Thursday, November 24, 2011

Are 'non-lethal' weapons really dangerous?

From an article from AlJazeera. See:
Fears that tear gas and rubber bullets, widely used in crackdown against protesters, could be cause of deaths in Egypt.
From Egypt, to Athens, to Oakland, police have employed "non-lethal weapons" to break down recent protests and disperse protesters.

As crowds have swelled to express discontent, variations of tear gas, rubber bullets, water cannons, and stun grenades have been fired back at them.

The US defence department describes non-lethal weapons as "primarily employed to immediately incapacitate targeted personnel or materiel, while minimising fatalities, permanent injury to personnel ... in the target area or environment.
"Non-lethal weapons are intended to have reversible effects on personnel and material."

Despite this, activists have reported grave injuries as a result of tear gas canisters fired at protesters from close range.

Moreover, the non-lethality of the gas is also in doubt, as serious questions are being raised about the causes of recent deaths during this week's protests in Cairo's Tahrir square.

Al Jazeera’s Mike Hanna, reporting from the Egyptian capital, said: "There have been repeated rounds of tear gas fired here. It is a particularly virulent form, stinging the face to an immense extent.

"Many of those who have been killed are said to have died of asphyxiation.

"Medical workers say the conditions of those brought in is serious, many with symptoms they have not seen before from tear gas inhalation."

Speaking to Al Jazeera, Khalid Hamdi, staffing a make-shift clinic in Tahrir square, said: “We've seen many faintings and we'd never seen that before.

"About 70 per cent of the injuries are fainting. People are coming in with asthma, convulsions sometimes - this wasn't often before."

Amnesty international has also expressed concern about the use of tear gas in the square.

"We have received reports from medical sources saying that some of those who died did so as as a result of suffocation after inhaling tear gas," Said Haddadi, a spokesman for the rights group, told Al Jazeera.

'Pain and discomfort'

US government agencies, the departments of state and commmerce in particular, regulate the export of tear gas and other non-lethal weapons by granting export licenses allowing US manufacturers to sell tear gas to foreign buyers.

Two US companies have been identified as major exporters of the devices: Combined Systems Inc and NonLethal Technologies Inc, both based in Pennsylvania.

Peter Felstead, editor of Jane’s Defence Weekly, said countries buying weapons from the UK, at least, are closely vetted and their contracts constantly reviewed.

“If something happens in Saudi Arabia, or Bahrain for example, withdrawing contracts in response to those kind of events would present something of a dilemma. The US and UK strategic alliances with Saudi Arabia in particular are very strong. If there is unrest in Saudi, the question is will the support be withdrawn?"

He said buyers are expected to obtain training packages along with their purchase to make sure the weapons are employed properly. A lack of proper training could be the cause of any fatalities that might result.

"There are times when employing crowd control is absolutely necessary. But if the non-lethal weapons are not employed properly, they could make things worse.

"For example, if you end up forcing a crowd away from security forces to stampede through a narrow gap, you could kill people in the process."

What exactly is being fired at protesters in Tahrir is unclear.

Two forms of tear gas are most commonly used: Chlorobenzylidene malononitrile (also referred to as CS) and Chloroacetophenone (often known as CN).

Both gases are irritants that affect the eyes, nose, mouth and lungs, and cause tearing, sneezing and coughing.

"The primary effect is shortness of breath, pain, and discomfort," reads the catalogue of Combined Systems Inc.

Dr Ziad Kazzi, from Grady Health System and assistant director of Georgia Poison Center, said large doses of the gas could be fatal to healthy individuals as well.

“Those with already existing conditions, such as asthma or lung disease, are at higher risk. However, if large doses are inhaled, particularly in enclosed space, it could damage lungs and lead to death, even for healthy people. But it depends on the dosage.”

“Dose determines the poison,” he said, adding that several factors such as concentration, potency of the gas, the amount that is being delivered, the environment that it is being released in, and the personal characteristics of the people receiving it all play a part.

He said small doses have not been proven to have lasting effects.

'A cloud of irritant agent'

Tear gas canisters come in various shapes and forms, for indoor and outdoor purposes.

Smoke grenades - both launched by hand as well as munitions launchers - "deliver a cloud of irritant agent with a discharge time of approximately 25 seconds," NonLethal Technologies Inc's catalogue says.

Smoke projectiles, the second method that tear gas can be used at protesters, are "designed to provide effective outdoor crowd dispersal while maintaining a safe stand-off distance of up to 80 yards," according to the catalogue.

The canisters weigh between 175 and 500 grammes, and are made of aluminum or stern steel. Much of the injuries are caused by the fact that these canisters are fired onto crowded areas.

"Danger: Do not fire directly at person[s]. Severe injury or death may result," is reportedly written on the canisters.

Rubber bullets have also been fired at protesters, causing severe injuries.

The bullets come in aluminum cartridges, with a total weight of about 185 grammes. In one of the models in the NonLethal Technologies catalogue, each cartridge contains "three rubber batons that are skip fired towards the subjects".

"Eyewitnesses and lawyers have told us that some were injured as a result of rubber bullets," Amnesty's Haddadi said about the use of rubber bullets in the protests in Cairo.

“People can be killed by rubber bullets, there is no doubt about that. It has happened in northern Ireland. If you fire from close range, or someone is hit in the head," Felstead said.

"It would be quite difficult to specifically target people lethally. But it could easily happen when firing into a crowd."

With over 36 killed in Egypt since November 19, and medical sources citing "suffocation after inhaling tear gas" as the cause of many of the deaths, the non-lethality of the weapons employed - as well as how they were imported - has come under serious question.

Khalid Abdala, an Egyptian actor and activist, told Al Jazeera from Tahrir that he held international governments "complicit in everything that is happening here".

"International governments have replenished the stocks of bullets that have been shot at people right now, and the tear gas that is clinging to my lungs," he said.

Monday, November 21, 2011

Heckler-Koch G36

HK G36 assault rifle (standard German army version with dual sight system) with 40mm AG36 underbarrel grenade launcher

The Heckler und Koch G-36 assault rifle had been born as HK-50 project in early 1990s. The reason behind that project was that the Bundeswehr (the German army), after the cancellation of the G11 and G41 projects, was left with outdated G3 rifle and no modern rifle, compatible with the current NATO standards. Therefore the famous company Heckler & Koch was set to develop a new assault rifle for both the German army and the export. The new 5.56mm assault rifle has been adopted by the Bundeswehr in the 1995, and in the 1999 Spain adopted its slightly different, export version, G36E as its standard infantry rifle. The G36 also found its way into the hands of various law enforcement agencies worldwide, including British police and some US police departments. It is a good rifle, accurate, reliable, simple in operations and maintenance, and available in a wide variety of versions - from the short-barreled Commando G36C and up to a standard G36 rifle. The MG36 squad automatic weapon (light machine gun), which was initially designed as a heavy-barreled version of the G36, was in fact a short-lived proposition that never went into mass production.
HK G36 assault rifle with optional accessory kit which includes forearm with four Picatinny rails and a low-profile scope rail on the receiver
The G36, in severely modified form, was used as a "kinetic energy" part of the now-cancelled US XM-29 OICW weapon and it also served as a base for XM8 assault rifle (also cancelled).
HK G36C 'Compact' or 'Commando' assault rifle, with optional Picatinny rails on forend
Technical description.
From the technical point of view, the G36 is a radical departure from all the previous HK rifles, based on the proven G3 roller-delayed system. The G36 is a conventional gas operated, selective fire rifle, made from most modern materials and using most modern technologies.
HK G36E rifle (Export version) with single 1.5X telescope sight and spare magazine clamped to the left side of the inserted one
The receiver and most of the others external parts of the G36 are made from reinforced polymers, with steel inserts where appropriate. The operating system appears to be a modification of the older American Armalite AR-18 rifle, with short stroke gas piston, located above the barrel, square-shaped bolt carrier and the typical rotating bolt with 7 locking lugs. Of course, there also are many differences from the AR-18. The bolt carrier rides on a single guide rod, with the return spring around it. The charging handle is attached to the top of the bolt carrier and can be rotated to the left or to the right. When not in use, the charging handle aligns itself with the axis of the weapon under the pressure of its own spring, and reciprocates with the bolt group at the top of the receiver. The gas block is fitted with the self-adjustable gas valve that expels all the used gases forward, away from the shooter. The ejection window is located at the right side of the receiver and features a spent cases deflector to propel the ejected cases away from the face of the left-handed shooter.

HK G36K "short" (Kurz) assault rifle, with buttstock folded; standard version with iron sights and Picatinny rail
All the major parts are assembled on the receiver using the cross- pins, so rifle can be disassembled and reassembled back without any tools.

The typical HK trigger unit is assembled in a separate plastic housing, integral with the pistol grip and the triggerguard. Thanks to this feature, a wide variety of firing mode combinations can be used on any rifle, simply by installing the appropriate trigger unit. Standard options are single shots, full automatic fire, 2 or 3 round bursts in any reasonable combinations. The default version is the single shots + 2 rounds burst + full auto. The ambidextrous fire selector lever also serves as a safety switch.
HK G36KE short assault rifle, export version, with 'E' type telescope sight / carrying handle setup
G36 is fed from the proprietary 30-rounds box magazines, made from translucent plastic. All magazines have special studs on its sides, so two or three magazines can be clipped together for faster reloading. The magazine housings of the G36 are made as a separate parts, so G36 can be easily adjusted to the various magazine interfaces. By the standard, the magazine release catch is located just behind the magazine, in the G3 or AK-47 style, rather than on the side of the magazine housing (M16-style). A 100-round Beta-C dual drum magazines of US origins also can be used (these magazines are standard for the MG36 squad automatic versions of the G36).

The side-folding skeletonized buttstock is standard on all G36 rifles. It folds to the right side and does not interfere with rifle operation when folded.

The standard sighting equipment of the G36 consists of the TWO scopes - one 3.5X telescope sight below, with the second 1X red-dot sight above it. The sights are completely independent, with the former suitable for long range accurate shooting, and the latter suitable for the fast target acquisition at the short ranges. Both sights are built into the plastic carrying handle. The export versions of the G36 are available with the single 1.5X telescope sight, with the emergency open sights molded into the top of the carrying handle. The subcompact G36K Commando version is available with the integral Picatinny-type scope and accessory rail instead of the carrying handle and standard sights.

The standard G36 rifles can be fitted with the HK AG36 40mm underbarrel grenade launcher. It also can be fitted with the bayonets. Interestingly enough, G36 uses an AK-74-type bayonets, which are left from the now non-existent NVA (East Germany Army) stocks.

G36 G36K G36C
Caliber 5.56x45mm (.223 Rem)
Length (buttstock open / folded) 998 / 758 mm 860 / 615 mm 720 / 500 mm
Barrel length 480 mm 320 mm 228 mm
Weight empty 3.6 kg (3.3 kg G36E) 3.3 kg (3.0 kg G36KE) 2.8 kg
Magazine capacity 30 rounds standard
Rate of fire 750 rounds per minute

Wednesday, November 16, 2011

The Panzerkampfwagen IV (Pz.Kpfw. IV), commonly known as the Panzer IV

A Panzer IV Ausf G. in desert colors, bearing the palm tree insignia of the 15th Panzer Division of the Afrika Korps.

The Panzerkampfwagen IV (Pz.Kpfw. IV), commonly known as the Panzer IV, was a medium tank developed in Nazi Germany in the late 1930s and used extensively during the Second World War. Its ordnance inventory designation was Sd.Kfz. 161.

Panzer IV Ausf. C

Designed as an infantry-support tank, the Panzer IV was not originally intended to engage enemy armor—that function was performed by the lighter Panzer III. However, with the flaws of pre-war doctrine becoming apparent and in the face of Soviet T-34 tanks, the Panzer IV soon assumed the tank-fighting role of its increasingly obsolete cousin. The most widely manufactured and deployed German tank of the Second World War, the Panzer IV was used as the base for many other fighting vehicles, including the Sturmgeschütz IV tank destroyer, the Wirbelwind self-propelled anti-aircraft weapon, and the Brummbär self-propelled gun, amongst others.

PzKpfw IV Ausf. D

Robust and reliable, it saw service in all combat theaters involving Germany, and has the distinction of being the only German tank to remain in continuous production throughout the war, with over 8,800 produced between 1936 and 1945. Upgrades and design modifications, often made in response to the appearance of new Allied tanks, extended its service life. Generally these involved increasing the Panzer IV's armor protection or upgrading its weapons, although during the last months of the war with Germany's pressing need for rapid replacement of losses, design changes also included retrograde measures to simplify and speed manufacture.

The 300 horsepower Maybach HL 120TRM engine used in most Panzer IV production models.

The Panzer IV was the most widely exported tank in German service, with around 300 sold to partners such as Finland, Romania, Spain and Bulgaria. After the war, the French and Spanish sold dozens of Panzer IVs to Syria, where they saw combat in the 1967 Six-Day War.


The short-barreled Panzer IV Ausf. F1.

The Panzer IV was the brainchild of German general and innovative armored warfare theorist Heinz Guderian. In concept, it was intended to be a support tank for use against enemy anti-tank guns and fortifications. Ideally, the tank battalions of a panzer division were each to have three medium companies of Panzer IIIs and one heavy company of Panzer IVs. On 11 January 1934, the German army wrote the specifications for a "medium tractor", and issued them to a number of defense companies. To support the Panzer III, which would be armed with a 37-millimetre (1.46 in) anti-tank gun, the new vehicle would have a short-barrelled 75-millimetre (2.95 in) howitzer as its main gun, and was allotted a weight limit of 24 tonnes (26.46 short tons). Development was carried out under the name Begleitwagen ("accompanying vehicle"), or BW, to disguise its actual purpose, given that Germany was still theoretically bound by the Treaty of Versailles. MAN, Krupp, and Rheinmetall-Borsig each developed prototypes, with Krupp's being selected for further development.

The 1942 Panzer IV Ausf. F2 was an upgrade of the Ausf. F, fitted with the KwK 40 L/43 anti-tank gun to counter Soviet T-34 and KV tanks.

The chassis had originally been designed with a six-wheeled interleaved suspension, but the German Army amended this to a torsion bar system. Permitting greater vertical deflection of the roadwheels, this was intended to improve performance and crew comfort both on- and off-road. However, due to the urgent requirement for the new tank, neither proposal was adopted, and Krupp instead equipped it with a simple leaf spring double-bogie suspension.

A Panzer IV Ausf H at the Musée des Blindés in Saumur, France, with its distinctive Zimmerit anti-magnetic mine coating, turret skirts, and wire-mesh side-skirts.

The prototype required a crew of five men; the hull contained the engine bay to the rear, with the driver and radio operator, who doubled as the hull machine gunner, seated at the front-left and front-right, respectively. In the turret, the tank commander sat beneath his roof hatch, while the gunner was situated to the left of the gun breech and the loader to the right. The turret was offset 66.5 mm (2.62 in) to the left of the chassis center line, while the engine was moved 152.4 mm (6.00 in) to the right. This allowed the torque shaft to clear the rotary base junction, which provided electrical power to turn the turret, while connecting to the transmission box mounted in the hull between the driver and radio operator. Due to the asymmetric layout, the right side of the tank contained the bulk of its stowage volume, which was taken up by ready-use ammunition lockers.

The Ausf. J was the final production model, and was greatly simplified compared to earlier variants to speed construction. This shows an exported Finnish model.

Accepted into service as the Versuchskraftfahrzeug 622 (Vs.Kfz. 622), production began in 1936 at Krupp-Grusonwerke AG's factory at Magdeburg.

Ausf. A to Ausf. F1

A Panzer IV Ausf. E showing signs of multiple hits to the turret, including the gun barrel.

The first mass-produced version of the Panzer IV was the Ausführung, A (abbreviated to Ausf. A meaning "Batch A"), in 1936. It was powered by Maybach's HL 108TR, producing 250 PS (183.87 kW), and used the SGR 75 transmission with five forward gears and one reverse, achieving a maximum road speed of 31 kilometres per hour (19.26 mph). As main armament, the vehicle mounted the Kampfwagenkanone 37 L/24 (KwK 37 L/24) 75 mm (2.95 in) tank gun, which was a low-velocity gun designed to mainly fire high-explosive shells. Against armored targets, firing the Panzergranate (armor-piercing shell) at 430 metres per second (1,410 ft/s) the KwK 37 could penetrate 43 millimetres (1.69 in), inclined at 30 degrees, at ranges of up to 700 metres (2,300 ft). A 7.92 mm (0.31 in) MG 34 machine gun was mounted coaxially with the main gun in the turret, while a second machine gun of the same type was mounted in the front plate of the hull. The Ausf. A was protected by 14.5 mm (0.57 in) of steel armor on the front plate of the chassis, and 20 mm (0.79 in) on the turret. This was capable only of stopping artillery fragments, small-arms fire, and light anti-tank projectiles.

A British Crusader tank passing a burning German Panzer IV during Operation Crusader, late 1941.

After manufacturing 35 tanks of the A version, in 1937 production moved to the Ausf. B. Improvements included the replacement of the original engine with the more powerful 300 PS (220.65 kW) Maybach HL 120TR, and the transmission with the new SSG 75 transmission, with six forward gears and one reverse gear. Despite a weight increase to 16 t (18 short tons), this improved the tank's speed to 39 kilometres per hour (24 mph). The glacis plate was augmented to a maximum thickness of 30 millimetres (1.18 in), and the hull-mounted machine gun was replaced by a covered pistol port. Forty-two Panzer IV Ausf. Bs were manufactured before the introduction of the Ausf. C in 1938. This saw the turret armor increased to 30 mm (1.18 in), which brought the tank's weight to 18.14 t (20.00 short tons). After assembling 40 Ausf. Cs, starting with chassis number 80341 the engine was replaced with the improved HL 120TRM. The last of the 140 Ausf. Cs was produced in August 1939, and production changed to the Ausf. D; this variant, of which 248 vehicles were produced, reintroduced the hull machine gun and changed the turret's internal gun mantlet to an external one. Again protection was upgraded, this time by increasing side armor to 20 mm (0.79 in). As the German invasion of Poland in September 1939 came to an end, it was decided to scale up production of the Panzer IV, which was adopted for general use on 27 September 1939 as the Sonderkraftfahrzeug 161 (Sd.Kfz. 161).

A PzKpfw IV Ausf. H of the 12th Panzer Division operating on the Eastern Front in the USSR, 1944.
In response to the difficulty of penetrating British Matilda Infantry tanks during the Battle of France, the Germans had tested a 50 mm (1.97 in) gun—based on the 5 cm PaK 38 L/60 anti-tank gun—on a Panzer IV Ausf. D. However, with the rapid German victory in France, the original order of 80 tanks was canceled before they entered production.

British officers inspect a German Pzkw-IV knocked out in France in June 1944 by the Durham Light Infantry.

In September 1940 the Ausf. E was introduced. This had 50 millimetres (1.97 in) of armor on the bow plate, while a 30-millimetre (1.18 in) appliqué steel plate was added to the glacis as an interim measure. Finally, the commander's cupola was moved forward into the turret. Older model Panzer IV tanks were retrofitted with these features when returned to the manufacturer for servicing. Two hundred and eighty Ausf. Es were produced between December 1939 and April 1941.

Pzkw-IV in Belgrade Military Museum, Serbia.

In April 1941 production of the Panzer IV Ausf. F started. It featured 50 mm (1.97 in) single-plate armor on the turret and hull, as opposed to the appliqué armor added to the Ausf. E, and a further increase in side armor to 30 mm (1.18 in). The weight of the vehicle was now 22.3 tonnes (24.6 short tons), which required a corresponding modification of track width from 380 to 400 mm (14.96 to 15.75 in) to reduce ground pressure. The wider tracks also facilitated the fitting of ice sprags, and the rear idler wheel and front sprocket were modified. The designation Ausf. F was changed in the meantime to Ausf. F1, after the distinct new model, the Ausf. F2, appeared. A total of 464 Ausf. F (later F1) tanks were produced from April 1941 to March 1942, of which 25 were converted to the F2 on the production line.

Ausf. F2 to Ausf. J

On May 26, 1941, mere weeks before Operation Barbarossa, during a conference with Hitler, it was decided to improve the Panzer IV's main armament. Krupp was awarded the contract to integrate again the same 50 mm (1.97 in) Pak 38 L/60 gun into the turret. The first prototype was to be delivered by November 15, 1941. Within months, the shock of encountering the Soviet T-34 medium and KV-1 heavy tanks necessitated a new, much more powerful tank gun. In November 1941, the decision to up-gun the Panzer IV to the 50-millimetre (1.97 in) gun was dropped, and instead Krupp was contracted in a joint development to modify Rheinmetall's pending 75 mm (2.95 in) anti-tank gun design, later known as 7.5 cm PaK 40 L/46. Because the recoil length was too long for the tank's turret, the recoil mechanism and chamber were shortened. This resulted in the 75-millimetre (2.95 in) KwK 40 L/43. When firing an armor-piercing shot, the gun's muzzle velocity was increased from 430 m/s (1,410 ft/s) to 990 m/s (3,250 ft/s). Initially, the gun was mounted with a single-chamber, ball-shaped muzzle brake, which provided just under 50% of the recoil system's braking ability. Firing the Panzergranate 39, the KwK 40 L/43 could penetrate 77 mm (3.03 in) of steel armor at a range of 1,830 m (6,000 ft).

The Ausf. F tanks that received the new, longer, KwK 40 L/43 gun were named Ausf. F2 (with the designation Sd.Kfz. 161/1). The tank increased in weight to 23.6 tonnes (26.0 short tons). One hundred and seventy-five Ausf. F2s were produced from March 1942 to July 1942. Three months after beginning production, the Panzer IV. Ausf. F2 was renamed Ausf. G. There was little to no difference between the F2 and early G models.

During its production run from May 1942 to June 1943, the Panzer IV Ausf. G went through further modifications, including another armor upgrade. Given that the tank was reaching its viable limit, to avoid a corresponding weight increase, the appliqué 20-millimetre (0.79 in) steel plates were removed from its side armor, which instead had its base thickness increased to 30 millimetres (1.18 in). The weight saved was transferred to the front, which had a 30-millimetre (1.18 in) face-hardened appliqué steel plate welded (later bolted) to the glacis—in total, frontal armor was now 80 mm (3.15 in) thick. This decision to increase frontal armor was favorably received according to troop reports on November 8, 1942, despite technical problems of the driving system due to added weight. At this point, it was decided that 50% of Panzer IV productions would be fitted with 30 mm thick additional armor plates. Subsequently on January 5, 1943, Hitler decided to make all Panzer IV with 80 mm frontal armor. To simplify production, the vision ports on either side of the turret and on the right turret front were removed, while a rack for two spare road wheels was installed on the track guard on the left side of the hull. Complementing this, brackets for seven spare track links were added to the glacis plate. For operation in high temperatures, the engine's ventilation was improved by creating slits over the engine deck to the rear of the chassis, and cold weather performance was boosted by adding a device to heat the engine's coolant, as well as a starter fluid injector. A new light replaced the original headlight, and the signal port on the turret was removed. On March 19, 1943, the first Panzer IV with Schürzen skirts on its sides and turret was exhibited. The double hatch for the commander's cupola was replaced by a single round hatch from very late model Ausf. G. and the cupola was up-armored as well. In April 1943, the KwK 40 L/43 was replaced by the longer 75-millimetre (2.95 in) KwK 40 L/48 gun, with a redesigned multi-baffle muzzle brake with improved recoil efficiency.

The next version, the Ausf. H, began production in April 1943 and received the designation Sd. Kfz. 161/2. This variant saw the integrity of the glacis armor improved by manufacturing it as a single 80-millimetre (3.15 in) plate. To prevent adhesion of magnetic anti-tank mines, which the Germans feared would be used in large numbers by the Allies, Zimmerit paste was added to all the vertical surfaces of the tank's armor. The vehicle's side and turret were further protected by the addition of 5-millimetre (0.20 in) side-skirts and 8-millimetre (0.31 in) turret skirts. During the Ausf. H's production run its rubber-tired return rollers were replaced with cast steel; the hull was fitted with triangular supports for the easily-damaged side-skirts. A hole in the roof, designed for the Nahverteidigungswaffe, was plugged by a circular armored plate due to shortages of this weapon. These modifications meant that the tank's weight jumped to 25 tonnes (27.56 short tons), reducing its speed, a situation not improved by the decision to adopt the Panzer III's six-speed SSG 77 transmission, which was inferior to that of earlier-model Panzer IVs.

Despite addressing the mobility problems introduced by the previous model, the final production version of the Panzer IV—the Ausf. J—was considered a retrograde from the Ausf. H. Born of German necessity to replace heavy losses, it was greatly simplified to speed production. The electric generator that powered the tank's turret traverse was removed, so the turret had to be rotated manually. The space was later used for the installation of an auxiliary 200-litre (44 imp gal) fuel tank; road range was thereby increased to 320 kilometres (198.84 mi), The pistol and vision ports in the turret were removed, and the engine's radiator housing was simplified by changing the slanted sides to straight sides. In addition, the cylindrical muffler was replaced by two flame-suppressing mufflers. By late 1944, Zimmerit was no longer being applied to German armored vehicles, and the Panzer IV's side-skirts had been replaced by wire mesh, while to further speed production the number of return rollers was reduced from four to three.

In a bid to augment the Panzer IV's firepower, an attempt was made to mate a Panther turret—carrying the longer 75 mm (2.95 in) L/70 tank gun—to a Panzer IV hull. This was unsuccessful, and confirmed that the chassis had, by this time, reached the limits of its adaptability in both weight and available volume.


The Panzer IV was originally intended to be used only on a limited scale, so initially Krupp was its sole manufacturer. Prior to the Polish campaign, only 262 Panzer IVs were produced: 35 Ausf. A; 42 Ausf. B; 140 Ausf. C; and 45 Ausf. D. After the invasion of Poland, and with the decision to adopt the tank as the mainstay of Germany's armored divisions, production was extended to the Nibelungenwerke factory (managed by Steyr-Daimler-Puch) in the Austrian city of St. Valentin. Production increased as the Ausf. E was introduced, with 223 tanks delivered to the German army. By 1941, 462 Panzer IV Ausf. Fs had been assembled, and the up-gunned Ausf. F2 was entering production. The yearly production total had more than quadrupled since the start of the war.

As the later Panzer IV models emerged, a third factory, Vomag (located in the city of Plauen), began assembly. In 1941 an average of 39 tanks per month were built, and this rose to 83 in 1942, 252 in 1943, and 300 in 1944. However, in December 1943, Krupp's factory was diverted to manufacture the Sturmgeschütz IV, and in the spring of 1944 the Vomag factory began production of the Jagdpanzer IV, leaving the Nibelungenwerke as the only plant still assembling the Panzer IV. With the slow collapse of German industry under pressure from Allied air and ground offensives — in October 1944 the Nibelungenwerke factory was severely damaged during a bombing raid — by March and April 1945 production had fallen to pre-1942 levels, with only around 55 tanks per month coming off the assembly lines.

Combat history

The Panzer IV was the only German tank to remain in both production and combat throughout World War II, and measured over the entire war it comprised 30% of the Wehrmacht's total tank strength. Although in service by early 1939, in time for the occupation of Czechoslovakia, at the start of the war the majority of German armor was made up of obsolete Panzer Is and Panzer IIs. The Panzer I in particular had already proved inferior to Soviet tanks, such as the T-26, during the Spanish Civil War.

Western Front and North Africa (1939–1942)

When Germany invaded Poland on 1 September 1939, its armored corps was composed of 1,445 Panzer Is, 1,223 Panzer IIs, 98 Panzer IIIs and 211 Panzer IVs; the more modern vehicles amounted to less than 10% of Germany's armored strength. The 1st Panzer Division had a roughly equal balance of types, with 17 Panzer Is, 18 Panzer IIs, 28 Panzer IIIs, and 14 Panzer IVs per battalion. The remaining panzer divisions were heavy with obsolete models, equipped as they were with 34 Panzer Is, 33 Panzer IIs, 5 Panzer IIIs, and 6 Panzer IVs per battalion. Although the Polish army possessed less than 200 tanks capable of penetrating the German light tanks, Polish anti-tank guns proved more of a threat, reinforcing German faith in the value of the close-support Panzer IV.

Despite increasing production of the medium Panzer IIIs and IVs prior to the German invasion of France on 10 May 1940, the majority of German tanks were still light types. According to Heinz Guderian, the Wehrmacht invaded France with 523 Panzer Is, 955 Panzer IIs, 349 Panzer IIIs, 278 Panzer IVs, 106 Panzer 35(t)s and 228 Panzer 38(t)s. Through the use of tactical radios and superior tactics, the Germans were able to outmaneuver and defeat French and British armor. However, Panzer IVs armed with the KwK 37 L/24 75-millimetre (2.95 in) tank gun found it difficult to engage French tanks such as Somua S35 and Char B1. The Somua S35 had a maximum armor thickness of 55 mm (2.17 in), while the KwK 37 L/24 could only penetrate 43 mm (1.69 in) at a range of 700 m (2,296.59 ft). Likewise, the British Matilda Mk II was heavily armored, with at least 70 mm (2.76 in) of steel on the front and turret, and a minimum of 65 mm on the sides.

Although the Panzer IV was deployed to North Africa with the German Afrika Korps, until the longer gun variant began production, the tank was outperformed by the Panzer III with respect to armor penetration. Both the Panzer III and IV had difficulty in penetrating the British Matilda II's thick armor, while the Matilda's 40-mm QF 2 pounder gun could knock out either German tank; its major disadvantage was its low speed. By August 1942, Rommel had only received 27 Panzer IV Ausf. F2s, armed with the L/43 gun, which he deployed to spearhead his armored offensives. The longer gun could penetrate all American and British tanks in theater at ranges of up to 1,500 m (4,900 ft). Although more of these tanks arrived in North Africa between August and October 1942, their numbers were insignificant compared to the amount of matériel shipped to British forces.

The Panzer IV also took part in the invasion of Yugoslavia and the invasion of Greece in early 1941.

Eastern Front (1941–1945)

With the launching of Operation Barbarossa on 22 June 1941, the unanticipated appearance of the KV-1 and T-34 tanks prompted an upgrade of the Panzer IV's 75 mm (2.95 in) gun to a longer, high-velocity 75 mm (2.95 in) gun suitable for antitank use. This meant that it could now penetrate the T-34 at ranges of up to 1,200 m (3,900 ft) at any angle. The 75 mm (2.95 in) KwK 40 L/43 gun on the Panzer IV could penetrate a T-34 at a variety of impact angles beyond 1,000 m (3,300 ft) range and up to 1,600 m (5,200 ft). Shipment of the first model to mount the new gun, the Ausf. F2, began in spring 1942, and by the summer offensive there were around 135 Panzer IVs with the L/43 tank gun available. At the time, these were the only German tanks that could defeat the Soviet T-34 or KV-1. They played a crucial role in the events that unfolded between June 1942 and March 1943, and the Panzer IV became the mainstay of the German panzer divisions. Although in service by late September 1942, the Tiger I was not yet numerous enough to make an impact and suffered from serious teething problems, while the Panther was not delivered to German units in the Soviet Union until May 1943. The extent of German reliance on the Panzer IV during this period is reflected by their losses; 502 were destroyed on the Eastern Front in 1942.

The Panzer IV continued to play an important role during operations in 1943, including at the Battle of Kursk. Newer types such as the Panther were still experiencing crippling reliability problems that restricted their combat efficiency, so much of the effort fell to the 841 Panzer IVs that took part in the battle. Throughout 1943, the German army lost 2,352 Panzer IVs on the Eastern Front; some divisions were reduced to 12–18 tanks by the end of the year. In 1944, a further 2,643 Panzer IVs were destroyed, and such losses were becoming increasingly difficult to replace. By the last year of the war, the Panzer IV was outclassed by the upgraded T-34-85, which had an 85 mm (3.35 in) gun, and other late-model Soviet tanks such as the 122 mm (4.80 in)-armed IS-2 heavy tank. Nevertheless, due to a shortage of replacement Panther tanks, the Panzer IV continued to form the core of Germany's armored divisions, including elite units such as the II SS Panzer Corps, through 1944.

In January 1945, 287 Panzer IVs were lost on the Eastern Front. It is estimated that combat against Soviet forces accounted for 6,153 Panzer IVs, or about 75% of all Panzer IV losses during the war.

Western Front (1944–1945)

Panzer IVs comprised around half of the available German tank strength on the Western Front prior to the Allied invasion of Normandy on June 6, 1944. Most of the 11 panzer divisions that saw action in Normandy initially contained an armored regiment of one battalion of Panzer IVs and another of Panthers, for a total of around 160 tanks, although Waffen-SS panzer divisions were generally larger and better-equipped than their Heer counterparts.Regular upgrades to the Panzer IV had helped to maintain its reputation as a formidable opponent. Despite overwhelming Allied air superiority, the Norman bocage countryside in the US sector heavily favored defense, and German tanks and anti-tank guns inflicted horrendous casualties on Allied armor during the Normandy campaign. On the offensive, however, the Panzer IVs, Panthers and other armored vehicles proved equally vulnerable in the bocage, and counter-attacks rapidly stalled in the face of infantry-held anti-tank weapons, tank destroyers and anti-tank guns, as well as the ubiquitous fighter bomber aircraft. That the terrain was highly unsuitable for tanks was illustrated by the constant damage suffered to the side-skirts of the Ausf. H's; essential for defence against shaped charge anti-tank weapons such as the British PIAT, all German armored units were "exasperated" by the way these were torn off during movement through the dense orchards and hedgerows.

The Allies had also been developing lethality improvement programs of their own; the widely-used American-designed M4 Sherman medium tank, while mechanically reliable, suffered from thin armor and an inadequate gun. Against earlier-model Panzer IVs, it could hold its own, but with its 75 mm M3 gun, struggled against the late-model Panzer IV (and was unable to penetrate the frontal armor of Panther and Tiger tanks at virtually any range). The late-model Panzer IV's 80 mm (3.15 in) frontal hull armor could easily withstand hits from the 75 mm (2.95 in) weapon on the Sherman at normal combat ranges, though the turret remained vulnerable.

The British up-gunned the Sherman with their highly effective QF 17 pounder anti-tank gun, resulting in the Firefly; although this was the only Allied tank capable of dealing with all current German tanks at normal combat ranges, few (about 300) were available in time for the Normandy invasion. The other British tank with the 17 pdr gun could not participate in the landings and had to wait for port facilities. It was not until July 1944 that American Shermans, fitted with the 76 mm (2.99 in) M1 tank gun, began to achieve a parity in firepower with the Panzer IV.

However, despite the general superiority of its armored vehicles, by August 29, 1944, as the last surviving German troops of Fifth Panzer Army and Seventh Army began retreating towards Germany, the twin cataclysms of the Falaise Pocket and the Seine crossing had cost the Wehrmacht dearly. Of the 2,300 tanks and assault guns it had committed to Normandy (including around 750 Panzer IVs), over 2,200 had been lost. Field Marshal Walter Model reported to Hitler that his panzer divisions had remaining, on average, five or six tanks each.

During the winter of 1944–45, the Panzer IV was one of the most widely used tanks in the Ardennes offensive, where further heavy losses—as often due to fuel shortages as to enemy action—impaired major German armored operations in the West thereafter. The Panzer IVs that took part were survivors of the battles in France between June and September 1944, with around 260 additional Panzer IV Ausf. Js issued as reinforcements.


A Syrian Panzer IV Ausf. G, captured during the Six-Day War, on display in the Yad La-Shiryon Museum, Israel.

In keeping with the wartime German design philosophy of mounting an existing anti-tank gun on a convenient chassis to give mobility, several tank destroyers and infantry support guns were built around the Panzer IV hull. Both the Jagdpanzer IV, initially armed with the 75-millimetre (2.95 in) L/48 tank gun, and the Krupp-manufactured Sturmgeschütz IV, which was the casemate of the Sturmgeschütz III mounted on the body of the Panzer IV, proved highly effective in defense. Cheaper and faster to construct than tanks, but with the disadvantage of a very limited gun traverse, around 1,980 Jagdpanzer IV's and 1,140 Sturmgeschütz IVs were produced. The Jagdpanzer IV eventually received the same 75 millimeter L/70 gun that was mounted on the Panther.

A Jagdpanzer IV/48 tank destroyer, based on the Panzer IV chassis, mounting the 75 mm PaK L/48 anti-tank gun.

Another variant of the Panzer IV was the Panzerbefehlswagen IV (Pz.Bef.Wg. IV) command tank. This conversion entailed the installation of additional radio sets, mounting racks, transformers, junction boxes, wiring, antennas and an auxiliary electrical generator. To make room for the new equipment, ammunition stowage was reduced from 87 to 72 rounds. The vehicle could coordinate with nearby armor, infantry or even aircraft. Seventeen Panzerbefehlswagen were converted from Ausf. J chassis, while another 88 were based on refurbished chassis.

The Wirbelwind armored anti-aircraft vehicle.

The Panzerbeobachtungswagen IV (Pz.Beob.Wg. IV) was an artillery observation vehicle built on the Panzer IV chassis. This, too, received new radio equipment and an electrical generator, installed in the left rear corner of the fighting compartment. Panzerbeobachtungswagens worked in cooperation with Wespe and Hummel self-propelled artillery batteries.

A Sturmpanzer IV Brummbär infantry-support gun (Casemate MG variant (flexible mount)).

Also based on the Panzer IV chassis was the Sturmpanzer IV Brummbär 150-millimetre (5.91 in) infantry-support self-propelled gun. These vehicles were primarily issued to four Sturmpanzer units (Numbers 216, 217, 218 and 219) and used during the battle of Kursk and in Italy in 1943. Two separate versions of the Sturmpanzer IV existed, one without a machine gun in the mantlet and one with a machine gun mounted on the mantlet of the casemate. Furthermore, a 105-millimetre (4.13 in) artillery gun was mounted in an experimental turret on a Panzer IV chassis. This variant was called the Heuschrecke, or Grasshopper. Another 105 mm artillery/anti-tank prototype was the 10.5 cm K (gp.Sfl.) nicknamed Dicker Max.

Four different self-propelled anti-aircraft vehicles were built on the Panzer IV hull. The Flakpanzer IV Möbelwagen was armed with a 37-millimetre (1.46 in) anti-aircraft cannon; 240 were built between 1944 and 1945. In late 1944 a new Flakpanzer, the Wirbelwind, was designed, with enough armor to protect the gun's crew and a rotating turret, armed with the 20mm quadmount Flakvierling anti-aircraft cannon system; at least 100 were manufactured. Sixty-five similar vehicles were built, named the Ostwind, but with a single 37-millimetre (1.46 in) anti-aircraft cannon instead. This vehicle was designed to replace the Wirbelwind. The final model was the Flakpanzer IV Kugelblitz, of which only five were built. This vehicle featured a covered turret armed with twin 30-millimetre (1.18 in) anti-aircraft cannons.

Although not a direct modification of the Panzer IV, some of its components, in conjunction with parts from the Panzer III, were utilized to make one of the most widely-used self-propelled artillery chassis of the war—the Geschützwagen III/IV. This chassis was the basis of the Hummel artillery piece, of which 666 were built, and also the 88 millimetres (3.46 in) gun armed Nashorn tank destroyer, with 473 manufactured. To resupply self-propelled howitzers in the field, 150 ammunition carriers were manufactured on the Geschützwagen III/IV chassis.

Sunday, November 13, 2011

Russian Tanks


It is estimated that some 50,000 examples of the T-54 and similar T-55 systems have been produced.

Designation: T-54
Classification Type: Main Battle Tank
Contractor: State Factories - USSR
Country of Origin: Soviet Union
Initial Year of Service: 1949

The T-54 series of Soviet main battle tanks came about with development after World War 2, ending with the system becoming operationally available by 1949. It can be said that no other Cold War or post-Cold War tank has seen as many production models or combat usage as has the T-54 and the similar T-55 series of tanks. Despite its heavy use by armies worldwide - many to this day fielding the system as a frontline unit - the T-54 has had its fair share of engine and transmission issues which have plagued the type since the beginning.

The T-54 is an identifiable brand of Soviet tank design, featuring a rounded cast turret mounting a 100mm main gun. Five road wheels adorn either track side and the large .50 caliber anti-aircraft gun at the loader's hatch is noticeable. A very fundamental tank design, a student of the Second World War can see definite similarities between the influence of late war systems apparent in this post-war design.

Power is derived from a V-12 diesel engine mounted at rear of the all-welded hull. The engine also serves a dual purpose in that diesel fuel is injected into the exhaust for a self-created smokescreen. As such, smoke grenade dischargers are not a standard component of the T-54 design. The T-54 tank is crewed by four personnel and features a driver at center front, whom also controls a bow-mounted 7.62mm fixed machine gun (another is a coaxial mount on the turret, controlled by the gunner). The commander, gunner and loader are situated in the turret with the former group at left and the latter at right. The T-54 has access to a variety of munitions to select from and many are of the standard modern variety. Up to 34 projectiles are carried in the turret and the D-10 main gun can engage and defeat targets some 1,000 yards away though limited downward traverse is a noted deficiency.

As one might assume, such a numerous system has produced an equally numerous amount of variants that include the standard conversions such as bridgelayer, armored recovery vehicle and command vehicles - all utilizing the base T-54 chassis. Additionally, the basic T-54 has been upgraded with various modifications that include gun stabilizers on both of the firing axis, infra-red nightvision capability, increased ammunition storage capability and deep fording equipment.

To this day, the T-54 is fielded en mass, having seen active combat in a variety of environments, especially with former Soviet allied nations and states. China produced their own version of the T-54 known as the Type 59. Though having the pedigree of the famous T-34 tank of World War 2, the T-54 is often seen as inferior to its contemporary counterparts in the West. In any case, the system will probably still maintain a battlefield presence for some time to come, thanks in large part to overwhelming production figures and modernization programs instituted by a variety of its owners over the years.


The PT-76 is billed as a Light Amphibious Tank and is still in service with several countries.

Designation: PT-76
Classification Type: Light Amphibious Tank
Contractor: State Arsenals - Soviet Union
Country of Origin: Soviet Union
Initial Year of Service: 1952

The PT-76 was developed shortly after Second World War. The weapon system is designated as a "Light Amphibious Tank" featuring a crew of three and the ability to traverse varying depths of water.

The PT-76 is armed with the World War Two-standard 76.2mm main gun, has turret traversal of -4/+30 and can fire the standard set of projectiles - from high explosive to AP-T and HE-FRAG rounds. For self-defense, the system features a 7.62mm machine gun while some models have also added a 12.7mm air defense heavy machine gun of DShKM type. Additional fuel tanks can be added to the system increasing the overall road range by 68 miles (110 km).

By design, many of the PT-76's components are also shared with the BTR-50, SA-6 Gainful SAM and the ZSU-23-4. The engine of the PT-76 is also the same one that powers the T-55 Main Battle Tank.

The PT-76 is marketed as being fully amphibious but features some noticeable drawbacks in the way of no NBC protection, a rather large overall size and thin armor protection for ammunition and crew.

Total production numbers of the PT-76 has reached over 7,000 vehicles. The last PT-76 entered service in 1967, though modernization programs and new turret designs have kept the system ongoing. China produces a version of the PT-76 locally as the Type 63.


Designation: T-55
Classification Type: Main Battle Tank
Contractor: State Factories - Soviet Union
Country of Origin: Soviet Union
Initial Year of Service: 1958

The T-55 Medium Tank is probably the most internationally prolific piece of tracked armor as it can be found in dozens of military inventories across the globe. It has seen military frontline service from the invasion of Hungary in 1956 to the Arab wars with Israel of the late 1960's and early 1970's.

The T-55 features a 100mm D-10 rifled main gun. Two 7.62mm defensive machine guns are provided, one coaxially and one in the bow front-hull. A 12.7mm air defense machine gun is provided in later models of the T-55.

Development of the T-55 stems from the base T-54 Main Battle Tank design, which itself can trace it's roots back to the World War Two-inspired T-34 tank design. The T-55 was superceeded by the T-62 detailed elsewhere on this website.

In all essence, the T-55 shares many common features, components and systems with the T-54, thus many sources may group their histories together as such (sometimes shown as T-54/T-55).

T-55 - Base production model. Basic T-54 with new turret and 12.7mm anti-aircraft machine gun.
T-55A - Added radiation protection and 12.7mm anti-aircraft machine gun.
T-55M - New 580hp engine sans cupola for loader; Ability to fire AT-10 Stabber ATGW missiles through main gun.
T-55M-1 - Passive armor protection
T-55MV - Explosive reactive armor protection
T-55AM-1 - Standardized to T-55A specifications with passive armor protection and AT-10 firing ability.
T-55K - Command Vehicle
T-55AK - Command Vehicle
T-55MK - Command Vehicle
T-55MVK - Command Vehicle
T-55AM2B - Czech-produced variant
T-55AM2P - Polish-produced variant
T-55AM2PB - Russian-produced variant
T-55AD - T-55M standardized specifications with specialized countermeasures system installed.
T-55AD-1 - Upgraded engine; Laser-rangefinder.

Length: 20.34ft (6.20m)
Width:11.81ft (3.60m)
Height: 7.61ft (2.32m)
Speed: 22mph (35km/h)
Range: 242miles (390km)

Accommodation: 4
Weight: 44.6 US Short Tons (40,500kg)
NBC Protection: None
Nightvision: Yes - Infrared
Engine(s): 1 x 462-516 kW 675 hp diesel engine.

Armament & Ammunition:

1 x 100mm D-10 rifled main gun
1 x 12.7mm anti-aircraft machine gun
1 x 7.76mm coaxial machine gun
1 x 7.62mm machine gun in bow

34 x 100mm projectiles
500 x 12.7mm ammunition
3,000 x 7.62mm ammunition

T-10 Josef Stalin

The T-10 was the last of the Josef Stalin heavy-caliber, heavy-armor tank designs dating back to the Second World War.

The T-10 can be considered the pinnacle "Josef Stalin" tank design as it is the tank that superseded previous forms and became the final product of the series. It sported an all new main gun, redesigned body and turret and put upon itself all of the lessons learned through armored conflict in World War 2. The tank was of a heavy classification and was such an outstanding and well-regarded design that the last known operational usage of the T-10 was reported in 1996.

Outwardly, the T-10 was similar to the preceding IS (Josef Stalin) tank series with a rounded turret placed forward of the hull design and had more in common with the IS-3 than other previous forms. The T-10 featured an all new turret and main gun armament along with a redesigned hull and improved engine performance. A crew of four personnel operated the machine with the drive in the front hull and the commander, loader and gunner in the turret in traditional Soviet tank design fashion (commander and gunner on left and the loader on the right inside the turret - contrasting Western design placement). Power was derived from a single 12 cylinder diesel generating around 700 horsepower.

Armor protection was excellent, reach some 10 inches at its thickest.

The T-10 appeared in two supplementary forms with subtle modifications as the T-10A and the T-10B. The final version in the series would be the T-10M, which fitted a longer M-62-T2 (L/43) main gun. This particular version also featured a new muzzle brake, NBC protection for the crew and infra-red nightvision. Additionally, self-defense machine gun protection was improved allowing for an optional 12.7mm anti-aircraft DShK machine gun to be installed.

The T-10 performed as expected and was well-regarded. It saw action with Egyptian forces against Israel in the Six Day War, losing many examples to Israeli control - to which the very same systems were used to guard the Suez Canal from Egyptian encroachment. Production of the T-10 ended in 1966, to which some 2,500 examples appeared overall, and were the last of the Soviet heavy tanks when that classification type fell out of favor with Red Army needs.

Thursday, November 10, 2011

Sd.Kfz. 251 - Half-track armored personnel carrier by Germany in WW2

The Sd.Kfz. 251 (Sonderkraftfahrzeug 251) half-track was an armored fighting vehicle designed and first built by Hanomag company during World War II. The largest and best armored of the wartime half-tracks, the Sd.Kfz. 251 was designed to transport the panzergrenadiers of the German mechanized infantry corps into battle. Sd.Kfz. 251s were the most widely produced German half-tracks of the war, with over 15,252 vehicles and variants produced in total by various manufacturers, and were commonly referred to simply as "Hanomags" by both German and Allied soldiers.

Sd.Kfz. 251/1 Ausf. A

There were four main model modifications (Ausführung A through Ausf. D), which formed the basis for at least 22 variants. The initial idea was for a vehicle that could be used to transport a single squad of panzergrenadiers to the battlefield protected from enemy small arms fire, and with some protection from artillery fire. In addition, the standard mounting of at least one MG 34 or MG 42 machine gun allowed the vehicle to provide support by fire for the infantry squad once they had disembarked in battle.

Positive aspects of the open top included greater situational awareness and faster egress by the infantry, as well as the ability to throw grenades and fire over the top of the fighting compartment as necessary while remaining under good horizontal cover. Downsides to the open top were a major vulnerability to all types of plunging fire; this included indirect fire from mortars and field artillery as well as depressed-trajectory small arms fire from higher elevated positions, lobbed hand grenades, and strafing by Allied aircraft.

Sd.Kfz. 251/7 "Pionierpanzerwagen"

The first two models were produced in small numbers from 1939. A and B model can be identified by the structure of the nose armor which comprises two trapezoids. The lower trapezoid has a cooling hatch. Production of the B modification from 1940 eliminated the fighting compartment's side vision slits. The C modification introduced into production in mid-1940 featured a simplified forward armoured plate for the engine. Ausf. A through C had rear doors of the vehicle bulging out. The C variant had a larger production run, but was a quite complex vehicle to build, involving many angled plates that gave reasonable protection from small arms fire. From early 1943, the Ausf D variant was developed with a purpose of reducing the number of angled body plates by 50%, simplifying the design and thus speeding up the production. Ausf D can be easily recognized by its single piece sloping rear (with flat doors).

Sd.Kfz. 251/9 "Stummel"

The standard personnel carrier version was equipped with a 7.92 mm MG 34 or MG 42 machine gun mounted at the front of the open compartment, above and behind the driver. A second machine gun could be mounted at the rear on an anti-aircraft mount.

Variants were produced for specialized purposes, including with anti-aircraft guns, light howitzers, anti-tank guns and mortars or even large unguided artillery rockets, as well as a version with an infrared search light used to spot potential targets for associated Panther tanks equipped with infrared detectors.

Another potentially good design feature of the Sd.Kfz.251 was the large track area, with the characteristic "slack track" design with no return rollers for the upper run of track, and overlapping and interleaved main road wheels common to virtually all German halftracks of the period. This lowered ground pressure and provided better traction, giving the Sd.Kfz.251 better cross country performance than most other nations' half-tracked vehicles. The interleaved and overlapping main road wheels, however, shared a chief problem with the Tiger I and Panther main battle tanks that also used such roadwheel configurations - in muddy or winter weather conditions, such as those during a rasputitsa mud season or the coldest Russian winter conditions, accumulated mud and/or snow could freeze solid between the road wheels, possibly immobilizing the vehicle.

The early production models of this vehicle were issued to the 1st Panzer Division in 1939.

These vehicles were meant to enable panzergrenadiers to accompany panzers and provide infantry support as required. In practice, there were never enough of them to go around, and most panzergrenadier units had to make do with trucks for transport.

Tuesday, November 8, 2011

HK G11 (Prototype)

HK G11 rifle
The development of the G11 rifle was started in the late 1960's, when West German government decided to replace existing G3 rifle with lighter weapon with much better hit probability.

HK G11K2 pre-productional rifle
The initial studies lead to the idea of the small-caliber, rapid-fire rifle that fires caseless ammunition. To ensure sufficient stopping/killing power for small-caliber bullets used, the rifle should had have the three-round bursts capability and high capacity magazine.
HK G11 rifle with the optional optical scope installed
The new design, called G11, was created by German company Heckler und Koch, with the Dynamit Nobel company in team. The HK was responsible for the rifle itself, while Dynamit Nobel had to develop caseless ammunition.
Second prototype of the G11
The basic concept of the G11 is as follows:
The rifle features unique cylinder breech/chamber system that rotates 90 degrees. The cartridges in the magazine are located above the barrel, bullets down. Prior to each shot, first cartridge is pushed down from magazine into chamber and then breech/chamber rotates 90 degrees to align the cartridge with the barrel (see pic). After that, the cartridge is fired and the breech/chamber rotates back, ready for the next cartridge to be chambered. In the case of the cartridge ignition failure, the failed cartridge is pushed down from the chamber by the next cartridge. The breech can be manually "cocked" by the rotating handle at the side of the rifle, located beyond the pistol handle. The cocking handle does not move when gun is fired. Another interesting detail is that barrel, rotating breech, feed module and magazine are mounted in the housing that can move in the rifle back and forth. When firing single shots, the housing moves back and forward after the each shot. When firing the full-auto, the housing moves back and forward during each shot, resulting in moderate rate of fire of some 600 round per minute. But, when firing the three-round bursts, second and third cartridges are feed and fired as soon as the chamber is ready for it, and third bullet leaves the barrel PRIOR to the moment when the housing becomes to its rearward position. This results in wery high rate of fire with three-shots bursts - ca. 2000 rounds per minute. Also, this results in that the actual recoil affects the rifle AFTER the last bullet in the burst is fired.
13th prototype of the G11
Rifle featured built-in 1X optical sight with simple circle aiming reticle. Early prototypes featured one 50 rounds polymer magazine, while latest versions featured 45 rounds magazines - one in the loaded position within the movable housing and two spare magazines on the top of the rifle, asides from the loaded magazine.

Caseless ammunition - early variant at the left, latest variant DM11 (cutout view) - at the right
The caseless ammunition in its early appearance was designed as a block of the propellant, coated with flammable laquer, with bullet and primer "glued on" the propellant. Final ammunition design DM11, that appeared in the mid-1980s, featured "telescopic" design, when bullet was fully enclosed in the block of the propellant. The cartridge propelled the bullet that weights 3.25 gramms, to the 930-960 meters per second.
Schematic drawing of the G11 bolt & feeding system
Early prototypes were prone to the ammunition cook-offs during the sustained fire, but later Dynamit Nobel solved this issue.

In the late 1980s the Bundeswehr (West German Army) began the field tests of the pre-production G11s. After the initial tests, some improvements were devised, such as removable optical sight, mounting of two spare magazines on the rifle, and bayonet/bipod mount under the muzzle.

The modified variant, called G11K2, was tested in 1989, scoring at least 50% better combat accuracy when compared to G3 rifle. Initial batch of some 1000 G11K2s was received by Bundeswehr in 1990 or so, but due to some reasons the whole programme was cancelled by German Government. Main reasons of this cancellation were, in my opinion, the lack of fundings after the re-union of the West and East Germanies, and the general NATO policy for unification of the ammunition and even magazines for the assault rifles.

The slightly modified G11 was also tested in the USA under the ACR (Advanced Cobat Rifle) programme, in 1990. The ACR programme was not intended to result in adoption of the new rifle for the US Army, just to test new technologies and designs, and the G11 proved itself as a very accurate, comfortable to handle and fire, and reliable weapon.

Caliber: 4.7 mm caseless
Action: Gas operated, rotating breech
Overall length: 750 mm
Barrel length: 540 mm
Weigth: 3.6 kg empty
Magazine capacity: 50 or 45 rds

Thursday, November 3, 2011

Water purifier

The individual water purification system provides the infantryman the ability to remove or destroy contaminants from all water sources. There are a number of civilian versions available in the market today.



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