Tanks Infantry and
Reconnaissance Vehicles
Artillery Support Vehicles


(Combat Car M1)



(Combat Car M2)

M3 Stuart


M5 Stuart

M22 Locust

M24 Chaffee

M41 Walker Bulldog

M551 Sheridan


Medium and MBT

Convertible M1


M3 Lee

M4 Sherman



M26 Pershing


M46 Patton

M47 Patton 47

M48 Patton 48




M1 Abrams




Half-track M3


Half-track M5


Universal Carrier T16








(V-100 Commando)


M2 Bradley

M1126 Stryker ICV

Armored Car No. 1

Armored Car No. 2

Mack/White/Locomobile Armored Cars

King Armored Car

Armored Car M1

Scout Car M1

Scout Cars M2/M3

Scout Car M4
(Scout Car T13)

Half-track M2

T17 Deerhound

T17E1 Staghound I

Half-track M9A1

M8 Greyhound


M38 Wolfhound



M3 Bradley


M1127 Stryker RV

Direct Fire
37mm GMC M6


57mm GMC T48

75mm GMC M3

75mm HMC M8


3" GMC M5

3" GMC M9

3" GMC M10

76mm GMC M18

90mm GMC M36

90mm SPG M56

M1128 Stryker MGS


106mm Multiple SPR M50

SP Flame Thrower M132

ITV M901


Indirect Fire
75mm HMC T30

81mm Mortar Carrier M4

81mm Mortar Carrier M21

81mm SPM M125


105mm HMC T19

105mm HMC M7

105mm HMC M37

105mm SPH M52

105mm SPH M108

4.2" MMC M2

4.2" SPM M84

107mm SPM M106

120mm SPM M1064

155mm GMC M12

155mm GMC M40

155mm SPG M53

155mm HMC M41

155mm SPH M44

155mm SPH M109

175mm SPG M107

8" HMC M43

8" SPH M55

8" SPH M110


Air Defense


T17E2 Staghound AA








M730 Chaparral






M1130 Stryker CV


M1200 Armored Knight




M1132 Stryker ESV











Smoke Generator M1059

ASV M1117 Guardian


The United States military has had a long, if at times strained, relationship with the armored vehicle. Mechanization of American armed forces has not always followed a smooth path, but its origins predate even the internal combustion engine. Development persisted, and today the armored vehicle is a ubiquitous component of the ground forces of the United States.

In the Beginning

As far back as the US Civil War, trains were used to quickly and easily move troops across distances, quiet steam locomotives were used as reconnaissance platforms, and trains were even armored with boiler plate and armed with naval cannons to act as rolling fortresses.McGrath, 33. Zumbro, The Iron Cavalry, 72-3. Half a century later, a handful of armored cars patrolled the country's southern border, and General John J. Pershing's forces were accompanied on their 1916 punitive expedition into Mexico by trucks and tracked tractors. A company of infantry was mounted in trucks, while the tracked vehicles, manufactured by the Holt Tractor Company, were used as cargo carriers, or more specifically cargo pullers as they towed supply-laden skids. Pershing was a frequent passenger in a Dodge passenger car, sometimes using it as a mobile command post.House, 14. Crismon, U.S. Military Wheeled Vehicles, 6. Crismon, U.S. Military Tracked Vehicles, 7. Blumenson, The Patton Papers 1885-1940, I: 354. D'Este, 169. In early 1925, Holt merged with the C.L. Best Tractor Company to form the Caterpillar Tractor Company. It was in this unlikely locale that the first motorized assault by American forces took place. Cavalry Second Lieutenant George S. Patton, Jr., who was commanding 14 men mounted in three cars trying to procure corn to feed horses, diverted from this mission to search two nearby ranches for Julio Cárdenas, second in command to Pancho Villa. Patton and his men used their cars to position themselves around the ranches and assaulted directly from the automobiles. Cárdenas was found at the second ranch and, along with two other Villistas, was killed in a firefight in which Patton's men suffered no losses.Blumenson, The Patton Papers 1885-1940, I: 359-66. D'Este, 172-5. Wilson, 14.

American tracked vehicles played a large role in the invention of the tank. Tracked vehicles were uncommon in Europe, and American-designed machines were imported to several countries. Great Britain, for example, used upwards of 1,000 Holt 75hp tractors as artillery prime movers during World War I, and these machines helped give the British experience with tracklaying vehicles. France and Britain experimented independently on their early tank designs, and Holt tractors took part in trials in both countries. The Holts were joined in British tests by machines built by the Bullock Creeping Grip Tractor Company and the Killen-Strait Manufacturing Company; indeed, a Killen-Strait machine may have become the first armored tracked vehicle in history when an armored car body was experimentally mounted on it. More concretely, the running gear of the French Schneider CA and Saint-Chamond tanks as well as that of Germany's A7V were based on Holt's design.Ventham and Fletcher, 16. Vauvillier, 17-8, 20. Fletcher, Landships, 4, 7-11. Fletcher, The British Tanks 1915-19, 25, 32-3. Liddell Hart, The Tanks, 1: 28, 33-5, 40-1. Smithers, A New Excalibur, 11, 31-5, 37. Perrett, 35-6. Stern, 21-2, 24, 29-30, 103. J.P. Harris, 17-8, 26, 28-9. Campbell, 58-9, 74-6, 80-1, 95-6, 301-2. Hundleby and Strasheim, 16-7.

World War I: The Tank Corps

Tanks, of course, debuted in the First World War, and America's delayed entry into that conflict also gave the country a late start on armored warfare. Gen. Pershing, now commanding the American Expeditionary Force (AEF), first read reports of British and French tank actions in June 1917, and he subsequently created committees to study the new form of warfare.Wilson, 9. Hunnicutt, Stuart, 9. It took until 10 November 1917 before AEF headquarters ordered Patton, by then a captain, to the AEF schools at Langres to set up a program for training American soldiers in the use of the French Renault FT light tank. Indeed Patton was the first man assigned to the American tank service, and 1LT Elgin Braine was detailed to be his assitant. Patton and his entourage observed Allied training and manufacturing methods and set about applying the lessons learned. Their efforts included meeting with tank experts such as French General J.E. Estienne and Britons Colonel J.F.C. Fuller, General Hugh Elles, and Lieut.-Colonel F. Searle. They also suggested four modifications to the FT, including mounting a self-starter and installing a bulkhead separating the crew from the engine. These suggestions were adopted.Wilson, 15. D'Este, 205-8, 213, 854. Cameron, 3. Patton was also offered command of an infantry battalion, but felt the tank position would be more beneficial to his career. See Blumenson, The Patton Papers 1885-1940, I: 468-73, 478-83, 501-2, 508. British rhomboid heavy tanks were also thought useful, and an American annex to the British Tank School at Wareham was formed.Wilson, 51. The AEF then requested from the War Department five heavy and twenty light tank battalions comprising of 375 British rhomboids and 1,500 French FTs.Johnson, 31. The Army formalized the Tank Corps on 26 January 1918, and Colonel Samuel D. Rockenbach was assigned to command the unit.Jones, Rarey, and Icks, 107. "Armored Force, Command, and Center," 1. Patton was appointed commander of the light tank training school that he set up near Bourg, and later commanded the US 1st Tank Brigade in the debut of American armored forces at the battle of St. Mihiel in September 1918.Wilson, 15, 96. Hunnicutt, Stuart, 6.

Manufacturing tanks domestically for the Tank Corps proved problematical due to bureaucratic hurdles, and American tankers fought in European-produced FT light tanks and Mark V and Mark V* heavy tanks for the whole of the war. American production of a copy of the FT was finally negotiated--with much work expended by Braine--leading to the 6-ton tank M1917, but the first of these didn't appear until October 1918, and only 64 were completed by the end of the war. Despite their tardiness, Patton rated them better than the French machines.Wilson, 86, 222. Hunnicutt, Stuart, 17. Blumenson, The Patton Papers 1885-1940, II: 710. It was also decided to employ a new heavy tank, which was developed into the Mark VIII, and it was intended to manufacture this tank in France using American and British components. Production was hampered by shortages of British supplies and the American Liberty aircraft engines that were to power the new tank; in addition, the intended assembly factory in France was not operational by the war's end.Johnson, 32. Childs, 47. J.P. Harris, 136. Stern reproduces the Anglo-American treaty on Mk. VIII tank production on pages 198-201. With the cessation of hostilities, the original contracts for 4,440 M1917s were cancelled after 952 had been built, and the US constructed 100 Mk. VIIIs to its own specifications once the manufacturing coalition decomposed after the Armistice.Hunnicutt, Stuart, 17. Hunnicutt, Firepower, 11. Childs, 47.

Between the Wars

The end of World War I meant a drastic culling of the world's armed forces, and the US armored forces were no exception. At the time of the Armistice, the US Tank Corps consisted of 1,235 officers and 18,977 other ranks, but in March 1919 its authorization was reduced to 300 officers and 5,000 enlisted men.Wilson, 219. Cameron, 9. In July 1919 Congress then declared that the Tank Corps would be limited to no more than 154 officers and 2508 other ranks.Wilson, 222. Cameron, 9. D'Este, 300

More distressing than the manpower cuts, however, was the drive to end the independence of the tankers. Despite articles authored by both Patton and the commander of the US tank training center at Camp Colt, a lieutenant colonel named Dwight D. Eisenhower, asserting that the tank had a future outside of infantry support and also that Tank Corps should be kept as a separate branch of the Army, the National Defense Act of 1920, passed on 2 June, did away with the Tank Corps and assigned all tanks and their units to the Infantry. The weighty opinion of Pershing, who was in favor of making the tanks a supporting arm of the Infantry, helped give impetus to legislators looking to keep the costs of a peacetime Army to a minimum; in addition, Rockenbach himself failed to articulate a role for tanks beyond that of infantry support. Officers like Patton and Eisenhower were even threatened with courts-martial if they persisted in espousing views contrary to the doctrine of using tanks as infantry support.Johnson, 39, 72. Wilson, 223. Jarymowycz, 24-6. Cameron, 14. Blumenson, The Patton Papers 1885-1940, II: 783. D'Este, 297-300. Rockenbach, while still in command of the Infantry's tanks, did later advocate adding tanks to Cavalry divisions. See Cameron, 29. The Act formed a Provisional Tank Brigade out of a number of National Guard tank companies, but this unit never even met as a whole since the individual companies were meted out to different infantry divisions for support duties.Salecker, 5-6. The subordination of tanks to the Infantry stifled tank design and doctrinal development, and tankers' morale and staffing also suffered. Patton, who had been mulling a return to the Cavalry since February 1918 thanks in part to its better career-advancement prospects, was pushed into action with the tanks' absorption by the Infantry and rejoined his former branch in September 1920.Wilson, 227. Cameron, 22. Blumenson, The Patton Papers 1885-1940, II: 525, 709, 805-7. D'Este, 276. Also Rockenbach, promoted to brigadier general in June 1918, became a colonel once more after the Act's passage. See Wilson, 226-7. Likewise, Colonel Patton reverted to a captain. Blumenson, The Patton Papers 1885-1940, II: 804. D'Este, 278, 300-302. Another side effect of the Act was the division of the Infantry's doctrinal and organizational responsibilities from the design and production of tanks, which was controlled by the Ordnance Department.Johnson, 59. Green, Thomson, and Roots, 194-5. Blumenson, The Patton Papers 1885-1940, II: 790-1. This decentralization, combined with the users' and designers' sometimes competing desires, would have repercussions in the next war.

Nevertheless the potential of the armored vehicle could not be ignored. The formation of the country's first Experimental Mechanized Force (EMF) was approved at the end of 1927, and it took to the field from 1 July to 20 September 1928. Inspired by a similar British formation, this unit was to test the ability of mobile mechanized units to be self-sufficient.Timothy K. Nenninger, "Organizational Milestones in the Development of American Armor, 1920-1940," in Camp Colt to Desert Storm, Hofmann and Starry, eds., 40. "Armored Force, Command, and Center," 1-2. Cameron, 32. Morton, 18. However, due to the niggardly defense spending policies of the interwar years, the EMF was forced to perform with vehicles such as worn-out M1917s and Cunningham M1 light tanks. By this point, some knowledgeable officers contended that the M1917s would actually be hazardous to the tank crews should they be needed in battle.Cameron, 133. A Mechanization Board was formed in May 1928 and recommended that a permanent mechanized force be formed. This Mechanized Force, commanded by Cavalry Colonel Daniel Van Voohris, appeared at Ft. Eustis, Virginia, in 1930, but Army Chief of Staff General Douglas MacArthur eliminated the Mechanized Force as a separate entity in 1931--assigning its remnants to the Cavalry--and ordered that all combat branches should modernize themselves as much as possible.Gillie, 43. Green, Thomson, and Roots, 192. Jarymowycz, 29. "Armored Force, Command, and Center," 2-3. Cameron, 45-8. House, 102. Morton, 26-8. Blumenson, The Patton Papers 1885-1940, II: 962-6. Due to this new policy, and the fact that tanks were still technically under control of the Infantry, the tanks used by the Cavalry were forced to undergo a change of nomenclature and were thereafter known as "combat cars."

MacArthur hoped that component development would improve under this policy, and this notion did bear fruit.Nenninger, 48. During the 1930s, the seeds were planted for the components that would make US tanks the most reliable in the world, including vertical volute spring suspension, rubber-shoed tracks with rubber bushings around the track pins, and radial engines. Standardized and accepted tanks were few and far between in the 1930s, and included the Infantry's M2 light tank and the Cavalry's M1 and M2 combat cars, which all used essentially the same hulls. The US also got some medium tanks in 1939 with the arrival of the M2. All of these tanks used vertical volute spring suspensions, which featured twin-wheeled bogies mounted externally. Their rubber-shoed tracks proved very durable on road surfaces; also, the rubber bushings reduced the force necessary to wrench the track around the drive sprocket, decreased wear between the track pins and pin holes, and made the track more flexible when responding to steering actions or shock forces.Cameron, 390; Research, Investigation and Experimentation in the Field of Amphibian Vehicles, 180, 191, 197. Enemy dry-pin tracks lasted approximately 600 miles (970km), while many US tracks could see 3,000 miles (4,800km). See Green, Thomson, and Roots, 309. Their radial engines were also used to power aircraft, and this would later emerge as a handicap when radial engine shortages forced numerous other motors into use. The Lee and Sherman tanks developed for World War II were powered by no less than five different powerplants, ranging from the aircraft-derived Wright and Continental radials and Ford V8 to automobile motors like GM's truck diesels and the Chrysler A57 multibank, which was comprised of five car engines arranged to run as a single unit. The M5 Stuart's development was initiated, in part, to preemptively solve a forecasted shortage of the radial engines used in the M3 Stuart.Hunnicutt, Sherman, 74. Hunnicutt, Stuart, 172.

Despite the improvements done on individual components during the early and mid-1930s, replacement of the country's park of tired and obsolete tanks was a glacially slow process. In 1933 MacArthur rated the Army's tanks as "completely useless" in battle, save for a few experimental vehicles; yet, war plans in 1933 did not provide for the initiation of tank production until seven months post-mobilization.Quoted in D'Este, 293. Cameron, 133. Ordnance's portion of the Army budget from 1922-35 was only 3.5%, contrasted to the 25% to which it was raised in 1939.Morton, 11. As a result of these budgetary shortfalls, the US produced a pathetic 35 tanks from 1920-35, and from 1925-39 the Army's tank development budget allowed for building, on average, a single experimental vehicle per year.Thomson and Mayo, 224; Blumenson, The Patton Papers 1885-1940, I: 1048; Green, Thomson, and Roots, 195. Cameron, 25, differs with Green, Thomson, and Roots by claiming the years included 1925-31.

Due to limited potential for funding, few private American armored vehicle designs emerged during the interwar period. Many of those that appeared were due to an enterprising and eccentric automobile engineer named J. Walter Christie. Christie had been designing self-propelled artillery mounts since 1916, and incorporated into many of his designs was the ability to move on tracks as normal or on road wheels only. Wheeled movement was usually powered by the use of chains connecting the drive wheels to the rear road wheels. This feature enabled the vehicles to travel at high speeds over roads on their wheels, while also giving them good cross-country mobility once the tracks were installed. Christie's early designs were unsprung or suspended by coil springs, but his M1928 tank debuted a suspension design that would become famously synonymous with his name. In this vehicle, the road wheels were individually sprung on leading or trailing arms using tall and relatively soft helical springs housed inside a double-walled hull. This design provided the wheels greater vertical movement than the previous bogie suspensions, and when combined with the soft springs used in the tank very high speeds could be achieved.

Due to a host of factors, though, Christie's suspension was not destined to play a large role in American tank design. Christie's prototype tanks had a history of shoddy workmanship and unreliability, and he continually refused to build his vehicles to the contract specifications laid out by the Army, often making modifications unilaterally. Christie's dealings with foreign governments, especially the USSR, also did little to endear him to the War Department.George F. Hofmann, "Army Doctrine and the Christie Tank: Failing to Exploit the Operational Level of War," in Camp Colt to Desert Storm, 110-1, 113-4. Hunnicutt, Sherman, 22-3. Crismon, U.S. Military Tracked Vehicles, 87. Johnson, 118-9. Zaloga, 11-2. Cameron, 129-30. The US Army never did wholly buy into the wheel-track conversion theory, but did go so far as to standardize and accept a handful of the Rock Island Arsenal-designed convertible medium tank M1, which used Christie's suspension design. A few combat car prototypes were also constructed along these lines, since Christie's dream of high-speed tanks was more suited to the Cavalry's mobile mission, however none of these vehicles was standardized. The early prototypes of the 76mm gun motor carriage M18 also used Christie's suspension, but this was dropped in favor of torsion bars, which took up less room inside the hull.Hofmann, 130. Hunnicutt, Stuart, 307. Dunham, 26, 61. Interestingly, even on the eve of the German invasion, some powerful forces in the Red Army also wanted production of the T-34 halted in favor of the T-34M design which used torsion bars instead of Christie springs. See Baryatinskiy, T-34 Medium Tank, 18-20, and Michulec and Zientarzewski, 145. In the end, the Army concluded that Christie's designs, even those classed as medium tanks, did not provide an appreciable offensive benefit over existing light tanks, despite being twice as expensive as contemporary vehicles.Hunnicutt, Stuart, 66. Hunnicutt, Sherman, 24. In the parsimonious environment of the interwar years, this finding was damning.

While not winning over his home government, Christie did clandestinely sell some of his tanks abroad to the Soviet Union and Britain. These countries developed tanks using his suspension, including many of Britain's cruiser tanks and the USSR's BT series and T-34.Hofmann, 116, 130. Fletcher, Mechanised Force, 120-3. J.P. Harris, 277-8. Liddell Hart, The Tanks, 1: 373-4. Fleischer, 18. Bean and Fowler, 19, 68. Habeck, 115, 150-2. Baryatinskiy, Light Tanks, 5, 36. Milsom, 96. Gudmundsson, 48. Potapov, <http://english.battlefield.ru/index.php?option=com_content&view=article&id=1:christie&catid=8&Itemid=102&tmpl=component&print=1&layout=default&page=>. Zaloga, 11-2. There is apparently some dispute as to the exact designation of the tanks Christie sold to the UK and USSR. Hofmann claims that the British received the M1930, while Fletcher says it was an M1931 or even a US Army prototype version of the M1931, called the convertible medium tank T3. Fleischer and Milsom say the Soviets imported two "M.1931(T-3)"s and "M-1931 (T-3)"s, respectively. Bean and Fowler agree that they were T3s, but Habeck mentions the T1E1, Potapov says the USSR bought two M1930s, and Baryatinskiy calls them M.1940s. This latter designation may be because that, as Bean and Fowler assert, Christie so labeled the tanks himself to reflect how advanced he thought the design was. The Soviets so respected Christie's work that Mikhail Tukhachevsky even proposed to Stalin that the USSR should offer Christie a large salary in exchange for assistance in designing Soviet tanks. This proposal was not acted upon.Milsom, 41.

The US Marines also busily experimented with armored vehicles between the wars. King armored cars and the little M1917 gave the Marines their first experience with armored vehicles, and weight and size limitations imposed by the Navy's cargo cranes and tank lighters forced the Marines to accept the unsuccessful turretless Marmon-Herrington CTL-3 before it was decided that standardization with the Army would be beneficial.Joseph H. Alexander, "Marine Corps Armor Operations in World War II," in Camp Colt to Desert Storm, 187-9. Estes, Marines Under Armor, 13-26. Gilbert, Marine Tank Battles in the Pacific, 18-21. Army M2A4 light tanks were procured starting in 1940, and M3 Stuarts were acquired the next year.Alexander, 198. Estes, Marines Under Armor, 28-9, 206. Gilbert, Marine Tank Battles in the Pacific, 21, 25.

World War II: Obscurity to Maturity

The outbreak of the Second World War forced the United States to reconsider the organization of its fledgling armored units. The US Army leadership, however, was still reluctant to organize its tanks and mechanized forces into all-arms teams, and the Infantry and horse-riding Cavalry each still wanted control over all tank units.Nenninger, 49. But the Army changed its mind thanks to practice maneuvers it performed in 1939 and 1940 as well as Germany's Panzerdivisionen racing through Poland and France, so the Armored Force was created on 10 July 1940. To get around the National Defense Act of 1920 and its assignment of tanks to Infantry, the War Department established the Armored Force "[f]or the purposes of service test."A new arm of the Army could only be created by an act of Congress. Greenfield, Palmer, and Wiley, 56. Gillie, 162-3. Johnson, 144. Cameron, 255. Yeide, The Infantry's Armor, 3. "Armored Force, Command, and Center," 9. House, 102. In essence, though, the Armored Force was a new branch that combined the separate armored assets of the Cavalry and Infantry, and with its inception the organization of US mechanized forces was finally modernized. The forward-thinking Cavalry Brigadier General Adna Chaffee, a proponent of mechanization who had experience commanding a mechanized brigade, was chosen as chief of the new organization. Cavalry was further entwined with the new organization when the 7th Cavalry Brigade (Mechanized) was tapped to become the nucleus of the 1st Armored Division. Prodigal son Patton also returned to armor by again taking command of an armored brigade, this time the 2nd Armored Brigade of the 2nd Armored Division.

However, on 9 March 1942 Army Ground Forces (AGF) was created to manage ground combat elements, including the Armored Force.Greenfield, Palmer, and Wiley, 31, 152. Christopher R. Gabel, "World War II Armor Operations in Europe," in Camp Colt to Desert Storm, 145. Cameron, 369-71. The Armored Force was renamed the Armored Command on 2 July 1943, and then downgraded to the Armored Center on 19 February 1944. The first change was to avoid confusion with the Army Air, Ground, and Service Forces, which enjoyed a degree of independence that the Armored Force did not after its subordination to AGF. The Armored Center, in view of the burgeoning policy to attach armored units directly to the command of regular corps or armies, was placed under the Army's Replacement and School Command, but kept the power, directly under AGF, to inspect armored units and to recommend changes to armored organization, doctrine, training and training literature, and equipment. AGF influence on armor policy grew as that of the Armored Force/Command/Center declined. "Armored Force, Command, and Center," 108-10. Gillie, 250, 254-5. Greenfield, Palmer, and Wiley, 409, 410. Cameron, 398-401.

As a concession to the Infantry, General Headquarters (GHQ) tank units were also created to help reinforce specific operations. From the start, these units were intended for infantry support, and the chiefs of Infantry and the Armored Force were to cooperate in creating tactics for them.These GHQ tank battalions were renamed "separate" tank battalions after the Army's March 1942 reorganization eliminated GHQ. Greenfield, Palmer, and Wiley 67. Jarymowycz, 72. Johnson, 145. "Armored Force, Command, and Center," 44-5. Although conceivable, there were no instances of separate tank battalions being attached to armored divisions in Europe. See General Board, European Theater, Separate Tank Battalions, 4; Greenfield, Palmer, and Wiley, 328; Cameron, 384; and Yeide, Steel Victory, 5. Although only fifteen of these separate tank battalions were initially planned, by early 1943 the Army had created forty-eight tank battalions in armored divisions versus sixty-three separate tank battalions; by late 1944 the ratio was sixty-five separate battalions to fifty-four in armored divisions. Seventy-four indepenent battalions would eventually be formed along with smaller separate units, including tank companies.Greenfield, Palmer, and Wiley, 333. Johnson, 146. Yeide, Steel Victory, 7. Cameron, 481. Yeide, The Infantry's Armor, 6. On the other hand, the Cavalry was totally divorced from tank design and doctrine after the creation of the Armored Force. Despite having a combined-arms mechanized cavalry regiment (which eventually grew to brigade size) in service since 1932, Cavalry was ultimately unwilling to totally embrace mechanization over the trusted horse.Major General John K. Herr, who became the final Chief of Cavalry in March 1938, was a staunch advocate of the horse up to his death in 1955. Gillie, 138-9. Johnson, 136-40. Jarymowycz, 67-8, 71. Yeide, Steeds of Steel, 21-6. "Armored Force, Command, and Center," 5. Morton, 54, 56-9, 64-81, 83-100, 111-4, 193-203, 217-9. That is not to say that Herr was completely opposed to modernization: He campaigned for the expansion of mechanized Cavalry and advocated the creation of an advanced mechanization course at the Cavalry School, but the latter was blocked by the War Department. See Cameron, 102, 210-20.

At the start of World War II, the US lagged technologically as well as organizationally. The most modern US tanks consisted of the M2 medium, and the M2 light tank and its combat car M1 derivative. The medium tank M2 was armed with a 37mm gun and several machine guns, and the M2 lights had thus far been armed with only machine guns. Most European countries, in contrast, had tanks in service that possessed more powerful weapons. In particular, the German Panzerkampfwagen IV was armed with a short 75mm gun, and it was decided that the next generation of American tanks would match the German vehicles in armament.Hunnicutt, Sherman, 45. Ogorkiewicz, Technology of Tanks, I: 24. Zaloga, 20. Baily, 5. Gillie, 170-1. This reversed the 1938 opinion of the Chief of Infantry that considered a 75mm gun medium tank unnecessary, despite contemporary reports of German experimental tanks armed with 88mm guns. See Green, Thomson, and Roots, 201. Curiously, though, the Germans apparently didn't actually have any tanks armed with an 88mm gun until Tiger prototypes were constructed in 1942. See Spielberger and Doyle, 27; and Jentz and Doyle, D.W. to Tiger I, 23-8, 67-9. At the time neither a turret that could mount a 75mm gun, nor a recoil system capable of handling such a weapon in a tank turret, had been designed in the US.Hunnicutt, Sherman, 47. Zaloga, 20. Johnson, 148. So in order to get the weapon to the field as quickly as possible the medium tank M3 mounted its 75mm gun in the right sponson, a setup that had been previously tested on a prototype of the M2 medium. Production commenced as soon as possible to ship tanks, including the British Grant version of the M3, to the British, who were embroiled in the fight against Panzergruppe Afrika.Hunnicutt, Sherman, 46. The British were sometimes given a higher priority for medium tank delivery than the US Armored Force. See Cameron, 264; Ross, 208; Smithers, Rude Mechanicals, 122. Production was so hurried, though, that defects occurring during manufacturing and shipping sometimes caused significant delays while these faults were repaired in field workshops. See Coombs, 89, 91. The M3 proved a capable vehicle despite being intended as an interim design, and its dual-purpose 75mm gun was able to take on enemy armor as well as antitank guns; to this point enemy guns had been difficult for British tanks since their 2 pounder gun did not have an effective high-explosive shell issued, and their machine guns were not supplied with armor-piercing ammunition for penetrating enemy antitank gun shields.Beale, 96-7. Ross, 173. Fletcher, The Great Tank Scandal, 90, 109. Buckley, 73-5, 145. Hunnicutt, Sherman, 88. Perrett, 86. Zaloga, 28. Jentz, Tank Combat in North Africa, 14, 47. Liddell Hart, The Tanks, 2: 227. House, 125. The Germans were impressed with the Grant upon its debut,See von Mellenthin, 111, 117. When it appeared, Rommel rated it higher than all tanks in the theater except the long-barreled Pz.Kpfw.IV Spezial. See Liddell Hart, The Rommel Papers, 185, 196-7, 206-7, 330. Some US troops fielded a less favorable view, however. See Cameron, 391. but development of the 75mm gun-turreted M4 Sherman commenced immediately upon the completion of the M3's plans, and the first M4A1 was accepted eight months after the first M3. The M4 was based on the mechanical components of the M3 series, which itself was based on the M2 medium, and the Lee's 75mm gun was retained on the Sherman.

From the beginning, though, plans were in place to arm the Sherman with a better armor-piercing gun. The Sherman's turret front plate was interchangeable, and it was proposed to use a 105mm howitzer and the 3" gun M7 as well as the 75mm gun. However the 3" gun, which had already been arming prototypes of the M6 heavy tank, turned out to be too unwieldy for the medium tank turret. The remedy to this problem, a weapon that was ballistically identical to the 3" gun M7 but light and compact enough to fit in the Sherman's turret, was produced by August 1942.Hunnicutt, Sherman, 198-9. One thousand Shermans armed with this new weapon, which was designated the 76mm gun M1, were desired by the Ordnance Department, but the Armored Force considered the design ergonomically unworkable.Ibid., 199, 202. Baily, 83. The turret of the prototype medium tank T23, which had been designed from the start for the 76mm gun, was then satisfactorily mated to the Sherman hull,Hunnicutt, Pershing, 73-4. Baily, 84. and production of 76mm gun medium tanks began in January 1944. Production of 75mm gun tanks was set to be replaced totally with 76mm gun tanks, but the Armored Command balked. They noted that the 75mm gun fired a more effective high explosive shell, the 76mm gun produced a blinding muzzle blast, and the larger 76mm rounds resulted in lower ammunition loads and more difficulty in handling the rounds inside the tank.The muzzle blast of the 76mm gun, especially early versions without muzzle brakes, was so obscuring that it was considered a "one shot" weapon. See General Board, European Theater, Tank Gunnery, 37. Hunnicutt, Sherman, 206. Cameron, 462. Baily, 84-5. Zaloga, 116. The British had a similar target obscuration problem with their 17 pounder-armed tanks. See Hayward, 56. Baily says that Ordnance was opposed to the 76mm gun Sherman, "possibly because it would compete with the T23", which Ordnance was then developing. Arming the Sherman with the 90mm antiaircraft gun was also briefly considered in 1942, but it was realized that performance degradations resulting from modifications required to make the gun and ammunition manageable inside a medium tank turret would render the upgrade moot.Hunnicutt, Sherman, 212. It should be noted that these developments began before the Pz.Kpfw.Panther was even designed, and 76mm gun tank production actually began before Panther was seen in the West.Panther first appeared in the West in Italy in August 1943 with I./SS-Pz.Rgt.1 of SS-Pz.Gren.Div.LSSAH, but these tanks returned to Germany without seeing action. Panthers did not actually engage the Allies in the West until tanks of I./Pz.Rgt.4 fought around Anzio in February 1944. See Jentz, Germany's Panther Tank, 144; Zaloga, 89; and Jentz, ed., Panzer Truppen, 2: 135-6, 144.

American designers had also gone immediately to work on a new improved tank after the introduction of the Sherman. Effort on this new design, which eventually culminated in the M26 Pershing, commenced in the spring of 1942.Hunnicutt, Pershing 49. However, the process was plagued by bureaucratic infighting and trouble with ammunition stowage and transmission and brake designs on the prototype tanks. By the fall of 1943, the Armored Command was in favor of a vehicle mounting the new 90mm tank gun, but preferred that the Sherman tank be upgunned to this standard rather than field a new vehicle. Ordnance asserted that the medium tank would be overloaded by the approximately 9200lbs (4200kg) that a 90mm gun turret would add, and instead preferred production of a 90mm version of their T20 prototype series. AGF had no objection to a new tank, but disagreed with both on the 90mm gun issue.Hunnicutt, Sherman 212. The commanding general of the Armored Command, MG Alvan Gillem, thought the 90mm gun turret would only weigh 4000lbs (1800kg) more than the 76mm gun turret, and his figure is probably more accurate than the Ordnance Department's. See Baily 86-7.

AGF was hesitant to approve the 90mm gun since it believed the new weapon would distract tankers from their primary missions by encouraging them to seek out duels with enemy armor, and also because there was no consensus among field commanders regarding its necessity. When queried in late 1943 about which versions of the T20 series were preferable, the European Theater of Operations replied that they would desire the 76mm gun versions, but would like work to continue on the 90mm gun versions. The North African Theater of Operations, commanded at the time by Eisenhower and containing the only two US armored divisions that had yet seen action, wanted the 76mm gun versions only and thought that the 90mm gun versions would be too heavy and stow too few main gun rounds.Baily, 92-3. The T26E1 only stowed forty-two 90mm rounds, far less than the requirement of seventy set down by the European Theater. Among other workarounds, wet stowage was dropped in favor of additional space for the 90mm rounds. See Hunnicutt, Pershing, 116. AGF may not have envisioned its tanks actively seeking enemy armor to engage, but Armored Force and War Department field manuals consistenly listed enemy armored forces as potential targets for medium tanks. Presciently, the European Theater changed its mind shortly before the Normandy invasion and requested that production of 75mm and 76mm gun tanks be halted in favor of 90mm gun and 105mm howitzer tanks.Hunnicutt, Pershing 195. Mayo, 330-1.

Initial resistance to the 90mm gun was partly due to faulty test data. Ordnance tests claimed the 3" and 76mm weapons could penetrate a Pz.Kpfw.Tiger Ausf.E frontally to 2000yd (1800m),Baily, 90. but actual encounters with heavier German tanks like the Tiger and Panther would prove that these tests were sadly incorrect. After July 1944 firing trials at Isigny, France, demonstrated the difficulty the US 76mm and 3" guns would have with the Panther, Eisenhower, by now the Supreme Allied Commander of the Allied Expeditionary Force, complained, "Ordnance told me this 76 would take care of anything the Germans had. Now I find you can't knock out a damn thing with it."Quoted in Baily, 107; Johnson, 194; Zaloga, 180; Ross, 288; Yeide, The Tank Killers, 135; Fletcher, The Universal Tank, 102. In July 1944 the Army again briefly considered mounting the Pershing's 90mm gun turret on the Sherman, but since the Pershing was anticipated to enter mass production in the months it would have taken to build up a useful number of 90mm Shermans it was decided to concentrate on the new design.Mayo, 331. Hunnicutt, Sherman, 212. Zaloga, 128-9. In the end, when Pershings were finally sent to Europe, AGF's earlier prediction about tankers in powerful gun tanks seeking out enemy armor rang true.The single T26E4 "Super Pershing" sent to Europe was hoping to encounter a Pz.Kpfw.Tiger Ausf.B. See Hunnicutt, Pershing, 28; Baily, 138; and Cooper, 231, 234. Hunnicutt claims that such an encounter never occurred, but the gunner of the T26E4 at least implies that a Tiger Ausf.B was destroyed. See Irwin, 82-3, 138. Zaloga, 290, asserts that the T26E4 potentially knocked out two Tigers, but does not specify ausführung for either.

The seeming impotence of the 75mm and 76mm guns against heavier German tanks soured US tankers' opinion of the Sherman,General Board, European Theater, Tank Gunnery, 26. For examples, see White's report and "Armored Force, Command, and Center," 88. but Great Britain was able to mount a better armor-piercing weapon in it. The British had been trying to get their 17 pounder antitank gun into a tank with their Challenger program, but the project floundered. In late 1943, it was discovered that the 17 pounder could be modified to fit in the 75mm gun turret of the M4 and M4A4 tanks with hydraulic turret traverse and the gun mount M34A1, and conversions using the 17 pounder Mk.IV or VII started that December.The British designated 17 pounder tanks and tank destroyers with a -C suffix; e.g., Sherman IC and Sherman VC. Hayward, 14-6. Fletcher, The Universal Tank, 85. Hunnicutt, Sherman, 304. Smithers, Rude Mechanicals, 177-8. These tanks, called Fireflies, were not without problems, however. Fitting the large gun to the original 75mm turret resulted in a cramped fighting compartment similar to what the US Armored Force had rejected in the original 76mm gun attempt, and the assistant driver was deleted in favor of 17 pounder ammunition stowage. Also, the 17 pounder was initially issued without high-explosive ammunition.Buckley, 111, 131. US tankers interviewed after the war unanimously desired a bow machine gun. See General Board, European Theater, Tank Gunnery, 33. 17 pounder HE shells did enter service, but there are British reports from as late as May 1945 calling them "unsatisfactory." Hayward, 16-7, 40-1. Once it was obvious that the Fireflies had better armor-piercing performance than the US 76mm guns, though, the US Army became interested and requested a number in August 1944. A shortage of the proper type of Sherman tank required for the conversions shelved the idea until March 1945. The US was then able to acquire eighty Fireflies, including some based on the M4A3. By this time, 90mm gun tanks had become available, and this combined with a shortage of 17 pounder ammunition (especially high-explosive) to end the American Firefly program with none of the US Fireflies seeing action.Hayward, 32-5. Hayward, <http://freespace.virgin.net/shermanic.firefly/usnew.html>. Zaloga, 180-1, 276-7.

American tanks may not have specialized in tank-versus-tank fighting, but one technological advantage possessed over enemy tanks was gyrostabilized guns on the medium tanks M3 and M4, and light tanks M3, M5, and M24. This innovation allowed the tanks a modicum of fire-on-the-move capability; coaxial machine gun accuracy was improved, and expert crews were doctrinally permitted to fire from moving tanks at ranges of up to 600 yards.FM 17-12, 4, 34. German tankers, on the other hand, were instructed to fire from the halt.Jentz, ed., Panzer Truppen, 1: 76. Jentz, Tiger I & II: Combat Tactics, 32. Jentz, Tank Combat in North Africa, 59. Fletcher, ed., Tiger!, 43. Drawbacks of using the device existed, however, and included radio interference and depletion of the tank's batteries. Of course the stabilizers required proper training for effective use, and until late in the war many US units still preferred to fire from the halt to ensure maximum accuracy and therefore simply disconnected the devices.Hunnicutt, Sherman, 215. Hunnicutt, Stuart, 142. Zaloga, 39. Green, Thomson, and Roots, 343. General Board, European Theater, Tank Gunnery, 54. Cameron, 392-3, 463.

Another benefit possessed by some later US tanks was wet ammunition stowage, introduced with other improvements to the medium tank design in January 1944. Once committed to battle, the M4 had earned a reputation for easily catching fire when hit. It was determined that ammunition fires were the main culprit, and although the crews themselves may have contributed to this risk by improperly stowing or carrying extra main gun ammunition, work was done to try to correct the tank's flammability. "Armored Force, Command, and Center," 96-7. Ross, 249. Hayward, 17. Yeide, Steel Victory, 21. Buckley, 128. Elson, 152. Neiman and Estes, Marines Under Armor, 94. Liddell Hart, The Tanks, 2: 248. At least some German and Italian crews also took part in this practice. See Green and Green, 77; Spielberger, Doyle, and Jentz, 66; and Riccio, 135. The resulting wet ammunition stowage layout moved main gun ammunition to below the sponson line and stored it in double-walled water-lined boxes. Wet stowage decreased the incidence of fires from 60-80% in knocked-out dry stowage tanks to 10-15% in tanks with the new arrangement.Zaloga, 118. Buckley, 128, agrees with the 15% burn rate for wet stowage Shermans. The light tank M24 was also equipped with wet stowage. Counterintuitively, a British survey found that the Sherman did not significantly differ from the Cromwell, Challenger, Churchill, or Stuart in regards to percentage of crewmen burn casualties. All those vehicles incurred about 25% of their casualties due to burns. The total casualties per knocked out tank was also similar between the different types in the survey. See Fletcher, The Universal Tank, 115-6.

Even though the US medium tank was not designed specifically to fight enemy armor, the Sherman would always be able to handle the opposition's main medium tank, the Pz.Kpfw.IV.Hunnicutt, Sherman, 183-4. A small British study conducted after the Falaise gap was closed found that it took 1.63 hits and 1.55 penetrations to knock out a Sherman during that action, compared to 1.2 hits and 1.2 penetrations to knock out a Pz.Kpfw.IV. See Hayward, 92-3. Nonetheless the Army did field specialized antitank units. The US tank destroyers arose in November 1941 in response to the results of recently concluded US Army maneuvers as well as the German "Blitzkrieg," and the organization was based on the erroneous assumption that centrally massed towed or self-propelled antitank guns would be able to defeat Germany's tank attacks once those attacks had broken through the friendly front line.General Board, European Theater, Study of Tank Destroyer Units, 12. Gabel, "Seek, Strike, and Destroy," 9, 17. Dunham, 4. Baily, 20-1. Cameron, 350-3. House, 145. The rules and umpiring were not necessarily realistic in the maneuvers, however. See Cameron, 353-7; Yeide, The Tank Killers, 5-6; and Gabel, "Seek, Strike, and Destroy," 14-17. The tank destroyers were to hold back if the enemy forces were accompanied by infantry or artillery fires, though, since the basis behind their creation was quite simply the destruction of hostile armor.Gabel, "Seek, Strike, and Destroy," 26. Yeide, The Tank Killers, 8-9. FM 18-5, 8, asserts that "tank destroyers are ill suited to close combat against strong forces of hostile foot troops." On the other hand, FM 18-20, 50, notes that self-propelled tank destroyers firing HE may deal with "moderate infantry attacks" if assisted by their security section machine guns and a few riflemen. FM 18-21, 68, says that, when the machine guns of towed tank destroyers' prime movers are added to this mix, "many" infantry attacks can be stopped. Unfortunately for the tank destroyers, the Germans were not so kind as to provide massed tank attacks, preferring instead to attack with concentrated combined arms forces.Guderian, 24. von Mellenthin, 20. Citino, 30-2. Macksey, Tank versus Tank, 60, 64. Jentz, Panzer Truppen, 1: 77. Jarymowycz, 256. Yeide, The Tank Killers, 43. "Armored Force, Command, and Center," 14. House, 112. This basic doctrinal flaw would often preclude the tank destroyers from being employed as they were intended, but the error was not realized until the tank destroyers had seen action in Tunisia,Gabel, "Seek, Strike, and Destroy," 42. and tactical doctrine and equipment designs for the tank destroyers forged ahead. The first, indeed only, purpose-built US self-propelled tank destroyer was the 76mm GMC M18, which did not appear until July 1943. Before this the tank destroyer forces had used interim designs based on existing vehicles, including the 37mm GMC M6, 75mm GMC M3, and the 3" GMC M10. Towed guns were also touted due to lessons learned in North African combat, but in Europe it became apparent how much more useful self-propelled tank destroyers were thanks to the different terrain and heavier antitank gun designs used there.Concealment was key for towed guns, and it was much easier to dig in and hide the earlier smaller guns in African terrain. General Board, European Theater, Study of Tank Destroyer Units, 10. Gabel, "Seek, Strike, and Destroy," 27-8. Baily, 105-6. Cameron, 427. House, 146. Field commanders commonly misunderstood or ignored the prescribed tank destroyer doctrine, thus frequently forcing tank destroyer units to perform missions for which they had been neither designed nor trained.Baily, 54-5. Yeide, The Tank Killers, 68. Greenfield, Palmer, and Wiley, 426. Cameron, 416-7, 496-8. Once the invalid assumptions of the tank destroyer doctrine were realized, the tank destroyers' influence quickly waned: the Tank Destroyer Command was downgraded to the Tank Destroyer Center in August 1942, and in October of the next year AGF tried to roll the Tank Destroyers into the Field Artillery.This merger was resisted by both arms due to the different tactics used by supporting artillery and the tank destroyers, but tank destroyer enlisted men nonetheless became Field Artillery personnel. Gabel, "Seek, Strike, and Destroy," 44, 46. Dunham, 20, 35. Cameron, 407, 431-2. The advent of 76mm and 90mm gun tanks added fuel to the fire by erasing the penetration advantage the tank destroyers had held over the 75mm gun tanks. Despite the issues with doctrine and their frequent use in missions foreign to their training, the tank destroyer troops provided yeoman service and ended World War II with a loss exchange ratio firmly in their favor.Yeide, The Tank Killers, 250. Dunham, 51.

After the war, the death knell of the Tank Destroyers was sounded when the General Board of the European Theater, after studying the after-action reports of the forty-nine tank destroyer battalions that fought there, recommended that the Tank Destroyer doctrine be revised and included in the defensive doctrines of the Armored Force; armored, self-propelled, high-velocity guns be included in infantry divisions; the Artillery be responsible for deepening the organic antitank defense; and that "the tank destroyers as a separate force be discontinued."General Board, European Theater, Study of Tank Destroyer Units, 29. The Board also explicitly stated, "The European campaign demonstrated that tanks fight tanks," and recommended that a gun capable of destroying any enemy tank be mounted to a vehicle that could keep up with friendly exploitation tanks.General Board, European Theater, Tank Gunnery, 29. A further recommendation was that an armored regiment be assigned to each infantry division, while the infantry division's antitank companies be deleted; the Board justified this by noting that "current thought is that the medium tank is the best anti-tank weapon."General Board, European Theater, The Infantry Division, 6. Patton had made such a recommendation during a meeting on 14 January 1945. Patton, 220. Likewise, the Board recommended against antitank units being a part of mechanized cavalry squadrons attached to armored and infantry divisions, since the tanks in those divisions could support the cavalry.General Board, European Theater, Mechanized Cavalry Units, 6. AGF's earlier stance that friendly tanks were not to seek out enemy armor had been debunked. With these recommendations in mind, the Tank Destroyers were quickly disbanded, and the last units were decommissioned by 1 November 1946.Gabel, "Seek, Strike, and Destroy," 65.

Combat experience showed the Marines that their light tanks were vulnerable, underarmed, and underpowered for moving through the thick Pacific jungles, so they made the move to the Sherman medium tank, which first fought with the Marines at the battle of Tarawa in November 1943.Alexander, 185, 194. Estes, Marines Under Armor, 53-4, 71. Gilbert, Marine Tank Battles in the Pacific, 78. Michael Green, 93-4. The Army had standardized on the gasoline-fueled M4A3 Sherman, meaning that the Marines could more quickly obtain numbers of the diesel-powered M4A2.Estes, Marines Under Armor, 56. The Corps was forced to convert to 75mm gun M4A3s, though, once M4A2 production switched to the M4A2(76)W in mid-1944.Ibid., 88-9. The Marines relished the excellent high-explosive power of the 75mm gun's M48 high-explosive shell, and preferred that capability over the increased armor penetration conferred by the 76mm gun. Eventually the Army, concentrating on the new M26, totally ceased production and support of the 75mm gun tanks, so in 1945 the Marines decided to standardize on the still-in-production M4A3(105); however, budgetary shortfalls ensured that not all Marine Shermans were armed with the 105mm howitzer even by 1950.Ibid., 90, 111, 117. Gilbert, Marine Tank Battles in Korea, 5, 269. In any case, the Sherman was the most powerful tank that fought in the Pacific Theater, and it proved devastating against Japanese armor.Japanese tanks were not helped by their usage in the field. Contrary to their armored doctrine, Japanese tanks were typically used in piecemeal counterattacks or as static artillery pieces. See "Japanese Tank and Antitank Warfare," 86-103. Usage of the heavier medium tanks, though, forced the design of more robust landing craft such as the landing ship, tank (LST), and landing craft, mechanized (LCM), since the Sherman's 35-ton (32-metric ton) bulk could not be handled by earlier vessels.Alexander, 194-5. Gilbert, Marine Tank Battles in the Pacific, 82. Croizat, 31. Tank-infantry cooperation was dismal in early operations, and it wasn't until after the debacles at Guadalcanal and Tarawa that training in this area intensified and matured.Alexander, 191. Gilbert, Marine Tank Battles in the Pacific, 141.

An innovation in infantry vehicles that was perfectly suited to the Pacific Campaign was the tracked landing vehicle (LVT). The first LVTs were modified versions of Donald Roebling's Alligator, which was used as a swamp rescue vehicle in Florida's Everglades.Donald was the son of John Roebling, designer of the Brooklyn Bridge, and was initially hesitant to design a military version of his vehicle. See Croizat, 31-2. At first the LVT was seen simply as an efficient mechanism of transporting supplies inland from ships until wheeled supply vehicles could be landed, but it wasn't long until a more direct military role as an assault craft was envisioned, and LVTs premiered in this role with the Marines at Tarawa and the Army at Makin in November 1943.Alexander, 191, 185. Estes, Marines Under Armor, 70-1. Gilbert, Marine Tank Battles in the Pacific, 78. Yeide, The Infantry's Armor, 97-8. Salecker, 93. Crowl and Love, 47-8. Croizat, 86, 97-8. Research, Investigation and Experimentation in the Field of Amphibian Vehicles, 51, 55. The amphibious tractor battalions were organized along the lines of a motor transport battalion. See Croizat, 40-1. Confidence in the vehicles was probably not inspired by FM 17-34, which noted on page 2 that the LVTs were "relatively seaworthy." LVTs initially used in assault landings were unarmored or fitted with applique armor plates, and the position of the engines in the rear of the vehicle made for a tension-filled dismount over the tall sides. LVT3 and LVT4 remedied that problem and greatly eased cargo handling by repositioning the engines and adding a rear loading ramp. Armored amphibians were also developed to give the assault craft direct fire support during the landing and immediately after. Although referred to as amphibian tanks, their thin armor was a hindrance in combat, especially when acting as "land tanks." The amphibian tanks were to lead the assault, firing on the beach defenses as they approached, then once ashore support the infantry or engage in indirect fire if needed. The armament of the armored amphibians started out as a small 37mm gun on LVT(A)1, but advanced to a 75mm howitzer on LVT(A)4. Armored amphibians were not used in the European Theater, but cargo LVTs were used by the US and British during a few river crossings and by the British and Canadians during the invasion of the Scheldt estuary and occupied islands around Antwerp.The Rhine was one such river crossed by the British with the help of amphibian tractors. General Board, European Theater, Armored Special Equipment, 23-4. Yeide, Steel Victory, 233, 244. Yeide, The Infantry's Armor, 240, 243. Fletcher, The Universal Tank, 106. Croizat, 190, 192-7. Liddell Hart, The Tanks, 2: 329, 418-20, 422-3, 428-9, 434, 436-7, 440, 442-4. Macksey, Armoured Crusader, 308-10, 313-5.

As is widely known, the industrial might of the United States was unmatched during World War II. Railway manufacturers were initally tapped for tank production, but the mass-production expertise of automotive companies was then harnessed in their own plants as well as specially-built tank factories. Over 49,000 Sherman tanks were produced from 1942 to 1945,Hunnicutt, Sherman, 525. along with almost 14,000 M3 and almost 9,000 M5 light tanks.Hunnicutt, Stuart, 464. The US was able to spare over 11,500 lightIbid. and 26,600 medium tanksHunnicutt, Sherman, 526. for the Allies under the Lend-Lease program. Germany, on the other hand, produced just over 25,000 tanks of all types from 1938 to 1945, and the British were outproduced in tanks by almost three-and-a-half times from 1940 to 1945.Chamberlain and Doyle, 261-3. Note that due to an offer of increased numbers of American Lend-Lease tanks, British tank production was intentionally throttled in favor of locomotive production. See Coombs, 41, 47-8, 55, 102, 109, 121-4, . Besides a few kept for unit training, the entire production runs of the T16 carrier, M5 and M9A1 half-tracks, and Staghound armored car were also allocated to the Allies through Lend-Lease.Hunnicutt, Bradley, 11. Hunnicutt, Half-Track, 52, 199. Hunnicutt, Armored Car, 82, 91. Crismon, U.S. Military Wheeled Vehicles,75. All of the engines and almost all of the transmissions for tank-based vehicles assembled in Canada were imported from US factories.Law, 51-2. These staggering figures were helped by the conservation of valuable materials achieved by the Ordnance Department, and armored vehicles played a large role in this process. Low-alloy armors saved valuable nickel, chromium, and vanadium without compromising protection; individual parts were even studied to trim unneeded material "fat" from their designs.Green, Thomson, and Roots, 484-5. Until the synthetic rubber program alleviated the shortage, the required runflat distance for combat tires was reduced from 75 to 40 miles (120 to 64km) in the interests of saving rubber from the tires' sidewalls.Ibid., 501.

One area where conservation was de-emphasized was in the makeup of tank tracks. Tracks with synthetic rubber shoes were not up to the task of handling the weight of medium tanks. So in the constant quest to save rubber, steel-shoed tracks were investigated to replace those with rubber shoes. The deleterious effect of the steel tracks on the tanks' running gear, however, led Ordnance to propose that only rubber-tracked tanks be sent overseas. But once so equipped, the troops in Italy requested steel tracks be sent again since they were more durable in the rocky terrain there. A rubber-backed steel track was finally developed as a compromise, and Ordnance was later authorized to issue whatever type of track would be suitable for specific operations or terrain.Ibid., 306-8, 502.

Notwithstanding early shortages in tank engines, armor steel, and machine tools for making final drives and transmissions, tank production progressed well enough that production requirements were lowered in late 1942. The planning and conservation measures instituted led to such a great tank production potential that in the last quarter of 1943, even after four tank plants had ceased operating, production output was less than half of the available plant capacity. More plants were shut down, but the previously mentioned tank shortage resulted in late 1944/early 1945 due to unanticipated replacement requirements and high numbers of old tanks being counted as resources. Despite protestations of theater commanders, who wanted a replacement factor of 20% for medium tanks, the War Department only authorized a fantastically low 7% replacement factor going into the Normandy invasion. War Department revisions to the replacement factor were not reflective of the actual battlefield experience until December 1944. The deficit was drastic enough that Lend-Lease shipments of tanks to Britain were cancelled in November and December 1944. Production from the remaining manufacturers was increased, but by March 1945 the crisis had passed.Fletcher, The Universal Tank, 102-3. Zaloga, 180-1. Thomson and Mayo, 244-50, 256-9. Coombs, 125-7. Ruppenthal, I: 522; and Ruppenthal, II: 236-41. After production, however, a large delay in delivery to the troops was induced by the geography of the war: shipment of the vehicles across either the Atlantic or Pacific Oceans was necessary to reach their final destinations. Studies in early 1945 showed that it normally took 87 days for supplies to arrive in European units from New York, and shipping across the broader Pacific Ocean to ports in Australia or New Guinea could double the transit time.Millett, 49, 58.

Wars Cold and Hot: The Struggle for Modernization

After World War II, the armored forces of the United States were again drawn down to skeleton-crew levels. The Armored Center was deactivated on 20 October 1945, and out of the ten regular divisions that made up the Army in 1948, only one was an armored division."Armored Force, Command, and Center," 110-1. Ogorkiewicz, Technology of Tanks, I: 30. Cameron, 509. According to Stone, 38, the ratio had decreased to the single armored division in fourteen divisions by 1950. A resurrection occurred, though: the Armored Center was revived in November 1946, and Armor was finally certified as a permanent branch of the Army with the passage of the Army Organization Act of 1950. Also because of the Act, the Cavalry--which had taken in the disbanded EMF almost two decades earlier, had given the country the basis for its first armored division, and even gave the Armored Force its first commander--had its independence revoked and was subsumed by the new Armor branch.Yeide, Steeds of Steel, 273. Michael Green, 10. Cameron, 510. Morton, 217.

Many returning American troops received only a short rest before being called upon to help stem the tide of North Korea's 25 June 1950 invasion of South Korea. The combination of budgetary constraints that allowed armored vehicles to fall into disrepair and concerns over damage medium tanks would cause to Japanese roads while on occupation duty meant that the heaviest tanks readily available to US forces in the region were light M24 Chaffees. This would haunt the first US forces into Korea: compared to North Korea's spearhead of Soviet-designed T-34-85 medium tanks, the Chaffees were wholly inadequate. American medium tanks were rushed to the theater after many were reconstructed in Japan, eventually allowing the M24s to resume their usual role of reconnaissance and flank security.Philip L. Bolté, "Post-World War II and Korea: Paying for Unpreparedness," in Camp Colt to Desert Storm, 225. Hunnicutt, Stuart, 441. The M4 Sherman in its later guises (i.e., 76mm gun tanks and 105mm howitzer tanks) was still useful in Korea, and the 76mm gun tanks were able to hole the T-34-85 at combat ranges.Hunnicutt, Sherman, 497. MacDonald et al., 166. The more powerfully-armed M26 and M46 tanks proved even more capable at antitank work, and some enterprising Marine M26 crews gave their tank commanders more firepower by relocating the .50cal machine gun (MG) mount to a more accessible location in front of the commander's position.Coox, 19-22. Hunnicutt, Pershing, 187. The 90mm hypervelocity armor piercing shot could go completely through a T-34-85 at close range. See Gilbert, Marine Tank Battles in Korea, 34-8, 18-9. World War II tankers felt that the existing antiaircraft machine gun mounts were hard to use. See General Board, European Theater, Tank Gunnery, 35. Improved flame throwing Shermans featuring a flame gun mounted coaxially with the 105mm howitzer instead of in place of the main gun or in the bow machine gun mount were also utilized; despite the danger shown to be associated with the practice in World War II, extra howitzer ammunition was sometimes carried to make up for stowage space lost to the flame gun fuel tanks and pressure unit.Hunnicutt, Sherman, 409-10. Ravino and Carty, x.The Sherman again emerged as the most reliable tank in US service, but mechanical issues were troubling enough that more tank losses were caused by breakdowns than by enemy action in the first year of the conflict.Shields et al., 111. MacDonald et al., 23-8. M26s, the most unreliable tanks in the first year of the war, were sometimes desperately shipped to Korea despite already needing repairs or even overhauls. All tanks had to deal with scarce mechanics and parts shortages caused by the hostile and mountainous terrain, but the M46 further suffered from unfamiliarity with its new engine and powertrain. Ibid., 68-9. Shields et al., 111-3.

The war entered a more static phase after 1950, where tanks were often used as artillery and for bunker reduction. Tanks were still very active during the later years of the war, though: the M26 and M46 tanks fired enough 90mm ammunition that a shortage in US stocks was encountered.Gilbert, Marine Tank Battles in Korea, 227. Ravino and Carty, 251. Sherman tanks were often preferred over the newer types during this period since the M4s could navigate the Korean terrain better than their heavier and wider replacements. In part due to this mobility advantage, the Sherman ended up being the most numerous American tank in the theater when the armistice was signed in 1953.Hunnicutt, Pershing, 187. Hunnicutt, Sherman, 503. The M26's torqmatic transmission could slip if the tank stopped on steep hills, sometimes necessitating an initial push from a Sherman. See Gilbert, Marine Tank Battles in Korea, 23. Size also mattered: a Provisional Tank Platoon comprised solely of Shermans was formed by the Marines on 18 November, 1950, to patrol the Main Supply Route past Majon-dong. The road was too narrow for the wider M26s. See ibid., 107-9, and Ravino and Carty, 65. Among the recommendations to come out of the Korean War regarding armored forces was a suggestion in 1951 by the Operations Research Office (ORO) of the Far East Command to reinforce combined arms training, since at times the cooperation between armor and infantry left much to be desired. A 1954 ORO report recommended better night training and night vision equipment.In part, more radios were recommended, since the tanks' infantry phones were prone to damage and their use required the infantry to expose themselves to enemy fire. MacDonald et al., 40-1, 169. Bolté, 253-5.

The possibility that the North Korean invasion might have led to another world war sparked a forecasted shortage in medium tanks that the US scrambled to head off. The M47 Patton 47 was created in June 1951 by mating the turret from the underpowered T42 tank project with a hull based on the M46.Hunnicutt, Patton, 52-3. Ogorkiewicz, Technology of Tanks, I: 45. The M47 was supposed to be no more than an interim design until the M48 could be unveiled, but almost 9,000 M47s were eventually constructed.Hunnicutt, Patton, 59, 79. Oscar C. Decker, "The Patton Tanks: The Cold War Learning Series," in Camp Colt to Desert Storm, 304. The M48 was accepted in early 1952, after the crisis period had passed. This was finally a fresh design and featured an elliptical hull and turret similar to those of the heavy tank M103 that was still under development. Nonetheless, the T95 program was begun in January 1955 to field a vehicle that was lighter but more powerful than the M48.Decker, 308. Hunnicutt, Abrams, 44. The T95 was to incorporate such novelties as the pulsed-light Optar rangefinder and a rigidly-mounted hypervelocity 90mm smoothbore gun firing APFSDS penetrators.Decker, 308. Hunnicutt, Abrams, 50, 61. Ogorkiewicz, Technology of Tanks, I: 48. But progress dragged, and in 1958 the Bureau of the Budget announced that after fiscal year 1959 it would require an improved tank and would no longer authorize procurement of the then-current M48A2s.Decker 309. Hunnicutt, Patton, 152. Hunnicutt, Abrams, 90. The Army had anticipated this and, since many components of the T95 were still being developed and it would not have offered a great advance over the M48A2 in any case, decided to simply increase the range and firepower of its current tank.Decker, 309-10. Hunnicutt, Patton, 153. This new version was dubbed M60 to differentiate it from the M48A2 whence it was developed, and it was accepted into service in 1960.

The Marines were modernizing their tank fleet as well, and although they realized that designs with more armor than their venerable Shermans were needed, they initially balked at the increase in weight that the extra protection imposed.Alexander, 213. The Pershing was only fully integrated into Marine armored units in 1949, and this seemed a wise choice after the North Korean invasion with its vanguard of T-34-85s.Kenneth W. Estes, "The Marine Corps's Struggle with Armor Doctrine during the Cold War (1945-70)," in Camp Colt to Desert Storm, 266. The M46 started replacing the Marines' Pershings in July 1951, M47s began arriving in October 1951, and the M48 entered service with the Marines in 1954.Ibid., 278, 281-2. The Marines also retained heavy tanks long after the Army had given up on the idea. The M103 was racked by teething problems upon its introduction, and initially the Marines alone accepted the M103A1.Hunnicutt, Firepower, 123-4, 140. The Army was so suitably impressed with the modifications, however, that it borrowed 72 M103A1s for its heavy tank battalion in Europe until 1962. The further improved M103A2 remained in the Marine Corps arsenal until 1972.Ibid., 140. Estes, "The Marine Corps's Struggle with Armor Doctrine during the Cold War (1945-70)," 285. Estes, Marines Under Armor, 150-3. Britain's Conqueror tank, analogous to the M103 and armed with a similar 120mm rifled gun, served until 1967. See Griffin, Conqueror, 148.

Infantry was not left behind, so to speak, during the Cold War years. From their trundling beginnings, tanks had quickly gained enough power and speed to necessitate motorized transportation for the accompanying footsoldiers. The marginal protection and off-road mobility of World War II half-tracks spurred development of better infantry carriers, and the advent of variable-timed artillery shells and atomic weapons obsoleted all open-topped designs.Haworth, 17-8. "Armored Force, Command, and Center," 91. The development of fully-enclosed and fully-tracked infantry carriers started even before the end of the war. The armored utility vehicle M44 was the first purpose-built design, but was cancelled due to its very large size and the disappearance of funds following the end of World War II.Haworth, 23. Hunnicutt, Bradley, 30-2. Ogorkiewicz, Design and Development of Fighting Vehicles, 157. The armored infantry vehicle M75, which entered service in 1952, was smaller than its predecessor, but there were concerns that it was excessively expensive during an era when budgets were dominated by atomic weapons.Haworth, 23-4. Hunnicutt, Bradley, 48. The M59 armored personnel carrier (APC) began replacing the M75 the following year, and thankfully for the Army cost about one-fourth as much as the M75. The M59 achieved this price difference largely by using commercial GMC truck engines instead of the specialized powerplant of the M75, which was related to that found in the 76mm gun tank M41 Walker Bulldog.Haworth, 24. Hunnicutt, Bradley, 62. Ogorkiewicz, Design and Development of Fighting Vehicles, 160-1. While being cheaper than the M75, the M59 was actually heavier. The search for an air-transportable armored personnel carrier culminated in 1960 with the introduction of the M113, which with its aluminum rather than steel armor weighed about half as much as the M59. The M113 became the most-produced American armored vehicle in history, and was modified to fill an almost uncountable number of roles. The overall shape of the APC changed little from the M44 to the M113: they were all essentially armored boxes on tracks. Also, the basic mission of these modern armored personnel carriers harkened back to the half-tracks of World War II: they were to transport infantry as close as possible to their objective, where the troops would dismount and fight on foot.Haworth, 25. Ogorkiewicz, Design and Development of Fighting Vehicles, 163. Bellanger, 228, 289. FM 17-20, 62. The infantry's inability to effectively fight while mounted would drive the protracted development of an entirely new class of infantry carrier.

Just like its land-based counterparts, the open-topped tracked landing vehicle was also eliminated by the threat of airburst artillery and nuclear weapons. The LVT3, on which the US had standardized after World War II, acquired a folding aluminum cargo cover beginning in 1949.Hunnicutt, Stuart, 274. Hunnicutt, Bradley, 323-4. The cargo cover also helped prevent water from entering the cargo area and swamping the vehicle. See Research, Investigation and Experimentation in the Field of Amphibian Vehicles, 61; Croizat, 201; and Estes, Marines Under Armor, 112. The vehicle's armament, which had consisted of machine guns mounted in the cargo compartment, was then necessarily rearranged: a machine gun turret was added to the roof and a second machine gun was mounted in the vehicle's bow. The improved vehicle was designated LVT3(C) and served until being replaced by the LVTP5, which along with its engineer, recovery, and command variants, was introduced in the mid-1950s. A 105mm howitzer version of the LVTP5 was also accepted, replacing the LVT(A)5.

The armored forces of the United States got another taste of jungle fighting in a country superficially similar to the Koreas when they were deployed to Vietnam. Initially, though, it appeared that no armored forces at all would be sent. Indeed, the first US tanks into Vietnam were unexpected by some US government officials and Army planners: When the 9th Marine Expeditionary Brigade landed northwest of Danang in March 1965, not all realized that its table of organization included an organic tank battalion.Gilbert, Marine Tank Battles in Vietnam, 28-31. Gott, 23. American commander General William Westmoreland sent a message to the Army Chief of Staff in July 1965 saying, "except for a few coastal areas ... Vietnam is no place for either tank or mechanized infantry units."Quoted in Starry, 56. When the 1st Infantry Division deployed to Vietnam in that same month, its tanks were kept home and its mechanized infantry forces were transformed into dismounted infantry.Ibid., 55. However, a study completed in 1967 showed that tanks could maneuver in 61% of the country in the dry season and 46% during the monsoon season; APCs could travel around 65% of Vietnam regardless of the rains.Ibid., 10. Haworth, 30. Sorely, 328.

The main medium tank that would fight with American units in Vietnam was the M48A3 Patton, although small numbers of M48A1s were issued due to a shortage of M48A3s following the 1968 Tet offensive.Starry, 129. The newer M60s with their 105mm guns guarded the Fulda Gap in Germany against Soviet armor. In any case, the M48A3 was plenty of tank for Vietnam. Its bulk and 750-horsepower engine allowed it to break trails through the thick jungle, and the 90mm gun was able to utilize a variety of ammunition for both direct and indirect fire.Busting a trail through the jungle was hard on men and equipment, however, and the noise and commotion caused by the vehicles allowed the enemy to emplace mines or ambushes in their path. See Haponski, 136-7. The lack of an antipersonnel canister round for the M60's 105mm gun influenced the decision to send its predecessor to Vietnam. See Nolan, 13. Unlike the useful 90mm gun, however, the sideways-mounted .50cal MG in the commander's cupola was prone to jams, and the cramped cupola provided neither enough outside vision nor enough room for MG ammunition. Reloading this small supply of ammunition was very difficult, even under the best of circumstances. These problems caused crews in both the Army and Marines to often create external mounts for the weapon in spite of the resulting increased exposure to enemy fire.Hunnicutt, Patton, 228. Gilbert, Marine Tank Battles in Vietnam, 26, 162. Peavey, 62. Birdwell and Nolan, 52. Michael Green, 143-4. Another Vietnam veteran described the M48A3's cupola machine gun as "the worst combat mount ever devised." See Zumbro, Tank Sergeant, 92.

The M113 APC also served in Vietnam, and it was the South Vietnamese who introduced new aggressive tactics in the use of these vehicles. They mounted an extra machine gun on each side of the rear cargo hatch, provided the commander and extra machine gunners with armored shields, and used these modified M113s much like light tanks.Starry, 41-2. Hunnicutt, Bradley, 251. Lewis Sorely, "Adaptation and Impact: Mounted Combat in Vietnam," in Camp Colt to Desert Storm, 331-2. Perrett, 189. This conversion was so successful that standardized kits for these Armored Cavalry Assault Vehicles were procured from the US and sent to Vietnam in 1966.Hunnicutt, Bradley, 252.

The M551 Sheridan was deployed to Vietnam in 1969. Designed for the European theater as a light reconnaissance and airborne assault vehicle, the M551 was fast and agile but very vulnerable to mines and handheld antitank weapons and less proficient at jungle busting than the heavier M48A3.Breaking a path through the jungle could cause the M551 to overheat. Starry, 143-4. Hunnicutt, Sheridan, 118. Perrett, 190. Keith, 12, 116-7, 298-9. Green, 181. The 152mm gun-launcher was devastating, especially with its antipersonnel ammunition, but incomplete combustion of the propellant casing presented problems. The closed-breech scavenging system was developed to resolve this dangerous situation.Hunnicutt, Sheridan, 107-8. The combustible casing of the ammunition further proved to be sensitive to the tropical humidity, fragile when not handled carefully, and prone to detonation upon penetration of the vehicle's armor.Starry, 144. Hunnicutt, Sheridan, 107, 263-4. Perrett, 190-1. Keith, 12, 301-2.

The Sheridan's soggy ammunition was not the only way that Vietnam's humidity and precipitation affected armored vehicles. Water that condensed in a vehicle's fuel tanks, for example, could breed algae that would clog fuel filters. Pumping water out of fuel tanks became a regular maintenance requirement for tankers.Gilbert, Marine Tank Battles in Vietnam, 27. Despite maintenance issues such as these, armored forces grew to become an important part of the Vietnam War. Although their utility in the mountainous jungles was at first far from taken for granted, the first tanks arrived almost by accident with the Marines, and forgotten tank-infantry skills had to be relearned,Ibid., 63. the armored units of formations leaving Vietnam were kept in country until last, buying more time for the American pullout.Starry, 164-5. Sorely, 353.

While the battles of the Vietnam War grabbed headlines in the 1960s, the development of a new main battle tank (MBT) began a scant three years after the first M60s were accepted. The war would be long over by the time the finished product appeared, however.Decker, 312-3. Hunnicutt, Abrams, 116. Cold War one-upmanship: In 1962 the Soviets quickly began production of the T-62, with its 115mm smoothbore main gun, in response to the M60 with its 105mm main gun. Soviet officials were displeased that the new US tank had a larger main gun than the T-55's 100mm rifle. See Hull, Markov, and Zaloga, 50-1. The first effort at a new tank, called MBT70, was intended to provide a common tank for the US and West German armored forces, and the vehicle itself was stuffed with high technology features. MBT70 was armed with an automatically-loaded 152mm gun-launcher capable of firing the Shillelagh antitank missile. It featured a 3-man crew, all of whom were in the turret. The driver was interestingly positioned in a counter-rotating cupola in the turret's front corner. A laser rangefinder and stabilization for its main weapon helped assure accuracy. MBT70 ran on a hydropneumatic suspension that allowed the vehicle to crouch or raise one end of the tank to better take advantage of hull-down positions.

It was hoped that by sharing the development effort and costs, the complex MBT70 could be produced more cheaply than its Soviet counterparts, but problems plagued the program from the beginning.Kelly, 25. Robert J. Sunell, "The Abrams Tank System," in Camp Colt to Desert Storm, 433. Difficulties with English-German translations, metric to English measurement conversions, and differences between German and American manufacturing and designing practices caused considerable headaches before the tank was even designed.Kelly, 30-3. Hunnicutt, Abrams, 117. Costs spiraled to unacceptable levels, and MBT70 was killed in 1970, leaving the Germans and Americans to go their separate ways.Kelly, 38. Hunnicutt, Abrams, 142. The Germans went on to design the Leopard 2.

The US chose to give the MBT70 another chance, but this time as an austere vehicle with toned-down technological gizmos. This project was dubbed XM803, and it featured a less powerful engine and simpler hydropneumatic suspension. Congress was especially cost-conscious after the Air Force's accounting fiasco with the C-5 Galaxy transport plane and difficulties with its F-111 fighter/bomber, and as the XM803 was being estimated to cost three to four times as much as an M60A1,Ogorkiewicz, Technology of Tanks, I: 50. Stone, 77. and with the Shillelagh missile system proving troublesome on the M551 and M60A2 tanks, XM803 was cancelled in December 1971.Kelly, 40-2. Sunell, 433-4. Hunnicutt, Abrams, 158. The death of the XM803 project, which the Marines hoped would replace their aging fleet of M48s, forced the Corps to instead acquire the M60A1 in 1974.Estes, Marines Under Armor, 174.

The M60 was over a decade old when work on the XM803 was stopped, and the US was forced to start fresh on its replacement. It was decided that the new vehicle, named XM1, would be armed with the familiar 105mm gun M68 found in the M60 tank, feature a four-man crew including a human loader, and run on a conventional suspension.Kelly, 100. Sunell, 435-6. The new tank would emphasize crew survivability above all else,Ogorkiewicz, Technology of Tanks, I: 51. Kelly, 108. Sunell, 436. Hunnicutt, Abrams, 172. and to this end a new type of armor designed by Dr. Gilbert Harvey at Britain's Fighting Vehicles Research and Development Establishment near Chobham would be used.Kelly, 111-2. Hunnicutt, Abrams, 177-8. This armor was composed of a matrix of ceramics and steel layers, and was very effective against high-explosive antitank warheads as well as kinetic energy projectiles. However its protective properties needed to be balanced against its heavy physical weight. Army Chief of Staff General Creighton Abrams himself made the decision to use the American version of this armor on the frontal arc of the tank, since in his opinion its promise of extra protection was more important than the weight penalty.Kelly, 128. Sunell, 437. This armor is what gives the tank its characteristically slab-sided look. The crews of the new tank were also protected by the layout of its ammunition stowage, with the majority of the main gun ammunition in the turret bustle behind a bulkhead. If the ammunition ignited, blowoff panels in the turret bustle's roof would vent the explosion out of the tank while the bulkhead doors protected the crew from danger. The XM1 was powered by a novel gas turbine engine that gave the vehicle an advantage in acceleration over conventional diesels. This engine proved thirstier than anticipated, but compared to diesel engines it used less power for cooling, was able to run on a larger range of fuels, could be started more easily in cold temperatures, was quieter and lighter, and emitted no smoke.Ogorkiewicz, Technology of Tanks, II: 260-1. Hunnicutt, Abrams, 174-5. Kelly, 144-5. The Soviets were concurrently working on a gas turbine tank, and it entered service in 1976 as the T-80. See Baryatinskiy, Main Battle Tank T-80, 7-11; Hull, Markov, and Zaloga, 142-5; and Koch, 62-3. An armament competition for the new tank was held in the mid-1970s, and entrants included the 105mm M68, a British 110mm gun, and a 120mm smoothbore gun manufactured by the German firm Rheinmetall. Test results indicated the M68 was still a dangerous weapon thanks to improved ammunition technology, but the 110mm gun was hampered in performance by using APDS vice APFSDS ammunition.Ogorkiewicz, Technology of Tanks, I: 52. It was decided that since the 120mm gun was thought to be full of growth potential, the Rheinmetall ordnance would eventually arm the tank, but the initial M1 tanks were armed with the old M68 since it was feared that the delay and expense involved in producing the 120mm gun would scare Congress into cancelling the entire Abrams program.There may have been some political pressure applied to the main gun choice: A number of US Army officers involved with the XM1 would rather have used the 105mm M68 until a new next-generation gun was designed, but the West Germans were looking for a financial quid pro quo for their potential purchase of American early warning aircraft. Kelly, 176-93. Sunell, 445-7. Hunnicutt, Abrams, 162-3.

Once fleshed out, the M1 prototypes suffered from problems with track shedding as well as engine and transmission failures, but these were eventually solved.Kelly, 162-8. Sunell, 450-1. Hunnicutt, Abrams, 201. Stone, 103-5. Stolarow, <http://www.gao.gov/assets/130/126252.pdf>. When the production tank finally emerged on 28 February 1980, after even enduring an abortive competition with the West German Leopard 2 tank,The Army asserted that the Leopard 2 was not as well-protected as the XM1 prototypes, would cost more, and would not be ready for production as quickly. There was some debate over the objectivity of the tests, but the chief German observer opined that the Leopard 2 was given a "fair and equitable" shake. See Staats, <http://www.gao.gov/assets/600/590075.pdf>. it was the most powerful and advanced tank the United States had yet produced. The M1's fire control system, which included a laser rangefinder and thermal imaging system, allowed it to engage targets on the move cross-country in any weather. Its composite armor provided the crew with enhanced protection, and features such as the ammunition bustle further shielded the crew from injury should a penetration occur. The new tank's firepower was upgraded in 1985 when the Rheinmetall 120mm was finally adopted on the M1A1. The Army's standardization on the M1 Abrams tank again forced the Marines to change for the sake of logistical commonality, and the M1A1 totally replaced Marine M60A1s by 1996.Estes, Marines Under Armor, 183-4.

The venerable M60, which was borne out of a failed replacement for the M48 and had been intended only as an interim design, had endured two more failed replacement programs and became the United States' de facto premier tank for twenty years, eventually facing off against impressive Soviet vehicles such as the T-64 and T-80. In a duel against the contemporary Soviet tanks, US intelligence estimated the M60A1 would suffer from a greater than 40% disadvantage.Gorman, 14. The M1 Abrams was introduced none too soon.

Concurrent with the work on the M60's successor, a new Army infantry vehicle was being designed. The then-current crop of APCs was not conducive to mounted combat, a capability thought to be required on a battlefield contaminated by nuclear, biological, and chemical (NBC) agents.Haworth, 45. The planned MBT70 project also seemed to necessitate a new infantry vehicle that could keep up with the highly-mobile tank.Ibid., 43. Diane L. Urbina, "'Lethal beyond all expectations': The Bradley Fighting Vehicle," in Camp Colt to Desert Storm, 404. Hunnicutt, Bradley, 274. The US had been working on its new infantry vehicle for almost a decade when the Soviets approved their new BMP for production in 1966.Haworth, 47. Hull, Markov, Zaloga, 243. Koch, 107, 113. The BMP was much more heavily armed than previous APCs, with a 73mm main weapon and an integral antitank missile launcher. It was also fitted with firing ports and periscopes in the passenger compartment to allow for mounted combat in an NBC environment. Compared to M113, the BMP was a major threat.

The US, however, was still trying to pound out a doctrine for its new infantry vehicle, and therefore as well the vehicle's basic characteristics. A hesitancy to decrease the number of men in the mounted rifle squad and a requirement for amphibious capability would dog the design of the American infantry fighting vehicle (IFV) to the end.Haworth, 50-2. The very authority over mechanized infantry was also debated upon, with the Infantry and Armor Schools both claiming responsibility.Ibid., 29-30. Urbina, 410-1. In the end, mechanized infantry became Infantry's burden. Complicating the program immensely was the merger of the future IFV with the struggling Cavalry scout vehicle in late 1975.Haworth, 75. Urbina, 411. What eventually emerged in 1981 were the Bradley fighting vehicles, the M2 IFV and M3 cavalry fighting vehicle.

The new vehicle was controversial in both its guises. Since the US Army had returned its attention after Vietnam to facing off with the Soviet Union and its huge park of armored vehicles, the proliferation of American antitank weapons was imperative.A contemporary report asserted that the USSR fielded five times the number of tanks and three times the number of modern infantry vehicles as the US. See Gorman, 2. Thus, the Bradleys were fitted with a twin TOW missile launcher, giving each mechanized squad a heavy, long-range antitank weapon. This was not universally viewed as a bonus, as some soldiers claimed the missile added unnecessary complication and distraction. Cavalry troopers railed against the large size and signature of the M3, which was a definite disadvantage when performing reconnaissance.Haworth, 114-5. The scouts certainly had cause for concern here, since a Bradley is dimensionally larger than a Sherman tank. The infantry were also nonplussed with the technical complexity of the vehicle, necessitating that an infantry squad leader essentially also become a tank commander.Ibid., 102. The Bradley fighting vehicle had defenders as well, though. Its proponents cited its increased firepower, armor protection, and mobility over the previous alternative, the M113 APC.Ibid., 116-7. Urbina, 410. At the heart of all the controversy was the very definition of an IFV. Infantry fighting vehicles are a hybrid design, bridging the gap between "battle taxi" armored personnel carriers and infantry-supporting light tanks. Designing a vehicle and doctrine to fulfill this complex niche occupied the US Army for almost a quarter century.

Marine infantry received upgrades as well. The venerable LVTP5 family served throughout Vietnam, taking part in the majority of the Marines' sixty-two amphibious landings during that conflict.Croizat, 235. Estes, Marines Under Armor, 166. However its replacement, the LVTP7/AAVP7, entered service in 1971 after a long gestation period partly caused by scant funding.Croizat, 235. Hunnicutt, Bradley, 344. Budgetary woes also were a factor in the lack of engineer and howitzer versions of the LVTP7. See Estes, Marines Under Armor, 174.

The Marines' tradition of being a light infantry force, as well as the introduction of the helicopter and the associated notion of vertical envelopment, led the Corps to embrace the light armored vehicle (LAV). The vehicles were thought necessary to keep the Marine infantry capable of performing maneuver warfare operations, and for this purpose an eight-wheeled version of General Motors Canada's version of the MOWAG Piranha was introduced to the Corps in 1983.Estes, Marines Under Armor, 181, 212. Hunnicutt, Armored Car, 221. A family of vehicles was produced on the LAV chassis, including--in addition to the standard 25mm gun turret vehicle--command, mortar, TOW missile, recovery, and logistics vehicles. Successfully integrating the reconnaissance and infantry support missions into a cohesive mechanized doctrine for the LAV crews turned into an arduous task for the Corps, though. The LAV battalions initially suffered from an ambiguous mission set and identity. At first the vehicles were used simply as land-based carriers. Infantry was not added permanently to the organization until the late 1980s; before this the LAV battalions had been forced to "borrow" infantry to use as dismounted scouts in their vehicles. Also, in their first decade of existence the battalions had undergone nomenclature changes from the original designation of LAV battalions to Light Armored Infantry battalions and finally to Light Armored Reconnaissance battalions. Estes, Marines Under Armor, 182, 187-8, 190. Hunnicutt, Armored Car, 250-2. Michaels, 3-4

America's newest generation of armored vehicles, including the M1 tank and Bradley fighting vehicles, gave rise to an entirely new doctrine of war. Developed and improved from 1973, AirLand Battle finally emerged in 1982 and emphasized combined arms warfare and tactical flexibility. Free-thinking subordinates were to quickly make and execute decisions based on their commanders' intentions. AirLand Battle was characterized by four concepts: initiative, depth, agility, and synchronization. Forces were intended to achieve and retain the initiative, be positioned in depth with relation to time and space, react to situations faster than the enemy, synchronize combined arms so that an enemy's reaction to one maneuver would put him at risk from another, and attack follow-on echelons before they could be brought to bear.Richard M. Swain, "AirLand Battle," in Camp Colt to Desert Storm, 384-5. Leonhard, 136, 166. Citino, 262-3. Stone, 113-5. House, 251-2. AirLand Battle replaced the Active Defense concept, which espoused that unengaged defending units would maneuver to the flanks of a penetration and chip away at the attack until it was halted. Active Defense was criticized for focusing on defensive attrition warfare, paying no mind to enemy echelons following up the initial attack, ignoring potential Soviet tactical changes, and being too formulaic and mathematical.Swain, 367-8. Leonhard, 134-5. Citino, 257-60. Stone, 47, 112. House, 240, 250-1. Like Active Defense before it, however, AirLand Battle was not immune to criticism for allegedly focusing on attrition instead of maneuver and for placing too much emphasis on air and artillery interdiction at the expense of combined arms.Leonhard, 136-7, 160-4.

AirLand Battle and America's post-Vietnam armed forces were put to the test in Operation Desert Storm in early 1991. A coalition army was built up over five months,Stephen A. Bourque, "The Hundred-Hour Thunderbolt: Armor in the Gulf War," in Camp Colt to Desert Storm, 502-3. and a long air campaign decapitated the Iraqi armed forces. America's newest armored vehicles, especially the M1 tank and Bradley fighting vehicles, overcame sand-related maintenance issues and were vindicated in the subsequent ground campaign.United States General Accounting Office, <http://www.gao.gov/assets/220/215553.pdf>. The engine air filters of the Abrams tank required cleaning after as little as 6 hours of desert operation, and daily even when the engine was not started. See Vernon et al., 52. As a result, 2/2 ACR, for example, went to battle with three times the normal stock of engine air filters. See Macgregor, 36. Despite this, readiness rates for the Abrams were typically over 90%. See Stone, 104. Marine LAVs had trouble with the higher-quality fuel used in the deployment, which cleaned their fuel tanks of sediment left by the previous diesel and deposited it in fuel filters and injectors, clogging them. See Michaels, 34-5. American forces were better trained, better led, better able to communicate and utilize information, and fighting with better equipment than their opponents. This combination helped lead the coalition to an Iraqi defeat in under five days.Borque, 524. Donnelly and Naylor, 248-51. According to House, 269, and Stone, 124-7, it must be realized that conclusions drawn from the conflict will be unique due to the desert terrain, air supremacy enjoyed by the Coalition, lengthy buildup allowed to Coalition forces, and at times lackluster morale and performance of the Iraqi forces. As a counterpoint, some veterans argue that some US senior commanders were overly timid, allowed little initiative in the lower ranks, and were focused on attrition warfare. For examples, see Leonhard, 267-72; Hayden, 29-31; and Macgregor, 209-18. Also, some commanders felt that air strikes were initially overly concerned with interdiction targets. See Morris, 12-3, and House, 270-1.

The Future

A replacement for the Marines' AAVP7 was being developed by General Dynamics Land Systems Division and was expected to enter low-rate production by 2010, a year before the fortieth anniversary of the AAVP7's entry into service. Called the Expeditionary Fighting Vehicle, the new amphibian was to utilize a planing hull to skim along the ocean's surface, making over-the-horizon assaults faster and therefore more viable.General Dynamics Land Systems (GDLS), <http://www.gdls.com/programs/efv.html>. United States Marine Corps, <http://www.efv.usmc.mil/>, <http://www.efv.usmc.mil/highlights.asp>. Croizat, 239. Hunnicutt, Bradley, 360-1. Due to budgetary concerns, though, the program was cancelled in January 2011.Amos, <http://www.defense.gov/releases/release.aspx?releaseid=14179>. In its stead, the Marines are looking to develop a cheaper amphibious combat vehicle as well as a wheeled armored personnel carrier; a service life extension program will keep the venerable AAVP7 in the field until the new vehicles are procured.Kuiper, <http://www.marines.mil/unit/mcbquantico/Pages/2011/EFVoustedforlesscostlytriumvirate.aspx>.

Since the Vietnam War, Army armored units had been prepared to take on the hordes of tanks possessed by the Soviet Union, and its collapse in December 1991 threw the entirety of America's armed forces into a semi-limbo state. The Persian Gulf War of 1991 had proved that the doctrinal concepts, training, and equipment developed to defeat the Soviet armies were viable and effective against an opponent modeled after the Soviet Union, but the amount of time it took to build up the forces used to evict Iraq from Kuwait, and the effort required to keep those forces supplied, seemed prohibitive.Despite the months-long buildup to the conflict, US forces nearly overburdened their logistic support, especially transportation services, during the hundred-hour ground war. Stone, 146-7. Gudmundsson, 174-5, 216. Leonhard, 296-7. Vernon et al., 308. A lighter, more deployable force was deemed necessary to respond to the type of threats envisioned for the future. To this end, the Future Combat System (FCS) was being developed and was expected to enter service around 2012.Federation of American Scientists, <http://www.fas.org/man/dod-101/sys/land/fcs.htm>. Defense Advanced Research Projects Agency (DARPA), <http://www.darpa.mil/fcs/news/news_release.htm>. The FCS was to consist of a family of vehicles, both crewed and unmanned, that would be able to be configured for a variety of missions.DARPA, <http://www.darpa.mil/tto/programs/fcs.html>. The manned vehicles were cancelled in June 2009, however, and the rest of the program was integrated into the Army Brigade Combat Team Modernization program.Grant, <http://www.dodbuzz.com/2009/06/23/its-official-fcs-cancelled/>.

To expedite the shift towards a more deployable armored force, an Interim Armored Vehicle (IAV) in the vein of the FCS was procured as a joint venture from General Motors and General Dynamics Land Systems Division. The IAV, which is intended to slot between light vehicles such as armored HMMWVs and heavy forces using tanks and IFVs, consists of a family of vehicles including an infantry carrier armed with a .50cal machine gun or an automatic 40mm grenade launcher, a mobile gun system armed with a 105mm gun, a self-propelled mortar carrier, a reconnaissance vehicle, an engineer vehicle, an ambulance, an NBC detection vehicle, and a command vehicle. It was chosen to base the IAV on the eight-wheeled General Motors LAV III, and the vehicle was named Stryker after two Medal of Honor recipients.Triggs, <http://www.dtic.mil/armylink/news/Feb2002/a20020228stryker022802.html>. One of the requirements of the IAV was that it be transportable in C-130 aircraft, which are the most numerous cargo planes in the USAF. Despite this mandate, eight of the ten IAV variants as designed were too heavy to fly on a C-130; designers had to look at ways to make the vehicles lighter.Jack Kelly, <http://www.post-gazette.com/nation/20020320mobilenat4p4.asp>. Triggs, <http://www4.army.mil/ocpa/read.php?story_id_key=965>. Even if the Strykers make the target weight, flight distance and airfield restrictions will still apply, especially if applique and reactive armor suites are added to the vehicles.United States Government Accountability Office, <http://www.gao.gov/new.items/d04925.pdf>.

Heavy forces still have a place on the battlefield, however, and this was illustrated during Operation Iraqi Freedom in 2003. M1A1 tanks engaged enemy armored vehicles both at long distances in the desert and at point-blank range in urban environments, were successful against dismounted and irregular forces in cramped city streets, and US armored convoys operated with virtual impunity despite braving withering gauntlets of fire during so-called thunder runs through downtown Baghdad.Zucchino, 4-5. Conroy with Martz, 3. Lacey, 109, 175-7. Tanks were able to shrug off most antitank rocket fire; due to this greater protection compared to other types of vehicles, tanks led most advances since local situational awareness about enemy forces was often severely lacking.Gordon and Pirnie, 86. Lacey, 25-6, 27-8, 46, 101. Michael Green, 270-1. When enemy troops fired on or ran from the leading tanks, closely-following Bradley IFVs would take the enemy under fire using their 25mm chain guns, which tended to cause less collateral damage than the tank cannon.Gordon and Pirnie, 86. Marine AAVP7s were also used as infantry fighting vehicles, but their thinner armor compared to the Bradley forced the Marines to dismount earlier and more often than Army mechanized infantry.Ibid., 87. With these lessons learned, the Abrams tank is expected to serve with the Marines until 2020Estes, Marines Under Armor, 194. and the Army until 2050.Williams, 4. To put that into perspective, it will make the Abrams 70 years old when it is retired. Conversely, only just over 63 years elapsed from the first action of tanks in late 1916 until the M1's intoduction in early 1980.

In Summary

The United States has employed armored vehicles for over a hundred years, and its men and AFVs have necessarily been involved in the largest conflicts in history. From their successful debut in French-built machines in the battle of Saint-Mihiel on 12 September 1918, the tank men of the US have crewed vehicles that were among both the most important and most-produced ever. Flawed doctrinal concepts hampered American tank development between the World Wars, but its tanks fought on all fronts and with virtually all its Allies during World War II, and its crews successfully engaged the enemy's more potently-armed and thickly-armored tanks.Data from World War II indicates that the crew that sees--and therefore engages--the enemy first has a high chance of success, despite armor and gun differences. See Hardison, 29-30; and Gee, 26-7. Tankers interviewed just after the war also "emphasized the urgency of being able to fire the first accurate round." (Emphasis in original.) See General Board, European Theater, Tank Gunnery, 27. Shortly after World War II, American medium tanks helped control the North Korean spearhead of Sovet armor and later provided accurate infantry-supporting direct and indirect fire in the difficult Korean terrain. Armored vehicles were intially dismissed as being unnecessary in Vietnam, but their value was soon shown, and they became an important tool in the theater. Failed replacement programs kept the M60 tank in frontline service for two decades during the Cold War, but the new generation of American armored vehicles proved its strength during the 1991 Persian Gulf War. The collapse of the USSR and the anticipated threat of low-intensity conflicts that require lethal forces to quickly arrive at the scene have spurred a trend away from the heavy main battle tanks of the Cold War to lighter, more deployable, and technologically sophisticated vehicles for the future. Heavy forces have demonstrated through actions during conflicts in the Middle East that they are still survivable and decisive, though.

American fighting vehicles have come a long way since their inception, and today the US remains at the forefront of AFV development. However, as illustrated by conflicts such as the Iran-Iraq war of 1980-88, high-tech weapons systems are not the crux of an army.Citino, 222-3. Half a decade before the appearance of the tank, Patton wrote, "we children of a mechanical age are interested in and impressed by machines to such an extent that we forget that no machine is better than its operator..."Quoted in Blumenson, The Patton Papers 1885-1940, I: 243. That sentiment is no less apt now that the mechanical age has progressed to the digital age and now that the tank and mechanized forces have matured over the past century: without highly-trained and motivated soldiers acting in accordance with innovative and sound doctrines, even the most technologically sophisticated fighting vehicles are transformed from terrible, swift swords into white war elephants.

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Last updated 25 Mar 2015.

Endnote code courtesy John Blythe Dobson.

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