Development M26 Pershing

1 development

1.1 improving on m4
1.2 t20
1.3 t22 , t23
1.4 t25 , t26
1.5 after war

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.