View source for M2 light tank

{{short description|1930s United States light tank}}
{{For|the modern infantry fighting vehicle|M2 Bradley}}
{{good article}}

{{Infobox weapon
|name               = Light Tank, M2
|image              = The British Army in the United Kingdom 1939-45 H17816.jpg
|image_size         = 300
|caption            = M2A4 light tank in British service, 11 March 1942
|type               = [[Light tank]]
|origin             = United States  <!-- [[WP:INFOBOXFLAG]] -->
|designer           = [[Rock Island Arsenal]]
|manufacturer       = [[Rock Island Arsenal]] (M2-M2A3), [[American Car & Foundry Company]] (M2A4)
|unit_cost          = $25,000 (M2A4, 1939 estimate)<ref>{{cite web | url=https://books.google.com/books?id=AIY0AAAAIAAJ&pg=PA470 | title=Third Deficiency Appropriation Bill for 1939: Hearings Before the Subcommittee of the Committee on Appropriations, House of Representatives, Seventy-sixth Congress, First Session on the Third Deficiency Appropriation Bill for 1939 | year=1939 }}</ref>
|production_date    = 1935–42
|number             = 698
|is_vehicle         = yes
|spec_label         = M2A4
|length             = {{convert|14|ft|6|in|m|abbr=on}}
|width              = {{convert|8|ft|1|in|m|abbr=on}}
|height             = {{convert|8|ft|8|in|abbr=on}}
|weight             = {{convert|11.6|t|lb|abbr=on}}
|suspension         = [[Vertical volute spring suspension]]
|speed              = {{convert|36|mph|km/h|abbr=on}}
|vehicle_range      = {{convert|200|mi|km||abbr=on}}
|primary_armament   = [[37 mm gun M3|37 mm gun M5]] <br /> 103 rounds
|secondary_armament = 5x [[.30-06 Springfield|.30-06]] (7.62 mm) [[M1919 Browning machine gun|Browning M1919A4]] machine guns<br />8,470 rounds
|armour             = {{convert|6|-|25|mm|in|abbr=on}}
|engine             = [[Continental R-670]]-9A, 7-cylinder, radial [[petrol engine|gasoline]]
|crew               = 4 (Commander/loader, gunner, driver, co-driver)
|engine_power       = {{convert|250|hp|kW|abbr=on}}
}}
The '''M2 light tank''', officially '''Light Tank, M2''', was an American [[light tank]] of the [[interwar period]] which saw limited service during [[World War II]]. The most common model, the M2A4, was equipped with one {{convert|37|mm|in|abbr=on}} [[37 mm gun M3|M5 gun]] and five .30 cal [[M1919 Browning machine gun]]s.

It was originally developed from the prototype T2 light tank built by the [[Rock Island Arsenal]], which had a Vickers-type [[leaf spring]] suspension. The suspension was replaced by the superior [[Vertical volute spring suspension|vertical volute]] system in the T2E1 series of 1935. This was put into production with minor modifications as the M2A1 in 1936, with ten produced. The main pre-war version was the M2A2, with 239 produced, becoming the main tank of the [[United States Army]] during the interwar period. The [[Spanish Civil War]] showed that tanks armed only with machine guns were ineffective. This led to the M2A4 with a 37&nbsp;mm gun as the main armament. A total of 375 were delivered, the last ten as late as April 1942.

The tank's only combat service was with the [[United States Marine Corps]]' [[1st Tank Battalion]] in 1942 during the [[Pacific War]]. While some sources claim that the M2A4 saw action with [[British Army]] tank units in the [[Burma campaign]] against the [[Imperial Japanese Armed Forces]], historian Mike Green states that the tanks were never issued to combat units.<ref name="Hunnicutt 1992, p. 396">Hunnicutt (1992), p. 396</ref><ref name="Zaloga 1999, p. 14">Zaloga (1999), p. 14</ref><ref name=Green131/> The M2A4 light tank led to the development of the [[M3 Stuart]] light tank and the [[M4 tractor]] artillery prime mover, the former of which saw widespread use throughout World War II.

==Development history==
{{multiple image
| align     = left
| direction = vertical
| width     = 260
| image1    = M2A3 light tank 1939 LOC hec 26434.jpg
| image2    = Fitters are at work assembling an American light tank which has just arrived at an English ordnance depot from the US... - NARA - 196324.jpg
| footer    = Top: M2A3 in annual Army Day Parade, Washington, 1939. Bottom: Fitters assembling an M2A4 light tank at a British ordnance depot.}}

US Army [[infantry tank]] design started with the [[T1 Light Tank|light tank, T1]] during the 1920s, which developed into a series of experimental designs which did not enter production. The T2 concept, starting five years later, incorporated several design lessons from the T1, but used a new suspension system copied from the British [[Vickers 6-Ton|Vickers six-ton]] tank. The first prototype was delivered in 1933.{{Citation needed|date=March 2015}}

The Defense Act of 1920 had defined tanks to be used in support of the infantry. Through the 1920s a number of theorists outlined an independent role for the tank that required it to move at high speed into the rear areas, a modern version of the [[cavalry]]. The British referred to these designs as "[[cruiser tank]]s", but similar high-speed designs were developed under a variety of names. As the Defense Act limited tank development to the infantry, the [[United States Cavalry]] began tank development under the name "combat car". In keeping with the high-speed role, the new [[M1 Combat Car|T5 combat car]] introduced the new vertical [[volute spring]] suspension (VVSS) system, which proved clearly superior to the Vickers [[leaf spring]] system.{{Citation needed|date=March 2015}}

This led to a second prototype of the T2, the T2E1, in April 1934, adopting the VVSS from the T5. The T2E1 was armed with one .30 cal (7.62&nbsp;mm) and one .50 inch (12.7&nbsp;mm) Browning machine gun mounted in a fixed turret; another .30 cal Browning was mounted on the hull front.<ref name=Chamberlain86>Chamberlain & Ellis (1969), pp. 86–87</ref> The T2E1 was selected for production in 1935 as the M2, which mounted only the M2 Browning in a small one-man [[gun turret|turret]], and the .30 cal in the hull.<ref name=Zaloga4>Zaloga (1999), p. 4.</ref>

After only 10 units were delivered, the [[Infantry Branch (United States)|Infantry Branch]] decided to switch to a twin turret configuration in the M2E2, with a .30-caliber (7.62&nbsp;mm) machine gun in a second turret. These early twin-turret tanks were given the nickname "[[Mae West]]" by the troops, after the popular busty movie star. The twin-turret layout was inefficient, but was a common feature of 1930s light tanks derived from the Vickers.<ref name=Jackson42/> Further refinements to the M2A2 produced the A3 model, which incorporated a modified suspension system that reduced the tank's ground pressure. The weight increased to 10 tons.<ref>Green (2014), p. 128</ref>

Following the Spanish Civil War, most armies, including the U.S. Army, realized that they needed tanks armed with cannon and not merely with machine guns.<ref>Zaloga (2008), pp. 4–5</ref> The Cavalry had already opted for a single, larger turret on its nearly identical M1 combat car. In December 1938, OCM No. 14844 directed that a single M2A3 be removed from the assembly line and modified with heavier armor and weapons, to meet the standards of the U.S. Infantry.<ref>Hunnicutt (1992), p. 118</ref>{{Copyright violation|sure=yes|date=January 2024}} This vehicle, after conversion, was re-designated as the M2A4. It was equipped with an M5 37&nbsp;mm main gun, 1&nbsp;inch (25&nbsp;mm) thick armor, and a seven-cylinder gasoline engine.<ref>Hunnicutt (1992), p. 475</ref> Other upgrades included improved suspension, improved transmission, and better engine cooling. Production of the M2A4 began in May 1940 at the [[American Car and Foundry Company]], and continued through March 1941; an additional ten M2A4s were assembled in April 1942, for a total production run of 375 M2A4 light tanks.<ref>Hunnicutt (1992), p. 120</ref><ref name=Green131/>

===Successor vehicles===
[[File:US tanks in Guadalcanal (closeup, hi res).jpg|thumb|An M2A4 on [[Guadalcanal]], followed by an M3 Stuart and another M2A4]]
The M2 light tank led to the US M3-series and M5-series light tanks.<ref name=Berndt45>Berndt (1994), p. 45.</ref> The [[Ordnance Department]] viewed the M2A4 as a stopgap tank; work to improve it further began in June 1940.<ref name=G135>Green (2014), p. 135</ref> The first M3 Stuart tanks began to be produced in March 1941; the original [[rivet]]ed M3s closely resembled the M2A4, and the two types occasionally served in the same units; an easy recognition feature was the rear idler wheel. On the M2A4, the idler was raised; on the M3 it trailed on the ground,<ref>Zaloga (1999), p. 27 plate C</ref> increasing the flotation of the heavier vehicle.<ref name=Jackson42/> The M3 retained the same Continental W-670 engine, but incorporated ½-inch thicker (1½ inch total thickness) armor;<ref>Hunnicutt (1992),  127</ref> with weight increased to 14 tons. The tank initially kept the same 37&nbsp;mm gun and the forward firing hull machine guns, but the turret incorporated improvements. Eventually over 4,500 examples of all variants were produced.<ref>Green (2014), pp. 135, 137</ref>

==Operational use==
By December 1941, the M2A1, M2A2 and M2A3 were used for training only.<ref>Zaloga (2008), p. 15</ref> The majority of M2A4s, which went to the US Army, were also used only for training between 1940 and 1942.<ref name=Green131>Green (2014), p. 131</ref> The [[United States Marine Corps|US Marine Corps]] ordered M3 Stuart tanks to outfit its armored units in 1940, but as the new tank was not yet in production, it received 36 M2A4s, after which point production of the M3 had come on line.<ref>Zaloga (2012), pp. 7, 10</ref> Many of these tanks were deployed during the [[Battle of Guadalcanal]] while assigned to A Company, [[1st Tank Battalion]], where they and M3 Stuarts were typically spread out among infantry units. Their use was generally limited to providing mobile fire support to the Marines, either in disabling Japanese [[bunker]]s or using [[canister shot]] against Japanese attacks. In defensive engagements, the M2A4s and Stuarts would deploy in pairs, so they could cover each other with machine gun fire against Japanese soldiers armed with [[satchel charge]]s.<ref>Zaloga (2012), pp. 10–11</ref>

Ultimately, the Marine Corps determined that the 37&nbsp;mm guns of the M2s and M3s were not powerful enough to defeat Japanese bunkers, and so they would be replaced with tanks armed with 75&nbsp;mm guns.<ref>Green (2014), p. 142</ref> Following the end of the Guadalcanal campaign, A Company returned to Australia, where the M2A4s were replaced with the new M4 Shermans in preparation for the [[Battle of Cape Gloucester]] in December 1943.<ref>Zaloga (2012), p. 16</ref> They remained in service in some areas of the [[Asiatic-Pacific Theater|Pacific Theater]] until 1943. After they served in the Pacific, they were used for training.<ref name=Chamberlain86/>

Britain ordered 100 M2A4s in early 1941. After 36 of them were delivered, the order was canceled in favor of an improved [[Stuart tank|M3 Stuart]]. The fate of these vehicles is unclear. There is evidence that indicates those 36 M2A4s were shipped off from North Africa as part of the [[British Army]]'s [[7th Queen's Own Hussars|7th Hussars]] and [[2nd Royal Tank Regiment]], fighting in the India and Burma campaigns against the Japanese 14th Tank Regiment.<ref name="Hunnicutt 1992, p. 396"/><ref name="Zaloga 1999, p. 14"/>

==Design==
Besides the machine gun mounted coaxially to the main gun, there were three .30 cal. machine guns in the hull. One was mounted in a ball mount in front of the bow gunner. The other two were mounted in fixed sponson mounts. These machine guns were fired by the driver; they were aimed by pointing the entire tank at the desired target. Another .30 cal machine gun was normally mounted on the top of the turret for anti-aircraft defense.<ref name=Green130/>

The 37&nbsp;mm M5 gun had a manually operated breechblock. The [[tank commander]] doubled as loader, like many other tanks of the time. There was no turret basket in the M2A4 light tank; the commander stood on the right side, while the gunner stood on the left side.<ref name=Green130>Green (2014), p. 130.</ref> The commander turned the turret onto the general direction of target. The gunner would then bring the target into the M5 telescopic sight. The M20 combination mount had 20° of traverse; this could either be by a handwheel driving the rack and pinion traverse gear mechanism or pressure on the gunners shoulder rest overcoming the friction in the mechanism. Depression and elevation of the gun was either through a geared mechanism or, with the gears disengaged, free through movement of the gunner's shoulder rest.<ref name=Green130/><ref>FM 23-80 37-mm Gun Tank M5 p. 13</ref>

==Variants==
*'''M2A1''' (1935)
**Initial production type with single fixed turret containing one .50 cal machine gun.<ref name=Chamberlain86/> Seventeen units were produced.{{citation needed|date=January 2024}}
*'''M2A2''' (1935)
**Twin turrets with single M2 Browning .50 machine gun in its left turret, and an M1919A4 .30 machine gun in its right turret; the turrets partly obstructed each other limiting fields of fire.<ref name=Chamberlain87>Chamberlain & Ellis (1969), p. 87</ref> Dubbed "[[Mae West]]".<ref name=Zaloga4/> 237 units produced from 1935 to 1937.<ref name=":0">{{Cite book |last=Ogorkiewicz |first=Richard |title=Tanks: 100 Years of Evolution |publisher=[[Osprey Publishing]] |isbn=978-1472829818 |publication-date=2018 |pages=85}}</ref>
[[File:M2A3 light tank U.S. Army Armor & Cavalry Collection 2023.jpg|thumb|right|M2A3 "[[Mae West]]" on display at the [[U.S. Army Armor & Cavalry Collection]], [[Fort Benning]], Georgia, in 2023]]
*'''M2A3''' (1938)
**Twin turrets with two machine guns, thicker armor at 22 mm, slightly lengthened hull, improved engine access, increased gear ratios, better engine cooling, improved suspension, and other minor detail changes.<ref name=Chamberlain86/> 73 units produced.<ref name=":0" />
*'''M2A4''' (1939)
**Single turret with 37mm gun. Thicker armor.<ref name=Zaloga5>Zaloga (1995), p. 5.</ref> 375 units produced, of which 40 in 1941 and 10 in 1942.<ref>{{cite web | url=https://books.google.com/books?id=YgAuFAAHRu8C&pg=RA3-PA37 | title=The United States Army in World War II: Statistics | year=1953 }}</ref> Orders went to the American Car & Foundry in October 1939 upon request by the Ordnance Department. Used in the early Pacific campaigns and training. Only service was in [[Guadalcanal Campaign|Guadalcanal]]. Used for training after December 1941.<ref name=Chamberlain86/>
*'''M2 AT''' (1937)
**An M2 chassis with the turret removed and replaced with a 47mm automatic gun. The gun penetration was deemed poor and canceled in 1937.<ref>{{Cite web|url=http://ftr-wot.blogspot.com/2013/04/revised-american-tank-destroyer-branch.html|title=For the Record: Revised American Tank Destroyer Branch|last=Unknown|date=2013-04-14|website=For the Record|access-date=2019-11-21}}</ref>

==Specifications (M2A4)==
The M2A4 was {{convert|14|ft|6|in|m|abbr=on}} long, {{convert|8|ft|1|in|m|abbr=on}} wide, {{convert|8|ft|8|in|m|abbr=on}} high, and weighed {{convert|11.6|t|lb|abbr=on}}. It had a vertical volute spring [[Suspension (vehicle)#Armoured fighting vehicle suspension|suspension]] and had a speed of {{convert|36|mph|km/h|abbr=on}}, and had a range of {{convert|200|mi|km|abbr=on}}. It had one M5 37&nbsp;mm gun (with 103 rounds), and five .30/06 cal [[M1919 Browning machine gun|M1919A4 Browning machine gun]]s (with 8,470 rounds) with 6 to 25&nbsp;mm of armor.<ref name=Chamberlain86/> It had a {{convert|250|hp|kW|lk=in|abbr=on}} [[Continental W-670]] 9A seven-cylinder [[radial engine]]. The vehicle was operated by a crew of four (commander/gunner, loader, driver, and co-driver).<ref name=Jackson42>Jackson (2010), p. 42.</ref><ref name=Foss122>Foss (1981), p. 122</ref>

==See also==

*[[List of "M" series military vehicles]]
*[[G-numbers]]

==References==
{{reflist}}

==Sources==
*{{cite book |last=Berndt |first=Thomas |date=1994 |title=American Tanks of World War II |location=Minnesota, MN |publisher=MBI Publishing Company |isbn=0-87938-930-3 |url-access=registration |url=https://archive.org/details/americantanksofw0000bern }}
*{{cite book|last1=Chamberlain|first1=Peter|last2=Ellis|first2=Chris|date=1969|title=British and American Tanks of World War II|location=New York|publisher=Arco Publishing|isbn=0-668-01867-4 |url=https://archive.org/details/britishamericant0000cham}}
*{{cite book|last=Foss|first=Christopher F.|date=1981|title=An Illustrated Guide to World War II Tanks and Fighting Vehicles|location=New York|publisher=Arco Publishing|isbn=978-0-6680-5232-0|url-access=registration|url=https://archive.org/details/illustratedguide00foss}}
*{{cite book|last=Green|first=Mike|date=2014|title=American Tanks & AFVs of World War II|location=Oxford|publisher=Osprey Publishing|isbn=978-1-7820-0931-3}}
*{{cite book|last=Hunnicutt|first=R. P.|date=1992|title=Stuart: A History of the American Light Tank|location=Navato, California|publisher=Presidio Press|isbn=0-89141-462-2|url=https://archive.org/details/historyofamerica0000hunn}}
*{{cite book|last=Jackson|first=Robert|date=2010|title=101 Great Tanks|location=New York|publisher=The Rosen Publishing Group|isbn=978-1-43583-595-5 |url=https://archive.org/details/101greattanksleg0000unse}}
*{{cite book |author=United States War Department Staff |title=FM 23-80 37-mm Gun Tank M5 |year=1941 |publisher=United States Government Printing Office |location=Washington, DC |oclc=41417142 |url=https://www.ibiblio.org/hyperwar/USA/ref/FM/PDFs/FM23-80.pdf}}
*{{cite book|last=Zaloga|first=Steven|date=1999|title=M3 & M5 Stuart Light Tank 1940–45|series=New Vanguard 33|location=Oxford|publisher=Osprey Publishing|isbn=1-85532-911-5}}
*{{cite book|last=Zaloga|first=Steven|date=2008|title=Armored Thunderbolt: The US Army Sherman in World War II|location= Mechanicsburg, Pennsylvania|publisher=Stackpole Books|isbn=978-0-8117-0424-3}}
*{{cite book|last=Zaloga|first=Steven|date=2012|title=US Marine Corps Tanks of World War II|location=Oxford|publisher=Osprey Publishing|isbn=978-1-8490-8560-1}}

==External links==
{{Commons|M2 Light tank}}
*[http://afvdb.50megs.com/usa/lighttankm2.html AFV database]
*[http://www.wwiivehicles.com/usa/tanks-light/m2.asp World War II vehicles]
* {{Internet Archive short film|id=TheTanksAreComing|name=The Tanks Are Coming}} from 1941, featuring the M2

{{Interwar tanks|style=wide}}
{{US tanks|style=wide}}
{{WWIIAmericanAFVs}}
{{Use dmy dates|date=June 2017}}

[[Category:Light tanks of the United States]]
[[Category:Interwar tanks of the United States]]
[[Category:World War II tanks of the United States]]
[[Category:Multi-turreted tanks]]
[[Category:Light tanks of the interwar period]]
[[Category:World War II light tanks]]
[[Category:Military vehicles introduced in the 1930s]]