Archive for the ‘War Documentary’ Category


The katana

Posted: December 2, 2011 in Fact, Gadgets, History, How To, War Documentary, Weapon

The katana is one of the traditional Japanese swords worn by the samurai class of feudal Japan, also commonly referred to as a “samurai sword”,

The katana is generally defined as the standard size moderately curved (as opposed to the older “tachi” style featuring more curvature) Japanese sword with a blade length greater than 60 cm (23.6 inches).

With a few exceptions katana and tachi can be distinguished from each other if signed, by the location of the signature (mei) on the tang (nakago). In general the mei should be carved into the side of the nakago that would face outward when the sword was worn. Since a tachi was worn cutting edge down and the katana was worn cutting edge up, the mei would be in opposite locations on the nakago of both types of swords.

The katana is characterized by its distinctive appearance: a curved, slender, single edged blade, circular or squared guard, and long grip to accommodate two hands. It has historically been associated with the samurai of feudal Japan, and has become renowned for its sharpness and cutting ability.

In the strictest sense the term katana in Japanese is applied to any kind of single-edged sword, of any origin, and does not necessarily refer to a Japanese sword.

“Katana” was originally used as a general term for a single-edged sword having a “sori” or curvature of the blade. While the “sugata” or form can take many shapes, including double edged, the term is now used incorrectly to describe nihontō that are 2 shaku (606 mm / 24 in) and longer, also known as “dai” or “daito” among Western sword enthusiasts.

This distinguishes them from the straight-bladed chokutō, which was brought from China by way of Korea. The chokutō is speculated to have been the first “sugata” type the katana took on, being modeled after the imported swords. This emergence of the first nihontō took place the same time period as the beginning of Japanese feudalism and recognition of the daimyo or “great family” in the late ninth century.

Pronounced kah-ta-nah, the kun’yomi (Japanese reading) of the kanji 刀, originally meaning dao (sword) or knife/saber in Chinese, the word has been adopted as a loanword by the Portuguese language. In Portuguese the designation (spelled catana) means “large knife” or machete. As Japanese does not have separate plural and singular forms, both “katanas” and “katana” are considered acceptable forms in English.

Another term, Daikatana, is a pseudo-Japanese term meaning “large sword”, formed by a mistaken reading of the kanji 大刀 (Japanese: daitō), derived from the Chinese dadao. The reading mistake comes from the different ways Japanese Kanji can be read, depending on their combination or not in a word. It has been used in some (English-language) fictional works to represent a kind of large katana; the video game Daikatana, for example used this pseudo-term as its title. The correct name of this type of weapon is tachi (太刀 – note the extra stroke, and different reading of 刀), and is different from ōtachi and nodachi.

Meibutsu (noted swords) is a special designation given to sword masterpieces which are listed in a compilation from the 1700s called the “Kyoho Meibutsucho”. The swords listed are Koto blades from several different provinces, 100 of the 166 swords listed are known to exist today with Soshu blades being very well represented. The “Kyoho Meibutsucho” also listed the nicknames, prices, history and length of the Meibutsy with swords by Yoshimitsu, Masamune, Yoshihiro, and Sadamune being very highly priced.

History

The katana evolved as a more sleek and compact alternative to the tachi. Its origins go at least as far back as the Kamakura Period, with several blades dated from that time residing in various national repositories.

Its growth in popularity is believed to have been due to the changing nature of close-combat warfare. The quicker draw of the sword was well suited to combat where victory depended heavily on fast response times. The katana further facilitated this by being worn thrust through a belt-like sash (obi) with the bladed edge facing upwards. Ideally, samurai could draw the sword and strike down the enemy in a single motion. Previously, the curved tachi had been worn with the edge of the blade facing down and suspended from a belt.

The length of the blade varied considerably during the course of its history. In the late 14th and early 15th centuries, katana blades tended to be between 70 to 73 cm (27.6 to 28.7 in) in length. While during the early 16th century, the average length was closer to 60 cm (23.6 in). By the late 16th century, the average length returned to approximately 73 cm (28.7 in).

The katana was often paired with a similar smaller companion sword, such as a wakizashi or it could also be worn with the tantō, an even smaller similarly shaped sword. The pairing of a katana with a smaller sword is called the daishō. The daisho could only be worn by samurai and it represented the social power and personal honor of the samurai.

Forging and construction

The authentic Japanese sword is made from a specialized Japanese steel called “Tamahagane” which consist of combinations of hard, high carbon steel and tough, low carbon steel. There are benefits and limitations to each type of steel. High-carbon steel is harder and able to hold a sharper edge than low-carbon steel but it is more brittle and may break in combat. Having a small amount of carbon will allow the steel to be more malleable, making it able to absorb impacts without breaking but becoming blunt in the process. The makers of a katana take advantage of the best attributes of both kinds of steel. The maker begins by folding and welding pieces of high and low carbon steel several times to work out most of the impurities. The high carbon steel is then formed into a U-shape and a billet of soft steel is placed in its center. The resulting block of steel is then drawn out to form a rough blank of the sword. At this stage it is only slightly curved or may have no curve at all. The gentle curvature of a katana is attained by a process of quenching; the sword maker coats the blade with several layers of a wet clay slurry which is a special concoction unique to each sword maker, but generally composed of clay, water, and sometimes ash, grinding stone powder and/or rust. The edge of the blade is coated with a thinner layer than the sides and spine of the sword, then it is heated and then quenched in water (some sword makers use oil to quench the blade). The clay slurry provides heat insulation so that only the blade’s edge will be hardened with quenching and it also causes the blade to curve due to reduced lattice strain along the spine. This process also creates the distinct swerving line down the center of the blade called the hamon which can only be seen after it is polished; each hamon is distinct and serves as a katana forger’s signature.

The hardening of steel involves altering the microstructure or crystalline structure of that material through quenching it from a heat above 800 °C (1,472 °F) (bright red glow), ideally no higher than yellow hot. If cooled slowly, the material will break back down into iron and carbon and the molecular structure will return to its previous state. However, if cooled quickly, the steel’s molecular structure is permanently altered. The reason for the formation of the curve in a properly hardened Japanese blade is that iron carbide, formed during heating and retained through quenching, has a lesser density than its root materials have separately.

After the blade is forged it is then sent to be polished. The polishing takes between one and three weeks. The polisher uses finer and finer grains of polishing stones until the blade has a mirror finish in a process called glazing. This makes the blade extremely sharp and reduces drag, making it easier to cut with. The blade curvature also adds to the cutting power.

SM-62 Snark

Posted: November 8, 2011 in Fact, Science, Technology, War, War Documentary, Weapon

The Northrop SM-62 Snark was a specialized intercontinental cruise missile with a W39 nuclear warhead operated by the U.S. Strategic Air Command from 1958 until 1961. It takes its name from Lewis Carroll’s snark.

The Snark was developed to offer a nuclear deterrence to the Soviet Union at a time when ICBMs were still in development. It was the only intercontinental surface-to-surface cruise missile ever deployed by the United States Air Force. With the deployment of ICBMs, it was rendered obsolete and taken out of service.

Design and development
Work on the project began in 1946. Initially there were two missiles — a subsonic design (the MX775A Snark) and a supersonic design (the MX775B Boojum).[2] Budget reductions threatened the project in its first year, but the intervention of Jack Northrop and Carl Spaatz saved the project. Despite this, funding was low and the program was dogged by requirement changes. The expected due date of 1953 passed with the design still in testing and SAC was becoming less enthusiastic. In 1955, Eisenhower ordered top priority to the ICBM and associated missile programs. The original designation was B-62.

Despite considerable difficulties with the missile and military reservations toward it, work continued. In the 1957 tests the missile had a circular error probable (CEP) of only 17 nautical miles (31.5 km). By 1958 the celestial navigation system used by the Snark allowed its most accurate test, which appeared to fall 4 nautical miles (7.4 km) short of the target. However, this apparent failure was at least partially because the British Navigation Charts used to determine the position of Ascension Island were based on position determination techniques less accurate than those used by the Snark. The missile landed where Ascension Island would be found if more accurate navigation methods had been used when developing the chart. However, even with the decreased CEP, the design was notoriously unreliable, with the majority of tests suffering mechanical failure thousands of miles before reaching the target. Other factors, such as the reduction in operating altitude from 150,000 to 55,000 feet (46 to 17 km) and the inability of the system to detect countermeasures and perform evasive maneuvers also made the Snark an undesirable strategic deterrent.

Technical description
The jet powered 20.5 m long unmanned aircraft had a top speed of 650 mph (1,046 km/h) and a maximum range of 5,500 nautical miles (10,200 km). The complex stellar navigation guidance system gave a claimed CEP of 8,000 ft (2.4 km).

The Snark was an air-breathing design, launched from a light platform by two rocket booster engines. It switched to an internal jet engine for the remainder of its flight. The jet was a Pratt and Whitney J57, the first 10,000 lbf (44 kN) thrust design, also used in the early B-52 and the F-100. Lacking a horizontal tail, the missile used elevons as its primary flight control surfaces, and flew an unusual nose high aspect during level flight. During the final phase of flight the nuclear warhead separated from the missile’s main body and followed a ballistic trajectory to the target. Upon separation, due to the abrupt shift in its center of gravity, the missile body performed an abrupt pitch-up maneuver to avoid colliding with the warhead.

One advanced feature of the Snark was its ability to fly missions of up to 11 hours and return for a landing. If the warhead did not detach, the missile could be flown repeatedly. Lacking landing gear, it was necessary for the Snark to skid to a stop on a flat, level surface. The runway at Cape Canaveral is still today known as the Skid Strip.

AK-47

Posted: November 7, 2011 in Gun, War, War Documentary, Weapon

The AK-47 is a selective-fire, gas-operated 7.62×39mm assault rifle, first developed in the Soviet Union by Mikhail Kalashnikov. It is officially known as Avtomat Kalashnikova. It is also known as a Kalashnikov, an “AK”, or in Russian slang, Kalash.

Design work on the AK-47 began in the last year of World War II (1945). After the war in 1946, the AK-46 was presented for official military trials. In 1947 the fixed-stock version was introduced into service with select units of the Soviet Army. An early development of the design was the AKS (S—Skladnoy or “folding”), which was equipped with an underfolding metal shoulder stock. In 1949, the AK-47 was officially accepted by the Soviet Armed Forces and used by the majority of the member states of the Warsaw Pact.

The original AK-47 was one of the first true “assault rifles” to be manufactured, after the original Sturmgewehr 44. Even after six decades the model and its variants remain the most widely used and popular assault rifles in the world because of their durability, low production cost, and ease of use. It has been manufactured in many countries and has seen service with armed forces as well as revolutionary and terrorist organizations worldwide. The AK-47 was the basis for developing many other types of individual and crew-served firearms. More AK-type rifles have been produced than all other assault rifles combined.

Firing the 7.62x39mm cartridge, the AK-47 produces significant wounding effects when the projectile tumbles and fragments in tissue; but it produces relatively minor wounds when the projectile exits the body before beginning to yaw

Design background

During World War II, the Germans first pioneered the assault rifle concept, based upon research that showed that most firefights happen at close range, within approximately 300 meters.[citation needed] The power and range of contemporary rifle cartridges was excessive for most small arms firefights. As a result, armies sought a cartridge and rifle combining submachine gun features (large-capacity magazine, selective-fire) with an intermediate-power cartridge effective to 300 meters. To reduce manufacturing costs, the 7.92x57mm Mauser cartridge case was shortened, the result of which was the lighter 7.92x33mm Kurz.

The resultant rifle was the Sturmgewehr 44 (StG44). An earlier firearm, the Italian Cei-Rigotti combined similar features but suffered poor reliability and ejection mechanism, as well as inferior magazine capacity. Towards the end of the war, the Germans fielded the StG44 against the Soviets; the experience deeply influenced Soviet military doctrine in the post-war years.

Mikhail Kalashnikov began his career as a weapon designer while in a hospital after he was shot in the shoulder during the Battle of Bryansk.[12] After tinkering with a sub-machine gun design, he entered a competition for a new weapon that would chamber the 7.62x41mm cartridge developed by Elisarov and Semin in 1943 (the 7.62x41mm cartridge predated the current 7.62x39mm M1943). A particular requirement of the competition was the reliability of the firearm in the muddy, wet, and frozen conditions of the Soviet front line. Kalashnikov designed a carbine, strongly influenced by the American M1 Garand, that lost out to the Simonov design (scaled down PTRS-41),that later became the SKS semi-automatic carbine. At the same time, the Soviet Army was interested in developing a true assault rifle employing a shortened M1943 round. The first such weapon was presented by Sudayev in 1944, but trials found it to be too heavy. A new design competition was held two years later where Kalashnikov and his design team submitted an entry. It was a gas-operated rifle which had a breech-block mechanism similar to his 1944 carbine, and a curved 30-round magazine.

Kalashnikov’s rifles (codenamed AK-1 and −2) proved to be reliable and the weapon was accepted to second round of competition along with designs by A.A Demetev and F. Bulkin. In late 1946, as the rifles were being tested, one of Kalashnikov’s assistants, Aleksandr Zaytsev, suggested a major redesign of AK-1, particularly to improve reliability. At first, Kalashnikov was reluctant, given that their rifle had already fared better than its competitors. Eventually, however, Zaytsev managed to persuade Kalashnikov. The new rifle was produced for a second round of firing tests and field trials. There, Kalashnikov assault rifle model 1947 proved to be simple and reliable under a wide range of conditions with convenient handling characteristics. In 1949 it was therefore adopted by the Soviet Army as ‘7.62mm Kalashnikov assault rifle (AK)’.

Design concept

The AK-47 is best described as a hybrid of previous rifle technology innovations: the trigger, double locking lugs and unlocking raceway of the M1 Garand/M1 carbine, the safety mechanism of the John Browning designed Remington Model 8 rifle, and the gas system and layout of the Sturmgewehr 44. Kalashnikov’s team had access to all of these weapons and had no need to “reinvent the wheel”, though he denied that his design was based on the German Sturmgewehr 44 assault rifle. Kalashnikov himself observed: “A lot of [Soviet Army soldiers] ask me how one can become a constructor, and how new weaponry is designed. These are very difficult questions. Each designer seems to have his own paths, his own successes and failures. But one thing is clear: before attempting to create something new, it is vital to have a good appreciation of everything that already exists in this field. I myself have had many experiences confirming this to be so.”

Receiver development

here were many difficulties during the initial phase of production. The first production models had stamped sheet metal receivers. Difficulties were encountered in welding the guide and ejector rails, causing high rejection rates. Instead of halting production, a heavy machined receiver was substituted for the sheet metal receiver. This was a more costly process, but the use of machined receivers accelerated production as tooling and labor for the earlier Mosin-Nagant rifle’s machined receiver were easily adapted. Partly because of these problems, the Soviets were not able to distribute large numbers of the new rifle to soldiers until 1956. During this time, production of the interim SKS rifle continued.

Once manufacturing difficulties had been overcome, a redesigned version designated the AKM (M for “modernized” or “upgraded”—in Russian: (Автомат Калашникова Модернизированный [Avtomat Kalashnikova Modernizirovanniy]) was introduced in 1959. This new model used a stamped sheet metal receiver and featured a slanted muzzle brake on the end of the barrel to compensate for muzzle rise under recoil. In addition, a hammer retarder was added to prevent the weapon from firing out of battery (without the bolt being fully closed), during rapid or automatic fire. This is also sometimes referred to as a “cyclic rate reducer”, or simply “rate reducer”, as it also has the effect of reducing the number of rounds fired per minute during automatic fire. It was also roughly one-third lighter than the previous model. Both licensed and unlicensed production of the Kalashnikov weapons abroad were almost exclusively of the AKM variant, partially due to the much easier production of the stamped receiver. This model is the most commonly encountered, having been produced in much greater quantities. All rifles based on the Kalashnikov design are frequently referred to as AK-47s in the West, although this is only correct when applied to rifles based on the original three receiver types. In most former Eastern Bloc countries, the weapon is known simply as the “Kalashnikov” or “AK”. The photo above at right illustrates the differences between the Type 2 milled receiver and the Type 4 stamped, including the use of rivets rather than welds on the stamped receiver, as well as the placement of a small dimple above the magazine well for stabilization of the magazine.

In 1978, the Soviet Union began replacing their AK-47 and AKM rifles with a newer design, the AK-74. This new rifle and cartridge had only started being exported to eastern European nations when the Soviet Union collapsed, drastically slowing production of this and other weapons of the former Soviet bloc.




The Convair NB-36 was a bomber that carried a nuclear reactor. It was also known as the ‘Crusader’, or the NB-36H. It was built from a B-36 that had been destroyed in a tornado. It was created for the Nuclear Powered Aircraft programme, or NPA, to show the feasibility of a nuclear powered aircraft. It ended with the cancellation of the NPA programme.

The ‘Crusader’, or NB-36, was built for the NPA, or Nuclear Powered Aircraft programme. It was made out of parts from a B-36 destroyed in a tornado. There was a front section, which the crew lived(a pilot, copilot, flight engineer, and 2 nuclear engineers) inside, and a rear section, where the reactor was. The nose was brand-new, and was heavily lined with lead and thick yellow glass to protect against radiation. The engines and reactor were checked on by a television camera system. The engines were six Pratt & Whitney propeller engines and four GE J47 jet engines. The reactor did not power any of the plane’s systems, nor did it power the plane itself.

In all, the NB-36 made only 47 flights, all in daylight, and starting and ending in Carswell AFB, Texas. The plane was also followed by several support planes. The reactor was only operated once, when it was over a test range in New Mexico. There was a hotline connected to the president’s office, and once it was nearly used. That was when a smoke marker went off in the reactor compartment. Luckily, the plane didn’t blow up.