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