M4 Sherman

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M4A1 with late features, note the A1's round-edged, fully cast upper hull, and the 75 mm gun used on most Shermans.
Medium Tank M4A1 (Sherman II) (early)
General characteristics
Crew	5
Length	19 ft 2 in, 5.84 m
Width	8 ft 7 in, 2.62 m
Height	9 ft, 2.74 m
Weight	28.4 tons, 28 tons (empty)
Armour and armament
Armour	2 inches (50 mm) (front upper hull glacis)
Main armament	75 mm M3 Gun 90 rounds
Secondary armament	.50 (12.7 mm) Browning M2 machinegun 300 .50 rounds 2×.30 (7.62 mm) Browning M1919 machineguns 4,750 .30 rounds
Mobility
Power plant	Continental R975 C1 gasoline 400 hp (298 kW) gross @ 2400 rpm 350 hp (253 kW) net @ 2400 rpm
Suspension	Vertical Volute Spring Suspension (VVSS)
Road speed	24 mph (38.5 km/h) brief level
Power/weight	14 hp / tonne
Range	120 miles @ 175 US gal (145 imp. gal) / 80 octane 193 km @ 660 l / 80 octane

WWII foreign variants and use: Lend-Lease Sherman tanks

Post-WWII foreign variants and use: Postwar Sherman tanks

The Medium Tank M4 was the main tank designed and built by the United States for allied forces in World War II, totaling roughly 50,000 tanks plus thousands more derivative vehicles under different model numbers with different abilities. In the United Kingdom lend-lease M4s were dubbed Sherman after Union General William Tecumseh Sherman, continuing a practice of naming American tanks after famous Generals. The British name became popular in the US and the two names are often combined into M4 Sherman or shortened to Sherman. After WWII, Shermans served the US (in the Korean War) and many other nations world-wide and saw combat in many wars in the late 20th century.

[edit] US Design Prototype

A cutaway showing the internal arrangement of a M4A4 sherman.

The US Army Ordnance Department designed the Medium Tank M4 as a replacement for the Medium Tank M3. Detailed design characteristics for the M4 were submitted by the Ordnance Department on 31 August, 1940, but development of a prototype had to be delayed so final production designs for the M3 could be finished, and the tank put into full scale production. On 18 April, 1941 the final design characteristics for the new tank were approved at a conference at Aberdeen Proving Grounds attended by representatives of the Armored Force and the Ordnance Department. The stated goal was to produce a fast, dependable medium tank that was capable of defeating any other tank currently in use by the Axis nations. The first pilot model of the M4 was completed on 2 September, 1941. The M4 was standardized and placed into production in February of 1942. (Source: R.P. Hunnicutt, "Sherman: The History of the American Medium Tank.")

[edit] US Production history

During the production period, the U.S. Army's seven main sub-designations, M4, M4A1, M4A2, M4A3, M4A4, M4A5, and M4A6, did not necessarily indicate linear improvement: for example, A4 is not meant to indicate 'better than' A3. Instead, these sub-types indicated standardized production variations, which were in fact often manufactured concurrently at different locations. The sub-types differed mainly in terms of engine, although M4A1 differed from M4 by its fully cast upper hull rather than by engine; M4A4 had a longer engine system that also required a longer hull, longer suspension system, and more track blocks; M4A5 was an administrative placeholder for Canadian production; and M4A6 also elongated the chassis but totaled fewer than 100 tanks. Only the M4A2 and M4A6 were diesel while most Shermans were gasoline. "M4" might refer specifically to the single sub-type with its Continental radial engine or generically to the entire family of seven Sherman sub-types, depending on context. Many details of production, shape, strength, and performance improved throughout production life without an "advance" to the tank's basic model number; more durable suspension units, safer "wet" (W) ammunition stowage, and stronger armor arrangements such as the M4 Composite which had a cast front hull section mated to a welded rear hull. Note that the British nomenclature differed from that employed by the U.S.

M4 and M4A1 (shown), the first Shermans, share the inverted U backplate and inherited their engine and exhaust system from the earlier Lee.

Early Shermans mounted a 75 mm medium-velocity general-purpose gun. Although Ordnance began work on the Medium Tank T20 as a Sherman replacement, ultimately the Army decided to minimize production disruption by incorporating elements of other tank designs into Sherman production. Later M4A1, M4A2, and M4A3 models received the larger T23 turret with a high-velocity 76 mm gun M1, which traded reduced HE and smoke performance for improved anti-tank performance. The British offered the QF 17 pounder (76.2 mm) anti-tank gun with its significantly better armour penetration to the Americans but the US Ordnance Department was working on a 90 mm tank gun and declined. Later M4 and M4A3 were factory-produced with a 105 mm howitzer and a new distinctive mantlet in the original turret. The first standard-production 76mm-gun Sherman was an M4A1 accepted in January 1944 and the first standard-production 105mm-howitzer Sherman was an M4 accepted in February 1944.

M4 with 105 mm howitzer and a dozer blade, note the square-edged, welded, upper-hull plates found on most Shermans.

The US accepted in June-July 1944 a limited run of 254 M4A3E2 Jumbo Shermans with very thick armor and the 75 mm gun in a new heavier T23-style turret in order to assault fortifications. The M4A3 was the first to be factory-produced with the new HVSS suspension with wider tracks for lower ground pressure and the smooth ride of the HVSS with its experimental E8 designation led to the nickname Easy Eight for Shermans so equipped. The US developed a wide array of special attachments for the Sherman; few saw combat and most remained experimental but those which saw action included the bulldozer blade for Sherman dozer tanks, Duplex Drive for "swimming" Sherman tanks, R3 flame thrower for Zippo flame tanks, and the T34 60-tube 4.5 inch Calliope rocket launcher for the Sherman turret.

The M4 Sherman's basic chassis further undertook all the sundry roles of a modern, mechanized force, totaling roughly 50,000 Sherman tanks plus thousands more derivative vehicles under different model numbers including M32 and M74 "tow truck"-style recovery tanks with winches, booms, and most with an 81 mm mortar for smoke screens, M34 (from M32B1) and M35 (from M10A1) artillery prime movers, M7B1, M12, M40, and M43 self-propelled artillery, and upgunned M10 and M36 tank destroyers. As part of the deception plan of Operation Fortitude that drew German attention to the Pas de Calais rather than Normandy, inflatable rubber Shermans were manufactured and deployed across fields in Kent alongside plywood artillery pieces, another vesion of dummy Sherman was made from painted canvas over a steel frame and could be built over a Jeep and driven to simulate a moving tank.

see also American armored fighting vehicle production during World War II

[edit] US Service History

M4 crew, 1942.

First type in US service: A US 7th Army M4A1 lands at Red Beach 2, Sicily on July 10, 1943 during Operation Husky.

During World War II, the M4 Sherman served with the US Army and US Marine Corps. US service history accommodated the large transfer of US Shermans to the allied forces of the United Kingdom (including Commonwealth), Soviet Union, Free French government-in-exile, Polish government-in-exile, Brazil, and China.

The US Marine Corps used the diesel M4A2 and gasoline-powered M4A3 in the Pacific. The US Army Tank Destroyer Command used the diesel M10 tank destroyer (based on the M4A2 chassis) in all theatres. However, the US Army Chief of the Armored Force Lt. Gen. Jacob L. Devers ordered that no diesel-engined Sherman tanks be used outside the Zone of Interior (ZI). The US Army used all types for either training or testing within the United States but intended the M4A2 and M4A4 to be the primary Lend-Lease exports. British needs also claimed a large share of the M4 and M4A1.

Last type in US service: M4A3E8(76)W Sherman used as artillery position during the Korean War

The first US Shermans in combat were M4A1 used for Operation Torch in November 1942, shortly after the first M4A1 Shermans saw battle with the British 8th Army at the Second Battle of El Alamein in October 1942. Additional M4 and M4A1s replaced M3 Lees in US tank battalions over the course of the North African campaigns. The M4 and M4A1 were the main types in US units until late 1944, when the preferred M4A3 with its more powerful 500 hp engine began replacing M4s and M4A1s as the main US version. However, older M4s and M4A1s continued in US service for the rest of the war.

The first 76 mm gun Sherman to enter combat in July 1944 was the M4A1, closely followed by the M4A3. By the end of the war, half the US Army Shermans in Europe had the 76 mm gun. The first HVSS Sherman to see combat was the M4A3E8(76)W in December 1944.

M4A3E8 Participating in a WWII Victory Parade

After WWII, the US kept the M4A3E8 "Easy Eight" in service with either 76 mm gun or 105 mm howitzer. The Sherman remained a common US tank in the 1950-1953 Korean War but the Army replaced Shermans with Patton tanks over the 1950s. The US continued to transfer Shermans to allies which contributed to wide foreign use worldwide.

[edit] US Combat performance

[edit] Armament

The US Army artillery branch chose the 75 mm gun primarily for its high-explosive capability rather than for its anti-tank capability. Nevertheless, when the Sherman first saw combat in 1942, its 75 mm gun, inherited from the M3 Lee, could kill the German tanks it faced in North Africa at normal combat ranges. In 1943, the 75 mm gun was ineffective against the front of the new medium Panther and heavy Tiger I tanks but the Americans encountered few Panthers or Tigers before D-Day. In 1944-45, Shermans with 105 mm howitzers provided even more powerful high-explosive armament.

Sherman armed with 105 mm howitzer.

This M4A2(76) HVSS shows the T23 turret with later 76 mm gun's muzzle brake.

After D-Day, the Tigers remained rare but Panthers became about 50% of all German tanks on the Western Front so the Army deployed 76 mm-gun Shermans to Normandy in July 1944. The higher-velocity 76 mm gun M1 gun gave Shermans anti-tank firepower comparable to many of the lighter German AFVs it encountered, particularly the Pz IV, and StuG vehicles. However, with a regular AP (Armour Piercing, Shot) ammunition (M79) or APCBC (M62) shells, the 76 mm could only reliably knock out a Panther with a shot to its flank or to the front from very close range and so the Sherman remained badly outmatched by the Panther whose higher velocity 75mm gun could easily penetrate the Sherman's frontal armor at all typical combat ranges. This contributed to very high Sherman tank losses during the Normandy Campaign.

Hypervelocity Armor Piercing HVAP ammunition, was developed for the 76 mm gun in late 1944. This new projectile could penetrate the front turret of the Panther at somewhat longer ranges than standard ammunition (out to about 800 yards instead of 200 yards). This ammunition did not arrive in the ETO until early 1945, and was in such short supply that many 76mm tank crews never fired it in combat.

A USMC M4A3R3 uses its flame thrower armament during the Battle of Iwo Jima.

In the relatively few Pacific tank battles, even the 75 mm gun Shermans outclassed the Japanese in every engagement. The use of HE (High Explosive) ammunition was preferred because anti-tank rounds punched cleanly through the thin armor of the Japanese tanks (light tanks of 1930s era design) without necessarily stopping them. Although the high-velocity guns of the tank destroyers were useful for penetrating fortifications, Shermans armed with flame throwers also destroyed Japanese fortifications. There was a variety of types of flame throwers, differing primarily in the type and location of launcher (and the US used similar devices on other tanks and LVTs, and also used flame-throwing Shermans in Europe).

[edit] Armor

This early 75 mm gun turret shows the single hatch.

Sherman armor was more evenly distributed and thicker at the side than the Panzer IV medium tank. The Sherman's frontal armor was designed to withstand a 37mm gun, which was a common German anti-tank gun and tank gun on the Panzer III medium tank in early WWII. However, the Sherman's armor, while good for an early war tank, was not adequate against the larger German guns coming into service in 1942. It was this lack of adequate frontal armor that made the Sherman very vulnerable to German high velocity 75mm and 88mm tank guns which almost all German tanks and tank destroyers used by 1944.

For crew survivability, the M4 had an escape hatch on the hull bottom and, in the Pacific, Marines used this Sherman feature in reverse to recover wounded infantry under fire. Combat experience indicated the single hatch in the 3-man turret to be inadequate for timely evacuation so Ordnance added a loader's hatch beside the commander's. Later Shermans also received redesigned hull hatches for better egress.

The 1943 modernization program for older tanks welded raised patches of applique armor to the sides of the turret and hull. Note also the "Rhino" Culin cutter on the bottom front, a field improvisation to break through the thick hedgerows of the Normandy bocage.

Early Sherman models were prone to burning at the first hit. The Sherman gained grim nicknames like "Tommycooker" (by the Germans who referred to British soldiers as "Tommys"), The British caleed them "Ronsons", after the cigarette lighter with the slogan "Lights up the first time, every time!" and Polish Tankers referred to them as "The Burning Grave". This vulnerability increased crew casualties and meant that damaged vehicles were less likely to be repairable. US Army research proved that the major reason for this was the use of unprotected ammo stowage in sponsons above the tracks. The common myth that the use of gasoline (petrol) engines was a culprit is unsupported; most WW2 tanks used gasoline engines and petrol was unlikely to ignite when hit with AP shells. Further, the diesel-engined M4A2 used by the Marines were considered to be much less prone to burn and explode than the diesel Soviet T-34.[1] At first a partial remedy to ammunition fire was found by welding one-inch thick applique armour plates to the vertical sponson sides over the ammunition stowage bins. Later models moved ammunition stowage to the hull floor, with additional water jackets surrounding the main gun ammunition stowage. This decreased the likelihood of "brewing up".

M4A3E2 Sherman Jumbo: Some units replaced the original 75 mm gun with a 76 mm gun.

Progressively thicker armour was added to hull front and turret mantlet in various improved models, while field improvisations included placing sandbags, spare track links, or even logs for increased protection against shaped-charge rounds. General George S. Patton, informed by his technical experts that the standoff produced by sandbags actually increased vulnerability to shaped-charge weapons (a controversial opinion) and that the machines' chassis suffered from the extra weight, forbade the use of sandbags and instead ordered tanks under his command to have the front hull welded with extra armour plates, salvaged from knocked-out American and German tanks. Approximately 36 of these up-armored Shermans were supplied to each of the armored divisions of the Third Army in the spring of 1945.

The (rare) M4A3E2 Sherman Jumbo variant had thicker frontal armor than the Tiger and Panther. Intended for the assault to breakout of the Normandy beachhead, it entered combat in August 1944.

[edit] Mobility

Strategic Mobility

The U.S. Army required the Sherman not to exceed certain widths and weights so that the tank could use a wide variety of bridge, road, and rail travel for strategic, industrial, logistical, and tactical flexibility. Eisenhower demanded an improved tank from Army Chief of Staff George C. Marshall, who explained that he couldn't move a larger tank along the rail tracks to the East coast for shipping to Europe. The comparatively compact size of the Sherman also made it suited for transportation across the Atlantic, Pacific and for amphibious operations.

Operational Mobility

Spares were readily available, an important consideration when more tanks were lost to mechanical failure than any other cause, including enemy action. Jim Dunnigan, a military analyst and war game designer, states that the number of tanks lost to mechanical failure in American, Soviet, and German armies in World War Two was in the ratio of one to five to ten. This is a striking testimony to the performance of the Sherman and highlights the relative mechanical unreliability of German tanks such as bedeviled the Tiger. The spectacular Allied mobility of 1944-45 could not have been achieved with tanks as unreliable as the Tiger or Panther, nor could the spectacular German mobility of 1939-41.

This M32 Tank Recovery Vehicle shows the E8 HVSS wider-track suspension for lower ground pressure.

Tactical Mobility

The Sherman had good speed both on and off-road for the era. Off-road performance varied. In the desert, the Sherman's rubber tracks performed well. In the confined, hilly terrain of Italy, the Sherman could often cross terrain German tanks could not. However, US crews found that on soft ground, such as mud or snow, the narrow tracks gave poor floatation compared to wide-tracked second-generation German tanks such as the Panther. Soviet experiences were similar and tracks were modified to give grip in the snow. The US Army issued extended end connectors or 'duckbills' to add width to the standard tracks as a stopgap solution. Duckbills were original factory equipment for the heavy M4A3E2 Jumbo to compensate for the extra armor weight. The M4A3E8 'Easy Eight' Shermans and other late models with wider-tracked HVSS suspension corrected these problems, but formed only a small proportion of all tanks in service even in 1945.

[edit] Summary

The Sherman tank was comparatively fast and maneuverable, mechanically reliable, easy to manufacture and service, and produced in many special-purpose variants, whose capabilities differed greatly. It was effective in the infantry support role.

The Sherman performed well against WWII Japanese tanks, Italian tanks, and the German standard tank of WWII, the Panzer IV medium series. However, the typical Sherman was significantly inferior in both armor and armament to the German Tiger heavy tanks, Panther "medium" (heavy by US standards) and most of the tank destroyers fielded by the Germans in 1944. When the US encountered German tank units containing large numbers of Panther tanks in 1944 this resulted in very high losses.

Shermans tried to defeat heavier tanks by weight of numbers or superior tactics, using upgunned Shermans working with tank destroyers such as the M36 Jackson (with a 90 mm anti-tank gun) and the M18 Hellcat (a mobile, fast tracked vehicle with the same 76 mm gun). Skilled US Sherman crews and commanders, such as Lieutenant Colonel Creighton Abrams or Sergeant Lafayette Poole, were able to knock out dozens of German tanks each.

US 3rd Armored Division Shermans under fire in Cologne, Germany during WWII. One dismounted tank crewman is running toward the camera for a medic. Second crewman is running to assist commander of burning Sherman at right, who has bailed out of his cupola after having both feet severed.

The majority of losses of Shermans were not in battle with other tanks, but from mines, aircraft, infantry anti-tank weapons and, on occasion, friendly fire. This should not be surprising considering that the entire strategy of blitzkrieg, as practiced first by the Germans and later by the Allies, was to strike the enemy where they are weakest and wreak havoc in their rear areas, rather than attempting brute-force frontal attacks. A noted exception would be Battle of Kursk where frontal attack might have fared better. Thus, although their tanks were less powerful, this turned out to be as irrelevant to the outcome of the final half of World War Two as the French and Russian superiority in tank forces was in the first half. US armoured forces ultimately triumphed over their German counterparts because of numerical superiority, a more consistent supply of fuel and ammunition, and the allied air superiority at Normandy, with aircraft being the biggest danger to the lines of supply of German tank units.

Nonetheless, the fact that the Sherman tank was significantly inferior on a one to one basis to the better German tanks in use by 1944 has remained a subject of sometimes bitter controversy and recrimination to this day. Sherman crews had been told prior to Normandy that the Sherman was the best tank in the world but this was patently untrue as demonstrated during that campaign and the high casualties among Sherman crews had a serious adverse effect on crew morale. While the US was usually able to field military equipment that was usually highly technologically advanced and at least as good as anything in its enemies arsenals, the failure to correctly anticipate the pace of German tank development and to produce a better US tank in time for the Normandy Campaign produced a rare (in US military experience) situation where qualitively US equipment was easily outmatched by the opponent's.

According to Belton Y. Cooper's memoir of his 3rd Armored Division service, the Shermans were "death traps"; the overall combat losses of the division were extremely high. The unit was nominally assigned by table of organization 232 Sherman medium tanks. 648 Sherman tanks were totally destroyed in combat, and a further 1,100 needed repair, of which nearly 700 were as a result of combat. According to Cooper, the 3rd Armored therefore lost 1,348 medium tanks in combat, a loss rate of over 580%, in the space of approximately only ten months. Cooper was the junior officer placed in charge of retrieving damaged and destroyed tanks. As such, he had an intimate knowledge of the actual numbers of tanks damaged and destroyed, the types of damage they sustained, and the kinds of repairs that were made. His figures are comparable to those given in the Operational History of 12th U.S. Army Group: Ordnance Section Annex. Some WWII Army officers made similar arguments during the war. Other officers disagreed with the negative assessment and Gen. George S. Patton argued that the Sherman tank was overall a superior tool of war.

The only other Second World War tank produced in comparable numbers to the Sherman was the Soviet T-34 series, which many critics consider as a contender for best tank of World War II, although it too had high losses during the war. Compared to the M4 Sherman, the T-34 had lower ground pressure, better armor and a better gun (at least on the T-34/85 models) while the M4's advantages included much better ergonomics and (on late models) fire-resistant "wet" ammunition stowage. Each was a general-purpose medium design that served as the main tank of its respective country in WWII, was upgraded, served into the Cold War, and outfitted allies. During the Korean War, US Shermans performed well against their T-34/85 adversaries, which could be due to a combination of better training and better equipment such as gunsights and gun stabilization.

[edit] US Variants

• M4 Sherman variants- annotated lists
• Vehicles that used the Medium Tank M4 chassis or hull, discussed in greater detail or greater context and in other articles:
  • 3in Gun Motor Carriage M10 - Tank Destroyer, aka Wolverine
  • 90 mm Gun Motor Carriage M36 - Tank Destroyer, aka Jackson
  • 105 mm Howitzer Motor Carriage M7 - self-propelled artillery, aka Priest
  • 155 mm Gun Motor Carriage M12 - GMC M12 with Cargo Carrier M30 (both used Sherman components)
  • 155/203/250 mm Motor Carriages - 155 mm GMC M40, 8 in. (203 mm) HMC M43, 250 mm (10 inch) MMC T94, and Cargo Carrier T30
  • Flame Tank Sherman - M4A3R3 Zippo, M4 Crocodile, and other flame-throwing Shermans
  • Rocket Artillery Sherman - T34 Calliope, T40 Whizbang, and other Sherman rocket launchers
  • Amphibious tanks - Duplex Drive (DD) swimming Shermans and deep wading Shermans
  • Engineer tanks - D-8, M1, and M1A1 dozers, M4 Doozit, Mobile Assault Bridge, and Aunt Jemima and other mine-clearers
  • Recovery tanks - M32 and M74 TRVs
  • Artillery tractors - M34 and M35 prime movers

[edit] Foreign variants and use

• Lend-Lease Sherman tanks
• Postwar Sherman tanks
• Sherman Firefly

[edit] See also

Wikimedia Commons has media related to:

M4 Sherman

• List of vehicles of the U.S. Armed Forces
• Vickers Tank Periscope MK.IV
• M4 Sherman Photos and Walk Arounds on Prime Portal

[edit] Sources

• Cooper, Belton Y. Death Traps: The Survival of an American Armored Division in World War II. Novato, CA: Presidio, 1998. ISBN 0-89141-670-6.
• Rodrigo Hernandez Cabos, John Prigent. M4 Sherman Osprey Publishing ISBN 1-84176-207-5
• M4 Sherman photo galleries at ww2photo.mimerswell.com: [2], [3], [4]
• Sherman Register
• OnWar
• AFV Database
• WWII vehicles
• battlefront.co.nz
• M4(105 mm) at tamiya.com
• israeli-weapons.com

[edit] References