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Cruiser Mk VIII Challenger

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The Ordnance Quick-Firing 17-pounder (or just 17-pdr ) was a 76.2 mm (3 inch) gun developed by the United Kingdom during World War II . It was used as an anti-tank gun on its own carriage, as well as equipping a number of British tanks. Used with the APDS shot, it was capable of defeating all but the thickest armour on German tanks. It was used to "up-gun" some foreign-built vehicles in British service, notably to produce the Sherman Firefly variant of the US M4 Sherman tank, giving British tank units the ability to hold their own against their German counterparts. In the anti-tank role, it was replaced after the war by the 120 mm BAT recoilless rifle . As a tank gun, it was succeeded by the 84 mm 20 pounder .

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126-593: The Tank, Cruiser, Challenger (A30) was a British tank of World War II . It mounted the QF 17-pounder anti-tank gun on a chassis derived from the Cromwell tank to add anti-tank firepower to the cruiser tank units. The design compromises made in fitting the large gun onto the Cromwell chassis resulted in a tank with a powerful weapon and reduced armour. However, the extemporised 17-pounder Sherman Firefly conversion of

252-659: A Neutrality Pact in April 1941, and Japan adopted the doctrine of Nanshin-ron , promoted by the Navy, which took its focus southward and eventually led to war with the United States and the Western Allies. In Europe, Germany and Italy were becoming more aggressive. In March 1938, Germany annexed Austria , again provoking little response from other European powers. Encouraged, Hitler began pressing German claims on

378-578: A cautious French probe into the Saarland . The Western Allies also began a naval blockade of Germany , which aimed to damage the country's economy and war effort. Germany responded by ordering U-boat warfare against Allied merchant and warships, which would later escalate into the Battle of the Atlantic . On 8 September, German troops reached the suburbs of Warsaw . The Polish counter-offensive to

504-470: A 40 mm gun mantlet; with the second batch this was replaced by a 102 mm mantlet. From the hundredth vehicle onwards appliqué 25 mm armour plates were fitted on the turret, that had already been applied to existing vehicles by field units. The tank was rendered obsolete when the Vickers HV 75 mm gun was developed to become the 77 mm HV (actually 3 inch = 76.2 mm calibre) to arm

630-524: A pretext to initiate the invasion. The first German attack of the war came against the Polish defences at Westerplatte . The United Kingdom responded with an ultimatum for Germany to cease military operations, and on 3 September, after the ultimatum was ignored, Britain and France declared war on Germany. During the Phoney War period, the alliance provided no direct military support to Poland, outside of

756-781: A pretext to worsen relations. On 29 August, Hitler demanded that a Polish plenipotentiary immediately travel to Berlin to negotiate the handover of Danzig , and to allow a plebiscite in the Polish Corridor in which the German minority would vote on secession. The Poles refused to comply with the German demands, and on the night of 30–31 August in a confrontational meeting with the British ambassador Nevile Henderson , Ribbentrop declared that Germany considered its claims rejected. On 1 September 1939, Germany invaded Poland after having staged several false flag border incidents as

882-510: A result, the A30 could not be landed in the initial phase of the Allied invasion of Normandy . Challenger crews had to wait until July 1944, when Mulberry harbours were operational and ports had been captured. The Challenger and Firefly, equipped with 17-pounder, were added to tank squadrons to deal with opposing heavy tanks and many Challengers were issued to reconnaissance units using Cromwells. It

1008-475: A secret protocol that defined German and Soviet "spheres of influence" (western Poland and Lithuania for Germany; eastern Poland , Finland, Estonia , Latvia and Bessarabia for the Soviet Union), and raised the question of continuing Polish independence. The pact neutralised the possibility of Soviet opposition to a campaign against Poland and assured that Germany would not have to face the prospect of

1134-774: A similar pact and rejected ceding part of its territory to the Soviet Union. The Soviet Union invaded Finland in November 1939, and was subsequently expelled from the League of Nations for this crime of aggression. Despite overwhelming numerical superiority, Soviet military success during the Winter War was modest, and the Finno-Soviet war ended in March 1940 with some Finnish concessions of territory . In June 1940,

1260-732: A tank powerplant from the Rolls-Royce Merlin aircraft engine. The Rolls-Royce Meteor gave the British a powerful, reliable engine, which was used in the A27M Cruiser Mk VIII Cromwell tank . Robotham's contributions gained him a place in the Ministry of Supply and on the Tank Board, despite his lack of experience in tank design. The General Staff brought forward specification A29 for a 45 ton, 17 pounder-armed cruiser tank based on needs identified in

1386-531: A two-front war, as it had in World War   I. Immediately afterwards, Hitler ordered the attack to proceed on 26 August, but upon hearing that the United Kingdom had concluded a formal mutual assistance pact with Poland and that Italy would maintain neutrality, he decided to delay it. In response to British requests for direct negotiations to avoid war, Germany made demands on Poland, which served as

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1512-417: A very large muzzle flash due to the large amount of propellant in its cartridges. Muzzle blast was also significant, described by crews of the anti-tank gun variant as resembling a hard slap on the chest. NH = non-hygroscopic; i.e. does not absorb moisture. HC = High capacity. EFC = Equivalent full charge. EFC was the basis of calculating the wear effect of propellent charges. Instructions were to examine

1638-536: The 17pdr SP Achilles (re-gunned US M10 GMC- equipped with 17pdr). While the Avenger was only used for trials and was ultimately unsuccessful in comparison with the purpose built vehicles, it provides an example of what could have been possible for the Challenger had it not been forced to accommodate a second loader in a larger (four-man) turret in its design. It may have been corrected had effort not been moved to

1764-604: The Anglo-German Naval Agreement and the German–Polish declaration of non-aggression . The situation became a crisis in late August as German troops continued to mobilise against the Polish border. On 23 August the Soviet Union signed a non-aggression pact with Germany, after tripartite negotiations for a military alliance between France, the United Kingdom, and Soviet Union had stalled. This pact had

1890-487: The Archer (SP1) and Alecto (SP3). The Avenger suffered in trials as the engine had to remain running to use the turret traverse motor, because the noise and exhaust could give the vehicle away. Winter trials in a prolonged stationary position also failed in comparison with Archer, when the Avenger's steering failed. Both vehicles had problems with camouflage. The vehicle was dropped from trials in 1950, along with removal of

2016-581: The German Revolution of 1918–1919 , and a democratic government, later known as the Weimar Republic , was created. The interwar period saw strife between supporters of the new republic and hardline opponents on both the political right and left. Italy, as an Entente ally, had made some post-war territorial gains; however, Italian nationalists were angered that the promises made by the United Kingdom and France to secure Italian entrance into

2142-692: The Italian Campaign . They became one of the most effective weapons on the battlefield, on both carriages and tanks. The 17-pounder anti-tank guns also saw action in Korea against tanks and in general support use against bunker positions. After Korea, the gun was largely replaced in the tank role by the 84mm calibre, Ordnance QF 20 pounder , and in the anti-tank role by the BAT, MOBAT and 120 mm L6 WOMBAT series of recoilless rifles . The 17-pounder outperformed all other Allied armour-piercing guns, and

2268-710: The Italian invasion of Abyssinia on 3 October 1935. The British historian Antony Beevor views the beginning of World War   II as the Battles of Khalkhin Gol fought between Japan and the forces of Mongolia and the Soviet Union from May to September 1939. Others view the Spanish Civil War as the start or prelude to World War II. The exact date of the war's end also is not universally agreed upon. It

2394-695: The League of Nations as a force to preserve peace. Both Italy and Ethiopia were member nations, but the League did little when the former clearly violated Article X of the League's Covenant . The United Kingdom and France supported imposing sanctions on Italy for the invasion, but the sanctions were not fully enforced and failed to end the Italian invasion. Italy subsequently dropped its objections to Germany's goal of absorbing Austria . When civil war broke out in Spain, Hitler and Mussolini lent military support to

2520-731: The Nationalist rebels , led by General Francisco Franco . Italy supported the Nationalists to a greater extent than the Nazis: Mussolini sent more than 70,000 ground troops, 6,000 aviation personnel, and 720 aircraft to Spain. The Soviet Union supported the existing government of the Spanish Republic . More than 30,000 foreign volunteers, known as the International Brigades , also fought against

2646-637: The North African Campaign , the first 100 prototype 17-pounder anti-tank guns were quickly sent to help counter this new threat. So great was the rush that they were sent before proper carriages had been developed, and the guns had to be mounted in the carriages of 25-pounder gun- howitzers . These early weapons were known as 17/25-pounders and given the codename Pheasant . They first saw action in February 1943. Fully developed 17-pounders started production in 1943 and were first used during

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2772-589: The Paris Peace Conference . The organisation's primary goals were to prevent armed conflict through collective security, military, and naval disarmament , as well as settling international disputes through peaceful negotiations and arbitration. Despite strong pacifist sentiment after World War   I , irredentist and revanchist nationalism had emerged in several European states. These sentiments were especially marked in Germany because of

2898-690: The Rome–Berlin Axis . A month later, Germany and Japan signed the Anti-Comintern Pact , which Italy joined the following year. The Kuomintang (KMT) party in China launched a unification campaign against regional warlords and nominally unified China in the mid-1920s, but was soon embroiled in a civil war against its former Chinese Communist Party (CCP) allies and new regional warlords . In 1931, an increasingly militaristic Empire of Japan , which had long sought influence in China as

3024-590: The Soviet–Japanese Neutrality Pact in April 1941. By contrast, the Germans were steadily making preparations for an attack on the Soviet Union, massing forces on the Soviet border. Hitler believed that the United Kingdom's refusal to end the war was based on the hope that the United States and the Soviet Union would enter the war against Germany sooner or later. On 31 July 1940, Hitler decided that

3150-543: The Stresa Front in April 1935 in order to contain Germany, a key step towards military globalisation ; however, that June, the United Kingdom made an independent naval agreement with Germany, easing prior restrictions. The Soviet Union, concerned by Germany's goals of capturing vast areas of Eastern Europe , drafted a treaty of mutual assistance with France. Before taking effect, though, the Franco-Soviet pact

3276-709: The Sudetenland , an area of Czechoslovakia with a predominantly ethnic German population. Soon the United Kingdom and France followed the appeasement policy of British Prime Minister Neville Chamberlain and conceded this territory to Germany in the Munich Agreement , which was made against the wishes of the Czechoslovak government, in exchange for a promise of no further territorial demands. Soon afterwards, Germany and Italy forced Czechoslovakia to cede additional territory to Hungary, and Poland annexed

3402-707: The Tanggu Truce was signed in 1933. Thereafter, Chinese volunteer forces continued the resistance to Japanese aggression in Manchuria , and Chahar and Suiyuan . After the 1936 Xi'an Incident , the Kuomintang and CCP forces agreed on a ceasefire to present a united front to oppose Japan. The Second Italo-Ethiopian War was a brief colonial war that began in October 1935 and ended in May 1936. The war began with

3528-579: The Trans-Olza region of Czechoslovakia. Although all of Germany's stated demands had been satisfied by the agreement, privately Hitler was furious that British interference had prevented him from seizing all of Czechoslovakia in one operation. In subsequent speeches Hitler attacked British and Jewish "war-mongers" and in January 1939 secretly ordered a major build-up of the German navy to challenge British naval supremacy. In March 1939, Germany invaded

3654-609: The Treaty of Craiova . The loss of one-third of Romania's 1939 territory caused a coup against King Carol II, turning Romania into a fascist dictatorship under Marshal Ion Antonescu , with a course set towards the Axis in the hopes of a German guarantee. Meanwhile, German-Soviet political relations and economic co-operation gradually stalled, and both states began preparations for war. In April 1940, Germany invaded Denmark and Norway to protect shipments of iron ore from Sweden , which

3780-709: The Wehrmacht rapidly advanced to the Channel and cut off the Allied forces in Belgium, trapping the bulk of the Allied armies in a cauldron on the Franco-Belgian border near Lille. The United Kingdom was able to evacuate a significant number of Allied troops from the continent by early June, although they had to abandon almost all their equipment. On 10 June, Italy invaded France , declaring war on both France and

3906-452: The 17-pounder and to prevent confusion over ammunition supplies, it was renamed the 77 mm HV —the 'HV' standing for High Velocity —although it was the same 76.2 mm calibre as the 17-pounder. The 17-pounder used the following ammunition types: APCBC ammunition was the standard ammunition for the gun, while APDS shot was used for about 6% of the average load of a 17-pounder-equipped British tank. While offering greater penetration,

Cruiser Mk VIII Challenger - Misplaced Pages Continue

4032-552: The 17-pounder; the resulting vehicles were called 17pdr SP Achilles or just 17-pdr M10C . These served with Royal Artillery as self-propelled guns. The 17-pounder was also successfully trialled on the Australian-designed Sentinel tank , though no Sentinels equipped with this gun entered service with the Australian Army . Efforts to fit the 17pdr on a Cromwell chassis in a better manner than

4158-504: The 17/25 pounder designation, a stop-gap measure named Pheasant mated the 17 pounder gun with a modified 25 pounder carriage. This enabled the gun to be pressed into service before its own carriage design was ready. A custom designed carriage for the 17 pounder comprising: In the immediate post-war era in the Middle East, Arab national armies - Transjordan, Egypt, Syria and Iraq - mainly used British manufactured artillery, including

4284-538: The 1917 Bolshevik seizure of power in Russia , which led to the founding of the Soviet Union. Meanwhile, the victorious Allies of World War I , such as France, Belgium, Italy, Romania, and Greece, gained territory, and new nation-states were created out of the dissolution of the Austro-Hungarian, Ottoman, and Russian Empires. To prevent a future world war, the League of Nations was established in 1920 by

4410-404: The 3-inch cartridge case firing from a standard 3-inch breech. This has the benefit of greater ease of use on tanks, many of which would not have sufficient turret space to accommodate the breech length and recoil distance of the 17-pounder. Similarly, the smaller 3"-based ammunition was easier to store and handle in the tank's cramped interior. This new gun's ammunition was not interchangeable with

4536-515: The African desert campaign. British tanks were generally underarmed compared to German vehicles. The design weight of this vehicle was subsequently seen as excessive and the specification was passed over in favour of the alternate specification, A30, which was 10 long tons (10 t) lighter. In 1942, an order for the development of an A30 based tank was placed with Birmingham Railway Carriage & Wagon Company (BRC&W) expecting it to be based on

4662-519: The Allies were attempting to cut off . Denmark capitulated after six hours , and despite Allied support , Norway was conquered within two months. British discontent over the Norwegian campaign led to the resignation of Prime Minister Neville Chamberlain , who was replaced by Winston Churchill on 10   May 1940. On the same day, Germany launched an offensive against France . To circumvent

4788-867: The Asia-Pacific , and by 1937 was at war with the Republic of China . In December 1941, Japan attacked American and British territories in Southeast Asia and the Central Pacific , including Pearl Harbor in Hawaii , which resulted in the US and the UK declaring war against Japan, and the European Axis declaring war on the US. Japan conquered much of coastal China and Southeast Asia , but its advances in

4914-400: The Axis war against the Soviet Union, in Romania's case partially to recapture territory ceded to the Soviet Union . In early June 1940, the Italian Regia Aeronautica attacked and besieged Malta , a British possession. From late summer to early autumn, Italy conquered British Somaliland and made an incursion into British-held Egypt . In October, Italy attacked Greece , but the attack

5040-421: The Blitz , but largely ended in May 1941 after failing to significantly disrupt the British war effort. Using newly captured French ports, the German Navy enjoyed success against an over-extended Royal Navy , using U-boats against British shipping in the Atlantic . The British Home Fleet scored a significant victory on 27   May 1941 by sinking the German battleship Bismarck . In November 1939,

5166-498: The British Army World War II Asia-Pacific Mediterranean and Middle East Other campaigns Coups World War II or the Second World War (1 September 1939 – 2 September 1945) was a global conflict between two coalitions: the Allies and the Axis powers . Nearly all the world's countries —including all the great powers —participated, with many investing all available economic, industrial, and scientific capabilities in pursuit of total war , blurring

Cruiser Mk VIII Challenger - Misplaced Pages Continue

5292-402: The Challenger tank, the British devised a conversion for their US-supplied M4 Sherman tanks to mount the 17-pounder. This was applied in sufficient numbers to put them into service in time for D-Day as the Sherman Firefly . The gun was a modified design that was produced specifically for the Firefly, the MkIV. A new horizontal-sliding breech was designed as the usual vertical-sliding breech of

5418-524: The Comet tank. The 77 mm HV used the same projectiles as the 17 pounder with a reduced propellant charge. The 17 pounder gun was used on the earliest marks of the Comet's successor, the Centurion tank . The turret mounted the Ordnance QF 17-pounder gun required in the Tank Board specification and the hull machine gun was removed to provide stowage space for the long 17-pounder cartridges. The War Office expected that this larger ammunition, together with its stowage forward, would require two loaders alongside

5544-512: The Comet. As the war came to a close, the 17-pdr was fitted to the new Centurion tank , then designated as a "heavy cruiser" tank until ultimately being replaced by the 20-pounder in 1949. The Centurion was the first tank designed around the 17pdr gun. The United States Army did not use the 17-pdr. Although the gun was offered to them and tested, they chose to stick with their 76 mm gun M1 . US forces did however request some Firefly conversions in March 1945 and as many as 18 were converted but

5670-412: The Comet. Two vehicles survive, one at the Overloon War Museum in the Netherlands, acquired from the Muzeeaquarium Delfzijl in 1976; the other was awaiting restoration at the Isle of Wight Military Museum in the United Kingdom until its closure. Once restored, it will be displayed at the Bovington Tank Museum . Background: British armoured fighting vehicle production during World War II , Tanks in

5796-403: The Cromwell components also being manufactured by BRC&W. The turret and gun mounting were in the hands of Stothert & Pitt . Birmingham Carriage had to modify the Cromwell hull to take a bigger turret. The first prototype was ready in August 1942, only seven months after development had commenced, but proved to be very flawed. An improved second prototype was presented in January 1943 but

5922-430: The Cromwell could not carry its intended armament. Vickers had been developing a 75 mm (3.0 in) 50-calibre-long high-velocity tank gun. It was realised late in the design process that the Cromwell's turret ring was too small for this gun. The Challenger would be the only British cruiser tank to mount a weapon that could tackle heavier German armour until the arrival of the A34 Comet . So in February 1943 an order

6048-484: The Cromwell. Applique armour, 25 mm thick, was later added to turret and hull front. The turret did not use a conventional turret ring: to increase the aperture diameter by four inches, it rested on a ball mount on the hull floor. Therefore the base of the turret was unprotected, and it would cantilever if struck by enemy rounds. A jacking feature, with four internal semi-automatic jacks, was fitted to clear jams. The additional length allowed larger hatches to be fitted in

6174-403: The Firefly, being lower, faster and more manoeuvrable but the early bad reputation persisted with others. Allied forces were issued with the Challenger, the 1st Polish Armoured Division receiving several in mid-1945 and the 1st Czechoslovak Independent Armoured Brigade used it (Unit Entitlements at the end of 1944 for CIABG was four Challengers) during the siege of Dunkirk in late 1944. After

6300-410: The French possessions of Syria and Lebanon , assisted by the Free French . With the situation in Europe and Asia relatively stable, Germany, Japan, and the Soviet Union made preparations for war. With the Soviets wary of mounting tensions with Germany, and the Japanese planning to take advantage of the European War by seizing resource-rich European possessions in Southeast Asia , the two powers signed

6426-426: The Germans, and the last large operational unit of the Polish Army surrendered on 6   October . Despite the military defeat, Poland never surrendered; instead, it formed the Polish government-in-exile and a clandestine state apparatus remained in occupied Poland. A significant part of Polish military personnel evacuated to Romania and Latvia; many of them later fought against the Axis in other theatres of

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6552-445: The Holocaust of European Jews, as well as from massacres, starvation, and disease. Following the Allied powers' victory, Germany , Austria , Japan , and Korea were occupied, and war crimes tribunals were conducted against German and Japanese leaders . The causes of World War II included unresolved tensions in the aftermath of World War I and the rise of fascism in Europe and militarism in Japan . Key events leading up to

6678-417: The Mks I and II made loading very difficult. An additional box was welded to the back of the turret to take the radio, which was moved to allow for the breech and its recoil. A new recoil mechanism, based on the 6-pounder design, was developed and the thicker section of the gun barrel in contact with the cradle was lengthened to match the new recoil system. The original experimental Sherman mounting at Lulworth

6804-450: The Nationalists. Both Germany and the Soviet Union used this proxy war as an opportunity to test in combat their most advanced weapons and tactics. The Nationalists won the civil war in April 1939; Franco, now dictator, remained officially neutral during World War   II but generally favoured the Axis . His greatest collaboration with Germany was the sending of volunteers to fight on the Eastern Front . In July 1937, Japan captured

6930-444: The Pacific were halted in mid-1942 after its defeat in the naval Battle of Midway ; Germany and Italy were defeated in North Africa and at Stalingrad in the Soviet Union. Key setbacks in 1943—including German defeats on the Eastern Front, the Allied invasions of Sicily and the Italian mainland , and Allied offensives in the Pacific—cost the Axis powers their initiative and forced them into strategic retreat on all fronts. In 1944,

7056-452: The Royal Navy putting three Italian battleships out of commission after a carrier attack at Taranto , and neutralising several more warships at the Battle of Cape Matapan . Italian defeats prompted Germany to deploy an expeditionary force to North Africa; at the end of March 1941, Rommel 's Afrika Korps launched an offensive which drove back Commonwealth forces. In less than a month, Axis forces advanced to western Egypt and besieged

7182-423: The Soviet Union occupied the entire territories of Estonia, Latvia and Lithuania, as well as the Romanian regions of Bessarabia, Northern Bukovina, and the Hertsa region . In August 1940, Hitler imposed the Second Vienna Award on Romania which led to the transfer of Northern Transylvania to Hungary. In September 1940, Bulgaria demanded Southern Dobruja from Romania with German and Italian support, leading to

7308-418: The Soviet Union and Mongolia . The Japanese doctrine of Hokushin-ron , which emphasised Japan's expansion northward, was favoured by the Imperial Army during this time. This policy would prove difficult to maintain in light of the Japanese defeat at Khalkin Gol in 1939, the ongoing Second Sino-Japanese War and ally Nazi Germany pursuing neutrality with the Soviets. Japan and the Soviet Union eventually signed

7434-575: The Soviet Union should be eliminated and aimed for the conquest of Ukraine , the Baltic states and Byelorussia . However, other senior German officials like Ribbentrop saw an opportunity to create a Euro-Asian bloc against the British Empire by inviting the Soviet Union into the Tripartite Pact. In November 1940, negotiations took place to determine if the Soviet Union would join the pact. The Soviets showed some interest but asked for concessions from Finland, Bulgaria, Turkey, and Japan that Germany considered unacceptable. On 18 December 1940, Hitler issued

7560-400: The Soviet Union was ever signed, although the state of war between the two countries was terminated by the Soviet–Japanese Joint Declaration of 1956 , which also restored full diplomatic relations between them. World War I had radically altered the political European map with the defeat of the Central Powers —including Austria-Hungary , Germany , Bulgaria , and the Ottoman Empire —and

7686-407: The US-supplied Sherman proved easier to produce and, with delays in production, only 200 Challengers were built. The Challenger was able to keep up with the fast Cromwell tank and was used with them. The driving force in the development of the Challenger was William Arthur Robotham . "Roy" Robotham had been a Rolls-Royce executive in the car division who, with no work to do, had led a team to develop

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7812-424: The United Kingdom and France guaranteed their support for Polish independence ; when Italy conquered Albania in April 1939, the same guarantee was extended to the Kingdoms of Romania and Greece . Shortly after the Franco - British pledge to Poland, Germany and Italy formalised their own alliance with the Pact of Steel . Hitler accused the United Kingdom and Poland of trying to "encircle" Germany and renounced

7938-489: The United Kingdom attacked on 3   July in an attempt to prevent its seizure by Germany. The air Battle of Britain began in early July with Luftwaffe attacks on shipping and harbours . The German campaign for air superiority started in August but its failure to defeat RAF Fighter Command forced the indefinite postponement of the proposed German invasion of Britain . The German strategic bombing offensive intensified with night attacks on London and other cities in

8064-401: The United Kingdom. The Germans turned south against the weakened French army, and Paris fell to them on 14   June. Eight days later France signed an armistice with Germany ; it was divided into German and Italian occupation zones , and an unoccupied rump state under the Vichy Regime , which, though officially neutral, was generally aligned with Germany. France kept its fleet, which

8190-473: The United States was assisting China and the Western Allies, and had amended the Neutrality Act to allow "cash and carry" purchases by the Allies. In 1940, following the German capture of Paris, the size of the United States Navy was significantly increased . In September the United States further agreed to a trade of American destroyers for British bases . Still, a large majority of the American public continued to oppose any direct military intervention in

8316-412: The Western Allies and the Soviet Union, culminating in the fall of Berlin to Soviet troops; Hitler's suicide ; and the German unconditional surrender on 8 May 1945 . Following the refusal of Japan to surrender on the terms of the Potsdam Declaration , the US dropped the first atomic bombs on Hiroshima and Nagasaki on 6 and 9 August. Faced with an imminent invasion of the Japanese archipelago ,

8442-413: The Western Allies invaded German-occupied France at Normandy , while the Soviet Union regained its territorial losses and pushed Germany and its allies westward. At the same time, Japan suffered reversals in mainland Asia, while the Allies crippled the Japanese Navy and captured key islands . The war in Europe concluded with the liberation of German-occupied territories ; the invasion of Germany by

8568-434: The Yellow River ; this manoeuvre bought time for the Chinese to prepare their defences at Wuhan , but the city was taken by October. Japanese military victories did not bring about the collapse of Chinese resistance that Japan had hoped to achieve; instead, the Chinese government relocated inland to Chongqing and continued the war. In the mid-to-late 1930s, Japanese forces in Manchukuo had sporadic border clashes with

8694-452: The aerial Battle of Britain and the Blitz , and naval Battle of the Atlantic . Through a series of campaigns and treaties, Germany took control of much of continental Europe and formed the Axis alliance with Italy , Japan , and other countries. In June 1941, Germany led the European Axis in an invasion of the Soviet Union , opening the Eastern Front and initially making large territorial gains. Japan aimed to dominate East Asia and

8820-415: The barrel for wear after every 40 EFC. The 17-pounder was a much bulkier and heavier weapon than its predecessor. As a result, it had to be towed by a gun tractor , such as the Morris Quad , M3 Half-track or the Crusader , as it could not effectively be moved by its gun crew alone, especially on poor ground. After firing on soft ground, the 17-pounder frequently had to be pulled out of the ground due to

8946-437: The beginning of the Pacific War include the start of the Second Sino-Japanese War on 7 July 1937, or the earlier Japanese invasion of Manchuria , on 19 September 1931. Others follow the British historian A. J. P. Taylor , who stated that the Sino-Japanese War and war in Europe and its colonies occurred simultaneously, and the two wars became World War II in 1941. Other proposed starting dates for World War II include

9072-517: The capital Nanking in December 1937. After the fall of Nanking, tens or hundreds of thousands of Chinese civilians and disarmed combatants were murdered by the Japanese . In March 1938, Nationalist Chinese forces won their first major victory at Taierzhuang , but then the city of Xuzhou was taken by the Japanese in May. In June 1938, Chinese forces stalled the Japanese advance by flooding

9198-412: The commander and gunner in the turret. To fit the larger weapon and additional crewman in the turret, a much larger turret than that of the Cromwell was specified, developed separately, which had a significant effect on the design and was not resolved until later development of Avenger. To carry the weight of the 17-pounder and ammunition, an extra wheel station and suspension arm was needed, lengthening

9324-403: The conflict well into 1941. In December 1940, Roosevelt accused Hitler of planning world conquest and ruled out any negotiations as useless, calling for the United States to become an " arsenal of democracy " and promoting Lend-Lease programmes of military and humanitarian aid to support the British war effort; Lend-Lease was later extended to the other Allies, including the Soviet Union after it

9450-526: The creation of a " New Roman Empire ". Adolf Hitler , after an unsuccessful attempt to overthrow the German government in 1923, eventually became the Chancellor of Germany in 1933 when Paul von Hindenburg and the Reichstag appointed him. Following Hindenburg's death in 1934, Hitler proclaimed himself Führer of Germany and abolished democracy, espousing a radical, racially motivated revision of

9576-507: The deployment of 17-pounder armed tanks was increased to two per troop. The Challenger was based on the reliable Cromwell tank, which used the new Rolls-Royce Meteor engine, which was far more reliable and powerful than the ageing Liberty engine used in earlier British Cruiser designs like the Crusader tank . Its reliability was slightly below that of the Cromwell, as a problem was experienced with track throwing, caused by mud building up in

9702-442: The directive to prepare for an invasion of the Soviet Union. OQF 77mm HV Before the QF 6-pounder had entered service, the British predicted that it would soon be inadequate given the increasing armour of German tanks. In late 1940, the design of a replacement began, and was largely completed by the end of 1941. A prototype production line was set up in spring 1942, and with the appearance of Tiger I tanks in early 1943 in

9828-402: The distinction between military and civilian resources. Tanks and aircraft played major roles , with the latter enabling the strategic bombing of population centres and delivery of the only two nuclear weapons ever used in war. World War II was the deadliest conflict in history, resulting in 70 to 85 million deaths , more than half being civilians. Millions died in genocides , including

9954-652: The end of May completed the German conquest of the Balkans. Partisan warfare subsequently broke out against the Axis occupation of Yugoslavia , which continued until the end of the war. In the Middle East in May, Commonwealth forces quashed an uprising in Iraq which had been supported by German aircraft from bases within Vichy-controlled Syria . Between June and July, British-led forces invaded and occupied

10080-575: The first step of what its government saw as the country's right to rule Asia , staged the Mukden incident as a pretext to invade Manchuria and establish the puppet state of Manchukuo . China appealed to the League of Nations to stop the Japanese invasion of Manchuria. Japan withdrew from the League of Nations after being condemned for its incursion into Manchuria. The two nations then fought several battles, in Shanghai , Rehe and Hebei , until

10206-864: The former Chinese imperial capital of Peking after instigating the Marco Polo Bridge incident , which culminated in the Japanese campaign to invade all of China. The Soviets quickly signed a non-aggression pact with China to lend materiel support, effectively ending China's prior cooperation with Germany . From September to November, the Japanese attacked Taiyuan , engaged the Kuomintang Army around Xinkou , and fought Communist forces in Pingxingguan . Generalissimo Chiang Kai-shek deployed his best army to defend Shanghai , but after three months of fighting, Shanghai fell. The Japanese continued to push Chinese forces back, capturing

10332-898: The gun recoil burying the trail spades. After the Second World War, it was issued to anti-tank units of the Royal Artillery in the British Army of the Rhine (BAOR) towed by the M3 Half Track. When the Royal Artillery anti-tank units were disbanded in 1951, it was transferred to Infantry battalions in the BAOR (six per battalion), towed by the Oxford Tracked Carrier . It was later replaced by the 120 mm BAT recoilless rifle anti-tank weapon. Also known by

10458-531: The high silhouette and the tracks being thrown. The track problem was caused by the smaller idler wheels compared to the Cromwell; these were in August replaced by idlers with a standard diameter. Troops used to the low profile of the Crusader and Cromwell found the height a serious problem, although it was still shorter than the comparable Sherman Firefly. Confidence in the vehicle grew and it became preferred over

10584-460: The hull while still clearing the turret, providing easier access than Cromwell. Upon Robotham's appointment as Chief Engineer to the Department of Tank Design, the lack of progress on an (A29) 17-pounder armed tank could not adequately be explained. Robotham's memoirs indicate a lack of awareness that any such requirement existed within the department and military users were still unsure whether

10710-471: The hull. This change in length, without a corresponding change in width across the tracks, reduced mobility compared to the Cromwell, although speed remained high at 25 mph. To limit the weight, the amount of armour was reduced but this could only be achieved on the turret, 63 mm (2.5 in) on the front (the mantlet was 102 mm of IT 90) and 40 mm (1.6 in) on the sides compared to 75 mm (3.0 in) and 60 mm (2.4 in) on

10836-525: The invasion of the Ethiopian Empire (also known as Abyssinia ) by the armed forces of the Kingdom of Italy ( Regno d'Italia ), which was launched from Italian Somaliland and Eritrea . The war resulted in the military occupation of Ethiopia and its annexation into the newly created colony of Italian East Africa ( Africa Orientale Italiana , or AOI); in addition it exposed the weakness of

10962-599: The port of Tobruk . By late March 1941, Bulgaria and Yugoslavia signed the Tripartite Pact ; however, the Yugoslav government was overthrown two days later by pro-British nationalists. Germany and Italy responded with simultaneous invasions of both Yugoslavia and Greece , commencing on 6 April 1941; both nations were forced to surrender within the month. The airborne invasion of the Greek island of Crete at

11088-414: The possibility of further atomic bombings, and the Soviet declaration of war against Japan and its invasion of Manchuria , Japan announced its unconditional surrender on 15 August and signed a surrender document on 2 September 1945 , marking the end of the war. World War II changed the political alignment and social structure of the world, and it set the foundation of international relations for

11214-722: The remainder of Czechoslovakia and subsequently split it into the German Protectorate of Bohemia and Moravia and a pro-German client state , the Slovak Republic . Hitler also delivered an ultimatum to Lithuania on 20 March 1939, forcing the concession of the Klaipėda Region , formerly the German Memelland . Greatly alarmed and with Hitler making further demands on the Free City of Danzig ,

11340-517: The rest of the 20th century and into the 21st century. The United Nations was established to foster international cooperation and prevent conflicts, with the victorious great powers—China, France, the Soviet Union, the UK, and the US—becoming the permanent members of its security council . The Soviet Union and the United States emerged as rival superpowers , setting the stage for the Cold War . In

11466-476: The same time the A 40 "Challenger Stage II" project was cancelled, which had envisaged a 36 tonne type with heavier armour. Future design priority was concentrated on the A34 Comet, which eventually replaced the Cromwell, Firefly and Challenger. Challenger production started in March 1944. That year 145 vehicles were delivered with another 52 in 1945. Production was in two batches. A first run of forty vehicles had

11592-432: The second loader's position and featured a much lower profile turret and lower superstructure on the hull. An additional stowage bin was provided on the glacis plate for a large camo net and return rollers were added to the tracks. The Avenger featured a permanent opening in the turret roof covered with an armoured cover supported a few inches above. This provided the commander and loader with full 360 degree visibility. By

11718-462: The second prototype was tested at Lulworth , it was found that although it would be effective at long range against the current best-gunned tank in German service (the Panzer IV "Special" with the long 75 mm (3.0 in) gun), at shorter ranges it would be at a disadvantage due to its slow firing rate and thin armour. The design received additional emphasis when, in May 1943, it was found that

11844-410: The significant territorial, colonial, and financial losses imposed by the Treaty of Versailles . Under the treaty, Germany lost around 13 percent of its home territory and all its overseas possessions , while German annexation of other states was prohibited, reparations were imposed, and limits were placed on the size and capability of the country's armed forces . The German Empire was dissolved in

11970-453: The smaller (sub-calibre) tungsten core of APDS was considered to provide less accurate fire than APCBC ammunition at ranges beyond 500 yards. This was due to the much lesser visible impact of rounds that fell short, making it hard to spot the fall of shot and correct aim. The APDS was also considered to cause less damage to an enemy tank if it did penetrate the armour. After penetration the core usually disintegrated. The 17-pounder produced

12096-593: The strong Maginot Line fortifications on the Franco-German border, Germany directed its attack at the neutral nations of Belgium , the Netherlands , and Luxembourg . The Germans carried out a flanking manoeuvre through the Ardennes region, which was mistakenly perceived by the Allies as an impenetrable natural barrier against armoured vehicles. By successfully implementing new Blitzkrieg tactics,

12222-519: The tank had a higher top speed and cross country mobility than the Panzer IV or StuG III . The Challenger could only hold 48 rounds of the large 17-pounder ammunition because the General Staff required four men in the turret, though later tanks like the Centurion used a three-man turret. The armour of the Challenger offered very little protection against contemporary German anti-tank guns and

12348-469: The tank was required at the point when the rushed A30 design had been completed and prototype vehicles run. The Challenger was then rushed into production alongside existing production runs of Cromwell, limiting the number of tanks that could be produced. The 17-pounder gun mounted on the Challenger offered sufficient performance against the majority of German AFVs, including the Tiger I and Panther tank and

12474-486: The time the pilot was complete, the British had lend-lease M10s for anti-tank work coming into service and the production of Avenger was de-prioritised in favour of Comet production As many as 500 vehicles appear to have been planned and 230 vehicles were ordered from BRC&W, but this dropped to 80 with the end of the war. It is not known how many were actually built; the SP2 nomenclature indicates its place in production with

12600-513: The ungainly Challenger resulted in the Comet tank. However the Comet could still not take the 17pdr. The 75mm High Velocity Gun project was resurrected and redesigned to use a shortened version of the 17pdr barrel and the 17pdr projectiles mated to the cartridge of the 3 inch 30cwt anti-aircraft gun. While often confused with the 17pdr, the 77mm HV, was an entirely separate weapon and was only used on

12726-413: The use of Cromwell tank components as a design expedient. The resulting Cruiser Mark VIII Challenger had a longer hull and provided a larger turret, allowing the 17-pounder to be mounted along with space for a second loader, thought to be required for the gun's larger ammunition. However, production of the tank took time and few could be completed before the allied invasion of Normandy. While developing

12852-601: The wake of European devastation, the influence of its great powers waned, triggering the decolonisation of Africa and Asia . Most countries whose industries had been damaged moved towards economic recovery and expansion . World War II began in Europe on 1 September 1939 with the German invasion of Poland and the United Kingdom and France 's declaration of war on Germany two days later on 3 September 1939. Dates for

12978-409: The war ended before they were shipped from the UK. The British started work on developing a gun that was small enough to fit on their tank designs—particularly the Cromwell cruiser tank then at the design stage. It was intended to fire the US 75 mm projectiles (AP shot and HE) at a higher velocity, avoiding a downgrade in armour penetration versus the 6-pounder, which the dual purpose 75 mm

13104-537: The war included Japan's invasion of Manchuria , the Spanish Civil War , the outbreak of the Second Sino-Japanese War , and Germany's annexations of Austria and the Sudetenland . World War II is generally considered to have begun on 1 September 1939, when Nazi Germany , under Adolf Hitler , invaded Poland , prompting the United Kingdom and France to declare war on Germany. Poland

13230-513: The war were not fulfilled in the peace settlement. From 1922 to 1925, the Fascist movement led by Benito Mussolini seized power in Italy with a nationalist, totalitarian , and class collaborationist agenda that abolished representative democracy, repressed socialist, left-wing, and liberal forces, and pursued an aggressive expansionist foreign policy aimed at making Italy a world power, promising

13356-424: The war, the Czechoslovak government purchased 22 Challengers from the brigade inventory, which served in the Czechoslovak army (first with the 11th, later 23rd, Tank Brigade and then with the 13th Independent Tank Battalion) until they were put in reserve in 1951 and scrapped in 1959. The A30 Avenger SP2 or SP 17pdr, A30 (Avenger) was a development of the Challenger to be used as a self-propelled gun . It removed

13482-475: The war. Germany annexed western Poland and occupied central Poland ; the Soviet Union annexed eastern Poland ; small shares of Polish territory were transferred to Lithuania and Slovakia . On 6 October, Hitler made a public peace overture to the United Kingdom and France but said that the future of Poland was to be determined exclusively by Germany and the Soviet Union. The proposal was rejected and Hitler ordered an immediate offensive against France, which

13608-512: The west halted the German advance for several days, but it was outflanked and encircled by the Wehrmacht . Remnants of the Polish army broke through to besieged Warsaw . On 17 September 1939, two days after signing a cease-fire with Japan , the Soviet Union invaded Poland under the supposed pretext that the Polish state had ceased to exist. On 27 September, the Warsaw garrison surrendered to

13734-491: The wheels but this was resolved in the field. Supply and maintenance were vastly simplified through the use of common parts with the Cromwell. In comparison with the Firefly, the tank lacked the sloping forward armour but presented a lower profile and avoided the Firefly's constraint on gun depression. The Challenger provided 10° of gun depression while Firefly was limited to 5°, which was a significant disadvantage in combat. It

13860-707: The world order , and soon began a massive rearmament campaign . France, seeking to secure its alliance with Italy, allowed Italy a free hand in Ethiopia , which Italy desired as a colonial possession. The situation was aggravated in early 1935 when the Territory of the Saar Basin was legally reunited with Germany, and Hitler repudiated the Treaty of Versailles, accelerated his rearmament programme, and introduced conscription. The United Kingdom, France and Italy formed

13986-614: Was invaded by Germany. The United States started strategic planning to prepare for a full-scale offensive against Germany. At the end of September 1940, the Tripartite Pact formally united Japan, Italy, and Germany as the Axis powers . The Tripartite Pact stipulated that any country—with the exception of the Soviet Union—that attacked any Axis Power would be forced to go to war against all three. The Axis expanded in November 1940 when Hungary , Slovakia , and Romania joined. Romania and Hungary later made major contributions to

14112-480: Was actually rigid with no recoil system. Production of the Challenger was cancelled with only about 200 built, and 2,200 - 2,400 Sherman Is and Vs were converted as Fireflies (sources vary) and deployed in Sherman regiments Italy and NW Europe. The Challengers were deployed with Cromwell regiments. The British also converted some of their US-produced M10 tank destroyers , replacing the 3-inch (76 mm) M7 gun with

14238-403: Was compensated by American production. In the lead up to D-Day , Sherman tanks were fitted with the 17 pounder, creating the interim 17 pounder Sherman Firefly . Converting Sherman tanks was simpler than producing Challengers, so it was decided in November 1943 to terminate the A30 production run after the two hundred vehicles had been built, allowing BRC&W to concentrate on the Cromwell. At

14364-825: Was divided between Germany and the Soviet Union under the Molotov–Ribbentrop Pact , in which they had agreed on " spheres of influence " in Eastern Europe. In 1940, the Soviets annexed the Baltic states and parts of Finland and Romania . After the fall of France in June 1940, the war continued mainly between Germany and the British Empire , with fighting in the Balkans , Mediterranean, and Middle East ,

14490-536: Was generally accepted at the time that the war ended with the armistice of 15 August 1945 ( V-J Day ), rather than with the formal surrender of Japan on 2 September 1945, which officially ended the war in Asia . A peace treaty between Japan and the Allies was signed in 1951. A 1990 treaty regarding Germany's future allowed the reunification of East and West Germany to take place and resolved most post–World War   II issues. No formal peace treaty between Japan and

14616-488: Was initially used by the Guards Armoured Division and the 11th Armoured Division , with about sixteen vehicles in each unit: one Challenger and three Cromwells in each troop. The latter division phased the type out from February 1945 onwards, while it was being introduced to the Cromwell units of the 7th Armoured Division . The tank was unpopular at first, with crews complaining about the lack of armour,

14742-564: Was lower than that of the Cromwell, which often operated with Challengers. In combat, the Challenger fulfilled much the same role as the Sherman Firefly, providing overwatch for the other tanks in the troop, as its 17-pounder could penetrate almost all German AFVs frontally, unlike the 75 mm. It was deployed in a similar manner at a troop level, this was typically one 17-pounder armed tank (such as Challenger or Firefly) to three 75 mm armed tanks (Cromwells or Shermans); at times,

14868-534: Was made of two hundred vehicles; the Army General Staff took five months to approve the Challenger design for production (in February 1943, the only significant alteration was to the ammunition stowage), and Robotham was also critical of the decision to continue manufacturing the Cromwell with a 6-pounder gun (the 17-pounder gun was "infinitely better"). British tank production was constrained by limited resources and insufficient numbers could be made. This

14994-456: Was postponed until the spring of 1940 due to bad weather. After the outbreak of war in Poland, Stalin threatened Estonia , Latvia , and Lithuania with military invasion, forcing the three Baltic countries to sign pacts allowing the creation of Soviet military bases in these countries; in October 1939, significant Soviet military contingents were moved there. Finland refused to sign

15120-486: Was preferred within Cromwell units as it shared similar mobility and manoeuvrability, whereas the Firefly was slower. Despite a lower design weight than the earlier A29 specification (32½ not 34 tons), the Challenger was heavy and required dockyard equipment to ship, making it impractical to use in amphibious assaults such as the D-day landings. No provision was made for deep wading , before the design went into production; as

15246-512: Was quickly adapted for use on various tank chassis. However, few tanks were capable of carrying such a large gun due to the size limitations of their turret rings. A new British tank specification, A29, was produced to meet the need for a 17-pounder armed cruiser tank . While the A29 was eventually cancelled without a successful design being produced, an amended specification, A30, reached production in 1943. The A30 specification reduced weight and enabled

15372-477: Was replacing. The new 50-calibre long gun, known as the Vickers HV 75 mm , fired a 75 mm projectile attached to a necked down 3-inch (76.2 mm) 20 cwt AA gun cartridge through a modified breech. The larger 3" cartridge provided a greater propellant charge compared with normal 75 mm shells. Although the 75 mm HV was a promising weapon, it proved to be too big for the Cromwell tank , which

15498-772: Was repulsed with heavy Italian casualties; the campaign ended within months with minor territorial changes. To assist Italy and prevent Britain from gaining a foothold, Germany prepared to invade the Balkans, which would threaten Romanian oil fields and strike against British dominance of the Mediterranean. In December 1940, British Empire forces began counter-offensives against Italian forces in Egypt and Italian East Africa . The offensives were successful; by early February 1941, Italy had lost control of eastern Libya, and large numbers of Italian troops had been taken prisoner. The Italian Navy also suffered significant defeats, with

15624-620: Was required to go through the bureaucracy of the League of Nations, which rendered it essentially toothless. The United States, concerned with events in Europe and Asia, passed the Neutrality Act in August of the same year. Hitler defied the Versailles and Locarno Treaties by remilitarising the Rhineland in March 1936, encountering little opposition due to the policy of appeasement . In October 1936, Germany and Italy formed

15750-461: Was still considered unacceptable. A committee met to determine whether a requirement for a 17-pounder tank existed. The Challenger had been developed in anticipation of more heavily armoured Axis tanks, following the trend in Nazi German tank design. At roughly the same time the Tiger I entered service with the German army, placing an immediate need for a 17-pounder armed tank in response. When

15876-429: Was ultimately fitted with the normal QF 75 mm gun in use on other British tanks. To account for this difference, tank squadrons were teamed with Challenger and Sherman Firefly tanks armed with the 17-pounder. When the Cromwell's replacement, the Comet , was at the design stage, the 75 mm HV concept was reworked to fire the same projectiles as the 17-pounder through a shortened 17-pounder barrel but retaining

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