Check Out These Amazing Self-Soldering Sleeves From World War II

January 31, 2024 by Lewin Day 18 Comments

Imagine you’re a commando, doing some big secret mission on the continent in the midst of World War II. You need to hook up some wires to your explosive charges, and time is of the essence. Do you bust out the trusty Weller and see if those petulant Axis chaps will let you plug it in somewhere? No! You use a pyrotechnic self-soldering sleeve, as [Our Own Devices] explains.

Like so many British inventions during the war, the sleeves really are ingenious. They were developed by the Special Operation Executive, an organization charged with sabotage and subversion operations in then-occupied Europe.

The soldering sleeves were designed to make electrical connections between detonators and firing wires for explosives. The sleeves consist of a copper tube through which wires to be joined are fed, with a lump of solder in the middle. The assembly is covered in pyrotechnic material with a safety match-style starter chemical dosed on top. Using the sleeves is simple. First, two stripped wires are fed into either end of the copper tube. The starter the sleeve is then ignited using the box, just like striking a match. The pyrotechnic material then gets red hot, melting the solder and making the connection.

It’s well worth watching the video to see how these field-expedient devices actually work. We’ve explored the use of more-typical solder sleeves before, too. Video after the break.

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The Fliegerfaust Roars Back To Life After 77 Years

March 9, 2022 by Tom Nardi 36 Comments

As their prospects for victory in the Second World War became increasingly grim, the Germans developed a wide array of outlandish “Wonder Weapons” that they hoped would help turn the tide of the war. While these Wunderwaffe obviously weren’t enough to secure victory against the Allies, many of them represented the absolute state-of-the-art in weapons development, and in several cases ended up being important technological milestones. Others faded away into obscurity, sometimes with little more then anecdotal evidence to prove they ever even existed.

One of these forgotten inventions is the Fliegerfaust, a portable multi-barrel rocket rocket launcher designed for use against low-flying attack planes. Although thousands were ordered to defend Berlin in 1945, fewer than 100 were ever produced, and there’s some debate about how many actually survived the war. But that didn’t stop [Jonathan Wild] of Wild Arms Research & Development from building a functional replica of the weapon based on contemporary documentation and blueprints.

Building the launcher was relatively straightforward, as it’s little more than nine tubes bundled together with a handle and a simplistic electric igniter. The trick is in the 20 mm (0.78 inch) rockets themselves, which are spin stabilized by the exhaust gasses exiting the four angled holes on the rear. With no fins or active guidance the path of each rocket is somewhat unpredictable, but this was known to be true of the original as well.

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Historical Hackers: Emergency Antennas Launched By Kite

May 12, 2021 by Al Williams 24 Comments

Your airplane has crashed at sea. You are perched in a lifeboat and you need to call for help. Today you might reach for a satellite phone, but in World War II you would more likely turn a crank on a special survival radio.

These radios originated in Germany but were soon copied by the British and the United States. In addition to just being a bit of history, we can learn a few lessons from these radios. The designers clearly thought about the challenges stranded personnel would face and came up with novel solutions. For example, how do you loft a 300-foot wire up to use as an antenna? Would you believe a kite or even a balloon?

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Abraham Wald’s Problem Solving Lesson Is To Seek What’s Not There

August 1, 2019 by Al Williams 26 Comments

You may not know the name Abraham Wald, but he has a very valuable lesson you can apply to problem solving, engineering, and many other parts of life. Wald worked for the Statistical Research Group (SRG) during World War II. This was part of a top secret organization in the United States that applied elite mathematical talent to help the allies win the war. Near Columbia University, mathematicians and computers — the human kind — worked on problems ranging from how to keep an enemy plane under fire longer to optimal bombing patterns.

One of Wald’s ways to approach problem was to look beyond the data in front of him. He was looking for things that weren’t there, using their absence as an additional data point. It is easy to critique things that are present but incorrect. It is harder to see things that are missing. But the end results of this technique were profound and present an object lesson we can still draw from today.

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Simulating The Enigma’s Oddball Cousin

June 16, 2019 by Tom Nardi 11 Comments

Even if you wouldn’t describe yourself as a history buff, you’re likely familiar with the Enigma machine from World War II. This early electromechanical encryption device was used extensively by Nazi Germany to confound Allied attempts to eavesdrop on their communications, and the incredible effort put in by cryptologists such as Alan Turing to crack the coded messages it created before the end of the War has been the inspiration for several books and movies. But did you know that there were actually several offshoots of the “standard” Enigma?

For their entry into the 2019 Hackaday Prize, [Arduino Enigma] is looking to shine a little light on one of these unusual variants, the Enigma Z30. This “Baby Enigma” was intended for situations where only numerical data needed to be encoded. Looking a bit like a mechanical calculator, it dropped the German QWERTZ keyboard, and instead had ten buttons and ten lights numbered 0 through 9. If all you needed to do was send off numerical codes, the Z30 was a (relatively) small and lightweight alternative for the full Enigma machine.

Creating an open source hardware simulator of the Z30 posses a rather unique challenge. While you can’t exactly order the standard Enigma from Digi-Key, there are at least enough surviving examples that they’ve been thoroughly documented. But nobody even knew the Z30 existed until 2004, and even then, it wasn’t until 2015 that a surviving unit was actually discovered in Stockholm.

Of course, [Arduino Enigma] does have some experience with such matters. By modifying the work that was already done for full-scale Enigma simulation on the Arduino, it only took a few hours to design a custom PCB to hold an Arduino Nano, ten buttons with matching LEDs, and of course the hardware necessary for the iconic rotors along the top.

The Z30 simulator looks like it will make a fantastic desk toy and a great way to help visualize how the full-scale Enigma machine worked. With parts for the first prototypes already on order, it shouldn’t be too long before we get our first good look at this very unique historical recreation.

Operation Backfire: Witness To The Rocket Age

February 5, 2019 by Tom Nardi 48 Comments

As the prospects for Germany during the Second World War began to look increasingly grim, the Nazi war machine largely pinned their hopes on a number of high-tech “superweapons” they had in development. Ranging from upgraded versions of their already devastatingly effective U-Boats to tanks large enough to rival small ships, the projects ran the gamut from practical to fanciful. After the fall of Berlin there was a mad scramble by the Allied forces to get into what was left of Germany’s secretive development facilities, with each country hoping to recover as much of this revolutionary technology for themselves as possible.

One of the most coveted prizes was the Aggregat 4 (A4) rocket. Better known to the Allies as the V-2, it was the world’s first liquid fueled guided ballistic missile and the first man-made object to reach space. Most of this technology, and a large number of the engineers who designed it, ended up in the hands of the United States as part of Operation Paperclip. This influx of practical rocketry experience helped kick start the US space program, and its influence could be seen all the way up to the Apollo program. The Soviet Union also captured V-2 hardware and production facilities, which subsequently influenced the design of their early rocket designs as well. In many ways, the V-2 rocket was the spark that started the Space Race between the two countries.

With the United States and Soviet Union taking the majority of V-2 hardware and personnel, little was left for the British. Accordingly their program, known as Operation Backfire, ended up being much smaller in scope. Rather than trying to bring V-2 hardware back to Britain, they decided to learn as much as they could about it in Germany from the men who used it in combat. This study of the rocket and the soldiers who operated it remains the most detailed account of how the weapon functioned, and provides a fascinating look at the incredible effort Germany was willing to expend for just one of their “superweapons”.

In addition to a five volume written report on the V-2 rocket, the British Army Kinematograph Service produced “The German A.4 Rocket”, a 40 minute film which shows how a V-2 was assembled, transported, and ultimately launched. Though they are operating under the direction of the British government, the German soldiers appear in the film wearing their own uniforms, which gives the documentary a surreal feeling. It could easily be mistaken for actual wartime footage, but these rockets weren’t aimed at London. They were being fired to serve as a historical record of the birth of modern rocketry.

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Prop WWII Machine Gun Courtesy Of Home Depot

May 16, 2018 by Tom Nardi 7 Comments

There’s perhaps nothing worse than working on a project and realizing you don’t have the part you need to complete it. You look through all your stuff twice, maybe three times, on the off chance it’s hiding somewhere. Perhaps even reach out to a few nearby friends to see if they might have something you can use. Forget local stores, what you need is so specific that nobody’s going to keep it in stock. You’re stuck, and now everything has to be put on hold.

That’s precisely what happened to [Nathan Cragun] recently. He needed a Japanese Type 96 Light Machine Gun for a particular scene in the independent World War II film he’s working on, and couldn’t find one anywhere. Out of options, he ended up building a replica with parts from the hardware store. OK, so it isn’t exactly like being short a passive component or two on that new PCB you’re putting together. But while we can’t say a project of ours has ever been short a 70+ year old Japanese machine gun, we can definitely relate to the feeling.

To start his build, [Nathan] printed out a full size diagram of the Type 96 and starting placing PVC pipes on top of it to get a sense for how it would all come together. Once the basic tubular “skeleton” of the weapon was completed, he moved on to cutting the rest of the parts out of EVA foam.

The major pieces that needed to be made were the stock and receiver, but even small details like the spiral ribbing on the barrel and the sights were created to scale using pieces of foam. In a particularly nice touch, [Nathan] even made the magazine removable. If we had to guess, some Japanese soldiers will be shown reloading the weapon onscreen for added authenticity.

The important thing to remember with a filming prop like this is that it doesn’t need to look perfect, just close. It might be used in the background, or seen only for a second during a fast pan. Even in professionally produced TV and movies, many of the props are little more than carved foam. With the excellent job [Nathan] did painting and weathering this build, we have no doubt it will look completely believable in the final production.

We’re no strangers to prop builds here at Hackaday, but they are generally of the science fiction or video game variety, so a historical build is a nice change of pace.