BY SCOTT THISTLE
NEWS TRIBUNE STAFF WRITER

If American submarines patrolling waters of the Middle East get ordered to action, it's likely that message, or at least part of it, will come by way of Clam Lake in northern Wisconsin.

It's there -- more than 5,800 miles from Afghanistan -- that the U.S. Navy's Extremely Low Frequency radio transmitting station sends out daily broadcast messages to submarines worldwide, said Richard Williamson, a civilian spokesman for the Navy's Space and Naval Warfare Systems Command.

"This system is about staying in touch with our sailors in subs when they are at depth and at speed,'' Williamson said. "This is about keeping our sons, our brothers, our fathers and our friends as safe as possible."

The ELF station's location is a unique combination of geology and geography that allows it to beam signals off the bedrock, which is called the Laurentian Shield and stretches into Canada. The shield bounces the signal into the ionosphere, the last layer of the Earth's atmosphere, 34 miles high. From there, the signal bounces back down and spreads out over the globe while penetrating deep below the ocean's surface, where subs can pick it up. Technology allows the subs to receive messages without surfacing, where they are most vulnerable to attack or detection.

The station contributes about $2 million a year to the Northland economy in payroll and pays more than $30,000 a month for electricity, Williamson said.

The station also has three 1-megawatt (million watt) generators that can be used to keep the station running despite a power failure. Those generators can also be used to offset any power shortages that might occur in the state's power grid, Williamson said.

ELF communications have been used in some fashion since World War II. The technology is also used for nonmilitary applications -- including oil and natural gas exploration, said Paul Weishaupt, a civilian deputy of public affairs.

The Clam Lake station, one of only two used by the Navy to talk to submarines, relies on two 14-mile-long antennas. They are above ground, forming a giant plus-sign pattern in part of the Chequamegon National Forest.

The other ELF station is in Michigan's Upper Peninsula at Republic. The stations simultaneously broadcast messages 24 hours a day, 365 days a year to U.S. subs. Those messages come from Pearl Harbor, Hawaii, or Norfolk, Va., by way of secure telephone lines or satellite signals.

Messages are sent to both nuclear-armed and smaller attack subs, which can carry the kind of cruise missiles used by the United States to attack terrorist hideouts in Afghanistan in 1998.

"We are talking to our subs around the world as we speak right now," Williamson said.