- You know, it's hard to believe
that if World War III would have ever started
it would have started right here.
(energetic ambient music)
- Nestled deep in the Chequamegon-Nicolet National Forest
in Northwest Wisconsin
is the small town of Clam Lake.
Clam Lake is best known for the excellent hunting
and fishing in the area,
and of course the herd of elk
that roam the countryside.
But the elk population is more of a side effect
of what I'm gonna talk about.
At one time this area was home to a military base
and in fact, World War III
could have been signaled from its location.
I'm talking about Project ELF,
the Navy's program to send messages
to submarines deep under water.
Let's explore Project ELF,
a Cold War relic, and still has an impact today.
Early in the Navy's nuclear submarine program
there was a clear need to communicate
to the subs underway.
Submarines would have to either rise to periscope depth
to deploy an antenna above the water
or tow along a wire at a shallow depth.
High frequency radio signals
could only penetrate a few feet,
leaving the sub vulnerable.
The conventional knowledge
is that lower frequency radio waves
have a greater degree of ground penetration
than higher frequency waves,
but how low can you go.
Research in the 1950's revealed
that extremely low frequency
in the area of 40 to 80 hertz
would give adequate penetration
through the ground and deep under water.
But early experiments in communicating
with submarines were based on a variety
of very low frequency and acoustic methods,
and not so much with the much lower
extremely low frequencies.
VLF stations were easier to deploy,
but the concern the Navy had
was that VLF station's proximity
could reveal the approximate location
of the submarines through direction finding techniques.
Other downsides of VLF signals
was the limited water penetration
and subs had to slow down and limit fast maneuvers
while the long VLF antennas were deployed.
In the early 1960's
a greek physicist, Nicholas Christofilos
made a discovery
that with above ground nuclear explosions,
the high energy particles would be trapped
in the ionosphere, causing a magnetic
and radio frequency disruption.
But ELF or extremely low frequency signals
were particularly immune to this effect
as they don't require the ionosphere
for propagation and have deep earth penetrating properties.
This imperviousness to nuclear electromagnetic pulses
led to a greater study of ELF signals
for submarine communications.
Early experiments in ELF communications were promising
and this led the Navy on
to continue experiments under the name Project Sanguine.
The key to effective extremely low frequency propagation
lies in the ground, the bedrock that is.
A transmitter site and antenna array
would need a location with deep rock
and very low ground conductivity.
The antenna system would be wires
strung along telephone poles
with ground points at each end of their length.
The signal carried by the wires
would resonate into the ground between the two points.
This signal, immune to the effect of nuclear detonation,
could be received by subs deep underwater
and then launch a counterstrike.
Project Sanguine was a practical test of this system,
in 1968, a transmitter was constructed
near Clam Lake Wisconsin
and a 28 mile antenna system
in a crossed configuration radiated out
into the Chequamegon-Nicolet National Forest.
This site, called the Wisconsin Test Facility
was on a large mass of pre-Cambrian granites
and bedrock of the Laurentian Plateau.
The bedrock located in Northern Wisconsin
was well suited for this project,
and the remote area of the national forest
was far from populations that could be affected
by the transmission.
The Wisconsin test facility consisted
of a single set of transmitters
and 28 miles of antenna in a crossed configuration,
but the Navy had grander plans
for up to 6,000 miles of buried antenna
and hundreds of hardened underground transmitters
pumping out signals 24 hours a day.
The project wasn't without opposition,
and in 1973, Melvin Laird the Secretary of Defense
at the time, and a former Wisconsin congressman,
killed the project.
This was mostly due to its now projected cost
of billions of dollars for the expansive antenna network,
but also growing environmental and public concerns
of the effects of these extremely low frequency signals
in his Wisconsin homeland.
ELF or E-L-F languished through much of the 1970s,
there was some research being done
under a similar project called Seafarer
and the Wisconsin test facility
managed to stay afloat in a ready state.
Enter 1981, President Ronald Reagan's
hard line approach to soviet communism
revived the ELF program but at a much smaller scale.
The 28 mile antenna array and transmitter
existing at Clam Lake
would be joined with a larger 57 mile array
in Republic, Michigan, 148 miles away.
This is near the K.I Sawyer Air Force base
in the Upper Peninsula.
These two stations could run independently
or be synchronized to increase their range and penetration.
With both stations on the air,
a signal would carry over the Arctic Circle,
through much of the Atlantic
and into the Pacific as far west as the Philippines.
Project ELF was back in business.
Construction began on a facility
in Republic, Michigan in 1985
and Clam Lake site was upgraded
with four 650 kilowatt transmitters.
And Republic would have four 500 kilowatt transmitters.
The combined power output of these sites
when synchronized was a 4.4 megawatt signal
that radiated deep into the ground.
Test transmissions continued through the 1980's
and by 1989, both Clam Lake and Republic
were on full time service transmitting
a signal 24 hours a day.
Now let's talk a little bit about the signal,
as you really can't send a voice message
to the submarines under water.
Instead a digital mode known as minimum shift keying
was used.
Minimum shift keying, or MSK modulates
each half of the signal's sine wave.
It is relatively impervious to linear distortion,
but the bit rate, which is determined
by the frequency separation, can be very slow.
Since we are talking about a signal of 76 hertz,
an MSK signal would have an extremely low bit rate
and it could take up to 15 minutes
to deliver a three character code.
The signal was carried on aluminum cables
strung out on 30 foot poles
in an antenna system radiating out seven miles
in each of four directions or 28 miles total.
To the casual observer
the antenna looked just like nondescript power lines.
At the end of each antenna was a terminator
at a dry well casing bored deep into the bedrock.
The signal would radiate deep into the ground.
The Navy, finding that the earth is resonant at 7.6 hertz,
used 76 hertz as the 10th fundamental frequency.
In essence using the very poor conductivity
of the bedrock to resonate the earth.
I find it hard to characterize
the sound of the ELF transmitters.
An author of a "Popular Communications" magazine article
in 1988 called the transmitter's hum
subtle but eerily powerful.
I think the best explanation I found
is that it sounded much like the Taos hum.
In Taos, New Mexico there is an otherworldly sound
that modulates around 80 hertz.
People in northern Wisconsin said
you could hear a similar humming noise
when the transmitters were operational,
but I have no definitive proof or recordings of that.
ELF transmissions continued at the Clam Lake
and Republic, Michigan sites until 2003.
At this time the technology of submarine signaling
had eclipsed the brute force
of extremely low frequency transmissions
and the ELF project was always
a lightning rod to political opposition.
From being held up as a waste in government spending
by politicians, to opposition by environmental
and anti war groups, the transmitter,
while seemingly benign, was never such.
Through much of the 1990's, protestors would cut down
antenna poles or sever transmission lines.
The 28 miles of antennas,
which were for the most part unguarded
as they were in the national forest.
While transmission lines were obscured
when they crossed roads or other public right of ways,
they were really pretty much an easy target to protest.
So where does that leave us today?
Even though the transmitter operated through the 1990's,
I believe the end of the cold war
and the disarmament of much of the world's nuclear weapons
left project ELF by the wayside.
It was not much of a necessity
to run a fail safe type transmission operation
especially since global nuclear war
is now seen as a low risk.
The forward march of technology
along with a lack of political favor
deemed the project obsolete.
In 2004 Project ELF officially ended.
The Republic, Michigan site was mothballed
but Clam Lake site was completely decommissioned.
The decision to close the facility
stated that it was functionally obsolete
as there were better methods of signaling submarines.
By 2007 the transmission lines had been completely removed
and the buildings, with the exception of one,
at the transmitter site, all razed.
But we can still visit the site
and get a feeling for the scope of Project ELF.
So Joe and I did just that.
On a sunny October day we took a trip
through the Chequamegon-Nicolet National Forest,
bouncing along poorly maintained forest roads
to look at antenna cuts in the forest
and the location of the Clam Lake transmitter itself.
All of the land has returned to the forest service
and there is nothing of a military interest left,
but walking into the site,
you get an inkling of what it must feel like
to be on the ground zero points
of global thermonuclear war.
- [Joe] Found one.
- [Michael] Yup.
- [Joe] There's the opening.
- [Michael] So this would be the drive
to the transmitter site.
- [Joe] Yeah.
- [Michael] And actually, that clearing there
is part of the facility.
This building here, I think is one
of the original buildings.
- I think it's used by the Forest Service now.
- [Michael] Yeah, they're just using it for storage.
Of course, when this was in operation,
this would've been all gated and fenced.
- And they would've probably had a couple M16's
in our face. - Yeah.
- So you can see right down this way
where one of the cuts was for the antenna.
Then it goes down this way. - Yup, and there's another
big cut.
Really, the facility wasn't that large.
It was just half a dozen buildings,
mostly steel sheds like this.
It held the transmitter, power generators,
and that's about it.
- Yeah, here's your grounding right back here.
- Whoa. - What?
- Yeah. (chuckles) - I thought you scared
me there. - No.
- Yeah, look at that cable.
It's like weaved almost, and so it's smaller strands
and then they weaved it into a bigger one.
- [Michael] Okay.
- And here are the big, then this must have been attached
with plastic, so insulator or something.
- [Michael] The transmission cables were aluminum.
- Yeah, this is aluminum,
this is real light. - Yeah, aluminum wire.
- This is real- - Aluminum cable I should say.
- I would say this may be
the same type of cable that they used
for the transmission. - And they're using it
for their grounding system. - Yeah.
It's real flexible actually, that's interesting.
Yeah.
(upbeat music)
- We're here on one of the many forest roads
that the Project ELF antenna array crisscrossed
along its 22 mile length.
The antennas, you know, they came out
in sort of a cross or an X configuration
from the transmitter site
and each leg was approximately seven-ish miles.
And here, you can kinda, you can still see the cuts
where the antenna ran.
The antenna's were on telephone poles
about 30 feet in height,
and they just went out down the cut,
and at the end of each leg where it terminated,
giant well casings driven into the bedrock.
They were terminated,
and the way in which the antenna resonated
is that the ground here, geologically
is very hard, the bedrock is close to the surface here,
it's very old, pre-Cambrian basalt,
so it's hard, igneous rock
that when the transmitter kicked in,
you know, there was practically
no ground conductivity.
So it had, the antennas you know, that the signal had
very good ground penetration
but nothing you know, nothing to really
radiate into the air, and that was the whole purpose
of Project ELF, is to get that signal
into the ground, go through the ground,
go through the water and reach the submarines.
The cuts here, they're a couple hundred yards wide
and they're still, you can't,
the antennas were removed in the early 2000's
so a lot of the scrubby poplars and that are growing up
so they're getting harder and harder to see.
But because there's an established elk herd here,
they're somewhat maintained
because the elk like to use these long antenna runs
as part of their habitat.
To this day you can still see the scars
of the transmitter site
and antennas in the national forest.
I think that this is the legacy of the ELF site,
a scar on landscape that's a reminder
of how close we were
to being on the brink of destruction
during the Cold War, to what is now a vital habitat
for the national forest's deer and elk population.
I'd like to thank everyone
that helped with the production of this video,
especially Aaron Webb for pitching me the idea
and Travis Augustine for showing us the forest roads
in and around the site.
Thank you to Joe for coming along on this adventure
and giving his perspective.
Also a big thank you to our patrons over on Patreon
for helping keep the mission alive
to educate and inspire the amateur radio community.
Your support helps us produce content like this.
Are you interested in more about Project Elf?
A bibliography with many of my references
are down in the video description below.
Questions, comments, leave them below
and I'll try to answer them.
Your support of this channel
drives the production of future videos,
so like and subscribe and check us out on Patreon.
That's it for this time,
I'm Michael, KB9VBR have a great day and 73