[HCARC] Fwd: [SFDXA] The Goliath Antenna Network Allowed Nazi Leadership to Communicate with their Covert U-Boat Fleet

[DON MURRAY W4WJ]

FYI... INTERESTING STUFF!! 73, DON, W4WJ

From: Bill <bmarx at bellsouth.net>
Date: Tuesday, March 24, 2020
Subject: [SFDXA] The Goliath Antenna Network Allowed Nazi Leadership to Communicate with their Covert U-Boat Fleet
To: 'SFDXA Reflector' <sfdxa at mailman.qth.net>, qcWA <qcwa69 at mailman.qth.net>
 From Tony N2MFT:


  The Radio Network that Allowed Communication with Submarines

Communicating with covert fleets during WWII required some special 
equipment.

Trevor English <https://interestingengineering.com/author/trevor-english>
By Trevor English 
<https://interestingengineering.com/author/trevor-english>
March 21, 2020
<https://www.reddit.com/submit?url=https%3A%2F%2Finterestingengineering.com%2Fthe-radio-network-that-allowed-communication-with-submarines>
The Radio Network that Allowed Communication with Submarines
FactoryTh/iStock 
<https://www.istockphoto.com/tr/en/photo/telecommunication-tower-on-the-green-field-gm1148194083-310001946> 


What do you do when you need to communicate with a crew of *50 sailors* 
submerged in a submarine in an undisclosed location across the world's 
oceans? That was a difficult question to answer for Navy leaders in WWII.

Radio waves don't easily travel through saltwater, which meant that 
getting active communication with a submarine crew meant making the 
submarine surface an antenna. This was the obvious solution, but it made 
a previously covert submarine now a visible target.


    The solution to the problem

Engineers tasked with finding a more covert solution soon discovered 
that radio waves with low frequencies, around *10 kHz*, could penetrate 
saltwater to depths up to around *20 meters*. They realized that if the 
transponders on submarines were switched to these frequency ranges, then 
they communicate with leadership 
<https://www.nonstopsystems.com/radio/hellschreiber-mil-tx-rx.htm> on land.

The problem with this idea was that creating and broadcasting these 
low-frequency radio waves required massive antennas. Essentially, the 
lower the frequency of a radio wave, the longer and larger the antenna 
is required to be.

*RELATED: WHEN THE INTERNET AND CELL PHONE NETWORKS GO DOWN, AMATEUR 
RADIO NETWORK OPERATORS STEP UP 
<https://interestingengineering.com/when-the-internet-and-cell-phone-networks-go-down-amateur-radio-operators-step-up>*

Engineers honed in on a range of frequencies lower than *30 kHz* for 
submarine communication. The wavelength of these frequencies were 
roughly *10 kilometers* or more, meaning that engineers would need 
massive antennas. The only way to produce these frequencies with such a 
high range was to use a massive system of antennas with massive amounts 
of power.

Nazi engineers seeking to communicate with their fleet of U-boats 
designed the Goliath antenna network in Saxony-Anhalt, Germany. After 
construction, it was operated during World War II and had a transmission 
power of up to *1,000 kilowatts*. For comparison, that's equivalent to 
the power draw of *500 average* American households.


    The Goliath Radio Transmitter

The Goliath network would regularly transmit frequencies between *15 
kHz* and *25 kHz*. It was powerful enough to reach any German submarine 
located anywhere in the world submerged up *20 meters*. The only time 
communication was hindered was when German U-boats were navigating deep 
Norwegian fjords.

The Goliath antenna used three different umbrella antennas. These were 
essentially massive antenna towers that were then draped with kilometers 
of guy wires radiating from the mast. These helped not support the 
antenna tower, but also formed part of the antenna itself.

The Radio Network that Allowed Communication with Submarines 
/Source: Евгений Катышев 
<https://en.wikipedia.org/wiki/Goliath_transmitter#/media/File:Royka_and_Goliath.jpg>/ 


In total, the system used three *210 meter* or *688-foot* masts arranged 
in a triangle. The system also had cables buried around it with a total 
length of *350 kilometers*. Once it was completed, it had an impressive 
efficiency of *50%* at *15 kHz* and *90%* at *60 kHz*.

*RELATED: YOU COULD DOWNLOAD VIDEO GAMES FROM THE RADIO IN DURING THE 
1980S 
<https://interestingengineering.com/you-could-download-video-games-from-the-radio-in-the-1980s>*

This massive antenna site was undoubtedly a key strategic tool used by 
the German Navy in communicating with their U-Boat fleet.

After the war ended, the Soviets came in and dismantled the Goliath and 
shipped it to Russia. It was then erected near Moscow. Today, one of the 
original towers is still in operation communicating low-frequency 
signals with submarines and broadcasting time signals.


    A deeper dive into how low-frequency networks function

Low-frequency radio frequencies are anywhere in the range of *30 to 300 
kHz* and their wavelengths range from *1 to 10 kilometers*.

Because their wavelengths are so long, they are the perfect tool for 
long-range communication networks. Low-frequency radio waves, or LF 
radio, is used for AM radio stations across the world, allowing them to 
broadcast the same message from a centralized location many hundreds of 
miles.

One of the other massive benefits of LF radio signals is the fact that 
their long wavelength allows them to diffract over very large physical 
obstacles, like mountains, or even the earth. LF waves can follow the 
curvature of the earth with ease utilizing ground wave propagation. Low 
frequency waves sent through ground propagation can be clearly received 
over *1,200 miles* from the original source.

Another way that LF radio waves can be transmitted ultra-long distances 
is by intentionally reflecting the waves off of the earth's ionosphere. 
This is called skip propagation or skywave, and it allows frequencies to 
be transmitted distances over *190 miles* from the original source. Not 
as far as ground wave propagation, but still an impressive distance.

The other benefit of low-frequency waves, underscored by the Goliath 
transmitter's use, is the fact that low kHz low-frequency waves, under 
*50 kHz*, can penetrate ocean depths of roughly *200 meters*. As the 
wavelength gets longer, the penetration depth gets deeper.

Most of the world's superpowers still use some form of this LF 
transmission to communicate with submarines and underwater vessels 
today. The Royal Navy nuclear submarines stationed around the United 
Kingdom listen to a *198 kHz* frequency for orders to launch their 
ballistic missiles.

The U.S. built out something called the Ground Wave Emergency Network, 
named GWEN. It ran between the ranges of *150* and *175 kHz* up until 
1999 when satellites far outperformed the LF network's usefulness.


https://interestingengineering.com/the-radio-network-that-allowed-communication-with-submarines 


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