World War 2 In Review No. 22: American Half-tracks

By Merriam Press

Merriam Press World War 2 In Review Series

2023 eBook Edition

Covers the M2 Halftrack Car and M3 Halftrack series of vehicles, including the variants in the M2, M3, M5, M9 Armored Personnel Carriers:

(1) M3, T48 GMC (Gun Motor Carriage) self-propelled guns

(2) T19, T30 HMC (Howitzer Motor Carriage) self-propelled howitzers

(3) MMC (Mortar Motor Carriage)

(4) M13, M14, M16, M17 MGMC (Multiple Gun Motor Carriage)

(5) M15 CGMC (Combination Gun Motor Carriage) anti-aircraft guns

(6) Experimental Variants

(7) The 3rd Field Artillery Battalion (Provisional) in the Philippines 1941-1942

(8) M3 Gun Motor Carriage

(9) M16 Half-tracks in the Philippines: After Action Reports of the 209th Anti-Aircraft Artillery Automatic Weapons Battalion

408 B&W/color photos/illustrations

• Language: English
• Publisher: Lulu.com
• Release date: Sep 30, 2017
• ISBN: 9781387264285

Book preview

On the Cover

American Half-tracks

The U.S. half-track is usually perceived as having been a sturdy, reliable, well-designed and well-protected quasi-tank. In actuality, it was anything but. And while it’s true that U.S. half-tracks were not underpowered as was the German Sd.Kfz. 251, that was about their only virtue.

Their armor plating (and most everything else) was continually vibrating loose (one writer described driving one on an improved road as rather like driving a ten-ton kitchen cabinet on a washboard].

Their floors were unarmored and gave no protection against mines—unlike their German counterparts; their side armor could be pierced by .50-cal. armor-piercing rounds at over 1,000 meters, and even by .30-cal. AP rounds out to 350 meters (the figures for the more heavily armored and ballistically well-sloped Sd.Kfz. 251 are about 600 meters and 30 meters respectively). And their tracks had about twenty-five per cent less ground contact area than those of the Sd.Kfz. 251 (al-though the U.S. half-track had driven front wheels while the German didn’t).

Speaking of tracks, the German tracks were very sophisticated, expensive, and maintenance intensive—but they were not plagued by frequent breakdowns. They did have a tendency to bind up if packed with mud or snow, but this seems to have been a problem only when the vehicle had been motionless long enough for the substance to freeze. On the other hand, U.S. tracks wore out quickly due to their construction, which consisted of steel plates attached to a loop of steel cables, with the whole assembly being covered with vulcanized rubber. At high speed (even on paved roads) or in loose terrain, the rubber was flung off by centrifugal force and/or abraded by the ground material, thus exposing the plates and cables and causing thrown tracks and damaged boogie wheels. Even with good tracks, good boogie wheels, and proper tension, tracks were often thrown at inconvenient times (R. Fines, as previously noted). The commander of the 1st Armored Division stated in a report to Allied Forces Headquarters (dated 13 June 1943) that half-tracks have been continually subject to the throwing of tracks and went on to declare that they were more trouble than they were worth and should be replaced by trucks!

This might sound incredible to readers who for so long had envisioned armored infantry assaults with squads ensconced in half-tracks; but in reality, such occurrences were rare. The infantry almost invariably dismounted to fight. It’s not surprising, considering the above penetration specs! And would it be any more surprising, in view of all of the above, if U.S. half-track drivers tended to be cautious when their vehicles were in close proximity to the enemy; moreover, would it be any more surprising that a half-track would sometimes throw a track at an inopportune moment?

The German half-tracks were far from perfect, but they were the product of a long design and development period and were generally superior for this reason, in contrast to the American design whose creation was somewhat of a fortuitous accident and whose production was halted even before the war’s end, in early 1944.

M2 Half-Track Car

The M2 Half Track was an half-track armored vehicle produced by the United States during World War II. It was based on Half-tracks brought in from France in the 1930s. It was made by the White Motor Company in 1940.

A similar vehicle was built by International Harvester Company as the M9 half-track.

The half-track design had been evaluated by the U.S. Ordnance department using Citroën-Kégresse vehicles.

The Cavalry arm of the U.S. Army found that their wheeled armored scout cars had trouble in rainy weather due to weight and high ground pressure.

In 1938, the White Motor Company took the Timken rear bogie assembly from a T9 half-track truck and added it to an M3 Scout Car, creating the T7 Half-Track Car. This vehicle was woefully underpowered, and when a further requirement came down from U.S. Army artillery units in 1939 for a prime mover (artillery tractor), a vehicle with an uprated engine was devised, then designated the Half Track Scout Car T14.

By 1940, the vehicle had been standardized as the M2 Half-Track car. The M2 design was recognized as having the potential for general mechanized infantry use and with a larger body the M3 Half Track was created. Both the M2 and M3 were ordered into production in late 1940. M2 contracts were placed with the Autocar Company, White and Diamond-T. The first vehicles were received by the army in 1941.

It was supplied to artillery units as prime mover and ammunition carrier for the 105mm howitzer, for armored infantry units to carry machine gun squads, and to armored reconnaissance units. For the latter it was to be an interim solution, until more specialized vehicles could be fielded.

Between 1942 and 1943, these vehicles, just like the larger M3s, would receive a number of modifications to the drive train, engine, and stowage, among other things.

Total production of M2 and derivatives was about 13,500 units. Later, to meet the needs of the Lend-Lease program, the International Harvester Company was brought in to manufacture vehicles similar to the M2, these M9 vehicles totaled a further 3,500 units.

The first M2s were fielded in 1941, and would be used in the Philippines, North Africa, and Europe by the U.S. Army, and around the Pacific by the Marines. About 800 M2 and M9 half-tracks were sent to the Soviet Union. Many remaining vehicles initially destined for lend-lease were transferred to other U.S. allies, primarily in South America. These vehicles often received a number of upgrades designed at extending service life. Nicaragua’s National Guard received 10 M2s in 1942, which saw heavy action during the 1978-79 Nicaraguan Revolution. The Argentine Army retired its last upgraded M9 in 2006 and donated them to Bolivia.

In 1947 the Finnish heavy vehicle producer Vanajan Autotehdas bought 425 M2 Half track vehicles from the Western Allied surplus stocks located in France and Germany. The vehicles were delivered without armor. 359 units were converted field and forest clearing vehicles, some were scrapped for parts and 60 units were equipped with conventional rear axles and converted into 4×4 or 4×2 trucks. They were badged as Vanaja VaWh. The last units were sold in 1952.

Variants

Prime Mover/Scout Vehicle

M2: White Half-Track with White 160AX engine. Fitted with a skate rail mount, featuring an M2HB machine gun.

M9: International Harvester built half-track, developed to complement the M2 for Lend-Lease, but did not feature the short hull of the M2. Also, did not feature the rear access doors, and is outwardly very similar to the M5, but with a different internal configuration.

M9A1: As for the M2A1, an M9 with the M49 machine gun mount. The M9A1 had a rear door.

M2E6/M2A1: Any vehicle with the improved M49 machine gun ring mount over the right hand front seat. Three fixed pintle mounts for 0.30 machine guns were often fitted at the unit level in the field.

Self-propelled Guns

M4/M4A1 81mm MMC: M2 based Motor Mortar Carriage equipped with the 81 mm M1 mortar. The mortar was intended to be fired dismounted from the vehicle, but could be fired in an emergency to the rear from a base inside the vehicle. The A1 modification allowed the weapon to be fixed facing forward and fired from within the vehicle.

M2 with M3 37 mm: Mechanized infantry units in the U.S. Army were supposed to receive the M6 Gun Motor Carriage, based on Dodge light trucks. With the overall failure in combat of these vehicles, some units removed the M3 37 mm gun and its assembly and mounted them on M2 Half-Track Cars.

Anti-aircraft Variants

T1E1: M2 based mobile anti-aircraft gun featuring an open rear with a Bendix mount featuring two .50 inch (12.7 mm) M2 machine guns. The Bendix mount proved to be unsatisfactory. Prototype only.

T1E2: T-1 with Maxson M33 mount in the place of the Bendix mount. The M33 mount also featured two .50 inch M2 machine guns. Would be developed into the M3 based T1E4.

T1E3: T-1 fitted with a partial hard top and a Martin turret, identical to that used on the Boeing B-17 Flying Fortress. Proved to be overly complicated and was ill-suited to the space available in the M2. Prototype only.

T28 CGMC: M2 based Combination Gun Motor Carriage with a single 37 mm Gun M1A2 autocannon flanked by two .50 inch M2 machine guns. The side armor was removed in order to make room for the mount. The project was canceled in 1942 but then revived the same year, when a decision was made to use the longer M3 Half-Track Personnel Carrier chassis for the subsequent T28E1

T10: Variant to test the feasibility of mounting U.S. made copies of the Hispano-Suiza HS.404 20 mm