Some qoute from wiki will give us an idea as
@Technogaianist mention ,how big the project might be. If Pakistan really install this kind of VLG ELF facilities without any previous news then Navy have done very important work without any footprints.
Project Sanguine
Clam Lake, Wisconsin
ELF transmitter in 1982, part of Project ELF, the downsized successor to Sanguine. Sections of the
right of ways for the power lines that make up the two 14-mile-long ground dipole antennas can be seen passing through the forest in lower left.
Project Sanguine was a U.S. Navy project, proposed in 1968 and only implemented in a more limited form, to create a hardened
extremely low frequency (ELF) radio
transmitter facility in
Wisconsin to communicate with deeply submerged submarines.
[1][2][3] The originally proposed system would have a giant "
antenna" consisting of 6000 miles of buried cables in a rectangular grid covering 22,500 square miles, 40% of the state of Wisconsin,
[1]powered by 100 underground power plants in concrete bunkers.
[2][3] The cables were
grounded at their ends, and loops of AC electric current flowed deep in the ground between the ends of the cable, generating ELF waves; this is called a
ground dipole. The original design was projected to cost billions
[4] and consume 800 megawatts of power.
[1][5] The goal was a system that could transmit tactical orders one-way to U.S. nuclear submarines anywhere in the world, and survive a direct nuclear attack.
[2]
The project was controversial from the start and was attacked by politicians,
antiwar and
environmental groups concerned about the effects of high ground currents and electromagnetic fields on the environment.
[2][3][6][7] The nuclear survivability of the system was made doubtful by Soviet development of
MIRV ballistic missiles.
[3]After an attempt to resite the project in the
Llano Uplift of Texas
[8] was also stopped by public opposition,
[3] the Navy abandoned Sanguine and proposed a series of increasingly modest variants: Project Seafarer (1975), Austere ELF (1978), and finally
Project ELF (1981), which was constructed.
[3][5] The system became operational in 1989, and was used until 2004, when it became obsolete and was shut down.
Project ELFEdit
Map showing location of the US Navy ELF transmitters. The red lines show the paths of the ground dipole antennas. The Clam Lake facility
(left) had two crossed 14 mi. ground dipoles. The Republic facility had two 14 mi. dipoles oriented east-west, and one 28 mi. dipole oriented north-south.
The scaled-down system the Navy eventually constructed, called Project ELF, began testing in 1982 and became operational in 1989.
[9] It consisted of two transmitter facilities, one at
Clam Lake, Wisconsin and one at
Republic, Michigan.
[9] with a total of 84 miles
[10] of above-ground transmission line antenna. The two transmitters normally operated synchronized together as one antenna for greater range, but could also operate independently. The scaled down system was not designed to survive a nuclear attack.
The Clam Lake facility, which served as the test site and was originally called the Wisconsin Test Facility (WTF) consisted of two 14-mile (24 km) transmission line antennas (called
ground dipoles) in the shape of a cross, with the transmitter station at their intersection.
[1][11] The Republic facility consisted of three transmission lines, two 14-mile and one 28-mile,
[1] in the shape of the letter "F" (the shape is not significant and was dictated by land availability).
[11] The lines, made of 1.5 cm aluminum cable supported on insulators on 40 ft. wooden utility poles, resembled ordinary power transmission lines.
[2] The ends of the transmission lines were
grounded by 1 to 3 miles of buried copper cable and ground rods,
[2] later replaced by arrays of electrodes in deep 300 ft. boreholes
[1] The transmitters sent
alternating currents of 300 amperes through the lines, which passed through the buried electrodes deep into the Earth.
[2]
Clam Lake ground dipole antenna, showing how it works. The alternating current
I in the line is shown flowing in only one direction for clarity.
The transmitters operated at a
frequency of 76 Hz in the
extremely low frequency band, with an alternate capability at 45 Hz
[2] and used a combined power of 2.6 megawatts.
[5]They were able to communicate with submarines over about half the world's surface. The system transmitted continuously, 24 hours a day, sending an "idle" message when it was not being used, so that submarines could verify they were within communication range.
[9][11]
Because of the extremely small
bandwidth of the ELF band, the transmitters had a very slow
data rate. They couldn't transmit voice (
audio) but only short coded text messages of a few letters.
[5][10] Reportedly it took 15 minutes to transmit a single 3 letter code group.
[10][11] Therefore the system was not used to relay operational orders, but served a "bell-ringer" function, ordering specific submarines to the surface to receive detailed orders by ordinary radio and satellite communications links.
[10]
The system was controversial, and was the target of legal attacks, suits and protests throughout its operating life.
[6][7] On five occasions protesters cut down transmission line poles, interrupting operation briefly.
[7]
In 2004 the Navy shut down both transmitters, with the explanation that
very low frequency (VLF) communication systems had improved to the point that the ELF system was unnecessary.
[7]
How ELF communication works
Other ELF transmittersEdit
The US, Russia and India are the only nations known to have constructed ELF communication facilities. The
Indian Navyhas an operational ELF communication facility at the
INS Kattabomman naval base to communicate with its
Arihant class and
Akula class submarines.
[12][13] The
Russian Navyreportedly operates an ELF transmitter,
ZEVS, located northwest of
Murmansk on the
Kola Peninsula in northern Russia.
[14]