Wisconsin - Clam Lake ELF transmitter site - info
1987 Popular Science Magazine article on ELF system and other sub comms
1988 Popular Communications Magazine article and photos
Briefing - "ELF Communication Concepts and Capabilities" - 6 MB pdf
Briefing - "ELF Communications System" - 4 MB pdf
Briefing - "ELF Communications System" - 3 MB pdf
Info sheet - "Information about ELF Communications" - 0.4 MB pdf
There were two feasibility tests in the 1960's. Many thanks to Don Utt for info, pointers, and corrections.
Clam Lake WI - Naval Electronic Engineering Office
|NC ELF experiment
||Proposed balloon VLF/ELF
From Naval Facilities Engineering Command History 1965-74, Chapter 10 - link
An important communications development during the period under consideration was extremely low frequency radio (ELF). Extremely low frequency radio utilizes forty-five to seventy-five hertz waves which can be detected almost everywhere on the earth and to a considerable depth at sea. The Navy began research and development on extremely low frequency broadcasting in 1960. The problem with this type of broadcasting was that a gigantic antenna was required. Such an antenna would represent a prodigious construction feat. The Naval Facilities Engineering Command would naturally be responsible for such construction. The code-name for the Navy's extremely low frequency broadcasting project was "Sanguine." Sanguine was to consist of a "hardened" grid antenna system approximately forty to eighty miles square. The antenna would be buried and the transmitter stations (one at each intersection in the grid) would also be subsurface so that they could withstand attack. Such an installation would allow the broadcasting of virtually unjammable radio waves, each about 2,500 miles long. These would fill the space between the ionosphere and the earth's surface and would penetrate sea water to a considerable depth. Deep running submarines trailing special receiving antennas could be in constant communication with their headquarters thus long-range strategic weapons would be even more finely controlled. Because of the low conductivity of their soils, central Texas and northern Michigan have been tentatively selected as sites for one or more of the antenna complexes.(22l)
Thus far the Naval Facilities Engineering Command's major involvement in this project has been in the area of data collection for site selection. The Command built a test facility in Wisconsin to determine whether the system would work and whether the system would adversely affect the environment. The test site consisted of two antennas, each twenty-five miles long in the form of a cross. A transmitter building was constructed at their intersection.(222) Operations at the test site proved that the system would indeed function as planned and that it had no significant adverse affect on the environment.(223)
During fiscal year 1975, project Sanguine took a new direction. It was
decided not to harden the transmitting facilities, but to build them on the
surface. Only the antenna itself would be buried. Because of this change,
Sanguine's name was changed to "Seafarer." Building the transmitter
stations on the surface would mean a substantial reduction in the total cost of
the project, bringing it down to an estimated $200 million. Of this sum, $46
million was programmed for the fiscal year 1978 Military Construction Program.
221 Luzum and Jackson interview.