leader for the Signal and Power section in the Ocean Engineering Division at Coast Guard Headquarters.

Not only are the new lanterns brighter, but their thick bronze-colored base, glowing light and antenna-like bird deterrent devices are reminiscent of the 1938 radio broadcast of "War of the Worlds" that panicked the nation with fears of an alien invasion. Fortunately these won't cause as much of a panic.

"It looks like a little UFO from The Jetsons," said BMC Eric Smith, of the 175-foot buoy tender CGC Katherine Walker.

Aside from the new lantern's retro-Hollywood space age styling, they are designed for simple installation to be maintenance free for the season and ultimately "withstand severe ice conditions," according to the manufacturer, Sabik. One battery will last through the winter until the buoy is relieved in the spring. The current system also uses only one battery, equal to about 240 "D" cell flashlight batteries, for the entire season, but since the new LED lamps use about half of the power, a reduced capacity battery may be used in the future. Grasson said the Coast Guard could save as much as $32,000.00 annually just in batteries.

"The batteries for these aids can be downsized to save money," said Grasson. "The present cost of the battery is $375 and the projected cost is about 25 percent less when we reduce the capacity 160 ampere hours for an estimated cost of $277, a $94 annual savings per battery. With 340 batteries purchased annually, the estimated annual savings is $32,000.

Another benefit from the LED lanterns is that they replaced an array of parts that made up the conventional lanterns. The conventional system consisted of a Lexan dome that protected the lantern, a colored or clear lantern lens that directs light from the lamp (specially cut to fit below the Lexan dome), a lamp changer, six lamps and a daylight control. In comparison to the new lanterns that have a proven track record overseas, the conventional ice buoy lanterns suffered from a lack of robustness and numerous failures of the protective dome, according to Grasson. Anticipating very few ice-related failures, approximately $41,000 will be saved from not having to replace damaged parts each year, he said.

The new technology is all about efficiency and durability when it comes to the new technology. Saving energy and lasting through harsh conditions is going to save man-hours. "I think these LEDs [lanterns] will help us be more efficient," said Lt. Brian Donahue, commanding officer of the CGC Katherine Walker. "Across the board we saved ourselves seven to eight minutes per buoy in part because of the maintenance required on the lanterns," said Donahue.

Those minutes add up considering that the crew replaces 55 lighted ice-hulls each season. Multiply those minutes by the numbers of buoys and you save more than seven hours. Still not convinced by the efficiency? According to COMDTINST 7310.1H Standard Rates, the average cost to keep a 175-foot ship underway for one hour is $2,655! So even though the LED lanterns are in the ballpark of $1500 each, which is about twice the price of the conventional lantern system, the cost is saved in the long run. "We are always looking for ways to be more efficient, said Charles Mosher of the Short Range Aids to Navigation Division at Coast Guard Headquarters. "If you can reduce your AtoN hours, and invest those hours in some other mission that's begging for WLM [175-foot buoy tender] hours, then that's a win."

"Because of the efficiency of the LED we can provide a better signal to the mariner and downsize the power system," said Grasson.

Predating even formal writing in approximately 3000 B.C., mariners may have burned animal fats as fuel to light the way into port.

Navigation today is light years ahead of bonfires on towers and this ice season's LED-equipped lanterns may just be a precursor for the fate of incandescent lamps being used in most of the Coast Guards aids to navigation.

Story and photos by PA1 Mike Hvozda, PADET New York

COPYRIGHT 2005 U.S. Coast Guard
COPYRIGHT 2005 Gale Group