A HISTORY OF DEVELOPMENT OF THE HALF-TRACK
A fully restored 1943 M4 Halftrack (81 mm Mortar Carrier) depicting the unit markings of the 2nd. AD 82nd Reconnaissance Battalion. The World War II home of 1SG. Pete Burland from D-Day until the final victory.
A consideration of primary importance in developing strategy for land warfare is the ability to move personnel and implements of war successfully across varying terrain. To this end, the Half-Track was designed to improve cross-country performance over wheeled scout cars and supplement other essential operational considerations. The Half-Track was used as a personnel carrier, prime mover and carriage for various howitzer configurations. A central use of the Half-Track was a platform from which armored columns could develop 'eyes and ears' while also conducting a reconnaissance in force in advance of the maneuver unit.
In the Half-Track story, there are numerous type accepted designs. While these differ in individual application, they all share the standardization used in power train and chassis design. The vehicle shared modified components of production. This is particularly seen in the chassis and axle drive line. Both axles were manufactured by Timken with a split housing in the front drive component and a banjo configuration in the rear. One interesting note is owing to a difference in drive wheel/sprocket size for the front and rear axle assembly, the differential ratios were not the same as seen in most four wheel drive military vehicles.
Troops Landing on Normandy Beach (D Plus One)
The rear compartment of each model was encapsulated with face-hardened quarter inch armor plate. While this posed a menacing appearance, it afforded little protection above the level of the rifleman's individual weapon. The armor was individual plates assembled with armor screws which were countersunk into the plate. Perhaps the most noted identifier to many persons is the distinctive 'Roller' assembly on the front of non-winch equipped Half-Tracks. The purpose of the roller was to prevent the vehicle from 'digging in' when traversing certain obstacles.
Reinforcements land on Normandy Beach (D Plus One)
In all, 43,000 Half-Tracks were produced by three primary vendors which were.
Autocar Company in Ardmore, Pennsylvania, Diamond T Motor Car Co. in Chicago, Illinois, White Motor Company, Cleveland, Ohio.
International Harvester (Specialized Production)
Of these by far the largest manufacturer was White Motor Company with a total of 15,414 accepted by War Department. The other manufactures, Auto Car made 12,168 and Diamond T with 12,421. Over half of the Half-Tracks produced were the basic M2 & M3 series. Of course the success story for this historic vehicle belongs to over a hundred sub-contractors and the American worker; both male and female.
INTERNATIONAL HARVESTER MODEL M-5 (M5A1) and M-9 (M9A1)
Departing from the standardization of production by White Autocar and Diamond T, were these two models from the sole vendor of Intentional Harvester. Essentially they represent a substantially different item altogether. The armor was thicker and of a one piece design. Another significant difference was the power plant. In the International Harvester model the engine was of the overhead valve design while the standardized American models utilized the 'flathead' engine. The front and read differential were both of the Banjo type and manufactured by International Harvester. The vast preponderance of these vehicles were given to allied forces with a few remaining the the United States as training units. In all, IHC produced 2026 model M-9, and 1407 model M9A1.
ENGINE COMPARISON OF IHC AND WHITE et al.
| IHC | 'Red' 450B | 6 | OHV | 450 CID | 4-3/8 x 5" | 6.3:1 | 130 at 2600RPM |
| White et al | 160AX | 6 | L-Head | 450 CID | 4 x 5-1/8 | 6.3:1 | 128 at 2800RPM |
Standardized US M Designated Models
| M3 & M3A1 | Personnel Carrier |
| M3 & M3A1 | 75 mm Gun Motor Carriage |
| M4 & M4A1 | 81 mm Mortar Carrier |
| M13 | Multiple Gun Carriage |
| M15 & M15A1 | Multiple Gun Carriage |
| M16 | Multiple Gun Carriage |
| M21 | 81 mm Mortar Carrier |
Other US Designed Models
| T-19 | 105 mm Howitzer Mortar Carriage |
| T-30 | 75 mm Howitzer Motor Carriage |
W.W.II Production of the Half-Track
| Model No | Weight | GVW | Prod. Total |
|---|---|---|---|
| M2 | 14,160 | 17,800 | 11,415 |
| M2A1 | 14,600 | 19,600 | 1,643 |
| M3 | 15,000 | 20,000 | 12,499 |
| M3A1 | 14,800 | 20,500 | 2,862 |
| M4 | 14,000 | 17,850 | 572 |
| M4A1 | 15,320 | 20,140 | 600 |
| M5 | 15,400 | 18,900 | 4,625 |
| M5A1 | 16,175 | 19,675 | 2,959 |
| M9 | 15,975 | 19,475 | 2,026 |
| M9A1 | 16,950 | 19,050 | 1,407 |
| M16 | 18,640 | 21,640 | 2,877 |
| M16A1 | 18,250 | 21,250 | 1,345 |
It should be noted that in the vehicle rebuild program, W.W.II produced items were often converted into specialized carriers.
In All, the Half-Track served the Allied cause honorably and well. Within the US force structure, the Half-Track gave way to full-tracked APC's with increased armored personnel protection and increased cross country speeds.