Tuesday, April 29, 2008

Military Attack Helicopter : AH-64 Apache

The AH-64 Apache is an all-weather day-night military attack helicopter and is the United States Army's principal attack helicopter, and is the successor to the AH-1 Cobra. The AH-64 is a twin-engined helicopter with four-bladed main and tail rotors. It has a crew of two which sit in tandem. The main fixed armament is a 30 mm M230 Chain Gun, it is also able to carry a mixture of AGM-114 Hellfire and Hydra 70 rockets on four hard points mounted on its stub-wing pylons.

An Apache Longbow armed with 16 Hellfire missiles, eight under each wing

The AH-64 is powered by two General Electric T700 turboshaft engines with high-mounted exhausts on either side of the rotor shaft. The Apache has a four-blade main rotor and four-blade tail rotor. The crew sits in tandem, with the pilot sitting behind and above the copilot-gunner in an armored crew compartment. The crew compartment and fuel tanks are armored against 23 mm gunfire. The main rotor blade is designed to remain intact after sustaining hits by 23 mm rounds.

The Apache has been designed for high survivability in combat

The Apache was first used in combat during the 1989 invasion of Panama, Operation Just Cause. The AH-64A Apache and the AH-64D Apache Longbow have played important roles in several Middle Eastern wars, including the Gulf War, Operation Enduring Freedom in Afghanistan, and Operation Iraqi Freedom in Iraq. The Apaches were proven to be excellent tank hunters and also destroyed hundreds of armored vehicles (mainly of the Iraqi army).

Hydra 70 and AGM-114 Hellfire

The advanced model, the AH-64D Apache Longbow, is equipped with an improved sensor suite and weapon systems. The key improvement over the A-variant is the AN/APG-78 Longbow dome installed over the main rotor which houses a millimeter-wave Fire Control Radar (FCR) target acquisition system as well as the Radar Frequency Interferometer (RFI). The elevated position of the radome allows detection and (arcing) missile engagement of targets even when the helicopter itself is concealed by an obstacle (e.g. terrain, trees or buildings). Further, a radio modem integrated with the sensor suite allows a D-variant Apache to share targeting data with other AH-64Ds that do not have a line-of-sight to the target. In this manner a group of Apaches can engage multiple targets but only reveal the radome of one D-variant Apache. Apaches that include all of the improvements of the Longbow Apache, with the exception of the Fire Control Radar are still designated as "AH-64D Apache Longbows", as the radome is removable and interchangeable between aircraft.

An AH-64 provides air support

The aircraft was updated with more powerful T700-GE-701C engines, and a fully-integrated cockpit. The forward fuselage of the aircraft was expanded to accommodate new systems. In addition, the aircraft receives improved survivability, communications, and navigation capabilities. Block III improvements, slated for 2008 onwards, include increasing digitization, the joint tactical radio system, enhanced engines and drive systems, capability to control UAVs, new composite rotor blade and landing gear upgrades. The new blades, which successfully completed flight testing in May 2004, increase the Apache's cruise speed, climb rate and payload capability. The Block III System Development and Demonstration (SDD) contract was awarded to Boeing in July 2006.

Apache Longbow at the International Aerospace Exhibition 2006

Sunday, April 27, 2008

Largest, Heaviest Battleships Ever Constructed : Yamato Class Battleships

The Yamato class battleships of the Imperial Japanese Navy (IJN) were the largest naval vessels of World War II and were the largest, heaviest battleships ever constructed to this day, displacing 72,800 metric tons (at full load). The class carried the largest naval artillery ever fitted to any warship - 460 mm (18.1 in) guns which fired 1.36 tonne shells.

30 October 1941: Yamato on sea trials

The Yamato class was built after the Japanese withdrew from the Washington Naval Treaty at the Second London Conference of 1936. The treaty, as extended by the London Naval Treaty of 1930, forbade signatories to build battleships before 1937. Design work on the class began in 1934 and after modifications the design for a 68,000 ton vessel was accepted in March 1937. Yamato was built in intense secrecy at a specially prepared dock to hide her construction at Kure Naval Dockyards beginning on 4 November 1937. She was launched on 8 August 1940 and commissioned on 16 December 1941. Originally, five ships of this class were planned. Yamato and Musashi were completed as designed. The third, Shinano, was converted to an aircraft carrier during construction after the defeat at the Battle of Midway. The un-named "Hull Number 111" was scrapped in 1943 when roughly 30% complete, and "Hull Number 797", proposed in the 1942 5th Supplementary Program, was never ordered. At the Kure Navy Yard, the construction dock was deepened, the gantry crane capacity was increased to 100 tonnes, and part of the dock was roofed over to prevent observation of the work. Many low-level designers and even senior officers were not informed of the true dimensions of the battleship until after the war. When the ship was launched, there was no commissioning ceremony or fanfare.

20 September 1941: Yamato fitting out at Kure Naval Yard

Yamato and Musashi made little direct impact during the war. The Musashi did not engage any Allied battleships during the war, yet the Yamato did have limited success when in October 1944 she opened fire on US escort carriers and destroyers. It was the first and last of her battles with enemy ships. She fired a total 104 rounds of 46cm projectiles as a result of which one escort carrier and one destroyer were sunk.

Yamato on sea trials in late 1941

Musashi and her crew on forward deck Jun 1942

Japanese battleship Musashi departing Brunei 1944

Both Yamato and Musashi were sunk by the bane of capital warships: overwhelming air power. Musashi was sunk by repeated aerial attack during the Battle of Leyte Gulf on October 24, 1944. After being hit by an estimated 17 torpedoes and 20 bombs, she went down with 1,700 of her 2,400 man crew.

Musashi under attack by US aircraft in the Sibuyan Sea 24 October 1944

The end of Yamato was even less glorious. Having seen little action during the previous four years (she served as Yamamoto's flagship during the Midway operation, as well as Kurita's during the action off Samar on 25 October 1944) she was sent on a planned suicide mission against the U.S. Navy forces massing for the attack on Okinawa. On April 7, 1945 she was hit by successive waves of U.S. carrier based aircraft and sank after absorbing 8 bombs and at least 13 torpedo hits. Fewer than 300 out of 3,332 crew onboard survived.

Yamato under aerial attack in the East China Sea, 7 Apr 1945

Yamato moments after exploding

Thursday, April 24, 2008

Malaysia First MBT - PT-91M

It is an extensive modernization of the T-72M1. With SAGEM Savan-15 fire control system, 1,000-hp S-1000R engine (variant with new, hydropneumatic transmission) bringing its top speed to 70 km/h, and a new communications system. Weapons have been changed to a Konstrukta 2A46MS 125mm gun, a 7.62mm FN MAG coaxial machine gun and a 12.7mm FN Browning M2 HB AA machine gun. This variant is also equipped with Sagem VIGY 15 gyro-stabilised panoramic sight optronics, a Sigma 30 laser gyro navigation system, a PCO SSP-1 Obra-3 laser-warning system, Wegmann 76mm grenade launchers and Type 570P Diehl Remscheid GmbH tracks

Tuesday, April 22, 2008

Definition Of Surface To Air Missile (SAM)

A surface to air missile (SAM) or ground-to-air missile (GTAM) is a missile designed to be launched from the ground to destroy aircraft. It is a type of anti-aircraft system.

An SA-7 in use

Stinger system

Land-based SAMs can be deployed from fixed installations or mobile launchers. The smallest SAMs are capable of being carried and launched by a single person. These types of SAM are also referred to as Man-Portable Air Defence Systems (MANPADS). Soviet MANPADS have been exported around the world and can still be found in many of their former client states. Other nations have developed their own MANPADS.

Wiesel AWC of the German Army

ADATS test firing

Land-based SAMs are deployed on mobile launchers, either wheeled or tracked. The tracked vehicles are usually armoured vehicles specifically designed to carry SAMs. Larger SAMs may be deployed in fixed launchers, but can be towed/re-deployed at will.

SM-3 launch from the USS Shiloh

Crotale launchers aboard the Tourville frigate

Ship-based SAMs are in widespread use. Virtually all surface warships can be armed with SAMs (see list below). In fact, naval SAMs are a necessity for all front-line surface warships. Some warship types specialise in anti-air warfare e.g. Ticonderoga-class cruisers equipped with the Aegis combat system or Kirov class cruisers with the S-300PMU Favorite missile system.

Patriot system

S-300PMU surface-to-air missiles during exercise

Targets for non-ManPAD SAMs will usually be acquired by air-search radar, then tracked before/while a SAM is "locked-on" and then fired. Potential targets, if they are military aircraft, will be identified as friend or foe systems before "lock-on".

Monday, April 21, 2008

The Battle of Hattin

The battle took place in the Galilee near Tiberias in present day Israel. The battlefield, near the town of Hittin, had as its chief geographic feature a double hill (the "Horns of Hattin") beside a pass through the northern mountains between Tiberias and the road from Acre to the west. The Darb al-Hawarnah road, built by the Romans, served as the main east-west passage between the Jordan fords, the Sea of Galilee and the Mediterranean coast.

Saladin's final invasion was triggered by the actions of Reynald of Chatillon. Reynald had first arrived in the Holy Land with the Second Crusade, and had decided to stay and make his fortune in the east. His behaviour demonstrated one of the main problems facing the crusader states. The established crusader barons had realised that to survive they needed to live on peaceful terms with their Muslim neighbours for as long as possible. However, to maintain their numbers they needed to attract new crusaders from the west, and these new crusaders were much less willing to live peacefully with the infidels that they had come to fight. Reynald had had an eventful career in the east, and by 1187 he had been lord of Oultrejourdain, on the south eastern edge of the Kingdom of Jerusalem, for over a decade. From his base at Kerak he had repeated broken treaties with Saladin, attacking trade caravans, and once mounting a naval raid into the red sea, attacking the ports of Medina and Mecca. This outrage enraged Saladin, and triggered an unsuccessful invasion of the Kingdom of Jerusalem.

Horns of Hattin, as viewed from the east

Now, at the end of 1186, and with the Kingdom in desperate need of a few years of peace to restore order, Reynald committed another outrage. As a huge caravan travelling north from Cairo passed through Frankish lands, under the protection of treaty, Reynald launched an attack on it, killing the guards, stealing the trade goods, and taking the merchants hostage. Saladin first attempted to act within the terms of the treaty, and sent envoys demanding the return of the merchants and their goods, first to Reynald, who ignored them, and then on to King Guy, who listened to them and agreed that they were in the right. However, he was far too dependant of Reynald for his power, and could not take the risk of an attack on his main ally. The envoys returned unsatisfied, and war was now inevitable.

Once it was clear that war was looming, the weakness and dissention of the crusader states became apparent. Bohemond of Antioch renewed an already existing truce, while Raymond of Tripoli rushed to make a new one. Significantly, this truce was extended to cover this wife's principality of Galilee, actually part of the kingdom of Jerusalem. The true impact of this division came in April. King Guy summoned his allies and marched into Galilee, hoping to crush all resistance before Saladin could launch his invasion. However, at the same time Saladin's son decided to launch an armed reconnaissance into Palestine. Obeying the terms of their truce, he sent envoys to Raymond to ask for free passage, and with great embarrassment, Raymond had to agree. On 1 May, a force of 7000 mamluk cavalry marched into Galilee, where they encountered the a force of Knights Templers, who despite being hugely outnumbered charged to the attack, and were almost entirely wiped out, with only three escaping. News of this disaster finally healed the split between Raymond and Guy. Raymond renounced his treaty with Saladin, and submitted to Guy, who accepted him with good grace. In contrast to this chaos, Saladin had been carefully gathering together his army, eventually gathering a force of some 20,000 men, forming the largest army he had ever commanded. Despite their arguments, the crusaders were able to raise a force of almost the same size. At this point there was nothing to suggest that a disaster was about to occur. The crusaders had defeated similar invasions by refusing to risk battle and occupying well supplied positions, while their enemies armies wilted away in the sun. This had happened four years before, and Saladin had been forced to withdraw without battle.

Artistic representation of Saladin

On 1 July Saladin crossed the Jordan. He attacked Tiberias, capturing the town and besieging the castle. Despite strong advice to remain at Acre, Guy was persuaded to march inland towards Tiberias. Even then, not all was lost. On 2 July the crusaders camped at Sephoria, where they had a good water supply and the best of the terrain. Although most of the knights spoke for moving on, Raymond of Tripoli himself, whose wife was defending Tiberias was strongly against such a move, arguing that Saladin would not be able to attack their position, while reinforcements from Antioch were expected, and when the council ended it appeared that he had won the day. Sadly for the crusader cause, Guy was easy to persuade, and after the council broke up the Grand Master of the Temple managed to change his mind. The next day the crusaders marched east along a barren, waterless road, under constant harassment by Saladin's skirmishers, and the crusaders soon suffered from thirst. By mid afternoon the crusaders reached the horns of Hattin, a barren hill top overlooking the village. Despite urgent calls to fight to the lake that afternoon, Guy decided to halt the march. This move has been criticised, but it is likely that the army was too drained to risk a fight. Moreover, the eventual campsite did have a well, and was probably picked for this. Unfortunately, the well was dry. While Saladin and his army spend the night in the well watered valley, the crusaders spent the night in misery on the dry hill top.

The battle itself was now something of a foregone conclusion. At dawn on 4 July, the crusader army found itself surround on the hill top. In normal circumstances this move would have been a mistake for Saladin, as the crusader army was quite close to his in numbers, and would have been able to punch a hole in the weakened Muslim cordon, but after a day and a night without water the crusader army had lost much of it's cohesion. The infantry broke from the army and made a desperate attempt to reach water, but failed, and were soon destroyed. The crusader cause was now doomed. The trapped knights fought with great determination, but were steadily forced back towards the summit. An attempt to force a breakthrough led by Raymond of Tripoli was foiled when Saladin's army simply opened a gap to let them through. Stuck on the outside of the battle there was nothing they could do, and so they escaped back to Tripoli. Those left on the hill fought to exhaustion, but eventually were forced to surrender. Saladin's triumph appeared to be complete. He had captured King Guy, along with Reynald of Chatillon and most of the great barons of the Kingdom, as well as capturing the Holy Cross. The prisoners were all well treated, apart from Reynald of Chatillon, whose foolish raids had led to the defeat, and for whole Saladin felt such hatred that he personally beheaded him.

The Battle of Hattin, from a medieval manuscript

Defeat at Hattin saw the effective destruction of the Kingdom of Jerusalem. With the King in his hands, and the army destroyed, Saladin was able to capture city after city. Tiberias surrendered quickly, Acre on 10 June and finally on 2 October, Jerusalem itself surrendered.

Saturday, April 19, 2008

La Fayette Class Frigate

F712 Courbet (French Navy)

The La Fayette class units are light multi-mission frigates built by DCN and operated by France (Marine Nationale). Derivative of the type are in service in Saudi Arabia, Singapore (Republic of Singapore Navy) and Republic of China (Taiwan) (Republic of China Navy).

F710 La Fayette (French Navy)

These frigates were referred to as "stealth" frigates. Their reduced radar cross section is achieved by a very clean superstructure compared to conventional designs, angled sides and radar absorbent material, a composite material of wood and glass fiber as hard as steel, light, and resistant to fire. Most modern fighting ships built around the world since the introduction of the La Fayette have followed the same principles of stealth.

F711 Surcouf (French Navy)

The shape of the hull and the superstructures is devised for the optimal reduction of the radar signature, which has been reduced by 60%: a 3000-tonne La Fayette unit has the typical radar signature of a 1200 tonne ship. Stealth is achieved with inclined flanks, as few vertical lines as possible, and very clean lines and superstructures: stairs and mooring equipment are internal, and prominent structures are covered by planes. The superstructures are built using radar-absorbent synthetic materials.

F714 Guépratte (French Navy)

All information gathered by the onboard sensors is managed by the Information Processing System, the electronic brain of the operation centre of the ship. It is completed by an electronic command aid system.

F713 Aconit (French Navy)

The La Fayette has space available for the future installation of the Aster 15 missile, the state-of-the-art anti-air European weapon, and currently carries the Crotale short-range defence system, and Exocet missile, mounted in two quad launchers.

RSS Formidable (Singapore Navy)

The ships are designed to accommodate a 10 tonne helicopter in the Panther or NH90 range (though they are also capable of operating the Super Frelon and similar heavy helicopters). These helicopters can carry anti-ship AM39 or AS15 missiles, and can be launched during sea state 5 or 6 due to the Samahé helicopter handling system.

The helicopter pad; the Crotale missile launcher is well visible on the top of the helicopter hangar

Friday, April 18, 2008

Definition Of Cavalry

Cavalry were soldiers or warriors who fought mounted on horseback in combat. The designation was not usually extended to any military force that used other animals, such as camels or mules. Infantry who moved on horseback but dismounted to fight on foot were in the seventeenth and early eighteenth centuries known as dragoons, a class of mounted troops which later evolved into cavalry proper while retaining their historic title.

Reenactor showing Roman military cavalry

From earliest times cavalry had the advantage of improved mobility, an "instrument which multiplied the fighting value of even the smallest forces, allowing them to outflank and avoid, to surprise and overpower, to retreat and escape according to the requirements of the moment." A man fighting from horseback also had the advantages of greater height, speed, and inertial mass over an opponent on foot.

Heavy cavalry

In modern armies, the term cavalry is often used for units that fill the traditional horse-borne light cavalry roles of scouting, screening, skirmishing and raiding. The shock role, traditionally filled by heavy cavalry, is generally filled by units with the "armored" designation.

Polish 66 Airforce Squadron of 25th Aeromobile Cavalry Brigade

Wednesday, April 16, 2008

World War 2 Heavy Tanks - Tiger I

The Tiger I was in use from late 1942 until the German surrender in 1945. It was given its "Tiger" nickname by Ferdinand Porsche . The design served as the basis for other armoured vehicles, the Sturmtiger heavy self-propelled gun and the Bergetiger amoured recovery vehicle. The initial official German designation was Panzerkampfwagen VI Ausführung H but the tank was redesignated as Panzerkampfwagen VI Ausf. E in March 1943. The tank also had the ordnance inventory designation SdKfz 181.

Tiger 1 tank at Bovington Tank Museum

The Tiger I represented a new approach that emphasised firepower and armour at the expense of mobility. Design studies for a new heavy tank had been started in the late 1930s, without any production planning. The real impetus for the Tiger was provided by the quality of the Soviet T-34. Although the general design and layout were broadly similar to the previous medium tank the Panzer IV, the Tiger weighed more than twice as much. This was due to its substantially thicker armour, the larger main gun, and the consequently greater volume of fuel and ammunition storage, larger engine, and more solidly-built transmission and suspension.

A front view of Tiger 1 on the move

The Tiger I had frontal hull armour 100 mm thick and frontal turret armour of 110 mm, as opposed to the 80 mm frontal hull and 50 mm frontal turret armour of contemporary models of the Panzer IV. It also had 80 mm thick armour on the sides and rear. The top and bottom armour was 25 mm thick; later, the turret roof was thickened to 40 mm. Armour plates were mostly flat, with interlocking construction. The armour joints were of high quality, being stepped and welded rather than riveted.

An early model parked in front of a factory

The rear of the tank held an engine room flanked by two floodable rear compartments each containing a fuel tank, radiator, and fans. The petrol (gasoline) engine was a 21-litre 12-cylinder Maybach HL 210 P45 with 650 PS (641 hp, 478 kW). Although a good engine, it was inadequate for the vehicle. From the 250th Tiger it was replaced by the uprated HL 230 P45 (23 litres) of 700 PS (690 hp, 515 kW). The engine was in V-form, with two cylinder banks at 60 degrees. An inertial starter was mounted on its right side, driven via chain gears through a port in the rear wall. The engine could be lifted out through a hatch on the hull roof.

An early model with barbed wire strung on the hull sides to prevent infantry from mounting the vehicle.

The internal layout was typical of German tanks. Forward was an open crew compartment, with the driver and radio-operator seated at the front, either side of the gearbox. Behind them the turret floor was surrounded by panels forming a continuous level surface. This helped the loader to retrieve the ammunition, which was mostly stowed above the tracks. Two men were seated in the turret; the gunner to the left of the gun, and the commander behind him. There was also a folding seat for the loader. The turret had a full circular floor and 157 cm headroom.

Tiger 1 in front of a thatched-roof farmhouse

The gun breech and firing mechanism were derived from the famous German "88" dual purpose flak gun. The 88 mm Kwk 36 L/56 gun was the variant chosen for the Tiger and was, along with the Tiger II's 88 mm Kwk 43 L/71, one of the most effective and feared tank guns of WW2. The Tiger's gun had a very flat trajectory and extremely accurate Zeiss TZF 9b sights. Tigers were reported to have knocked out enemy tanks at ranges greater than a mile (1,600 m), although most WW2 engagements were fought at much closer range.

Captured Tiger I in Tunis in 1943

The Tiger was first used in action in September 1942 near Leningrad. Under pressure from Hitler the tank was put into action months earlier than planned and many early models proved to be mechanically fragile. In its first action on 23 September 1942, many of the first Tigers broke down. Others were knocked out by dug-in Soviet anti-tank guns. One tank was captured largely intact, which gave the Soviets a chance to study the tank and prepare a response. In the Tiger's first actions in North Africa, the tank was able to dominate Allied tanks in the wide-open terrain. However, mechanical failures meant that there were rarely more than a few in action. In a replay of the Leningrad experience, at least one Tiger was knocked out by towed British six-pounder antitank guns.

Whitewashed Tigers on the march

The Tiger's armour and firepower, however, were feared by all its opponents. In tactical defence, its poor mobility was less of an issue. Whereas Panthers were the more serious threat to Allied tanks, Tigers had a bigger psychological effect on opposing crews, causing a "Tiger phobia". Allied tankers would sometimes evade rather than confront a Tiger, even a tank that only looked like one, such as the Panzer IV with turret skirts applied. In the Normandy campaign, it could take four to five Shermans to knock out a single Tiger tank by maneuvering to its weaker flank or rear armour; the Soviet T-34s fared similarly against the German tanks, as had the German PzIII earlier against the Soviet heavy tanks.

The Das Reich Tiger of SS-Oberscharfuhrer Paul Egger passing panzer grenadiers near Bykowka, Russia in July 1943 during Operation Citadel.

An accepted Allied tactic was to engage the Tiger as a group, one attracting the attention of the Tiger crew while the others attacked the sides or rear of the vehicle. Since the ammunition and fuel were stored in the sponsons, a side penetration often resulted in a kill. This was, however, a risky tactic, and often resulted in the loss of several Allied vehicles. It took a great deal of tactical skill to eliminate a Tiger.

The Tiger from the drivers side