Thursday, May 30, 2013

The Mighty M4 Sherman Tank

TankshermanM4.jpgThe M4 Sherman, formally Medium Tank, M4, was the primary tank used by the United States during World War II. Thousands were also distributed to the Allies, including the British Commonwealth and the Soviet Union, via lend-lease. In the United Kingdom, the M4 was named after Union General William Tecumseh Sherman, following the British practice of naming their American-built tanks after famous American Civil War generals. Subsequently, the British name found its way into common use in the U.S.
The Sherman evolved from the Grant and Lee medium tanks, which had an unusual side-sponson mounted 75 mm gun. It retained much of the previous mechanical design, but added the first American main 75 mm gun mounted on a fully traversing turret, with a gyrostabilizer enabling the crew to fire with reasonable accuracy while the tank was on the move. The designers stressed mechanical reliability, ease of production and maintenance, durability, standardization of parts and ammunition in a limited number of variants, and moderate size and weight. These factors made the Sherman superior in some regards to the earlier German light and medium tanks of 1939-41. The Sherman ended up being produced in large numbers and formed the backbone of most offensives by the Western Allies, starting in late 1942.
When the Sherman tank arrived in North Africa in 1942, it was clearly superior to both the Panzer III German main battle tank and the short barreled version of the Panzer IV. Against the 75mm KwK 40 L/43 long barreled Panzer IV the match was about even. For this reason, the US Army believed the Sherman would be completely adequate to win the war, and no pressure was exerted for further tank development. The Sherman proved to be outmatched by the 45 ton Panther tank, and wholly inadequate against the 56 ton Tiger I and later 70 ton Tiger II heavy tanks, suffering high casualties against their heavier armor and more powerful 88 mm L/56 and L/71 cannons. Mobility, mechanical reliability and sheer numbers, supported by growing superiority in supporting fighter-bombers and artillery, helped offset these disadvantages strategically. The relative ease of production allowed huge numbers of the Sherman to be produced. This allowed many divisions, including infantry divisions, their own organic Sherman assets. Some U.S. infantry divisions had more tanks than German panzer divisions did, which was a great advantage for the Americans.
Production of the Sherman was favored by the commander of the Armored Ground Forces, albeit controversially, over the heavier M26 Pershing, which resulted in the latter being deployed too late to play any significant role in the war. In the Pacific Theater, the Sherman was used chiefly against Japanese infantry and fortifications; in its rare encounters with much lighter Japanese tanks with weaker armor and guns, the Sherman's superiority was overwhelming. Almost 50,000 vehicles were produced, and its chassis also served as the basis for numerous other armored vehicles such as tank destroyers, tank retrievers, and self-propelled artillery. Only the Soviet T-34 tank was produced in larger numbers during World War II.
The Sherman would finally give way to post-war tanks developed from the M26. Various original and updated versions of the Sherman would continue to see combat effectively in many later conflicts, including the Korean War, Arab-Israeli Wars, and Indo-Pakistani War (where it was used by both sides) into the late 20th century.


An M4A3E8 76 mm armed Sherman tank made during the Second World War
TypeMedium tank
Place of origin United States
Service history
In service1942–1955 (USA)
Used by United States, and many others (see Foreign variants and use)
WarsWorld War II, Greek Civil War, Arab-Israeli War, Korean War, Revolución Libertadora, Suez Crisis, Indo-Pakistani War of 1965, Six-Day War, Indo-Pakistani War of 1971, Yom Kippur War, 1958 Lebanon crisis, Lebanese Civil War, Cuban Revolution, Nicaraguan Revolution
Production history
Designed1940
Produced1941–
Number built49,234
Specifications
Weight66,800 pounds (30.3 tonnes; 29.8 long tons; 33.4 short tons)
Length19 ft 2 in (5.84 m)
Width8 ft 7 in (2.62 m)
Height9 ft (2.74 m)
Crew5 (Commander, gunner, loader, driver, co-driver)

Armor76 mm maximum
Main
armament
75 mm M3 L/40 gun (90 rounds)
or 76 mm gun M1 (55 rounds)
Secondary
armament
.50 cal Browning M2HB machine gun (300 rounds),
2 × .30-06 Browning M1919A4 machine guns (4,750 rounds)
EngineContinental R975 C1, air-cooled, radial, gasoline
400 hp (298 kW) at 2,400 rpm
M4A4 Model - Chrysler A57 Multibank 30 cylinder 21-litre engine. 470 hp at 2,700 rpm.
Power/weight15.8 hp/tonne
TransmissionSpicer manual, synchromesh, 4 forward (plus 1 overdrive) and 1 reverse gear
SuspensionVertical Volute Spring Suspension (VVSS)
Operational
range
120 miles (193 km) at 175 U.S. gal (660 L); 80 octane
Speed25 to 30 mph (40 to 48 km/h)

M4A4 Cutaway
1 - Lifting ring
2 - Ventilator
3 - Turret hatch
4 - Periscope
5 - Turret hatch race
6 - Turret seat
7 - Gunner's seat
8 - Turret seat
9 - Turret
10 - Air cleaner
11 - Radiator filler cover
12 - Air cleaner manifold
13 - Power unit
14 - Exhaust pipe
15 - Track idler
16 - Single water pump
17 - Radiator
18 - Generator
19 - Rear propeller shaft
20 - Turret basket
21 - slip ring
22 - Front propeller shaft
23 - Suspension bogie
24 - Transmission
25 - Main drive sprocket
26 - Driver's seat
27 - Machine gunner's seat
28 - 75 mm gun
29 - Drivers hatch
30 - M 1919A4 machine gun
M4A4 cutaway.svg

Wednesday, April 3, 2013

Adolf Hitler Short Biography


 Adolf HitlerAdolf Hitler was leader of Germany during the Third Reich (1933 – 1945) and the primary instigator of both the Second World War in Europe and the mass execution of millions of people deemed to be "enemies" or inferior to the Aryan ideal. Born: April 20, 1889, died: April 30, 1945.
Adolf Hitler was born in Braunau am Inn, Austria, on April 20th 1889 to Alois Hitler (who, as an illegitimate child, had previously used his mother’s name of Schickelgruber) and Klara Poelzl. A moody child, he grew hostile towards his father, especially once the latter had retired and the family had moved to Linz. Alois died in 1903 but left money to take care of the family. Hitler was close to his mother, who was highly indulgent of Hitler, and he was deeply affected when she died in 1908. He left school at 16 in 1905, intending to become a painter.
Hitler moved to Vienna in 1907 where he applied to the Viennese Academy of Fine arts, but was twice turned down. This experience further embittered the increasingly angry Hitler, and he remained in Vienna living off his small family inheritance and what he could make from selling his art, moving from hostel to hostel, a lonely, vagabond figure. During this period Hitler appears to have developed the world view that would characterise his whole life: a hatred for Jews and Marxists. Hitler was well placed to be influenced by the demagogy of Karl Lueger, Vienna’s deeply anti-Semitic mayor.
Hitler moved to Munich in 1913 and avoided Austrian military service in early 1914 by virtue of being unfit. However, when the First World War broke out in 1914 he joined the 16th Bavarian Infantry Regiment, serving throughout the war. He proved to be an able and brave soldier as a dispatch runner, winning the Iron Cross (First Class) on two occasions. He was also wounded twice, and four weeks before the war ended suffered a gas attack which temporarily blinded and hospitalised him. It was here he learnt of Germany’s surrender, which he took as a betrayal. He especially hated the Treaty of Versailles.
After WW1 Hitler became convinced he was destined to save Germany. In 1919, working for an army unit, he was assigned to spy on a political party of roughly 40 idealists called the German Workers Party. Instead he joined it, swiftly rose to a position of dominance (he was chairman by 1921) and renamed it the Socialist German Workers Party (NSDAP). He gave the party the Swastika as a symbol and organised a personal army of ‘storm troopers’ (the SA or Brownshirts) and a bodyguard of black shirted men, the SS, to attack opponents. He also discovered, and used, his powerful ability for public speaking.
In November 1923 Hitler organised Bavarian nationalists under a figurehead of General Ludendorff into a coup (or 'putsch'). They declared their new government in a beer hall in Munich and then 3000 marched through the streets, but they were met by police, who opened fire, killing 16. Hitler was arrested and tried in 1924, but was sentenced to only five years in prison, a sentence often taken as a sign of tacit agreement with his views. Hitler served only nine months in prison, during which he wrote Mein Kampf (My Struggle), a book outlining his theories on race, Germany and Jews. It sold five million copies by 1939.
After the Beer-Hall Putsch Hitler resolved to seek power through subverting the Weimar government system, and he carefully rebuilt the NSDAP, or Nazi, party, allying with future key figures like Goering and propaganda mastermind Goebbels. Over time he expanded the party’s support, partly by exploiting fears of socialists and partly by appealing to everyone who felt their economic livelihood threatened by the depression of the 1930s, until he had the ears of big business, the press and the middle classes. Nazi votes jumped to 107 seats in the Reichstag in 1930.
In 1932 Hitler acquired German citizenship and ran for president, coming second to von Hindenburg. Later that year the Nazi party acquired 230 seats in the Reichstag, making them the largest party in Germany. Helped by support from conservative politicians believing they could control Hitler, he was appointed Chancellor of Germany on January 30th 1933. Hitler moved with great speed to isolate and expel opponents from power, shutting trade unions, removing communists, conservatives and Jews.
Later that year Hitler perfectly exploited an act of arson on the Reichstag (which some believe the Nazis helped cause) to begin the creation of a totalitarian state, dominating the March 5th elections thanks to support from nationalist groups. Hitler soon took over the role of president when Hindenburg died and merged the role with that of Chancellor to become Führer (‘Leader’) of Germany.
Hitler continued to move with speed in radically changing Germany, consolidating power, locking up “enemies” in camps, bending culture to his will, rebuilding the army and breaking the constraints of the Treaty of Versailles. He tried to change the social fabric of Germany by encouraging women to breed more and bringing in laws to secure racial purity; Jews were particularly targeted. Employment, high elsewhere in a time of depression, fell to zero in Germany. Hitler also made himself head of the army. Hitler engineered territorial expansion, uniting with Austria in an anschluss, and dismembering Czechoslovakia. It was in September 1939, when German forces invaded Poland, that other nations took a stand, declaring war. This was not unappealing to Hitler who believed Germany should make itself great through war, and invasions in 1940 went well. However, arguably his fatal mistake occurred in 1941 with the invasion of Russia, through which he wished to create lebensraum, or ‘living room’. After initial success, German forces were pushed back by Russia, and defeats in Africa and West Europe followed as Germany was slowly beaten. During this time Hitler became gradually more paranoid and divorced from the world, retreating to a bunker. As armies approached Berlin from two directions, Hitler married his mistress, Eva Braun, and on April 30th 1945 killed himself. Hitler will forever be remembered for starting the Second World War, the most costly conflict in world history, thanks to his desire to expand Germany’s borders through force. He will equally be remembered for his dreams of racial purity, which prompted him to order the execution of millions of people, perhaps as high as eleven million. Although every arm of German bureaucracy was turned to pursuing the executions, Hitler was the chief driving force. In the decades since Hitler’s death many commentators have concluded that he must have been mentally ill, and that if he wasn’t when he started his rule the pressures of his failed wars must have driven him mad. Given that he ordered genocide and ranted and raved it is easy to see why people have come to this conclusion, but it’s important to state that there is no consensus among historians that he was insane, or what psychological problems he may have had.

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