The Manhattan Project was a research and development undertaking during World War II that produced the first nuclear weapons. It was led by the United States with the support of Canada. From 1942 to 1946, the project was under the direction of Major General Leslie Groves of the U. S. Army Corps of Engineers. Nuclear physicist Robert Oppenheimer was the director of the Los Alamos Laboratory that designed the actual bombs; the Army component of the project was designated the Manhattan District. Along the way, the project absorbed Tube Alloys; the Manhattan Project began modestly in 1939, but grew to employ more than 130,000 people and cost nearly US$2 billion. Over 90% of the cost was for building factories and to produce fissile material, with less than 10% for development and production of the weapons. Research and production took place at more than 30 sites across the United States, the United Kingdom, Canada. Two types of atomic bombs were developed concurrently during the war: a simple gun-type fission weapon and a more complex implosion-type nuclear weapon.
The Thin Man gun-type design proved impractical to use with plutonium, therefore a simpler gun-type called Little Boy was developed that used uranium-235, an isotope that makes up only 0.7 percent of natural uranium. Chemically identical to the most common isotope, uranium-238, with the same mass, it proved difficult to separate the two. Three methods were employed for uranium enrichment: electromagnetic and thermal. Most of this work was performed at the Clinton Engineer Works at Tennessee. In parallel with the work on uranium was an effort to produce plutonium. After the feasibility of the world's first artificial nuclear reactor was demonstrated in Chicago at the Metallurgical Laboratory, it designed the X-10 Graphite Reactor at Oak Ridge and the production reactors in Hanford, Washington, in which uranium was irradiated and transmuted into plutonium; the plutonium was chemically separated from the uranium, using the bismuth phosphate process. The Fat Man plutonium implosion-type weapon was developed in a concerted design and development effort by the Los Alamos Laboratory.
The project was charged with gathering intelligence on the German nuclear weapon project. Through Operation Alsos, Manhattan Project personnel served in Europe, sometimes behind enemy lines, where they gathered nuclear materials and documents, rounded up German scientists. Despite the Manhattan Project's tight security, Soviet atomic spies penetrated the program; the first nuclear device detonated was an implosion-type bomb at the Trinity test, conducted at New Mexico's Alamogordo Bombing and Gunnery Range on 16 July 1945. Little Boy and Fat Man bombs were used a month in the atomic bombings of Hiroshima and Nagasaki, respectively. In the immediate postwar years, the Manhattan Project conducted weapons testing at Bikini Atoll as part of Operation Crossroads, developed new weapons, promoted the development of the network of national laboratories, supported medical research into radiology and laid the foundations for the nuclear navy, it maintained control over American atomic weapons research and production until the formation of the United States Atomic Energy Commission in January 1947.
The discovery of nuclear fission by German chemists Otto Hahn and Fritz Strassmann in 1938, its theoretical explanation by Lise Meitner and Otto Frisch, made the development of an atomic bomb a theoretical possibility. There were fears that a German atomic bomb project would develop one first among scientists who were refugees from Nazi Germany and other fascist countries. In August 1939, Hungarian-born physicists Leó Szilárd and Eugene Wigner drafted the Einstein–Szilárd letter, which warned of the potential development of "extremely powerful bombs of a new type", it urged the United States to take steps to acquire stockpiles of uranium ore and accelerate the research of Enrico Fermi and others into nuclear chain reactions. They had it delivered to President Franklin D. Roosevelt. Roosevelt called on Lyman Briggs of the National Bureau of Standards to head the Advisory Committee on Uranium to investigate the issues raised by the letter. Briggs held a meeting on 21 October 1939, attended by Szilárd, Wigner and Edward Teller.
The committee reported back to Roosevelt in November that uranium "would provide a possible source of bombs with a destructiveness vastly greater than anything now known."The Advisory Committee on Uranium became the National Defense Research Committee Committee on Uranium when that organization was formed on 27 June 1940. Briggs proposed spending $167,000 on research into uranium the uranium-235 isotope, the discovered plutonium. On 28 June 1941, Roosevelt signed Executive Order 8807, which created the Office of Scientific Research and Development, with Vannevar Bush as its director; the office was empowered to engage in large engineering projects in addition to research. The NDRC Committee on Uranium became the S-1 Section of the OSRD. In Britain and Rudolf Peierls at the University of Birmingham had made a breakthrough investigating the critical mass of uranium-235 in June 1939, their calculations indicated that it was within an order of magnitude of 10 kilograms, small enough to be carried by a bomber of the day.
Their March 1940 Frisch–Peierls memorandum initiated the British atomic bomb project and its Maud Committee, which unanimously recommended pursuing the development of an atomic bomb
A tank destroyer or tank hunter is a type of armoured fighting vehicle, armed with a direct-fire artillery gun or missile launcher, with limited operational capacities and designed to engage enemy tanks. Tanks are armoured fighting vehicles designed for front-line combat, combining operational mobility and tactical offensive and defensive capabilities; the tank destroyer on the other hand is designed to take on enemy tanks and other armoured fighting vehicles. Many are based on a tracked tank chassis. Since World War II, gun-armed tank destroyers have fallen out of favor as armies have favored multirole main battle tanks; however armored anti-tank guided missile carriers are used for supplementary long-range anti-tank work. The resurgence of expeditionary warfare in the first two decades of the 21st century has seen the emergence of gun-armed wheeled vehicles, sometimes called protected gun systems, which may bear a superficial resemblance to tank destroyers, but are employed as direct fire support units providing support in low-intensity operations such as the wars in Iraq and Afghanistan.
Dedicated anti-tank vehicles made their first major appearance in the Second World War as combatants developed effective armored vehicles and tactics. Some were little more than stopgap solutions, mounting an anti-tank gun on a tracked vehicle to give mobility, while others were more sophisticated designs. An example of the development of tank destroyer technology throughout the war are the Marder III and Jagdpanzer 38 vehicle, that were different in spite of being based on the same chassis: Marder was straightforwardly an anti-tank gun on tracks whereas the Jagdpanzer 38 traded some firepower for better armor protection and ease of concealment on the battlefield. Except for most American designs, tank destroyers were all turretless and had fixed or casemate superstructures; when a tank destroyer was used against enemy tanks from a defensive position such as by ambush, the common lack of a rotating turret was not critical, while the lower silhouette was desirable. The turretless design allowed accommodation of a more powerful gun a dedicated anti-tank gun that had a longer barrel than could be mounted in a turreted tank on the same chassis.
The lack of a turret increased the vehicle's internal volume, allowing for increased ammunition stowage and crew comfort. Eliminating the turret let the vehicle carry thicker armor, let this armour be concentrated in the hull. Sometimes there was no armored roof to keep the overall weight down to the limit that the chassis could bear; the absence of a turret meant that tank destroyers could be manufactured cheaper and more than the tanks on which they were based, they found particular favor when production resources were lacking. After hard lessons early in the war, machine guns were mounted for use against infantry, but the limited traverse of the mounting meant that they were still less effective than those used on turreted tanks. Variants of the Polish TKS and TK-3 tankettes up-armed with 20 mm gun were operationally deployed in the invasion of Poland, they were used as an anti-tank component of the reconnaissance units. Due to the quick defeat of France, few French vehicles were built; the Laffly W15 TCC was an attempt to build a light tank destroyer by mounting a 47 mm SA37 anti-tank gun onto a armored Laffly W15T artillery tractor.
Other French tank destroyers were being developed, including the SOMUA SAu-40, ARL V39 and various ad hoc conversions of the Lorraine 37L. The first German tank destroyers were the Panzerjäger, which mounted an existing anti-tank gun on a convenient chassis for mobility with just a three-sided gun shield for crew protection. For instance, 202 obsolete Panzer I light tanks were modified by removing the turret and were rebuilt as the Panzerjäger I self-propelled 4.7 cm PaK. Panzer II tanks were used on the eastern front. Captured Soviet 76.2 mm anti-tank guns were mounted on modified Panzer II chassis, producing the Marder II self-propelled anti-tank gun. The most common mounting was a German 75 mm anti-tank gun on the Czech Panzer 38 chassis to produce the Marder III; the Panzer 38 chassis was used to make the Jagdpanzer 38 casemate style tank destroyer. The Panzerjäger series continued up to the 88 mm equipped Nashorn. German tank destroyers based on the Panzer III and German tanks were unique in that they had more armor than their tank counterparts.
One of the more successful German tank destroyers was designed as a self-propelled artillery gun, the Sturmgeschütz III. Based on the Panzer III tank chassis, the Sturmgeschütz III was fitted with a low-velocity gun, was assigned to the artillery arm for infantry fire support. After encountering Soviet tanks, it was refitted with a comparatively short-barreled high-velocity anti-tank gun with a muzzle brake, enabling it to function as a tank destroyer; the Sturmgeschütz III from its 1938 origin used a new casemate-style superstructure with an integrated design similar to the Jagdpanzer to enclose the crew. It was employed in infantry support and offensive armored operations as well as in the defensive anti-tank role; the StuG III was the most-produced German armored fighting vehicle of any ty
M1918 Browning Automatic Rifle
The Browning Automatic Rifle is a family of American automatic rifles and machine guns used by the United States and numerous other countries during the 20th century. The primary variant of the BAR series was the M1918, chambered for the.30-06 Springfield rifle cartridge and designed by John Browning in 1917 for the American Expeditionary Forces in Europe as a replacement for the French-made Chauchat and M1909 Benét–Mercié machine guns that US forces had been issued. The BAR was designed to be carried by infantrymen during an assault advance while supported by the sling over the shoulder, or to be fired from the hip; this is a concept called "walking fire" — thought to be necessary for the individual soldier during trench warfare. The BAR never lived up to the original hopes of the war department as either a rifle or a machine gun; the U. S. Army, in practice, used the BAR as a light machine gun fired from a bipod. A variant of the original M1918 BAR, the Colt Monitor Machine Rifle, remains the lightest production automatic firearm chambered for the.30-06 Springfield cartridge, though the limited capacity of its standard 20-round magazine tended to hamper its utility in that role.
Although the weapon did see some action in World War I, the BAR did not become standard issue in the US Army until 1938, when it was issued to squads as a portable light machine gun. The BAR saw extensive service in both World War II and the Korean War and saw limited service in the Vietnam War; the US Army began phasing out the BAR in the late 1950s, when it was intended to be replaced by a squad automatic weapon variant of the M14, was without a portable light machine gun until the introduction of the M60 machine gun in 1957. The US entered World War I with an inadequate and obsolete assortment of domestic and foreign machine gun designs, due to bureaucratic indecision and the lack of an established military doctrine for their employment; when the 1917 United States declaration of war on Germany was announced on 6 April 1917, the high command was made aware that to fight this trench war, dominated by machine-guns, they had on hand a mere 670 M1909 Benét–Merciés, 282 M1904 Maxims and 158 Colts, M1895s.
After much debate, it was agreed that a rapid rearmament with domestic weapons would be required, but until that time, US troops would be issued whatever the French and British had to offer. The arms donated by the French were second-rate or surplus and chambered in 8mm Lebel, further complicating logistics as machine gunners and infantrymen were issued different types of ammunition. In 1917, prior to America's entry to the war, John Browning brought to Washington, D. C. two types of automatic weapons for the purposes of demonstration: a water-cooled machine gun and a shoulder-fired automatic rifle known as the Browning Machine Rifle or BMR, both chambered for the standard US.30-06 Springfield cartridge. Browning had arranged for a public demonstration of both weapons at a location in southern Washington, D. C. known as Congress Heights. There, on 27 February 1917, in front of a crowd of 300 people, Browning staged a live-fire demonstration which so impressed the gathered crowd, that he was awarded a contract for the weapon and it was hastily adopted into service.
Additional tests were conducted for US Army Ordnance officials at Springfield Armory in May 1917, both weapons were unanimously recommended for immediate adoption. In order to avoid confusion with the belt-fed M1917 machine gun, the BAR came to be known as the M1918 or Rifle, Caliber.30, Browning, M1918 according to official nomenclature. On 16 July 1917, 12,000 BARs were ordered from Colt's Patent Firearms Manufacturing Company, which had secured an exclusive concession to manufacture the BAR under Browning's patents; however Colt was producing at peak capacity and requested a delay in production while they expanded their manufacturing output with a new facility in Meriden, Connecticut. Due to the urgent need for the weapon, the request was denied and the Winchester Repeating Arms Company was designated as the prime contractor. Winchester gave valuable assistance in refining the BAR's final design, correcting the drawings in preparation for mass production. Among the changes made, the ejection pattern was modified.
Since work on the gun did not begin until February 1918, so hurried was the schedule at Winchester to bring the BAR into full production that the first production batch of 1,800 guns was delivered out of spec. The initial contract with Winchester called for 25,000 BARs, they were in full production by June 1918, delivering 4,000 guns, from July were turning out 9,000 units per month. Colt and Marlin-Rockwell Corp. began production shortly after Winchester got into full production. Marlin-Rockwell, burdened by a contract to make rifles for the Belgian government, acquired the Mayo Radiator Co.'s factory and used it to carry out production of the BAR. The first unit from this source was delivered on 11 June 1918 and the company's peak output reached 200 automatic rifles per day. Colt had produced only 9,000 BARs by the time of the armistice due to the
The M2 Machine Gun or Browning.50 Caliber Machine Gun is a heavy machine gun designed toward the end of World War I by John Browning. Its design is similar to Browning's earlier M1919 Browning machine gun, chambered for the.30-06 cartridge. The M2 uses the much larger and much more powerful.50 BMG cartridge, developed alongside and takes its name from the gun itself. It has been referred to in reference to its M2 nomenclature; the design has had many specific designations. It is effective against infantry, unarmored or armored vehicles and boats, light fortifications and low-flying aircraft; the Browning.50 caliber machine gun has been used extensively as a vehicle weapon and for aircraft armament by the United States from the 1930s to the present. It was used during World War II, the Korean War, the Vietnam War, the Falklands War, the Soviet–Afghan War, the Gulf War, the Iraq War and the War in Afghanistan in the 2000s and 2010s, it is the primary heavy machine gun of NATO countries, has been used by many other countries as well.
The M2 has been in use longer than any other firearm in U. S. inventory except the.45 ACP M1911 pistol designed by John Browning. The current M2HB is manufactured in the U. S. by General Dynamics and U. S. Ordnance for use by the U. S. government, for allies via Foreign Military Sales, as well as foreign manufacturers such as FN Herstal. Machine guns were used in World War I, weapons of larger than rifle caliber began appearing on both sides of the conflict; the larger rounds were needed to defeat the armor, being introduced to the battlefield, both on the ground and in the air. During World War I, the Germans introduced a armored airplane, the Junkers J. I; the armor made aircraft machine guns using conventional rifle ammunition ineffective. The American Expeditionary Force's commander General John J. Pershing asked for a larger caliber machine gun. Pershing asked the Army Ordnance Department to develop a machine gun with a caliber of at least 0.50 inches and a muzzle velocity of at least 2,700 feet per second.
U. S. Col. John Henry Parker, commanding a machine gun school in France, observed the effectiveness of a French 11 mm incendiary armor-piercing round; the Army Ordnance Department ordered eight experimental Colt machine guns rechambered for the French 11 mm cartridge. The French 11 mm round was found to be unsuitable. Pershing wanted a muzzle velocity of 2,700 ft/s. Development with the French round was dropped. Around July 1917, John M. Browning started redesigning his.30-06 M1917 machine gun for a larger and more powerful round. Winchester worked on the cartridge, a scaled-up version of the.30-06. Winchester added a rim to the cartridge because the company wanted to use the cartridge in an anti-tank rifle, but Pershing insisted the cartridge be rimless; the first.50 machine gun underwent trials on 15 October 1918. It fired at less than 500 rounds per minute, the muzzle velocity was only 2,300 ft/s. Cartridge improvements were promised; the gun was heavy, difficult to control, fired too for the anti-personnel role, was not powerful enough against armor.
While the.50 was being developed, some German T Gewehr 1918 anti-tank rifles and ammunition were seized. The German rounds had a muzzle velocity of 2,700 ft/s, an 800 gr bullet, could pierce1 in at 250 yd. Winchester improved the.50 caliber round to have similar performance. The muzzle velocity was 2,750 ft/s. Efforts by John M. Browning and Fred T. Moore resulted in the water-cooled Browning machine gun, caliber.50, M1921. An aircraft version was termed the Browning aircraft machine gun, caliber.50, M1921. These guns were used experimentally from 1921 until 1937, they had the ammunition fed only from the left side. Service trials raised doubts whether the guns would be suitable for aircraft or for anti-aircraft use. A heavy barrel M1921 was considered for ground vehicles. John M. Browning died in 1926. Between 1927 and 1932, S. H. Green studied the design problems of the needs of the armed services; the result was a single receiver design that could be turned into seven types of.50 caliber machine guns by using different jackets and other components.
The new receiver allowed left side feed. In 1933, Colt manufactured several prototype Browning machine guns. With support from the Navy, Colt started manufacturing the M2 in 1933. FN Herstal has manufactured the M2 machine gun since the 1930s. General Dynamics, U. S. Ordnance and Ohio Ordnance Works Inc. are other current manufacturers. A variant without a water jacket, but with a thicker-walled, air-cooled barrel was designated the M2 HB; the added mass and surface area of the heavy barrel compensated somewhat for the loss of water-cooling, while reducing bulk and weight: the M2 weighs 121 lb with a water jacket, but the M2 HB weighs 84 lb. Due to the long procedure for changing the barrel, an improved system was developed called QCB; the lightweight "Army/Navy" prefixed AN/M2 "light-barrel" version of the Browning M2 weighing 60 pounds was developed, became the standard.50-caliber aviation machine gun of the World War II-era for American military aircraft of nearly every type replacing Browning's own air-cooled.30 caliber machine gun design in nearly
The British Army is the principal land warfare force of the United Kingdom, a part of British Armed Forces. As of 2018, the British Army comprises just over 81,500 trained regular personnel and just over 27,000 trained reserve personnel; the modern British Army traces back to 1707, with an antecedent in the English Army, created during the Restoration in 1660. The term British Army was adopted in 1707 after the Acts of Union between Scotland. Although all members of the British Army are expected to swear allegiance to Elizabeth II as their commander-in-chief, the Bill of Rights of 1689 requires parliamentary consent for the Crown to maintain a peacetime standing army. Therefore, Parliament approves the army by passing an Armed Forces Act at least once every five years; the army is commanded by the Chief of the General Staff. The British Army has seen action in major wars between the world's great powers, including the Seven Years' War, the Napoleonic Wars, the Crimean War and the First and Second World Wars.
Britain's victories in these decisive wars allowed it to influence world events and establish itself as one of the world's leading military and economic powers. Since the end of the Cold War, the British Army has been deployed to a number of conflict zones as part of an expeditionary force, a coalition force or part of a United Nations peacekeeping operation; until the English Civil War, England never had a standing army with professional officers and careerist corporals and sergeants. It relied on militia organized by local officials, or private forces mobilized by the nobility, or on hired mercenaries from Europe. From the Middle Ages until the English Civil War, when a foreign expeditionary force was needed, such as the one that Henry V of England took to France and that fought at the Battle of Agincourt, the army, a professional one, was raised for the duration of the expedition. During the English Civil War, the members of the Long Parliament realised that the use of county militia organised into regional associations commanded by local members of parliament, while more than able to hold their own in the regions which Parliamentarians controlled, were unlikely to win the war.
So Parliament initiated two actions. The Self-denying Ordinance, with the notable exception of Oliver Cromwell, forbade members of parliament from serving as officers in the Parliamentary armies; this created a distinction between the civilians in Parliament, who tended to be Presbyterian and conciliatory to the Royalists in nature, a corps of professional officers, who tended to Independent politics, to whom they reported. The second action was legislation for the creation of a Parliamentary-funded army, commanded by Lord General Thomas Fairfax, which became known as the New Model Army. While this proved to be a war winning formula, the New Model Army, being organized and politically active, went on to dominate the politics of the Interregnum and by 1660 was disliked; the New Model Army was paid off and disbanded at the Restoration of the monarchy in 1660. For many decades the excesses of the New Model Army under the Protectorate of Oliver Cromwell was a horror story and the Whig element recoiled from allowing a standing army.
The militia acts of 1661 and 1662 prevented local authorities from calling up militia and oppressing their own local opponents. Calling up the militia was possible only if the king and local elites agreed to do so. Charles II and his Cavalier supporters favoured a new army under royal control; the first English Army regiments, including elements of the disbanded New Model Army, were formed between November 1660 and January 1661 and became a standing military force for Britain. The Royal Scots and Irish Armies were financed by the parliaments of Ireland. Parliamentary control was established by the Bill of Rights 1689 and Claim of Right Act 1689, although the monarch continued to influence aspects of army administration until at least the end of the nineteenth century. After the Restoration Charles II pulled together four regiments of infantry and cavalry, calling them his guards, at a cost of £122,000 from his general budget; this became the foundation of the permanent English Army. By 1685 it had grown to 7,500 soldiers in marching regiments, 1,400 men permanently stationed in garrisons.
A rebellion in 1685 allowed James II to raise the forces to 20,000 men. There were 37,000 in 1678. After William and Mary's accession to the throne England involved itself in the War of the Grand Alliance to prevent a French invasion restoring James II. In 1689, William III expanded the army to 74,000, to 94,000 in 1694. Parliament was nervous, reduced the cadre to 7000 in 1697. Scotland and Ireland had theoretically separate military establishments, but they were unofficially merged with the English force. By the time of the 1707 Acts of Union, many regiments of the English and Scottish armies were combined under one operational command and stationed in the Netherlands for the War of the Spanish Succession. Although all the regiments were now part of the new British military establishment, they remained under the old operational-command structure and retained much of the institutional ethos and traditions of the standing armies created shortly after the restoration of the monarchy 47 years earlier.
The order of seniority of the most-senior British Army line regiments is based on that of the English army
The Sherman Firefly was a tank used by the United Kingdom and some Commonwealth and Allied armoured formations in the Second World War. It was based on the US M4 Sherman, but fitted with the powerful 3-inch calibre British 17-pounder anti-tank gun as its main weapon. Conceived as a stopgap until future British tank designs came into service, the Sherman Firefly became the most common vehicle mounting the 17-pounder in the war. Though the British expected to have their own new tank models developed soon, the rejected idea of mounting the 17-pounder in the existing Sherman was accepted, despite initial government resistance; this proved fortunate, as both the Cruiser Mk VIII Challenger and Cruiser Mk VIII Cromwell tank designs experienced difficulties and delays. After the difficult problem of getting such a large gun to fit in the Sherman's turret was solved, the Firefly was put into production in early 1944, in time to equip Field Marshal Montgomery's 21st Army Group for the Normandy landings.
It soon became valued, as its gun could always penetrate the armour of the Panther and Tiger tanks it faced in Normandy. In recognition of this, German tank and anti-tank gun crews were instructed to attack Fireflies first; because the Firefly had a visibly longer barrel, crews tried to camouflage it so the tank would look like a normal 75 mm-gun Sherman from a distance. Between 2,100 and 2,200 were manufactured before production wound down in 1945; the idea of fitting a 17-pounder gun into a Sherman tank had been rejected by the Ministry of Supply's Tank Decision Board. Although the British Army had made extensive use of the American-built Sherman tank, it was intended that a new generation of British tanks would replace it in the anti-tank role. First, there was the Cromwell tank, expected to use the Vickers high velocity 75 mm gun; the second was the A30 Challenger, based on the Cromwell but with the more powerful 17-pounder gun. These two tanks—and their successors, the Comet and the Centurion, which were on the drawing board—were to replace the Sherman in British service, so the prospect of diverting resources to mount the 17-pounder on the Sherman seemed undesirable.
Nonetheless, several unofficial attempts were made to improve the firepower of the Sherman. The earliest attempt can be credited to Major George Brighty of the Royal Tank Regiment while he was at Lulworth Armoured Fighting School in early 1943. Despite the A30 Challenger undergoing initial trials at Lulworth, Brighty was convinced that the Sherman was a better mount for the 17-pounder. However, the turret of the Sherman was too small to allow for the long recoil of the gun. In a radical adjustment, Brighty removed the recoil system and locked the gun in place, thus forcing the entire tank to absorb the recoil, but this was a far from ideal situation and there was no telling how long the tank would have been able to handle such a set-up. Around June 1943, a colleague of Brighty, Lieutenant Colonel George Witheridge of the Royal Tank Regiment, arrived at Lulworth. A veteran of the North Africa campaign, Witheridge had experienced first-hand the one-sided battles between British tanks armed with 2-pounder guns against Rommel's formidable tanks and anti-tank guns.
During the Battle of Gazala in mid-1942, Witheridge had been blown out of his M3 Grant medium tank, though he recovered from his wounds, he was declared unfit to return to combat duty. Instead, in January 1943, he was posted to Fort Knox in the United States for six months to advise on gunnery, where he was "sold" on American tanks. While at Lulworth, Witheridge inspected the A30 Challenger, "joined in the chorus of complaints" about the tank. Upon looking up Brighty and learning of his attempts to use the Sherman, Witheridge lent his assistance, he advised Brighty on methods to solve the recoil issue. Not long after and Brighty received a notice from the Department of Tank Design to cease their efforts. Unwilling to abandon the project, using his connections with such influential people as Major General Raymond Briggs, former GOC of the 1st Armoured Division in North Africa and now director of the Royal Armoured Corps, lobbied Claude Gibb, Director-General of Weapons and Instruments Production at the Ministry of Supply, to make it an official ministry project.
In doing so, the endeavour was taken out of the hands of the enthusiastic and devoted amateurs at Lulworth who had initiated it and given to professional tank developers. It was W. G. K. Kilbourn, a Vickers engineer working for the DTD at the time, who transformed their idea into the reality of the prototype of the tank that would serve the British forces from the invasion of Normandy in June 1944 onwards; the first thing Kilbourn had to fix was the lack of a workable recoil system for the 17-pounder. The 17-pounder travelled 40 in back; this was too long for the Sherman's turret. Kilbourn solved this problem by redesigning the recoil system rather than modifying it; the recoil cylinders were shortened and placed on both sides of the gun to take advantage of the width of the turret. The gun breech itself was rotated 90 degrees to allow loading from the left rather than from on top; the radio mounted in the back of the turret in British tanks, had to be moved. The next problem encountered by Kilbourn was that the gun cradle, the metal block on which the gun sat, had to be shortened to allow the gun to fit into the F
The Lend-Lease policy, formally titled An Act to Promote the Defense of the United States, was an American program to defeat Germany and Italy by distributing food and materiel between 1941 and August 1945. The aid went to the United Kingdom and the Soviet Union, Free France, other Allied nations, it included warplanes, along with other weaponry. The policy was signed into law on March 11, 1941, ended overnight without prior warning when the war against Japan ended; the aid was free for all countries, although goods in transit when the program ended were charged for. Some transport ships were returned to the US after the war, but all the items sent out were used up or worthless in peacetime. In Reverse Lend Lease, the U. S. was given no-cost leases on army and naval bases in Allied territory during the war, as well as local supplies. The program was under the direct control of the White House, with Roosevelt paying close attention, assisted by Harry Hopkins, W. Averell Harriman, Edward Stettinius Jr..
Roosevelt sent them on special missions to London and Moscow, where their control over Lend Lease gave them importance. The budget was hidden away in the overall military budget, details were not released until after the war. A total of $50.1 billion was involved, or 11% of the total war expenditures of the U. S. In all, $31.4 billion went to Britain and its Empire, $11.3 billion to the Soviet Union, $3.2 billion to France, $1.6 billion to China, the remaining $2.6 billion to the other Allies. Reverse lend-lease policies comprised services such as rent on bases used by the U. S. and totaled $7.8 billion. The terms of the agreement provided that the materiel was to be used until destroyed. In practice little equipment was in usable shape for peacetime uses. Supplies that arrived after the termination date were sold to Britain at a large discount for £1.075 billion, using long-term loans from the United States. Canada was not part of Lend Lease; however it operated a similar program called Mutual Aid that sent a loan of C$1 billion and C$3.4 billion in supplies and services to Britain and other Allies.
This program ended the United States' pretense of neutrality and was a decisive change from non-interventionist policy, which had dominated United States foreign relations since 1931. After the defeat of France during June 1940, the British Commonwealth and Empire were the only forces engaged in war against Germany and Italy, until the Italian invasion of Greece. Britain had been paying for its material with gold as part of the "cash and carry" program, as required by the US Neutrality Acts of the 1930s, but by 1941 it had liquidated so many assets that its cash was becoming depleted. During this same period, the U. S. government began to mobilize for total war, instituting the first-ever peacetime draft and a fivefold increase in the defense budget. In the meantime, as the British began becoming short of money and other supplies, Prime Minister Winston Churchill pressed President Franklin D. Roosevelt for American help. Sympathetic to the British plight but hampered by public opinion and the Neutrality Acts, which forbade arms sales on credit or the lending of money to belligerent nations, Roosevelt came up with the idea of "lend–lease".
As one Roosevelt biographer has characterized it: "If there was no practical alternative, there was no moral one either. Britain and the Commonwealth were carrying the battle for all civilization, the overwhelming majority of Americans, led in the late election by their president, wished to help them." As the President himself put it, "There can be no reasoning with incendiary bombs."In September 1940, during the Battle of Britain the British government sent the Tizard Mission to the United States. The aim of the British Technical and Scientific Mission was to obtain the industrial resources to exploit the military potential of the research and development work completed by the UK up to the beginning of World War II, but that Britain itself could not exploit due to the immediate requirements of war-related production; the shared technology included the cavity magnetron, the design for the VT fuze, details of Frank Whittle's jet engine and the Frisch–Peierls memorandum describing the feasibility of an atomic bomb.
Though these may be considered the most significant, many other items were transported, including designs for rockets, gyroscopic gunsights, submarine detection devices, self-sealing fuel tanks and plastic explosives. During December 1940, President Roosevelt proclaimed the U. S. A. would be proposed selling munitions to Britain and Canada. Isolationists were opposed, warning it would result in American involvement with what was considered by most Americans as an European conflict. In time, opinion shifted as increasing numbers of Americans began to consider the advantage of funding the British war against Germany, while staying free of the hostilities themselves. Propaganda showing the devastation of British cities during The Blitz, as well as popular depictions of Germans as savage rallied public opinion to the Allies after the defeat of France. After a decade of neutrality, Roosevelt knew that th