M3: General | |||
Date of first acceptance | May 1941 | Total acceptances | 12,391 + 108 converted from 75mm HMC T30 (2,209 converted to M3A1) |
Manufacturers |
|
Crew | 13 men |
M3: Dimensions | |||
Combat weight | 20,000lbs 9,100kg |
Height | 89" 230cm |
Length with roller | 242.63" 616.28cm |
Width | 77.25" 196.2cm |
Front tread | 64.5" 164cm |
Rear tread | 63.8" 162cm |
Wheelbase | 135.5" 344.2cm |
Ground clearance | 11.2" 28.4cm |
Ground pressure, tires | 29.4psi 2.06kg/cm² |
M3: Armament | ||||
Type | Mount | Ammunition | Traverse | Elevation |
.30cal M1919A4 MG | Flexible on pedestal mount M25 | 4,000 rounds | 360° (manual) |
+35° to -25° (manual) |
M3: Armor | ||
Assembly | ||
Bolting | ||
Hull | ||
Rolled face-hardened steel | ||
Location | Thickness | Angle from vertical |
Radiator louvres | .25" .64cm |
26° |
Windshield cover | .50" 1.3cm |
25° |
Sides | .25" .64cm |
0° |
Rear | .25" .64cm |
0° |
Hood top | .25" .64cm |
83° |
M3: Automotive | |||||
Engine | White 160AX; 6 cylinder, 4 cycle, in-line gasoline | ||||
Horsepower | Net: 147@3,000rpm | Torque | Net: 325 ft-lb@1,200rpm | Fuel capacity | 60gal 230L |
Transmission | Spicer 3461 constant mesh, 4 speeds forward, 1 reverse | ||||
Steering | Steering wheel | ||||
Brakes | Hydraulic (Hydrovac) |
M3: Suspension | ||
Type | Road wheels | Track return rollers |
Front: Semi-elliptic longitudinal leaf spring Rear: Vertical volute spring |
Front: Steel ventilated disc Rear: 1 bogie/track; 4 dual/bogie |
1 dual/track |
Drive sprockets | Idlers | Shock absorbers | 18-tooth front drive | Adjustable fixed at rear of track | On front wheels |
M3: Track | |||||||
T68E1 | |||||||
Center guide band type | |||||||
Width | 12" 30cm |
Pitch | 4" 10cm |
Pitches/track | 58 | Track ground contact length | 46.75" 118.7cm |
M3: Performance | |||
Max level road speed | 45mph 72kph |
Max grade | 60% |
Angle of approach | With winch: 33° Without winch: 37° |
Angle of departure | 45° |
Max vertical obstacle | 12" 30cm |
Min turning diameter | 59' 18m |
Max fording depth | 32" 81cm |
Cruising range | ~200mi, roads ~320km, roads |
The M3 half-track used the same chassis and mechanical components as the half-track car M2, but the rear armored body was 10" (25cm) longer and featured a door in the rear to ease entry and exit from the vehicle. The M3 lacked side ammunition stowage compartments, and the fuel tanks were moved from their rear position on the M2 to just behind the driving compartment. Improvements in the M3 paralleled those in the M2, with spring-loaded idlers, smaller demountable headlights, mine racks, and winch featured on late vehicles. A 2lb (.9kg) CO2 portable fire extinguisher was carried.
M3A1: General | |||
Date of first acceptance | October 1943 | Total acceptances | 2,862 + 2,209 converted from personnel carriers M3 + 1,360 converted from 75mm GMC M3 + 281 converted from 57mm GMC T48 + 90 converted from 105mm HMC T19 |
Manufacturers |
|
Crew | 13 men |
M3A1: Dimensions | |||
Combat weight | 20,500lbs 9,300kg |
Height | 106" 269cm |
Length with winch | 249.63" 634.06cm |
Width over mine racks | 87.50" 222.3cm |
Front tread | 64.5" 164cm |
Rear tread | 63.8" 162cm |
Wheelbase | 135.5" 344.2cm |
Ground clearance | 11.2" 28.4cm |
Ground pressure, tires | 29.4psi 2.06kg/cm² |
M3A1: Armament | ||||
Type | Mount | Ammunition | Traverse | Elevation |
.50cal M2HB MG | Flexible on ring mount M49 or M49A1 | 700 rounds | 360° (manual) |
+80° to -20° (manual) |
.30cal M1919A4 MG | Flexible on pintle mounts | 7,750 rounds | 360° (manual) |
Manual |
M3A1: Armor | ||
Assembly | ||
Bolting | ||
Hull | ||
Rolled face-hardened steel | ||
Location | Thickness | Angle from vertical |
Radiator louvres | .25" .64cm |
26° |
Windshield cover | .50" 1.3cm |
25° |
Sides | .25" .64cm |
0° |
Rear | .25" .64cm |
0° |
Hood top | .25" .64cm |
83° |
M3A1: Automotive | |||||
Engine | White 160AX; 6 cylinder, 4 cycle, in-line gasoline | ||||
Horsepower | Net: 147@3,000rpm | Torque | Net: 325 ft-lb@1,200rpm | Fuel capacity | 60gal 230L |
Transmission | Spicer 3461 constant mesh, 4 speeds forward, 1 reverse | ||||
Steering | Steering wheel | ||||
Brakes | Hydraulic (Hydrovac) |
M3A1: Suspension | ||
Type | Road wheels | Track return rollers |
Front: Semi-elliptic longitudinal leaf spring Rear: Vertical volute spring |
Front: Steel ventilated disc Rear: 1 bogie/track; 4 dual/bogie |
1 dual/track |
Drive sprockets | Idlers | Shock absorbers | 18-tooth front drive | Spring-loaded at rear of track | On front wheels |
M3A1: Track | |||||||
T68E1 | |||||||
Center guide band type | |||||||
Width | 12" 30cm |
Pitch | 4" 10cm |
Pitches/track | 58 | Track ground contact length | 46.75" 118.7cm |
M3A1: Performance | |||
Max level road speed | 45mph 72kph |
Max grade | 60% |
Angle of approach | With winch: 33° Without winch: 37° |
Angle of departure | 45° |
Max vertical obstacle | 12" 30cm |
Min turning diameter | 59' 18m |
Max fording depth | 32" 81cm |
Cruising range | ~200mi, roads ~320km, roads |
The M3A1 featured the M49 ring mount for the .50cal weapon over the right front of the vehicle, and socket mounts for the .30cal MG were added to each side of the passenger compartment. The later ring mount M49A1 added a a deflector shield and a skate-type backrest for the gunner, and substituted a different carriage with a connecting stabilizer.
Due to the similarity between the M3 and M2 half-tracks, a proposal was put forth in August 1942 by Army Ground Forces that the types be combined into a single vehicle. International Harvester Corporation was given five M3s to convert according to plans drawn up for a single half-track body, and the first pilot was completed on 7 January 1943. The new design could be used for different missions by changing the interior radio, etc., stowage, and was armed with an M49 ring mount and machine gun pintle sockets like the -A1 half-tracks. The vehicle was also built with folding rear stowage racks, and ladder-like side stowage racks above the mine racks that could be used to secure the canvas cover over the passenger compartment. The ammunition lockers with outer doors were dispensed with, and the rear door was retained. The combined design used a long passenger compartment body like that found on the M3A1. This vehicle was standardized as the M3A2 on 2 October 1943 and was set to replace the M2 and M3 half-tracks starting on 1 March 1944, but production of half-tracks had been discontinued by that point and only the M3A2 pilots were built.