| Light Tank, M1 | |
|---|---|
 M1 Combat Car | |
| Type | Light tank |
| Place of origin | United States |
| Service history | |
| In service | 1937–1943 |
| Used by | United States |
| Production history | |
| Manufacturer | Rock Island Arsenal |
| Produced | 1935–? |
| No. built | 113 |
| Specifications (M1) | |
| Mass | ~10 short tons (9.1 t)[1] |
| Length | 4.14 m (13 ft 7 in) |
| Width | 2.4 m (7 ft 10 in) |
| Height | 2.26 m (7 ft 5 in) |
| Crew | 4 |
| Armor | 6–16 mm |
Main armament | .50 cal (12.7 mm) machine gun .30 cal (7.62 mm) machine gun |
Secondary armament | .30 cal (7.62 mm) machine gun |
| Engine | Continental R-670 7-cylinder air-cooled radial gasoline 250 hp (190 kW) |
| Suspension | Vertical volute spring |
Operational range | 161 km (100 mi) on roads |
| Maximum speed | 72 km/h (45 mph) on roads |
TheM1 combat car, officiallyLight Tank, M1, was alight tank used by theUnited States Cavalry in the late 1930s[2] and developed at the same time as theU.S. Army Infantry Branch's very similarLight Tank, M2.
After theSpanish Civil War, most armies (including theU.S. Army), realized that they needed tanks armed with cannons, not merely vehicles armed with machine guns,[3] and so the M1 became obsolete.
TheNational Defense Act of 1920 set tanks as the responsibility of the infantry and the general staff defined the purpose of tanks as the support of infantry units.[4] Light tanks were defined as weighing five tons or less – so they could be carried by trucks – and medium tanks no greater than 15 tons to meet bridge weight limits. With very tight restrictions on spending, tank development in the U.S. was limited to a couple of test vehicles a year. The mechanization of the army was promoted by GeneralDouglas MacArthur (at the time theChief of Staff of the US Army) who believed that the cavalry should have tanks for an exploiting role rather than acting in support of the infantry.[4] To allow U.S. Army cavalry units to be equipped witharmored fighting vehicles, the tanks developed for the cavalry were designated "combat cars".[note 1]
In the mid-1930s, theRock Island Arsenal built three experimental T2 light tanks inspired by the BritishVickers 6-ton tank. At the same time, they built a light tank similar to the T2 for the cavalry – the T5 combat car. The only major difference between the two was that the T5 usedvertical volute suspension while the T2 hadleaf springs as on the Vickers. The T5 was developed further and the T5E2 was accepted for production as the "M1 Combat Car".[4]
The M1 entered service in 1937. A change to the suspension so that the idler wheel rested on the ground ("trailing") increased the length of track in contact with the ground and improved the ride. Together with a different engine and improved turret, this produced the M2 combat car.[4] In 1940, the distinction between infantry and cavalry tank units disappeared with the establishment of theArmored Force to manage all tanks in the U.S. Army. The "combat car" name was superfluous, and the cavalry unit tanks redesignated the M1 combat car as the "light tank M1A1" and the M2 combat car as the "light tank M1A2".[5][4]
The M1 was fielded by the Philippines military early on in WWII during thePhilippines campaigns of 1941-1942 when armored vehicles of all manner were needed. All M1s that served that were not destroyed by enemy action or by their own crews, subsequently fell to enemy Japanese forces.[6]
The M1 and M2 combat cars were not used in combat by the U.S. Army after this during World War II; though some were used for training purposes.[4]
