M3 half-track

The M3 half-track is an American armored personnel carrier half-track widely used by the Allies during World War II and in the Cold War. Derived from the M2 half-track car, the M3 was extensively produced, with about 15,000 standard M3s and more than 38,000 variant units manufactured.

The M3 was extensively modified with several dozen variant designs produced for different purposes. During World War II, the M3 and its variants were supplied to the U.S. Army and Marines, as well as British Commonwealth and Soviet Red Army forces, serving on all major fronts throughout the war. The M3 and its variants were produced by many manufacturers including Diamond T, White Motor Company, and Autocar. They were adapted for a wide variety of uses, such as a self-propelled anti-aircraft weapon or self-propelled artillery. Although initially unpopular due to its lack of significant armor or a roof to protect the passengers and crew from shrapnel, it was used by most of the Allies during the war.

In the Cold War era, the vehicle was used by a variety of state and non-state operators in conflicts in South America, the Middle East, Africa, and Asia, remaining in service until as late as the mid-1990s.

Specifications

The M3 half-track was long, wide, high and had a gross weight of either (M3) or (M3A1). The wheelbase was long. The suspension consists of a leaf spring for the two front wheels, while the rear treads had vertical volute springs. With a fuel capacity of 60 US gallons (230 L), the M3 could carry its crew (one driver) and a squad of 12 soldiers before refueling, while protecting them from small arms with light armor (6–12 mm of armor

Design

The design, which used many commercial components to improve reliability and the rate of production, was standardized in 1940 and built by the Autocar Company, Diamond T Motor Company, and the White Motor Company. The vehicle uses two tracks made of molded rubber over steel cabling with metal track guides.

Infantry rifles were held in brackets behind the seats while ammunition and rations were generally stored underneath. In 1942, the vehicles were fitted with small racks for land mines on the outside of the hull, just above the tracks. In combat, many squads found it necessary to stow additional rations, rucksacks and other crew stowage on the outside of the vehicle. Luggage racks were often added in the field, and later vehicles were fitted with rear-mounted racks for this purpose.

Early vehicles had a pintle mount just behind the front seats that mounted a .50-caliber (12.7 mm) M2 Browning machine gun. The later M3A1 adopted a raised, armored "pulpit" mount for the .50-caliber machine gun over the front passenger seat, and additional mounts for .30-caliber (7.62 mm) machine guns along the sides of the passenger compartment. Many M3s were later converted to M3A1s. The vehicle body was fully armored, with an adjustable armored shutter for the engine radiator, and adjustable bulletproof panels with vision slits for the windshield, driver windows, and passenger windows.

Development

thumb|upright|left|On display in Ursel (Northwest of [[Ghent), Belgium]]

The development of an armored half-track began with ordnance directive OCM 14188 to convert an M3 Scout Car into a half-track. The prototype was built at Rock Island Arsenal with help from White Motor Company and was designated the T7. It had the same chassis and engine as the M3, but had larger front wheels and a shorter front clip. The armor consisted of 1/4-inch thick hardened armor plate, and it was armed with two M1919 machine guns and one M2 Browning machine gun operated by a crew of eight. Tests at Aberdeen Proving Ground in 1938 demonstrated unsatisfactory performance due to the front-wheel drive. The T7 was converted back into a scout car and returned to the Army.

Throughout 1939 and 1940, the M2 half-track car was prototyped and developed by the Army at Aberdeen Proving Grounds. The M3 was developed as a larger version of the M2 equipped with two M1919 machine guns and an M2 Browning machine gun for combat usage. The M3 also added a rear door and five additional seats in the rear. The M3 was tested at Aberdeen Proving Grounds in the summer of 1941 and was accepted into service soon after.

Service history

thumb|[[Erwin Rommel|Rommel in Tunisia speaking with troops riding a captured American built M3 half-track during Battle of Kasserine Pass.]]

In US service, it was intended that the M3 would be issued to armored infantry regiments. It was also quickly put into action with the Provisional Tank Group when the Japanese Army began their invasion of the Philippines. At first, there were multiple complaints due to several mechanical difficulties. These were rectified by the Ordnance Department after receiving field reports from the Philippines. The M3s first use in its intended role was during Operation Torch. Each armored division had 433 M2s or M3s, 200 in the armored regiments and 233 in the armored infantry regiment. Another major issue with the M3 was its fixed rear idler, which often broke on rough terrain. Commanders in North Africa bought parts to build spring-loaded rear idlers that could handle the rough terrain, which the Ordnance Department then approved as an official fix. In 1943, the M3 served in Sicily and Italy and received positive reports of it in action. It operated in Operation Overlord and served in Europe for the remainder of the war.

The vehicle was generally considered very mechanically reliable, although there were two major complaints: the vehicle had a wide turning radius and lacked power steering, the latter especially evident when using narrow European streets. The unique design of the track, made up of steel bands with a rubber contact surface vulcanized to them, made replacement difficult; if the track became damaged or the steel bands stretched out, the entire track had to be replaced. A track with replaceable blocks was suggested as an alternative.

Total production of the M3 and its variants ran to nearly 54,000 vehicles. To supply the Allied nations, International Harvester produced several thousand of a very similar vehicle, the M5 half-track, for Lend-Lease.

Variants

Armored personnel carriers

M3 – White and Autocar half-track with White 160AX engine. Fitted with either an M32 anti-aircraft machine gun mount or a pedestal mount, both featuring an M2HB machine gun.
M5A1 – Similar to the M3A1, the M5A1 was an M5 with the M49 machine gun mount. It could fit one .50-caliber (12.7 mm) and two .30-caliber (30.06) machine guns.
M9 half-track – Same body as the M5, but with stowage arranged as in the M2 half-track car, access to radios from inside (as opposed to outside) and rear doors, plus an pedestal MG mount.
M3A1 75 mm GMC – The M2A2 gun carriage was substituted for the A3, as stocks of the former were exhausted. Later variants featured a purpose-built gun shield (59 rounds).
T21 – M3 based mortar carrier fitted with a 4.2 inch mortar. Never adopted.
T21E1 – The T21's mortar could only fire rearward as with the M2 based M4 MMC. The T21E1 reoriented to the mortar to fire forward.
T38 105 mm HMC – M3 based howitzer motor carriage equipped with the M3 105 mm howitzer. Cancelled with the success of the T19 105 mm HMC.
T48 gun motor carriage – M3 based gun motor carriage equipped with the M1 57 mm gun, an American copy of the British QF 6 pounder anti-tank gun. A total of 962 T48s were produced during the war. Of these, 60 were supplied under lend lease to Britain, and 650 to the USSR who designated it SU-57 (99 rounds). A total of 31 were converted into M3A1s, while one entered service with the U.S. Army.

Anti-aircraft variants

T1E4/M13 half-track – M3 based multiple gun motor carriage equipped with the Maxson M33 mount with two M2HB machine guns (5,000 rounds). The T1E4 prototypes had the hull sides removed for ease of working with the mount. These were reintroduced on production M13s. This was a development of previous T1s that had all been based on the M2 half-track car.

thumb|An M16 MGMC in action in [[Korean War|Korea, 1953]]

M16 half-track – M3 based multiple gun motor carriage equipped with the Maxson M45 Quadmount (specifically the M45D) with four M2HB machine guns (5,000 rounds).
M16A1 MGMC – Standard M3 personnel carriers converted to multiple gun motor carriages by removing rear seats and installing a Maxson M45 mount (more specifically the M45F, which featured folding "bat wing" gun shields on both sides of the mount over the machine guns). These vehicles are easily identified by the lack of the folding armored hull panels found on purpose-built M16s.
M15 half-track – T28E1 variant, equipped with an armored superstructure on the turreted mount to provide crew protection, and switched to M2HB machine guns.
M15A1 CGMC – Reorganization of the weapons, with the M2HB machine guns being fitted under the M1A2 37 mm autocannon instead of above.
T10E1 – Variant to test the feasibility of mounting US made copies of the Hispano-Suiza HS.404 20 mm cannon on modified Maxson mounts. All were later rebuilt as M16s. The original T10 was based on the M2 half-track car chassis.

40 mm experiments

Various attempts were made to mate the 40 mm Bofors L/50 gun to the M3 chassis. In most cases the weapon's recoil was too severe or the mounting too heavy, and the attempts were finally stopped with the adoption of the M19 MGMC on the M24 light tank chassis.

T59 – A development of the T54/E1, fitted with outriggers to help stabilize the vehicle during sustained firing. Still proved to be too unstable for anti-aircraft use. Prototype only.
M15 "Special" – Field conversions by US Army depots in Australia of standard M3s, not M15s, fitted with turreted 40 mm Bofors L/50 guns. These were the only successful mating of this weapon to the M3 chassis, and were used more for direct fire support than for anti-aircraft purposes.

Post-war Israeli variants

thumb|An Israeli modified M3 half-track, armed with a 20 mm cannon

M3 Mk. A (M3 Degem Alef) – M5 APC. Israeli half-tracks were all designated M3, even M2/M9 variants and known as the Zakhlam or "half-catepillar" () in Hebrew for its hybrid propulsion. The Mk. A APCs were generally identified as IHC M5s because of their RED-450 engines. While the M49 mount was retained, various machine guns were used.
M3 Mk. B (M3 Degem Bet) – M5 converted as a command carrier with extra radios and a front winch bumper. Mk. Bs featured M2HB machine guns.
M3 Mk. D (M3 Degem Dalet) – Another M3 based mortar carrier, fitted with the 120 mm Soltam mortar. Development began in 1952.

Operators

(ex-British surplus M3s)
– Bundesheer
– Belgian Army
– Canadian Army
– French Army
– The German Wehrmacht used captured vehicles in North Africa and on the Western front during World War II.
– Italian Army
Kingdom of Laos – Royal Lao Army
– Malian Army
– Peruvian Army
– Philippine Army and Philippine Constabulary
– Soviet Army
– Turkish Army
– Army of the Republic of Vietnam
– People's Army of Vietnam
– Yugoslav People's Army
– Forces Armées Zaïroises, used into the 1980s

Non-state former operators

Kataeb Regulatory Forces (KRF) – supplied by Israel.
22px|border Tigers Militia – supplied by Israel.
Lebanese Forces – Inherited from the KRF and the Tigers Militia.
22px People's Liberation Army (Lebanon) (PLA) – captured from the Lebanese Forces.
South Lebanon Army (SLA) – supplied by Israel.
Amal Movement – captured from the SLA.
– captured from the SLA.

References

Citations

Bibliography

David François, El Salvador – Volume 1: Crisis, Coup and Uprising 1970-1983, Latin America@War Volume 32, Helion & Company Limited, Warwick UK 2023.
David François, El Salvador – Volume 2: Conflagration 1984-1992, Latin America@War Volume 34, Helion & Company Limited, Warwick UK 2023.

External links

Half-track Gets Farm Job
WWII Vehicles – US half-tracks
FM 17–71: Crew Drill for Half-Track Vehicles
The various versions of Israeli Half-track