I’ll finish off AGF’s history of tank development here, and then put a couple of observations at the end. We’re probably not going to be done with this, though. There is another file on AGF's perspective on tank destroyers, though Armored Force's is more worried about organisation and doctrine than about equipment procurement. Still, that's all for some weeks in the future.
So, back to AGF’s historian again.
The heavy and medium tank progressed through four distinct phases during the war:
1) Original heavy tanks. Up to the end of 1943, the development program for increase in tank effectiveness visualized super-heavy tanks. These were found by test to exceed the limitations on the mechanical capabilities and firepower imposed by existing technical achievements.
2) Improvement of the M4 Series. Faced with the necessity of providing many thousands of tanks not only for American but for all Allied armies, the emphasis shifted from heavy tanks to production and improvements of the new M4 tank, which was to be the bulwark of the armored forces. During the war, extensive improvements were made in armor, suspension, fire power, flotation and mechanical reliability.
3) Development of new heavy tanks. The third phase was ushered in as a result of the many conferences in the winter of 1943-44, when it was definitely decided to continue the development program of the T20 series, which could be classed as heavy tanks (45 tons) in contrast to the M4 series (35 tons). After some false starts with the untried electric drive (T23, T25, T26), a successful tank of this series was finally developed and modified to become battleworthy in time to be used in France and Germany (T26E3/M26). In this tank, forward strides were taken in lowered silhouette and greater fire power but with no corresponding improvement in maneuverability, reliability, or flotation over the dependable M4 series. Although used only in the latter phases of the conflict and in small quantities, the using troops generally considered the tank to be a definite improvement over the M4 series. Analysis of reports indicates that much of this praise was directed to the greater fire power provided by the 90mm gun.
4) New tank developments. The tanks on the drawing boards at the termination of hostilities, if designed in accordance with military characteristics prepared by Army Ground Forces, would initiate a new principle in tank development. Guns would be designed for the single purpose of tank employment, and vehicles would be developed to mount those guns. Extensive improvements in flotation, suspension, and power trains would be incorporated in these tanks in order to make their increased fire power and armor usable under battlefield conditions.
Certain conclusions can be deduced from the history of tank development in World War II. The following bear directly on the problems of development encountered by Army Ground Forces under the wartime organization of the War Department.
Experience in combat proved illusory the assumption that additional armor and weight and bigger guns would guarantee superiority over enemy tanks: In other words, that a bigger tank was a better tank. The problem was more difficult. In this war the better tank was the one which met tactical requirements by combining, in a balanced relation, a number of factors to which weight and size were only incidentally related. These include, first, mechanical reliability and fire power. A tank that does not provide reliable performance under combat conditions with a minimum of maintenance is no tank at all. Of almost equal importance is fire power – Not measured by projectile mass and explosive effect, but by the ability to penetrate armor of considerable thickness at ranges of 1,000 yards and over with the smallest feasible caliber. This attribute calls for guns of very high muzzle velocity. Subsidiary advantages were derived from such tank cannon – the smaller, lighter projectiles permit easier handling, firing, and greater ammunition stowage, and the short, flat trajectory greatly improves direct fire against moving targets.
Maneuverability and good flotation (low ground pressure) were almost as important in the balanced relation as reliability and fire power, for the tank must be where it is needed when it is needed. Armor protection for the crew is perhaps of less importance than any of the other characteristics, highly desirable as it is. It remained true that the best gun on the battlefield has, and will in the future, pierce the best armor.
Another point to consider is that any slight addition to armor of existing thickness only adds weight and creates a false sense of security without providing material additional protection. The penetrative power of large-calibre tank and anti-tank weapons was such that existing armor would almost need doubling to provide real protection within medium ranges. Additional protection afforded at longer ranges by slight increases in armor would hardly justify the additional weight and consequently increased load on engines and suspension.
Experience also proved that the best tank in the world could be defeated by a numerical superiority of tanks which were individually inferior in many respects. There is no substitute for quantity in tank warfare if both quantity and quality can not be achieved. This was the decision made by Army Ground Forces in the trying days of 1943. It was one that contributed immeasurably to the sweeping successes of our armored forces, even though the desired quantities were never quite attained.
The difficulties encountered by Army Ground Forces in getting effective action on recommendations justified by existing and subsequent experience in the field indicate the necessity for the closest kind of co-operation between the using arm and the developing agency in successful development of tanks. Stating the problem suggests the logical solution. The agency controlling the using arm should likewise control the actual development program. This principle is all the more valid since a tank has not even a remote civilian counterpart, and following commercial practices in tank development only promotes failures and delays. Had such unified control existed on levels lower than the War Department General Staff in, say, 1937 or 1938, the appearance of modern tanks, possessing attributes desired by those who had to fight them in combat might have been accomplished. Instead they were still, at best, on the drawing boards when the war ended. The M26, perhaps the best tank we had because of increased fire power and heavier armor, fell far short of the tank desired by the Army Ground Forces. But there was no reason to believe that it could not have been achieved if the proper personnel, time and effort had been devoted to the purpose.
Now that that salvo is over, let’s have a gander at the whole lot, and compare/contrast with Ordnance’s view of things.
It is interesting to compare the line just above, “The agency controlling the using arm should likewise control the actual development program", with the position of General Barnes over at Ordnance: “For these reasons, it is necessary for the Ordnance Department to take a strong lead over the using services in the development of new equipment and then to get the help of those using services in determining where the weapon best fits into battlefield operations.”
Put simply, they are mutually exclusive propositions. In effect, you have the scientists saying “If we just let the using arms come up with the equipment needs, nothing ‘new’ or revolutionary would ever be developed”, and you have the using arms saying “Stop focusing on hypothetical wonderweapons, and put all your energy into this thing we know we need right now.”
One can see arguments both ways. Certainly the military branches can be some of the most conservative organizations which ever existed, but I think General Barnes may have been doing them a disservice. The US Army has an “Operational Needs” process, whereby a field unit can pass up the line a requirement for a capability which they really would like to have. For example, in WWII, one unit sent up to Ordnance a requirement for a device which could detect mines sufficiently in front of a tank that it would give them enough time to brake. We still don’t really have that today, let alone in 1942. On the other hand, there are also times when someone in a line unit might go “Hmm. I didn’t know that was even physically possible in order to ask for it” (I’ve done it myself, when I found out about some classified US military capabilities overseas) when they discover that the engineers have come up with something that could be used.
What I find a little less acceptable in Ordnance’s position though was its belief that it apparently knew better than the using arms what they wanted, with its attempts to ramrod new stuff into production, or bypass normal processes, almost in an effort to justify itself. Which is silly, as Ordnance was doing absolutely sterling work as it was.
AGF’s position, on the other hand, seems a lot more supportable. They really didn’t mind the R&D boffins spending effort on researching new things, but they had to win a war, and it was much easier for them to do this when they knew what their equipment could and could not do, as efficiently as possible, as opposed to having equipment whose capability was really more a roll of the dice on that particular morning. Their steadfast refusal to accept T23, T25 and T26 until they were sure that the tank would do what they wanted it to do cannot be faulted, especially in view of the earlier disasters such as the M7 Light-ish/Medium Tank or the M5 GMC. Ordnance did not have to pay the money for vehicles which may sit around rusting (as T23 did) or have to figure out how to get thousands of tanks to Berlin.
That said, AGF could be argued to have gone a bit too far the other direction. They had a definite insistence to keep with what they knew was working at that time. Perhaps they had a bit too much faith in Ordnance to be able to provide the materiel that they desired, such as a 76mm cannon capable of punching through anything it faced. Ordnance did well, there is no doubt that the 76mm Sherman was an outstanding tank overall, but it was to Ordnance’s credit that the 76mm tank was as capable as it was as soon as it was given that Barnes had been advancing its development. If only AGF had realized how much it needed the tank in mid 1944. That said, even at that it wasn’t as if AGF had their heads in the sand, but there was no emphasis, no sense that a better punch was required. Then again, it might be perhaps a bit hypocritical to say that AGF should have told the theater commanders to take the equipment into France whether they wanted it or not, while also maintaining that AGF should have the ability to not bring the equipment which Ordnance attempted to push onto them. It is also, perhaps, fortunate that AGF (Read: McNair) did not have final say on things like tank armament, but then, neither did Ordnance. The people making that decision were the end users.
It’s important, of course, to remember that both parties were doing what they strongly felt was in the country’s, and the front-line soldier’s, best interest. That may both raise the question, and explain, why the official histories don’t necessarily say good things about the other branch, even though after the war one would probably excuse some rose-tinted glasses. It’s the difference between the micro and the macro levels of war. Ordnance was concerned about any individual item of equipment. They tested the M4 medium. They tested the M18 Gun Motor Carriage. And that’s as far as they took the analysis. Figuring out if it could cross a river on an Engineering Corps’ bridge wasn’t their problem. On the other hand, AGF looked predominantly from the higher level. Whether or not the tank had an extra inch of armor was of much less relevance to them that the tank had about as much armor as it could carry while still being able to get to where it needed to be. As the AGF line says, “a tank that does not provide reliable performance under combat conditions with a minimum of maintenance is no tank at all”
Now, that’s not to say that a tank has to be absolutely bullet-proof. I will long remember the one and only telephone conversation I had with Tom Jentz (in which he somehow made me realize I knew basically nothing in comparison without in any way being demeaning or belittling) where he challenged me on the common assertion that M4 was particularly more reliable than any other tank commonly found. And it’s a fair question. Was M4 more reliable, as measured by mean time or distance between failures, than anything else? Does a commander care? Or, more importantly, does the commander care about the operational readiness rate? What’s important to him is that when he launches the assault tomorrow morning, he has all his tanks present. If the tank is sitting in a motor pool today because the transmission housing is off for three hours to replace a component it’s of no consequence because the mechanics will have it back together again in short notice, and then move onto the next tank. The tank was easily repairable. The tank was built with interchangeable components. The tank was given to an Army with sufficient mechanics to do it all. So when the ‘advance’ signal was given to move to the front line, the commander had almost all of his tanks. It can be argued that the 'quantity over quality' statement above refers not only to the production line, but also the quantity of tanks which makes it to any particular fight. It's a long way from the shipping department in Detroit to the Lorraine Valley. Of course, there is also the question of 'just how much more reliable did the British tanks become after the testing disasters of 1943?" in order for the M4 to lose its relative advantage.
It is far too easy for us to criticize Army Ground Forces for not putting the best, most awesome equipment into the field immediately, and certainly there were occasions where they got it wrong. But AGF didn’t care about whether gun A could reliably penetrate armor plate B. AGF was worried about whether Tank X, if produced in sufficient quantity, was the most effective way of helping the Theater Commanders win the war if units were equipped with them.
The last paragraph, about tank development in the late 1930s probably bears a bit of analysis at a future point. There is no denying the truth of it. The US military was not building fantastic tanks, and neither were they being produced to acceptable standards of economy and scale. Contrast with the building of airplanes, where Boeing just had to convert production from airliners to cargo aircraft and bombers, but the raw technologies were predominantly the same. However, the economy and the political climate in the 1930s was what it was.
Ultimately, however, one cannot argue with success. There may have been other ways of getting there, but with AGF responsible for anything from kitchen trailers through artillery, to training infantrymen, it’s difficult to say that their philosophies were wrong.