USA - Halftracks

M2 Halftrack Car

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, it did not feature the rear access doors, and is outwardly very similar to the M5, but with a different internal configuration.
      • M9A1 - 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 w/ M3 37 mm - Mechanized infantry units in the US 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 guns and their assemblies 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 - T1 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 - T1 fitted with a partial hard top and a Martin turret, identical to that used on the Boeing B-17 Flying Fortress. Proved to be overcomplicated 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 US made copies of the Hispano-Suiza HS.404 20 mm cannon on modified Maxson mounts. Developed into the T10E1 based on the longer M3 chassis.

M3 Halftrack and Variants

Armoured Personel Carrier
  • M3 – White and Autocar Half-Track with White 386 in3 (6,330 cc) 160AX engine. Fitted with either an M32 anti-aircraft machine gun mount or a pedestal mount, both featuring an M2HB machine gun.[1]
    • M3A1 – A M3 with the improved M49 machine gun ring mount over the right hand front seat. Between 1942 and 1943 all M3 Half-Tracks (standard and A1s) were continually upgraded. These improvements included a number of drive train, engine, and stowage improvements.[1]
    • T29/M3A2 – Developed in 1943 to combine features such that existing M2 and M3 production could be switched to a common vehicle. Came at a time where the need for additional half tracks turned out to be not as great as projected. The M3A2 was, therefore, not produced.[1]
  • M3E2/M5 Half-track – International Harvester Half-Track, externally largely identical to the M3, but with 450 in3 (7,400 cc),[1] IHC RED-450-B engine, different drive train and fuel and electrical system. In fact, only the chassis, bogies, track, idler and drive sprockets, wheels, winches, transfer case, rollers, and machine gun mount were interchangeable. The M5 is heavier than the M3, due in part to heavier armor. Its body was welded, rather than bolted. The M5 was primarily for Lend-Lease, to Britain, Canada, France, and the Soviet Union.[13]
    • M5A1 – As for the M3A1, 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.[13] The IHC models had a slightly lower top speed (only 42 mph (68 km/h)) and lower range (125 mi (201 km)) as well.[1]
    • T31/M5A2 – Similar in principle to the M3A2, a vehicle developed by the US Ordnance Department to combine the production of the M5 and M9 into a single vehicle. As with the M3A2, the projected need was never seen, and this version was never produced en masse.[14]
    • M9 Half-track – Same vehicle as the M5, with stowage arranged as in the M2 halftrack, with access to radios from inside (as opposed to outside) and rear doors, plus pedestal MG mount.[13]
    • M9A1 – Same as M9, with ring mount and three MG pintles.[13]

Self Propelled Guns
  • T12/M3 75 mm GMC – M3 based Gun Motor Carriage equipped with the M1897A5 75 mm gun. These vehicles were fitted with the M2A3 gun carriage and shield.[15]
    • M3A1 75 mm GMC – The M2A2 gun carriage was substituted for the A3, as stocks were exhausted. Later variants featured a purpose-built gun shield (59 rounds).[15]
  • T19 105 mm HMC – M3 based Howitzer Motor Carriage equipped with the M2A1 105 mm howitzer (8 rounds).[16]
  • T19/M21 81 mm MMC – M3-based Motor Mortar Carriage equipped with the M1 mortar (81 mm)(97 rounds), designed to allow the mortar to be fired from within the vehicle.[17]
  • T21 – M3 based mortar carrier fitted with a 4.2 inch mortar. Never adopted.[18]
    • 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.[18]
  • T30 75 mm HMC – M3 based Howitzer Motor Carriage equipped with the M1A1 75 mm howitzer in a simple box mount (60 rounds). Used by the US Army. Also provided to the Free French Army, later used in Indochina.[16]
  • 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.[19]
  • 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 called it SU-57 (99 rounds). 31 ended up getting converted into M3A1s, while one entered service with the U.S. Army.[20][21]

  Anti Aircraft Guns
  • 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.[22]
    • M14 Half-track – M13 MGMC variant, based on the M5 chassis. Supplied under lend-lease to Britain (5,000 rounds).[22]
  • 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).[23]
    • 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.[23]
    • M16A2 MGMC – M16 MGMC variant, basically M16s brought up to M16A1 standard and with the addition of a rear door to the hull compartment. For existing M16s, this essentially meant a replacement of the M45D mount for the M45F mount.[23]
    • M17 Half-track – M16 MGMC variant, based on the M5 chassis. Sent under lend-lease to USSR (5,000 rounds).
  • T58 – Similar to the M16/M17, the T58 featured the Maxon quad-mount fitted to a special electric powered turret. Prototype only.
  • T28E1 CGMC – M3 based Combination Gun Motor Carriage equipped with one M1A2 37 mm autocannon (240 rounds) flanked by 2 M2WC machine guns (3,400 rounds). The original T28 had been based on the shorter M2 Half-Track Car chassis.
    • 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 as on the M15.
  • 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 shorter M2 Half-Track Car chassis.

40mm 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.
  • T54/E1 – Tested in 1942, the gun mount quickly proved to be unstable when fired, and the improved T54E1, which also added a circular armored shield and rear armor to the vehicle, could not fix the inherent problem. Prototype only.[28]
  • 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.
    • T59E1 – T59 fitted with the T17 fire control system. Prototype only.
  • T60/E1 – Similar to the T54 and the T59, but featured two .50 caliber M2 machine guns flanking the 40 mm cannon (the mounting's designation was T65). The T60E1 featured an armor configuration similar to that of the T54E1. Suffered from the same stability issues as previous attempts. Prototype only.[29]
  • T68 – Perhaps the most radical of the experiments, the T68 featured two 40 mm cannons, one mounted on top of the other, plus a stabilizer on top of the two guns. The recoil force proved to be too much for the mount, and the idea was abandoned. 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.
  • M34 – Like the M15 "Special" above, 102 M15s were converted to M34s in Japan in 1951. The M34 mounted a single 40 mm Bofors gun in place of the M15's combination gun mount. This was due primarily to a shortage of 37 mm ammunition, which was no longer manufactured. M34s served with at least two AAA (automatic weapons) battalions (the 26th and 140th) in the Korean War.[30]

M5 Halftracks and Variants

  • M3E2/M5 – An IH half-track, that was virtually identical to the M3. The only differences was the thicker armor (up to 20 mm), different engine (IHC RED-450-B), and lower range (125 mi (201 km)). This model was mainly supplied to the Soviet Union, the British Commonwealth, and France. A total 4,625 were produced.[8]
  • M5A1 – M5 with a M49 machine gun mount.[16] It could fit one 0.5 inch (12.7 mm) M2 Browning heavy machine gun, and two 0.3 inch M1919 Browning machine guns,[7] and 2,859 were produced.[8]
  • M5A2 – Similar to the M3A2, the M5A2 was a combination of the M5 and M9 Half-tracks. This was a project that was never mass produced.[8]
  • M9 – Same as the M5, stowage arranged as the M2 Half-track, with access to radios from inside (as opposed to outside) and rear doors, plus pedestal machine gun mount,[7] with 2,026 being produced.[8]
  • M9A1 – Same as the M9, with ring mount and three machine gun pintles,[7] with 1,407 being produced.[17]
  • M14 Half-track – A version of the M13 Multiple Gun Motor Carriage, based on the M5. It had two 0.5 in machine guns mounted in a M33 Maxson turret on the rear of the chassis. Several hundred were produced before it was replaced by the M16 MGMC and M17 MGMC, with a total 1,605 were produced.[17]
  • M17 Half track – M5 with the same quadruple 0.5 inch machine gun turret as the M16 MGMC. All 1,000 were supplied to the USSR.[18] It saw limited use at end of World War II and was also deployed during the Korean War.[19]
  • M3 Mk. A – A modified M5. The only difference was the variety of machine guns were used in place of the M49 mount.[10]
  • M3 Mk. B – A M5 modified as a command carrier. It had extra radios and a front winch bumper.[10]

M9 Halftrack

The M9 half-track was a half-track produced by International Harvester in the United States during World War II for lend-lease supply to the Allies. It was designed to provide a similar vehicle to the M2 half-track car. It had the same body and chassis as the M5 half-track (also built by International Harvester for lend-lease) but had the same stowage and radio fit as the M2 half-track.