Official designation: M4A3
Common designation: Sherman IV
Type: Medium Tank
Manufacturer: Ford, Grand Blanc
M4A3 Production: 12,596
Total M4 Production: Approx. 49,234
Engine: GAA-III V-WC
Horsepower: 400 at 2,600 rpm
Crew: 5
Weight (tons): 32.3 Gearbox: Synchromesh, 5 forward 1 reverse
Length (meters): 7.52 Speed (km/hr): 47
Width (meters): 2.68 Range (km): 130
Height (meters): 3.25 Radio: SCR528, Push-button (FM)- voice-operated

Standard Armament: One 75mm - 105mm, One .50 cal AA, One .30 cal coaxial, One .30 cal hull
Traverse: 360° (36°/sec) powered
Elevation: +25° to -10°
Ammunition: 97, 300, 4750

Armour (mm): Front Side Rear Top/Bottom
Turret: 75 50 50 25
Hull Upper: 50 38 38 25
Hull Lower: 38 38 38 12

History: Powerplants for the American tank production effort was always a major problem. A search for alternatives in powerplants being produced in automotive plants led to the development of the 8 cylinder Ford engine. This engine was originally designed for aircraft, was fueled by gasoline, and developed 500 gross horsepower. After testing this engine, it was designated the Ford GAA, and in January of 1942, the Ordnance Committee authorized it's use in Sherman tank production. The "new" Sherman was designated the M4A3. This tank was to serve the U.S. Army for well over a decade. First tanks were completed in May 1942 and sent for testing at the General Motors Proving Grounds. Minor changes were accepted for production and the early versions still retained the direct vision blocks. A distinguishing feature is that all early production vehicles through the late war production changes used the heavy duty VVSS (Vertical Volute Spring Suspension) bogies. The differential and final drive housing was a one piece casting. The front plate assembly was rolled steel plates and castings but the number of pieces was reduced from that used as on the M4A2 model. Ammunition storage was of the "Dry" type and later modifications were undertaken to remedy this by the addition of 1" armor plate welded to the sides of the hull at the proper location for added protection. The Ford GAA engine proved to be popular and became the "workhorse" of the U.S Army.

The production numbers for the first model of the M4A3 armed with the 75mm was 1,690 , and production was completed in September of 1943. Ford left the tank production program at this time and the continued production of the M4A3 was passed onto other manufacturers such as the Detroit Tank Arsenal and the Fisher Tank Arsenal. By the middle of 1943 modifications for changes related to all models of the Sherman tank were extensive. These resulted from both combat experiences and test programs. A decision was made to "win the war" with the Sherman and to improve it's combat efficiency markedly. Major changes would include main gun - 76mm, a 105mm howitzer, "Wet" ammunition stowage and much larger hatches for the driver and assistant driver in the hull. Production efficiency had to be accomplished as well so concern arose over standardization between models and this was eventually accomplished.

The first noticeable difference is the changeover to "Wet" ammunition stowage for both 75mm and 76mm armed variants. Ammunition stowage being moved from the sponsons ("Dry" models) to racks below the turret which are further protected by water (actually solutions of water and ethylene glycol). "Ready" rounds were also protected this way. The only variant that did not use this method was the 105mm howitzer armed variants but they used armored racks. Floor ammunition racks required that the turret basket be eliminated with a partial floor suspended from the turret ring. The most noticeable external feature is the 47 degree front hull with a newly designed and much larger driver /assistant driver hatches.

Features: Distinguishing turret features included an all around vision cupola for the commander, except on early production which retained the earlier circular split ring hatch and an oval shaped loader's hatch. Those vehicles produced with the circular split ring commanders hatch had it replaced by the all round vision cupola in the field as supplies became available. The M4A1 was first to enter production closely followed by the M4 105 howitzer version. The M4A3 was started in production with 75mm, 76mm and 105mm howitzer armament. The Fisher Tank Arsenal manufactured "wet" stowage 76mm and 75mm armed models while at the Detroit Tank Arsenal production began with the 76mm "wet" stowage and the 105mm howitzer models. Production figures for "wet" stowage 75mm armed models totals 3,071 tanks and ended in March 1945.

First prototype (T6) appeared in September 1941. Production started at 1,000 per month and increased to 2,000 and were built at 11 plants. Production was able to quickly switch over from the M3 to the M4 as they both shared bottom hulls, engines, suspension, and tracks. Gun had velocity of 2,030 ft/sec, and penetrate 3.1 inches at 1,000 yards. Gyrostabilizer was installed. Turret rotated on ball bearing race that was recessed and thus protected from enemy fire. Two hatches in the bow and 1 in turret, plus escape hatch in floor. Auxiliary generator provided extra power and could be used in preheating engine. The tanks had azimuth and elevation controls installed so that the main gun could be used an artillery weapon. Also FM communication radio systems were installed and could be tied into any local field artillery fire control. It could often run 2,500 miles before major maintenance on the tracks and bogies. In 1944 the Horizontal Volute Spring Suspension (HVSS) was phased into production. It enhanced mobility.

 

 

 

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Grateful acknowledgement to:
MBI Publishing Company (2000) "Tanks of World War Two" - Steve Crawford
Images and Text
P.80 and P.81
Additional Informative Sites:
Tanks in WWII