Retrotechtacular: Firepower For Freedom

As the United States were settled, its leaders found that they needed firepower to preserve freedom. This became especially apparent during the military engagements of the era, so a number of specialized facilities were founded to manage the research, development, manufacture, and dissemination of different types of munitions.

Picatinny Arsenal in New Jersey was the place for both nuclear and conventional weapon development. The men and women working in this facility created anti-personnel devices, including a flexible, adhesive charge called Flex-X that could be affixed to almost anything. This demolition charge could be layered for increased power, and could even detonate underwater. Picatinny also developed new rocket engines, propellants, and liquid propulsion for projectiles.

In Pennsylvania, a small-arms ammunition plant called Frankford Arsenal developed a duplex rifle cartridge. That is, a lead projectile fires on target, and a second one sitting behind it in the cartridge shoots at an angle, landing an inch or so near the lead bullet. Frankford workers also ground precision optics for target sighting and centering, and developed a case-less cartridge. Propellants geared for a wide variety of uses also came out of Frankford. These propellants were employed to deliver nerve agent antidotes, inflate life rafts quickly, and eject pilots from sketchy situations.

The Edgewood Arsenal in Baltimore specializes in the research and development, manufacture, and supply of chemical weapons. They are particularly adept at fire suppression. Edgewood research has provided civilian benefits as well, such as an anthrax vaccine. In addition, Fort Detrick, Maryland contains a biological R&D wing where vital antidotes and vaccines are developed.

All of this R&D and manufacture was orchestrated by the Ammunition Procurement and Supply Agency (APSA) located near Joliet, IL. In addition to reviewing all contractor bids with equal consideration, APSA controlled distribution, maintaining inventory on large computers that could crunch numbers like nobody’s business.

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Retrotechtacular: Gone Fission

This week’s film begins as abruptly as the Atomic Age itself, though it wasn’t produced by General Electric until 1952. No time is wasted in getting to the point of the thing, which is to explain the frightening force of nuclear physics clearly and simply through friendly animations.

[Dr. Atom] from the Bohr Modeling Agency describes what’s going on in his head—the elementary physics of protons, neutrons, and electrons. He explains that atoms can be categorized into families, with uranium weighing in as the heaviest element at the time. While most atoms are stable, some, like radium, are radioactive. This evidently means it stays up all night doing the Charleston and throwing off neutrons and protons in the process of jumping between atomic families. [Dr. Atom] calls this behavior natural transmutation.

Artificial transmutation became a thing in the 1930s after scientists converted nitrogen into oxygen. After a couple of celebratory beers, they decided to fire a neutron at a uranium nucleus just to see what happened. The result is known as nuclear fission. This experiment revealed more about the binding force present in nuclei and the chain reaction of atomic explosions that takes place. It seemed only natural to weaponize this technology. But under the right conditions, a reactor pile made from graphite blocks interspersed with U-235 and -238 rods is a powerful and effective source of energy. Furthermore, radioactive isotopes have advanced the fields of agriculture, industry, medicine, and biochemistry.

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Hanging Out With Someone Who Walked On The Moon

Lunar dune buggy rides, piloting the most powerful machine made by humankind, stuck thrusters, landing, eating, sleeping, and working on the moon. It does not get any more exciting than the Apollo program! I was recently given the opportunity to sit in on the MIT course, Engineering Apollo: the Moon Project as a Complex System where I met David Scott who landed on the moon as commander of Apollo 15. I not only sat in on a long Q and A session I also was able to spend time with David after class. It is not every day you that you meet someone who has landed on the moon, below are my notes from this experience.

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Retrotechtacular: The Spirit of Radio

Many of us still tune in to terrestrial radio for one reason or another, be it baseball games, talk radio, or classic rock. But do you know how the sound is transmitted to your receiver? This week, our spotlight shines upon a short film produced by KYW Radio that serves as a cheerful introduction to the mysteries of amplitude modulation (AM) radio transmission as they were in 1940.

Sound vibrations enter a microphone and are converted to electrical current, or an audio waveform. The wave is amplified and sent several miles away to the transmitting station. During this trip, the signal loses power and so is amplified at the transmitting station in several stages. This audio wave can’t be transmitted by itself, though; it needs to catch a ride on a high-frequency carrier wave. This wave is generated on-site with a huge crystal oscillator, then subjected to its own series of amplifications prior to broadcast.

The final step is the amplitude modulation itself. Here, the changing amplitude of the original audio wave is used to modulate that of the high-frequency carrier wave. Now the signal is ready to be sent to the tower. Any receiver tuned in to the carrier frequency and in range of the signal will capture the carrier wave. Within the reciever, these currents are converted back to the vibrations that our ears know and love.

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Retrotechtacular: Radar Jamming

It’s been said that the best defense is a good offense. When aloft and en route to deliver a harmful payload to the enemy, the best defense is to plan your approach and your exit carefully, and to interfere with their methods of detection. If they can’t find you, they can’t shoot you.

As of May 1962, the United States military was using three major classifications of radar jamming technology as described in this week’s film: the AN/ALQ-35 multiple target repeater, the AN/ALQ-55 communications link disrupter, and the AN/ALQ-41 and -51 track breakers. The most important role of these pieces of equipment is to buy time, a precious resource in all kinds of warfare.

The AN/ALQ-35 target repeater consists of a tuner, pulse generator, transmitter, and control panel working in concert to display multiple false positives on the enemy’s PPI scopes. The unit receives the incoming enemy pulse, amplifies it greatly, repeats it, and sends them back with random delays.

The AN/ALQ-55 comm disrupter operates in the 100-210MHz band. It distinguishes the threatening enemy communication bands from those of beacons and civilians, evaluates them, and jams them with a signal that’s non-continuous, which helps avoid detection.

Finally, the AN/ALQ-41 and -51 track breakers are designed to break enemy lock-on and to give false information. It provides simultaneous protection against pulse ranging, FM-CW, conical, and monopulse radar in different ways, based on each method’s angle and range.

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Retrotechtacular: Stateside Assembly and Launch of V-2 Rockets

At the end of World War II, the United States engaged in Operation Paperclip to round up German V-2 rockets and their engineers. The destination for these rockets? White Sands Proving Grounds in the New Mexico desert, where they would be launched 100 miles above the Earth for the purpose of high altitude research.

This 1947 War Department Film Bulletin takes a look inside the activities at White Sands. Here, V-2 rockets are assembled from 98% German-made parts constructed before V-E day. The hull of each rocket is lined with glass wool insulation by men without masks. The alcohol and liquid oxygen tanks are connected together, and skins are fitted around them to keep fuel from leaking out. Once the hull is in place around the fuel tanks, the ends are packed with more glass wool. Now the rocket is ready for its propulsion unit.

In the course of operation, alcohol and liquid oxygen are pumped through a series of eighteen jets to the combustion chamber. The centrifugal fuel pump is powered by steam, which is generated separately by the reaction between hydrogen peroxide and sodium permanganate.

A series of antennas are affixed to the rocket’s fins. Instead of explosives, the warhead is packed with instruments to report on high altitude conditions. Prior to launch, the rocket’s tare weight is roughly five tons. It will be filled with nine tons of fuel once it is erected and unclamped.

At the launch site, a gantry crane is used to add the alcohol, the liquid oxygen, and the steam turbine fuels after the controls are wired up. The launch crew assembles in a blockhouse with a 27-foot-thick roof of reinforced concrete and runs through the protocol. Once the rocket has returned to Earth, they track down the pieces using radar, scouting planes, and jeeps to recover the instruments.

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Retrotechtacular: Using the Jet Stream for Aerial Warfare

Unmanned Aerial Vehicles (UAV) are all the rage these days. But while today’s combative UAV technology is as modern as possible, the idea itself is not a new one. Austria floated bomb-laden balloons at Venice in the middle 1800s. About a hundred years later during WWII, the Japanese used their new-found knowledge of the jet stream to send balloons to the US and Canada.

Each balloon took about four days to reach the western coast of North America. They carried both incendiary and anti-personnel devices as a payload, and included a self-destruct. On the “business end” of the balloons was the battery, the demolition block, and a box containing four aneroid barometers to monitor altitude. In order to keep the balloons within the 8,000 ft. vertical range of the jet stream, they were designed to drop ballast sandbags beginning one day into flight using a system of blow plugs and fuses. In theory, the balloon has made it to North American air space on day four with nothing left hanging but the incendiaries and the central anti-personnel payload.

Although the program was short-lived, the Japanese launched some 9,300 of these fire balloons between November 1944 and April 1945. Several of them didn’t make it to land. Others were shot down or landed in remote areas. Several made the journey just fine, and two even floated all the way to Michigan. Not bad for a rice paper gas bag.

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