Coast Guard Announces Plans to End LORAN C Service, Again

WASHINGTON — The U.S. Coast Guard has once again announced the end of the world, at least insofar as mariners know it.


Late last month, the Coast Guard announed that it would begin phasing out its LORAN C navigation system beginning Jan. 4 of next year if, as expected, U.S. Secretary of Homeland Security Janet Napolitano certifies that it is no longer needed as a backup for the satellite-based Global Positioning System (GPS) that has replaced it on most commercial and recreational vessels. The shutdown was a mandated in the Congressional DHS appropriation bill signed into law by Presidnet Obama in October. The Coast Guard has already certified that dispensing with LORAN C will not have an adverse impact on maritime safety.

This isn’t the first time the Coast Guard has announced that it was shutting down a system that has exhibited as many lives as the provebial cat. Some members of Congress have been pushing for elimination of LORAN since the development of GPS more than a decade ago, claiming that the shore-based system of long wave radio transmitters was redundant and too expensive to maintain in light of the small number of mariners who still relied on it. LORAN proponents argued that the system was less prone to disruption by hackers or enemies of the United States than the radio signals broadcast from the constellation of GPS satellites orbiting the globe.

Until recently, LORAN’s defenders were able to stave off a system shutdown. As recently as April, Congressional budget writers expressed support for continuing the current LORAN system until a newer version was implemented as a backup to GPS. Assuming that Napolitano signs off on the proposal, though, it appears that the Coast Guard will finally begin to turn off its LORAN transmitters next year.

LORAN was first developed as a navigational aid during World War II and was named Loomis Radio Navigation, after the system’s developer, Alfred Lee Loomis. The system is based on measuring the minute time difference in the receipt of radio signals from transmitters sited at known locations. By measuring the time difference using two pairs of stations, it is possible to determine the receiver’s geographic location using specialized charts showing “time difference lines” or TDs. Because of the relatively short range of the radio signals, LORAN was used primarily within a few hundred miles of shore at most.

Until relatively recently, most of the Maine fishing fleet navigated using TDs. Fisheries regulators and others set boundaries using the TDs, and fishermen identified navigation hazards and favorite fishing grounds by referencing them. Today, most fishermen rely on GPS and advanced electronic chart plotters for navigation purposes, but it is still possible to hear mention of the old TDs in radio chatter.

While it appears that LORAN is finally on the way out in the United States, the rest of the world isn’t in a hurry to dispatch the system. In 2007, Great Britain’s Department for Transport signed a 15-year contract for the deployment of an “enhanced LORAN” (eLORAN) system for the waters around the United Kingdom and Western Europe.

Currently, LORAN stations continue to operate in far-flung locations such as Saudi Arabia, Greenland, Norway, India, Iceland, Spain, Japan and China.

For more maritime news, pick up a copy of The Ellsworth American.




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