Some objected that such signal energy demonstrated an alarming ability to permeate even “enemy” ground. Once launched from their geological “chutes”, deepest VLF signals spread out rapidly across the surface of the earth. Entering its meandering routes, such VLF signals could easily be intercepted anywhere, by anyone. While this fact was not problematic during the early years of ground conduction VLF systems before World War I, strict techniques for the preservation of military secrecy would now be an absolute. Furthermore, such energies could not be served by the military encryption systems which served radiotelephonic channels. New digital code encryption techniques would now be developed and implemented. Deepest VLF wave transmission was the available reliable communications channel.

An objection to the establishment of these stations considered the that these easily discerned structures would be among the very first target-strike zones. The large fixed VLF installations were captives of their own monstrous size. RCA directed the construction of the 10 Megawatt Jim Creek Station, call letters NLK, in Oso, Washington. The Naval VLF station NAA is a 2 Megawatt station which operates at 14.8 Kilocycles. Comprising 26 towers, each an average of 900 feet height, NAA occupies a peninsula of 300 acres in Cutler, Maine. Military planners did not appreciate the fact that VLF stations such as this represented such easy wartime targets. VLF wave stations could be destroyed in a single blast. For this reason, the military devised an elaborate ground-based scheme to incorporate a great number of simultaneous triggered stations, a VLF Network. Operating in synchronous intermittent blasts, the VLF stations would be switched on and off by a central command control system. The possible destruction of any one such site would in no way damage the integrity of the whole Network. No one site would carry all the information of a single transmission. In addition, VLF is virtually impossible to triangulate. The nature of the deep ground-hugging signal precludes any ordinary radio scanning means by which to ascertain the exact target location of any one such station. Therefore, unless espionage had provided very exact coordinates on these systems, there would be no possibility of their immediate destruction. In addition, these sites would be the most highly defended national zones in such an emergency.

A small amount of deep VLF energy was found to have an effective and remarkable long distance range. Ionospheric ceilings did not drastically distort deep VLF wave signals. Both NUCLEAR and RADAR EMP methods could scramble all electromagnetic wave channels for dangerously long time periods by disturbing the ionosphere directly, artificial chaotic conditions. All channels which relied on excessive skywave components were thus rendered useless by the method, a new breed of electronic push-button weaponry. But deep VLF wave channels were not nearly affected at all. This proved to be especially true with decreasing VLF frequency, an inference that at lowest frequencies, one might find a zero disturbance condition. Such a frequency band would then offer secure-communications continuity despite the disturbing detonation of hundreds of nuclear warheads. This observation prompted several new projects, the first practical necessity being to establish more resilient deep VLF wave stations.

The NRL began working closely with VLF experts to produce an ELF communications system which, relying on ground wave conduction, could not be disrupted by high altitude EMP’s. Several preliminary tests were conducted with LORAN-C broadcasts to assess the power efficiencies of such a scheme. Naval VLF stations joined in several cooperatives, broadcasting and monitoring signals along specific pathways. Terrestrial magnetic variables were extremely responsive to EMP currents. Deep VLF wave correlated studies followed nearly perfect compass headings. Such channels were not completely impervious to space EMP effects. The last two nuclear space blasts of Project ARGUS proved the availability of ELF channels in catastrophic EMP. The direction was clear, the new quest was to devise an ELF communications system.

There was another purpose in these directions. The newly established nuclear submarine fleet had new and demanding requirements. The obvious need for complete secrecy in deep submarine communications brought about an amplified interest in ELF systems. Fleet ballistic missile submarines (POLARIS) necessarily remained submerged at very great depths for long time periods. Traditional surface communications modes were abandoned by these submarine nuclear armories, where such vulnerability would be negated by a new mode. It was well established that radiowaves were attenuated by seawater inversely as the frequency decreased. ELF ground conduction waves were found capable of reaching any required depth. Continually transmitting and receiving command base messages while completely submerged, POLARIS submarines could then engage enemy forces with previously unheard tactical efficiency. In addition to these low propagation losses, ELF signals demonstrated a remarkable resistance to natural and EMP disturbances. A project was initiated for the explicit construction of an EMP safe radiowave communications system in the Extra Low Frequency band of the wave radio spectrum.


Not surprisingly, RCA initiated experiments on the first new Naval ELF technologies. Their project was originally called PANGLOSS (1959), a reference to panglobal submarine systems. The ominous project tide was changed to SANGUINE (1962). RCA supplied over 100 senior engineers and science advisers to this task by 1963. In the interest of averting engagements with a growing public awareness, the name SEAFARER as finally chosen (1973).

This latter less threatening name referred analysts to communications aspects of the project. The Project had several problems to solve. The first was the establishment of landbased ELF antennas. The second was the deployment of systems made for submerged craft. ELF brought with it an encumbrance to submarines, the required antennas being extreme in length. Submarines would be equipped with a highly insulated trailing antenna of a kilometer or more length. Antennas used in the SEAFARER project would necessarily be deployed during communications, and reeled back into the craft during battle.

Rogers VLF wave antennas formed the original group of patents serving submarines. Naval high classification status was periodically granted and revoked on these antenna systems throughout the years between the World Wars. These patents formed the core of renewed interest in ELF communications, the conductivity and propagation attributes of seawater being critical to the success of the venture. The World War I Rogers designs were restudied. Rogers employed VLF dipoles which spanned the submarines of that time. Because of the frequencies employed, submarines would necessarily rise close to the surface when communicating with their command base. If these methods were scarcely acceptable during World War II, they were now certainly out of the question. POLARIS bearing submarines would have to remain completely submerged at all times, and only ELF could completely penetrate seawater to their extreme depths. Engineering contracts were issued to several research groups in order to learn more about this mysterious extra low frequency region. The hope was that ELF would provide military with an “invincible” communications system.