Production history M26 Pershing

1 production history

1.1 development

1.1.1 improving on m4
1.1.2 t20
1.1.3 t22 , t23
1.1.4 t25 , t26
1.1.5 after war


1.2 delayed production
1.3 production
1.4 super pershing
1.5 post world war ii

production history
development

the m26 culmination of series of medium tank prototypes began t20 in 1942 , represented significant design departure previous line of u.s. army tanks had ended m4 sherman; number of design features tested in various prototypes, of experimental dead-ends, many of become permanent characteristics of subsequent modern u.s. army tanks. prototype series began medium tank upgrade of m4 sherman , ended u.s. army s first operational heavy tank.

improving on m4

the army s first lineage of tanks had evolved m1 combat car , progressed m2 light tank, m2 medium tank, m3 lee, , m4 sherman; these tanks shared common traits of using rear-mounted continental air-cooled radial aircraft engines , front sprocket drive. rear engine-front sprocket drive layout required driveshaft pass underneath turret, increased overall height of tank, characteristic shared german tanks of world war ii used layout. in addition, large diameter of radial engines in m4 line of tanks added further hull height. these mechanical features accounted high silhouette , large side sponsons characteristic of m4 lineage.

in spring of 1942, m4 sherman entering production, u.s. army ordnance began work on follow-up tank. t20 tank reached mock-up stage in may 1942, , intended improved medium tank follow m4. earlier heavy tank, m6, had been standardized in february 1942, proved failure. u.s. army had no doctrinal use heavy tank @ time.

t20

the t20 designed have more compact hull m4. ford gan v-8, lower silhouette version of gaa engine used in later variants of m4, had become available. engine had been effort ford produce v-12 liquid-cooled aircraft engine patterned after rolls-royce merlin, failed earn aircraft orders , adapted v-8 use in tanks; use of lower profile engine choice of rear transmission , rear sprocket drive layout made possible lower hull silhouette , eliminate side sponsons.

the t20 fitted new 76 mm m1a1 gun, developed 3 inch anti-aircraft gun. 3 inch front hull armor .5 in (13 mm) thicker 63 mm (2.5 in) front armor of m4. glacis plate slope similar @ 46°. t20 s overall weight approximately same m4.

the t20 used version of horizontal volute spring suspension (hvss), improvement compared less robust vertical volute spring suspension (vvss) of versions of m4. later prototypes of m26 tested torsion bar suspension, become standard future u.s. tank suspension systems.

t22 , t23

the t22 series reverted m4 transmission because of problems torqmatic transmission used in t20. t22e1 tested autoloader main gun, , eliminated loader s position small two-man turret.

t23 production cast turret mounting 76 mm m1a1 gun. t23 turret used 76-mm m4 sherman. note vertical volute spring suspension.

through of 1943, there little perceived need within u.s. army better tank 75 mm m4 sherman, , so, lacking insights rest of army needed, ordnance department next took developmental detour electrical transmissions t23 series.

the electrical transmission built general electric, , had engine driving generator powered 2 traction motors. concept similar drive system of german porsche tiger (later rebuilt ferdinand/elefant). had performance advantages in rough or hilly terrain, system better handle rapid changes in torque requirements.

the electrical transmission t23 championed ordnance department during phase of development. after initial prototypes built in 1943, additional 250 t23 tanks produced january december 1944. these first tanks in u.s. army 76 mm m1a1 gun go production. however, t23 have required army adopt entirely separate line of training, repair, , maintenance, , rejected combat operations.

the primary legacy of t23 production cast turret, designed outset interchangeable turret ring of m4 sherman. t23 turret used on production versions of 76 mm m4 sherman original m4 75 mm turret found small mount 76 mm m1a1 gun. first production 76 mm m4 t23 turret, m4e6, built in summer of 1943.

t25 , t26

t25e1 variant

the t25 , t26 lines of tanks came being in midst of heated internal debate within u.s. army in mid-1943 1944 on need tanks greater firepower , armor. 90 mm gun mounted in massive new turret installed in both series. t26 series given additional frontal hull armor, glacis plate increased 4 in (10 cm). increased weight of t26 series on 40 short tons (36 t) , decreased mobility , durability engine , powertrain not improved compensate weight gain.

the t26e3 production version of t26e1 number of minor modifications made result of field testing. following introduction combat, renamed m26 in march 1945.

after war

post world war ii, 800 m26 tanks upgraded improved engines , transmissions , 90-mm gun , redesignated m46 patton.

delayed production

the m26 introduced late world war ii , saw limited amount of combat. tank historians, such richard p. hunnicutt, george forty , steven zaloga, have agreed main cause of delay in production of m26 opposition tank army ground forces, headed general lesley mcnair. zaloga in particular has identified several specific factors led both delay of m26 program , limited improvements in firepower of m4:

1. tank destroyer doctrine
mcnair, artillery officer, had promulgated tank destroyer doctrine in u.s. army. in doctrine, tanks infantry support , exploitation of breakthroughs. tactics dictated enemy tanks engaged tank destroyer forces, composed of lightly armored relatively fast vehicles carrying more powerful anti-tank guns, towed versions of these anti-tank guns. under tank destroyer doctrine, emphasis placed on improving firepower of tank destroyers, there strong bias against developing heavy tank take on enemy tanks. limited improvements in firepower of m4 sherman. army ground forces supported doctrine got approval of new td projects, 1 of them using same 90 mm gun, while @ same time blocking tank projects.
2. simplification of supply
mcnair established battle need criteria acquisition of weapons in order make best use of america s 3,000-mile-long (4,800 km) supply line europe preventing introduction of weapons prove unnecessary, extravagant or unreliable on battlefield. in view, introduction of new heavy tank had problems in terms of transportation, supply, service, , reliability, , not necessary in 1943 or 1944. tank development took time, , sudden appearance of new tank threat not met enough under such criteria.
3. complacency
a sense of complacency fell upon in charge of developing tanks in u.s. army because m4 sherman, in 1942, considered americans superior common german tanks: panzer iii , models of panzer iv. through of 1943, 75-mm m4 sherman adequate against majority of german armor, although widespread appearance of german 7.5 cm kwk 40 tank gun during time had led growing awareness m4 becoming outgunned. there insufficient intelligence data processing , forward thinking understand there ongoing arms race in tanks , u.s. needed anticipate future german tank threats. tiger , panther tanks appeared in 1943 seen in limited numbers u.s. forces , hence not considered major threats. end result that, in 1943, ordnance department lacking guidance rest of army, concentrated efforts in tank development on major project, electrical transmission t23. contrast, russians , british engaged in continuous effort improve tanks; in 1943, british begin development of became 51-ton centurion tank (although tank reach service late see combat in world war ii) and, on eastern front, full-blown tank arms race underway, soviets responding german heavy tanks starting development work on t-34-85 , is-2 tanks.

mid-1943 mid-1944, development of 90 mm up-armored t26 prototype continued proceed due disagreements within u.s. army future tank needs. accounts of happened during time vary historian, agree army ground forces main source of resistance delayed production of t26.

in 2008 book armored thunderbolt, zaloga revised earlier treatment appeared in 2000 book m26/m46 pershing tank 1943–53, quoting more extensive list of original documents ordnance department, army ground forces , general mcnair s correspondence. in september–october 1943, series of discussions occurred on issue of beginning production of t26e1, advocated head of armored force, general jacob devers. ordnance favored 76 mm gun, electrical transmission t23. theater commanders favored 76 mm gun medium tank such t23, , against heavy 90 mm gun tank. however, testing of t23 @ fort knox had demonstrated reliability problems in electrical transmission of army commanders unaware. new 76 mm m1a1 gun approved m4 sherman seemed address concerns firepower against german tanks. participants in debate were, however, unaware of inadequacy of 76 mm gun against frontal armor of panther tank, had not researched effectiveness of gun against new german tanks, had been encountered in combat.

single prototype of 90 mm gun t26 turret mounted on m4a3 chassis.

gen. lesley j. mcnair had agreed production of 76 mm m4 sherman, , opposed additional production of t26e1. in fall of 1943, wrote letter devers, responding latter s advocacy of t26e1:

the m4 tank, particularly m4a3, has been hailed best tank on battlefield today. there indications enemy concurs in view. apparently, m4 ideal combination of mobility, dependability, speed, protection, , firepower. other particular request—which represents british view—there has been no call theater 90 mm tank gun. there appears no fear on part of our forces of german mark vi (tiger) tank... there can no basis t26 tank other conception of tank versus tank duel—which believed unsound , unnecessary. both british , american battle experience has demonstrated antitank gun in suitable number , disposed master of tank. attempt armor , gun tanks outmatch antitank guns foredoomed failure... there no indication 76 mm antitank gun inadequate against german mark vi (tiger) tank.

general devers pressed on advocacy t26, going on mcnair s head general george marshall, , on 16 dec 1943, marshall overruled mcnair , authorized production of 250 t26e1 tanks. then, in late december 1943, devers transferred mediterranean, led invasion of southern france 6th army group. in absence, further attempts made derail t26 program, continued support generals marshall , eisenhower kept production order alive. testing , production of t26e1 proceeded slowly, however, , t26e1 did not begin full production until november 1944. these production models designated t26e3.

a single prototype of t26 turret mounted on m4a3 chassis built chrysler in summer of 1944, did not progress production.

hunnicutt, researching ordnance department documents, asserts ordnance requested production of 500 each of t23, t25e1, , t26e1 in october 1943. agf objected 90 mm gun of tanks, whereas armored force wanted 90 mm gun mounted in sherman tank chassis. general devers cabled london request production of t26e1. in january 1944, 250 t26e1s authorized. general barnes of ordnance continued press production of 1,000 tanks.

according forty, ordnance recommended 1,500 of t26e1 built. armored force recommended 500. agf rejected 90 mm version of tank, , wanted built 76 mm gun instead. somehow, ordnance managed production of t26e1 started in november 1944. forty quoted post-war report ordnance dept.

production

production began in november 1944. ten t26e3 tanks produced month @ fisher tank arsenal, 30 in december, 70 in january 1945, , 132 in february. detroit tank arsenal started production in march 1945, , combined output 194 tanks month. production continued through end of war, , on 2,000 produced end of 1945.

super pershing

the so-called super pershing before armor welded on. note 73 caliber gun compete 88 mm kwk 43 l/71 gun on king tiger.

the 90mm m3 gun of pershing similar german 88 mm kwk 36 used on tiger i. in effort match firepower of king tiger s more powerful 88 mm kwk 43, t15e1 90 mm gun developed , mounted in t26e1 in january 1945. tank designated t26e1-1. t15e1 gun 73 calibers in length , had longer high-capacity chamber. gave muzzle velocity of 3,750 ft/s (1,140 m/s) t30e16 apcr shot , penetrate panther s frontal armor @ 2,600 yd (2,400 m). model shown used single-piece 50-inch-long (1,300 mm) ammunition , super pershing sent europe.

a second pilot tank converted t26e3 , used modified t15e2 gun had two-piece ammunition. twenty-five production models of tank, designated t26e4, built. improved mounting removed need stabilizer springs.

post-war, 2 m26 tanks had t54 gun installed, had same long gun barrel, ammunition cartridge designed shorter , fatter, while still retaining propellant force of original round. tanks designated m26e1 tank, lack of funds cut off further production.

post world war ii

in may 1946, due changing conceptions of u.s. army s tank needs, m26 reclassified medium tank. designed heavy tank, pershing significant upgrade m4 sherman in terms of firepower , protection. on other hand, mobility unsatisfactory medium tank (it used same engine powered m4a3, ten tons lighter) , transmission unreliable. in 1948, m26e2 version developed new powerplant. eventually, new version redesignated m46 general patton , 1,160 m26s rebuilt new standard. m26 became base of patton tank series, replaced in 1950s. m47 patton m46 patton new turret. later m48 patton , m60 patton, saw service in later vietnam , mideast conflicts , still serve in active duty in many nations today, evolutionary redesigns of original layout set down pershing.