Inexperience and refusal to adapt. We didn't think in terms of heavily defended concrete fortifications until too late.
Don't agree, since the Churchill AVRE disproves that.
Originally Posted by Mountain Man
The Soviets rapidly came up with assault guns that got larger and larger ending in the ISU152's.
I actually believe that it was the nature of the Eastern Front that led to the heyday of AG's. Germany first built them because it was the easiest way of given infantry a mobile artillery piece, one that could keep up with the infantry once they had advanced beyond static artillery support. Manstein stated it was his idea, a lesson learnt from WW1.
The Soviets used them for the same reason. Their artillery, sans SU-76's, was also very static, and having a method of having artillery keeping up with the infantry, one that can also take out tanks, seems advantageous.
Once you also factor in cost, the number of afv's required, and the huge campaign the Eastern Front was, having 3 Stug's with a 75mm gun, to 2 Panzer III's with a 50mm, seems reasonable.
While the Germans and Soviets did have self propelled artillery, they never achieved the level of competence the USA and CW did by the end of the war. In a similar case to tanks, the West employed systems that delivered superior HE than AT effect. While the Germans employed Stug's and SU-76's in numbers, the West used SP artillery instead, namely Sextons and Priests.
Given the immense scope of the Eastern Front, a dual purpose AT/HE weapon system will be more useful, since armour will generally be a rarity. In the West, armour is copious, since the campaign is in a more condensed area. Therefore, dedicated TD's and dedicated SPG's make more sense than AG's.
I would imagine the large numbers of Tank Destroyers and Self Propelled Howitzers got in the way of any call "Assault Guns" like the German and Soviet variety. The British did make some open top Tank Destroyers early on.
Tanks do have an advantage over Assault Guns. They carry the main gun higher off the ground. The Jagdpanzer IV seems to have had a nasty habit of digging the end of the main gun into the ground when the elevation changed in front rapidly. The Panther carried the same gun and never had that problem.
The Americans and British designed Super Assault Guns. The British effort became the A-39 Tortoise. The American effort was designated the Gun Motor Carriage T-95 in 1945. In 1946 it was re-designated the Super Heavy TankT-28. Neither design went into series production. Both would have faced problems in the field from their weight. Transport and Wrecker Service would also have been a problem.
Along with all the other reasons mentioned, transporting the AFV would have been another consideration and the red text above underscores that and provides another tactical reason.
With a turret, you can swing it to the rear and have your barrel protected over the hull of the tank, such as when slinging up into the hold of a ship, or loading onto a rail flatcar or tank transporter trailer. The barrel over hang isn't in the way and at risk for damage.
Operationally/tactically, with the main gun somewhat higher off the ground, less chance of plowing into something if crossing uneven ground, and usually can get better depression with the turret mount over the hull mount.
There was also the advantage of being able to swing the gun to the side using a turret rather than the whole vehicle which provides greater flexibility, quicker response, and accuracy when in a hot situation.
Looking over the chassis/hulls available to the USA at the start and early into the war, the modification needed to either the light or medium M3 chassis doesn't offer that much lower of a profile, would likely eliminate the extra driver(relief) position, and likely be a less effective mount for the main gun. Only upping the size of the main gun would seem the only incentive here.
More sandbags or armor plate on the front of an M7 might have provided a field expedient version.
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TANSTAAFL = There Ain't No Such Thing As A Free Lunch Bock's First Law of History: The Past shapes the Present, which forms the Future. *
AVREs continued in use well beyond the Normandy campaign, though in reduced numbers as 79th Armd Div converted units to amphibious equipments. The preference was to use small teams of various types of specialist armour (flails, Crocs, AVREs, etc).
As the British Army continued to use infantry tanks throughout the war I don't think there was any need for an assault gun as well. 'I' tanks were created to accompany infantry in the assault.
The first Stugs were deployed in France in 1940 I think (I can't recall if they were seen in Poland) so way before the PzIII was considered obsolete. They started life as part of the artillery arm, with short-barrelled 7.5-cm guns as found on the early PzIV; not too far removed from the British close support tanks, in that they were to deliver HE rather than AP. It was probably around 1943 that the blurring of whether Stugs were infantry support vehicles, self-propelled anti-tank guns or knock-off panzers began in earnest.
The US TDs were misused as assault guns at times, same as AVREs or anything with some degree of armour protection and a 'big gun' in the cause of hard pressed infantry. The 105-mm armed M4 was considered an assault gun, in terms of dropping HE and smoke in support of infantry.
I don't think that Britain/Canada/the US needed to develop assault guns as they had more than enough tank production capacity to meet demand most of the time. As others have said, once you go for a fixed main gun rather than a turreted one you lose flexibility of deployment.
I agree with all of Nicks points post #16 and Cult's book suggestion is spot on. An excellent book on a StuG unit. I think that the German AG's served them very well on the eastern front throughout the entire war used in attacks supporting infantry, destroying tanks, and in fluid defensive fire brigades during the back peddling of the Wehrmacht post Citadel. In the fluid defense posture during the period of Autumn 1943 until the wars end the radius of the StuG's was much better then the German tanks. The long treks to and from different areas where they were needed were often 100-200 kilometers or more and the mechanical failures of the StuG's was not on the level of the tanks in the panzer divisions. There were some torsion bar problems when heavier armor and cannons were installed on the later versions but this was quickly worked out.
The scenario's I listed above did not pertain to the allies post D day as they were constantly moving forward on the attack with far superior numbers of men, artillery, and especially aircraft and the reliable Sherman in which there was an endless supply. Therefore the need for a tracked assault gun was not on the must have list of the allies in NWE. Whereas the StuG's supported the infantry in the Wehrmacht, this was the job of the Shermans and the other tanks of British design by the allies.
The StuG battalions were subordinate to the infantry and not panzer divisions. Their performance was so good though,IIRC, Guderian wanted them in panzer divisions.
Artillery was not directly subordinate to the infantry and hence, supporting fire had to be requested from the superior commander headquarters. In planned operations this was not a problem, but in emergencies approval for support generally came to late to be effective
Artillery needed a relatively long time to prepare for firing when positions were changed (during the two and half year retreat post Citadel this was always the case). Gun crews had to limber up their guns and unlimber them afterwards. In these phases, guns were not able to fire. In the event of large scale troop movements, at least parts of artillery units were unable to bring their fire to bear.
The indirect firing mode of artillery called for a complex, widespread organization including observation posts, gun positions and supply depots. For the artillery strikes of corps and divisions when preparing attacks or blocking actions on sections of the front, this level of effort was justified. Immediate support of infantry, however, could have been achieved more simply.
The above factors led to the concept of self-propelled guns, instantly ready to fire. As they were designed as fully tracked vehicles, they could follow infantry in the field and support the battle continuously.
In 1935, future Field Marshal Erich von Manstein drafted a memorandum to the chief of the general staff and the commander in chief of the army. In it, he demanded that the concept of assault batteries from WWI be updated to match the advanced state of technology. He called for an appropriate weapon, mounted on a self propelled gun carriage that would provide direct artillery support for the infantry. His supporters included Generaloberst Beck, Chief of the General Staff of the Army. Nevertheless, a considerable amount of persuasion was required within the General Staff and in the senior echelons of the army because:
1. The proponents of the assault artillery were labeled as the "grave diggers of the tank arm" by the advocates of the armored forces.
2. In this early stage, the artillerymen did not yet recognize the value and the potentials opened up by the idea put forward by von Manstein.
However, at the end of 1943, this was written by the General of Artillery attached to the Chief of General Staff of the Army:
Assault artillery is effectively the backbone of our infantry, who are frequently confronted with virtually insurmountable challenges. Wherever it appears it is, as a rule decisive in combat.
__________________ Our world at Khe Sanh was blood, death, and filth with deafening gunfire and blinding explosions as a constant soundtrack...Barry Fixler http://sempercool.com/
Of interest is how the stugs had much superior optics and gunnery compared to the panzer arm.
They were direct fire artillery, manned by the artillery branch with a panzer branch driver. Same emphasis on gunnery as the 75mm Infantry Gun and pretty much the same role in the early years. They were self-propelled rather than towed/manhandled and had all-around armor rather than just a gun shield, so they could easily keep up with an infantry attack and still be shifted between locations as needed. They were much more flexible than the regiment's IG battery.
Also note that the original short-barrelled StuGs were just as easy to transport by truck or rail as panzers.
Finally, I recall reading that for Finnish StuG gunners, a basic part of training was learning to write their name on a piece of wood with a pencil attached to the end of the barrel.
When I've heard of the Churchill engineering tank with its "Flying Dustbin" mortar, it is in connection with the "Hobart's Funnies" used in the Normandy landings.
Where they used latter in the war much? How effective was their gun in its intended role of demolishing fortifications?
Most every thing I see on them either gives little detail, or is from gaming sites.
The You Tube demonstration is impressive
If you are interested in Churchill's, they were allocated to the US 17th Airborne Division. This book here states how great their combination was. A unit of professional tankers supporting elite paratroopers is always going to be a winning team. The British were as impressed with the Americans as were the Americans with the Brits.
That's interesting to hear. I wonder if they had a better survival rate hence experienced crews last longer, get better.
The Stug arm was considered the elite of the Artillery branch and recruited artillerymen into their ranks. The Stug and Jagdpanzers started small, with only small forces deployed in 1941. By late 1944 they rivaled tanks and by 1945 exceeded them IIRC. In 1944/1945 majority of the Stug, Jagdpanzer, and Tiger arm was in the Eastern front while the West fought a higher proportion of panzers.
The Stugs themselves had forward observer equipment, like the scissors scopes and superior optics in their AGs with several times more magnification.
The most experienced Stug battalions/brigades had kill claims similar to the leading Tiger battalions, which is interesting in light of the fact that a stug is 3 times cheaper per unit than a Tiger. They had a higher 'kill ratio' than the panzer arm in general.
Their operational readiness is in the range of 65% +/-. This can be compared to 50 +/- for the panzers and say, 80% (ballpark) for the T-34 and 90% for the Sherman.
The overwhelming majority of their ammo expenditure was against enemy infantry and support weapons in small counterattacks and in the defense.
Tactically, they were unable to do certain things or navigate certain terrain as effectively as tanks so this was a concern. In the heavy panzer divisions like the 1.SS, 2.SS, 3.SS, GD, the organic Stug battalions were used separately from the panzers in roles that they were more suitable to. The deployment was pretty similar to the SU/ISUs of the Soviet Tank Armies.
The Heer loved their assault guns (AG's), the Stug being the most massed produced 'tank' made by Germany in WW2. Upon seeing such assault guns in action, the Soviets also made them in huge quantities. Given that the Soviets and especially the Germans often understood armoured warfare at a level above the West, at least early in the War, why no AG in the West? Was it an oversight?
The West did have CS tanks, to deliver greater HE, such as 105mm Sherman and 95mm Cromwells, but these were issued to armoured and tank Squadrons, and not used separately, certainly not in quantity.
Given that AG's are cheaper to produce than tanks, and that you get the same firepower (and more armour in German Stugs), than the equivalent tank, why not use a greater amount of AG's attached to Infantry units, rather than a fewer amount of tanks?
The Sturmgeschütz (StuG) was concieved by the Germans when it was decided that tanks should be organized in armoured divisions. That left the infantry without any armoured support. In this context, Manstein suggested that the infantry would need armoured support in the form of a self-propelled infantry support gun, operating like the infantry-support batteries of WWI.
So the German starting point was the infantry-support gun around which they built an armoured, self-propelled platform.
The British had concieved the tank as an infantry-support vehicle and as the capabilities of the tank developed leading to armoured divisions, they stuck with the notion that the infantry should be supported by tanks. Hence the development of Cruiser and Infantry tanks.
The US and France stuck with notion that tanks were mainly for infantry support and that light tanks could be used for modernized cavalry formations, the US creating armoured divisions only when the lessons of the campaigns in Poland and France had shown the potential of such formations.
The Soviets were also seeing the role of the tank as being either specialized infantry-support or as part of mechanized formations.
So basically, the French, the British, the US and the Germans were reaching back into their WWI base of experience, the French, US and the British drawing the obvious conclusion that they needed tanks for infantry support, while the Germans saw the need for a modernized version of the infantry support gun to support the infantry, creating a new weapons system, the StuG.
The Germans stuck with that concept for the rest of the war.
The rivalry between the artillery branch and the armoured force over who should control the StuGs had no bearing on the concept itself, nor did economic deliberations. The naming of the StuGs as either StuGs or Jagdpanzer had nothing to do with different roles or concepts, it was just a function of the inter-service rivalry. The increase in the number of StuGs as the war progressed was due the increased need to support the infantry in both offense and defense. The change in armament from a low velocity gun to a high velocity weapon represented nothing more than a small change in emphasis from fighting the enemys heavy weapons in attack to protecting the infantry from enemy tanks as both roles had been part of the StuG concept from the start.
I think the proper answer to Nicks question is that the British, French and US armies simply did not percieve a need for StuGs, they had solved the problem of armoured infantry support in a different way, based on their own experience and doctrine.
The US and the British were not indifferent to the idea of the infantry support gun. IIRC the US used M7 105mm GMC in that role in North Africa and the 95mm gun that ended up in the Cromwell and Churchill started its life as a proposal for an infantry support gun. But they never went beyond thinking of it as anything other than a gun, like the German 75mm and 150mm infantry guns. And why should they? They had plenty of artillery and tanks to support the infantry.
StuGs were never about economy, so it is hardly surprising that the US and the British did not think about it in that way. And it is not like they lacked production capacity for tanks - so why build a specialized - or in case of the British another specialized - armoured vehicle to do a job already covered by other vehicles?
As for the Soviets, it is my understanding, that by 1942 they had established a need for more firepower to support their infantry support tanks and of course the infantry these were supporting. In solving this problem, they looked across the battlefield and found a technical solution. Using their light-tank production capacity to make self-propelled gun - the SU-76 - and their medium and heavy tank production capacity to make selfpropelled 85mm, 122mm and 152mm guns, they created the fire-support vehicles they needed. But impressions is that the Soviets copied the technological solution - they did not copy the concept, but rather stuck with their own doctrine and organization, incorporating the technical solution into it.