Whenever I go about researching this, what always comes up is that either US doctrine did not call for heavy tanks like the German Tiger or the Russian IS-2 or that the US Army did not consider practical to ship heavy tanks to Europe.
My question is different though; since the US evidently had the funds and the capacity to employ tanks that would offer better protection to their crews than the vulnerable M4 Sherman, why didn't they? Even the excellent M4A3E2 "Jumbo", was produced in very limited numbers, and the M26 Pershing came very late in the war and wasn't considered too reliable, if I recall correctly.
The US did have the funds and shipping capacity to employ heavy tanks, but did not do so because of the requirements and thought process of the Army Ground Forces, and the US's insistence on testing their weapon designs thoroughly to ensure they performed effectively. The bullheadedness of the head of the AGF, General Leslie McNair, also contributed to this decision.
McNair's insistence on the tank destroyer doctrine (US tanks were to be used as an exploitation force and not primarily used to fight other tanks, this job being left up to the tank destroyers and their high-velocity guns*) meant that many tank designs (like the ancestors of the M26) went through months and even years of worming their way around the Army bureaucracy (undoubtedly also trying to find a way around McNair the AGF!) before the designers could find a way to approve them for production. The death of Leslie McNair in July 1944 essentially cleared the way for production of the M26.
A popular misconception is that US medium tanks were never supposed to fight other tanks. FMs 17-10 and 17-33 contain several pages of doctrine and illustrations. Medium tanks were supposed to protect the light tanks from the attack of hostile tanks, and could assist or even take the place of the tank destroyers when necessary. The US began trials of the Sherman with a 76 mm gun in August of 1942, months before the Tiger or Panther ever entered combat. The project died, but was resurrected after the T23 was cancelled (see below)
The two main criteria of the AGF when accepting or rejecting a vehicle for production were:
Battleworthiness: McNair was very wary of the Ordnance Department's foisting of poorly thought out designs (that were thusly rejected) onto the Army Ground Forces in 1941 and 1942. All US tank designs were heavily tested for problems before being shipped overseas. Why ship a hurriedly developed tank 3,000 miles only to have it break down immediately due to poor design or for want of spare parts?
Battle need: The AGF used a logical thought process; the using arms (armor or infantry) that were in need of a new weapon or modification would submit a request to the Ordnance Department for design and testing. Once the weapon was built and tested thoroughly enough, it would go to the Army Ground Forces headquarters for acceptance or rejection. At some point, McNair probably saw it and had a fit over it.
Another problem was also time; new tank designs take a long time to work out the kinks (see below), and if the design gets rejected, it's back to the drawing board.
The M26 Story
Here I'll track the evolution of the M26, and give some perspective just as to why the M26 entered production so late. The program to replace the Sherman began in late 1942, and started with the T20 medium tank, which sort of looked like a squashed Sherman that drives backwards. Oddly, the T23 was completed first. Crossed out variants were cancelled or rejected.
T20 series: Ford GAN V-8 engine with hydramatic transmission
T20E2: 3 inch gun and early HVSS (completed as T20E3)
T20E3 (M27B1): Converted T20E2 with 76 mm gun and torsion bar suspension
T22 series: Ford GAN V-8 engine with M4 Sherman transmission
T22E2: 3 inch gun and torsion bar suspension (never constructed)
T23 Series: Ford GAN V-8 engine with electric transmission
The T23E3 was to be accepted for serial production as the M27, and the T20E3 the M27B1. The T23 pilot was tested at Fort Knox in early 1944, but it was rejected. The turret designed for the T23 program was not wasted, but used as the turret design for the 76 mm Sherman. They can be recognized for their extra lifting ring on the turret side; the very earliest ones lacked a ventilator, which was later added. About 500 of these "XLR" turrets, ventilator or not, were mixed into the first four months of 76 mm Sherman production
The T25 and T26
In late 1943 the T23 pilot was eventually fitted with the later HVSS suspension and a turret with a 90 mm gun, becoming the T25. The T25E1 had a torsion bar suspension. A more heavily armored version of the T25, the T26, evolved into the T26E1 (a T26 with torsion bar suspension), and finally the T26E3, later renamed the M26 Pershing in March 1945.
The head of the Armored Force, General Jacob L. Devers, strongly advocated for the production of the T26E1, but General McNair essentially blew him off. Divers went over McNair's head directly to George C. Marshall, who approved the production of 250 T26E1s on December 16, 1943. After Devers was transferred to the Mediterranean, McNair saw the opportunity and continued pestering the T26E1 program into 1944. Chrysler mounted a T26 turret onto an M4A3 Sherman chassis in the summer of 1944, but the project died. General McNair also died (in a botched American air support mission on July 25, 1944, the start of Operation Cobra) and the way was cleared for the production of the T26E1. Meanwhile, the Army Service Forces and various General Staff officials had agreed on their tank production plan for 1945; three 105 mm howitzer-armed tanks for every 90 mm tank. 2,060 T26E1s were to be produced with 90 mm guns, 2,728 T26E1s with 105 mm howitzers, and 3,000 M4A3 Shermans with 105 mm howitzers. The 2,728 howitzer T26E1s were later dropped, and it was agreed to produce 90 mm T26E1s in their place, for a total of 4,716.
Production of the T26E1 did not begin at Fisher until November 1944. After the first ten T26E1s were built, modifications were made and it was redesigned the T26E3.
| Month | Number Built |
|---|---|
| November 1944 | 10 |
| December 1944 | 30 |
| January 1945 | 70 |
| February 1945 | 132 |
The ZEBRA Mission
After Army Ground Forces objections, General Gladeon M. Barnes, Chief of Research and Engineering at the Ordnance Department, appealed to George C. Marshall's G-4 and ordered 20 T26E3s to be shipped to Europe immediately. They arrived in theater before the end of January 1945.
Headed by General Barnes who was accompanied by the head of the Tank-Automotive command and various personnel from Aberdeen Proving Ground and Fort Knox, the purpose of the ZEBRA mission was to introduce new equipment to combat in order to test its suitability, as well as evaluate new equipment that was already in theater (read: M24 Chaffee) The mission comprised the 20 T26E3s, a T83 155 mm Gun Motor Carriage, and a T89 8-inch Howitzer Motor Carriage. A T26E4 (a T26E3 with a the high velocity long-barreled T15E1 90 mm gun) was also shipped.
The T26E3s were delivered to the 559th Ordnance Maintenance Battalion on February 9th, and split up evenly, with 10 each going to the 3rd and 9th Armored Divisions of First Army. 3rd Armored Division split their 10 T26E3s evenly among their two armored regiments; select companies each received one T26E3. Companies in the 3rd Armored Division that were known to have received a T26E3 included:
Company E, 32nd Armored Regiment (the famous Cologne Pershing)
Company D, 33rd Armored Regiment (destroyed two Tigers)
Company E, 33rd Armored Regiment (destroyed a Tiger at 900 yards and two Panzer IVs at 1,200 yards)
Company F, 33rd Armored Regiment (knocked out, killing the loader and gunner; returned to service)
Company H, 33rd Armored Regiment (knocked out and permanently disabled; crew survived)
The 9th Armored Division gave 5 to the 14th Tank Battalion, who formed a 4th platoon in Company A. The other five went to the 19th Tank Battalion, who put one in Company A and gave a pair to Companies B and C. These 20 tanks first entered combat in late February.
On March 5, 1945, General Barnes, impressed with the T26E3, ordered more to be shipped to Europe. By March 25, 53 T26E3s (by this time type-standardized as the M26 Pershing) were at port facilities or already en route, and 157 more were in the process of shipping. Ninth Army had received 19 Pershings by the end of March, but they hadn't been issued because of the speed of the US advance gave little time for training. In the last two weeks of April, the Pershings began to arrive in greater quantities; Third Army had 90 at this time. By V-E Day, 310 were in theater, with about 200 issued to the troops. Only the first 20 Pershings associated with the ZEBRA mission saw any significant combat.
Sources:
Armored Thunderbolt: The US Army Sherman in World War II, by Steven J. Zaloga
M26/M46 Pershing Tank 1943-1953, by Steven J. Zaloga
See this post.
