sloping armour on Tanks

Ok, I'll bite...

I think you're on the right track in terms of vertical armor vs. sloped. The trend in early armor was thicker is better but that causes weight/suspension/engine problems if you don't have the corresponding design to support extremely thick armor. Armor development in the 1920's and 1930's was fairly slow and didn't truly advance until the 1940's with the onset of the war. A lot of the countries fought with what they had on hand and as the war went on, new platforms were introduced.

The Panther's sloped armor was a direct response to the Russian innovation on the T34...which came as something of a surprize to the Germans when first encountered but they readily adapted in a nutshell.

In terms of why did they stay with the Pz IV platform throughout the war even though it had vertical armor? It's about the economies of retooling manufacturing lines and ability to produce quantity, even upgraded variants, vs. an entirely new production line. The same reason why the US continued to produce the Sherman throughout the war. The Pz IV in all its variants was the most heavily produced tank of the German forces during the war because they could churn them out, they were mechanically reliable, they were a good platform for the 75mm gun, and could be up-armored to hold their own.

The true impact of Porsche and Henschel's designs can later be seen in the US and Russian post-war designs and their influence in some areas continues to be felt right down to the current day.

My in a nutshell on this topic.

I think Bill's thoughts are on target (pardon the pun). The main advantage to sloped armor is an increase in thickness for less weight. In other words, a one inch thick plate at 90 degrees becomes two inches (or more) when sloped at >30 degrees. A projectile incoming on a 90 degree plane to the sloped plate has a lot more steel to travel through. Tank gun and projectile technology soon countered the sloped armor on the T34, however.

The main technological breakthrough was in welding sloped armor plate. The Russians solved the structural problems associated with beveled armor construction (on the T34) in thye late 30's (with foreign help) through the development of full penetration ballistic weldments. (Remember, the US entered the war with riveted armor!) The Germans lagged behind in weld technology as well, and only after capturing and evaluating the T34, were they able to replicate it. Mass producing flame cut beveled armor plate is not and easy process, and requires advanced tooling and the raw material resources to produce weld electrodes that will penetrate the armor plate and fuse the base metal. The weld must be as balisticallly sound as the steel. It is much easier and cheaper to achieve a sound ballistic weldment when joining 90 degree armor plate (Pz IV, Tiger 1). To Bill's point, the US decided that casting homogenius turrets and hulls was the only alternative available to quickly manufacture tanks in the numbers required to fight a global conflict. We all can see the desperate measures implemented by the Germans to speed up production of the Panther G, with it's simplified hull construction later in the war. Neither the Panther or TIgers could be produced in the volumes needed, even if the bombing campaign hadn't existed.

There's my 2 cents worth!

Steve

I have to agree with what has been said. The Panzer IV owes its longetivity to the fact that it was mechanically reliable, easy to produce, low weight, and high velocity gun that could deal with any Allied armor. Sure it was outclassed in 1943, but it's simplicity in construction and the fact that it could be upgraded and produced at a greater scale than the Panther and Tiger when the Whermacht needed as many tanks as possible, lead to a longer life. A big question is: what if the Germans gave full industrial output to the Panther in 43 instead of all th other types? The war may have been prolonged. Also the Panther 2 may have been introduced.

Given the teething problems of the Panther, putting it into full production vs. the other tanks available at the time would not have addressed the quantity problem I don't think. I don't have it handy but I remember seeing a time/cost comparison between the different models available in terms of production capacity (one of the factors that increasingly drove the Germans to use Assault guns in place of tanks even when they were trying to produce the Pz IV in quantity) and the cost and assembly of the Panther vs. the Pz IV were substantial. The argument could be made that if they had halted all production and focused solely on the Panther, the war could have ended sooner rather than later...assuming of course you take the position that the armor forces decided the pace of the war and not the infantry, but I'm not opening that can of worms.

I know I read that 2 Panthers could be produced for every Tiger. I'm sure it's possible that 2 Panzer IV's could be produced for Panther. However, if you take in account that they say it takes 5 Shermans to destroy a Panther as oppose to 1:1 or 2:1 for the Panzer IV, then maybe you might think it over again? True the Panther had it's problems in 43, but as the war progressed they simplified production and whatnot.

It's not the Shermans that I'm thinking about...I'm thinking about the hoards of Russian armor that were unleashed in '43 starting with Kursk. We Americans tend to forget about the sheer volume of men and equipment the Russians were able to put up against the German army but they are the main influence behind what drove German armor decisions since virtually every design decision was influenced by Russian abilities. The KT for example with it's long 88 is perfectly suited for battle on the open steppes but has a much harder time bringing it's superiority to bear in the West. It's an interesting theory to entertain, but I don't think it would have brought victory to the German army because they were already doomed by the time the Panther could be produced, it was just a matter of time as the Russians bludgeoned them into submission so I guess the Panther could have prolonged the war, but I don't think it would have altered the outcome.

You can talk about which tank might have prolonged the war and which tank was responsible for later technological developements, but you all all overlooking one vital point in the struggle in the East. It's true that the Russians could field more tanks than the Germans, but that's only because they were able to move their production facilities far behind the Ural Mtns. The Germans did not have the strategic capability to knock out the Soviet production lines due to not only the thinking of the time(tactical support v strategic) but also the death of General Walter Wever. If he had remained alive it would have been a whole `nother ball game. As for the sloping armor on tanks. The Soviets were still working on the T-34 during the period when they and the Germans were still on speaking terms. They , as well as the Germans sent trade and tech delegations to one another to check out their latest "toys". Knowing they had the T-34 the Russians were a bit miffed when shown the latest Pzkw (Mk IV L/24 gun) they couldn't believe that such a thing could be the latest innovation from the Germans. In fact, they came damn close to just walking out of the factory!!

And that Gents, is my wotth

Welcome Hipshot and yes you are correct, the Russian factories were untouchable and that was huge. I agree with you Bill, building Panthers wouldn't have altered the outcome, the Germans best chance for success was 1941. After that is was basically downhill for them. The early blunders by Hitler more than anything were there cause for defeat. One must note that the Panzerwaffe from mid 43 and on maintained a qualitative advantage, but were tremendously outnumbered. Very doubtful that Panthers and King Tigers alone could have slowed the Russians down.

Welcome to the forums Hipshot! It is very ironic to read about the Soviet-Nazi relations prior to Barbarossa, particularly the demands on both sides for foddstuffs, raw materials, and examples of military hardware. The Soviets had complete working examples of all the front-line equipment the Germans used in Barbarossa, including planes as part of their trade deals with Hitler. Right up until the moment the Germans crossed the border the Soviets were still sending shipments of grain and raw materials to Germany across Poland in the ultimate example of denial despite clear indications of what was coming. Unreal to say the least.

It's a great advantage to have your industrial capacity out of reach of the enemy to allow for uninterrupted production and development to take place. If we want to talk about theoretical impacts on the war, imagine if the industrial capacity of the US had been not across the Atlantic but in say, England, would the war have been any different?

QUOTE: Originally posted by tigerman A big question is: what if the Germans gave full industrial output to the Panther in 43 instead of all th other types? The war may have been prolonged. Also the Panther 2 may have been introduced.

I think it is fortunate that we don't know the answer to that question. The Germans seemed to have an interesting mix of pumping out yesterday's technology in volume while then trying to leap current technology to get to the wonder weapons stage. To be fair, it is very easy in hind sight to decide what is the best replacement lifecycle for different weapons systems. It's much more difficult at the time to decide how long to produce something and decide when you want to replace it. Had they been more effective at choosing good quality weapons and then mass producing them, they might have achieved a superior result in WWII. They did a lot the same thing with the type VII u-boat and the BF-109 fighter which were good weapons at the start of the war, but in serious need of replacement by 1943-44.

Generally speaking, I think America did better on the quality vs quantity question on weapons produced in WWII. Of course, we weren't perfect either, settling on the Sherman as THE TANK to produce in huge quantity was a big mistake. I think America might have done a lot better if they had viewed the Sherman as something to tide us over in 1942-43 until we could develop a proper tank like the Pershing which could then carry us forward through the end of the war. On the other hand, our submarine and airplane decisions worked out fairly well.

QUOTE: Originally posted by ABARNE Had they been more effective at choosing good quality weapons and then mass producing them, they might have achieved a superior result in WWII.

Had they had a smarter Fuhrer, they may have dominated over all of Europe and Russia. His mistakes more than the deficienties of the armaments lead to inferior results on the battlefields from 40-41.

I absolutely agree that Hitler's mis-management of the war, the politics leading up to the war, and the timing of the war itself would be the biggest factor in the Reich's downfall. The Germans had a lot of opportunity early on to strike while the iron was hot as the saying goes, but just continually came up just short, often due in some fashion to Hilter's meddling. When I objectively analyze WWII, almost as though rehashing a football game, I usually end up shaking my head in wonderment that the Germans lost, and lost so badly. Even for as silly as attacking the Soviet Union seemed to be, had he let his generals run the campaign as they saw fit, they might well have pulled it off.

I guess that their early superiority explains some of their mis-guided weapons upgrades. Early on, acheiving a lot of success and expecting a quick victory, it probably made sense to them to continue slapping out the weapons with which they began the war. When the war started turning, the situation rapidly went downhill so pretty soon I think the may have felt that wonder weapons were the only way out.

QUOTE: Originally posted by bismark9 This may be a really silly question, but why did anyone ever use 90 degree surfaces on armoured vehicles? I understand that it would be easier to manufacture and build but why did it take so long to come out with slopes like that found on the Panther? My first thought is that armour was way ahead of the penetration power of anti-armour weapons, but Why keep building the Pz IV so long with all those 90 degree surfaces. I am not an engineer but guys like Porsche and Henschel with umpteen billion IQ points must have understood basic physics. Open for explanations................

At the beginning of the war German armor was way ahead of the penetrating power of most AT weapons. Bear in mind that most AT wepons of the time were KE (Kinetic Energy) rounds, HEAT and shaped charges were still in their infancy.

The advantages of sloped armour are:
1) Added thickness without added weight.
2) The angle deflects energy. An AT round is most efficient when striking flat, if it strikes at an angle penetration/explosive energy is deflected away from the armor.

Why continue using the Pz IV?
1) As mentioned, it was already in production.
2) KE rounds had a hard time penetrating the existing armor.
3) By adding the skirts (stand-off armor) HEAT/shaped charges were defeated. The outer skirt detonated the round and the resulting energy was dissipated between the skirt and the main armor.

just my

QUOTE: Originally posted by claymore68 At the beginning of the war German armor was way ahead of the penetrating power of most AT weapons. Bear in mind that most AT wepons of the time were KE (Kinetic Energy) rounds, HEAT and shaped charges were still in their infancy. just my

Claymore,

This is part of the perceived "superiority" myth of the German armor due to Blitzkrieg successes but the reality is very different. Until the introduction of spaced armor and hardened face plate, German armor was extremely vulnerable to both the British 2 pdr AT gun and the French 47mm AT platforms. Until late 1941-early 1942, the Pz III was the MBT of the German forces with the Pz IV as the supporting "heavy" tanks. German early war tanks were built for speed and maneuverability and sacrificed armor protection to achieve that, something they would belatedly realize later on and be forced to scramble to counter.

Check out the penetration tables for various AT weapones here (armor thickness are in mm):

German Pz III Armor thickness: (notice that on the variants through the H the armor thickness maxed out at 30 mm with the H variant using bolt-on additional 30 mm plates in some areas)

http://www.wwiivehicles.com/html/germany/pzkpfw_iii.html

British:
http://www.wwiivehicles.com/html/unitedkingdom/PenetrationTables.htm

America:
http://www.wwiivehicles.com/html/usa/guns.html

Russian:
http://www.wwiivehicles.com/html/ussr/guns.html

Gentlemen. I think we need to set the record straight here. Sorry Scratchbuilt, but the Germans were not really they far ahead of their potential enemies. They had a nasty habit of installing tank guns that could take out an enemy AFV that was equivalently armored as the firing platform. Don't forget that their first tanks, the Mk Is started out armed with only a pair of 7.92mm machine guns. The MkII had a 20mm cannon. The Mk III started out with a 37mm gun! It was only later when they noted the shortcomings of that round that they moved up to the longer barrel 37mm as well as the short and long 50mms. Their biggest tank gun at the time was the 75mm L24 as used in the Stugs and PzIV support tanks. That's why they had a lot of trouble with the French tanks. And I'm talking AFVs likea the Char Bs. They could give the German MkIIIs a very hard time, but were also easy to outmaneuver, letting the Germans get in close enough to plant a couple of rounds in their louvered cooling systems. thereby disabling the vehicle. Another thing that worked in the German's favor during Blitzkreig was the fact that almost every German tank had radio. Very few of the French AFVs did. And as for the Brit's 2 pdr, it was near useless against the panzers. A nice "door knocker" as would later be said, but nothing for any serious social meetings. After all, a relatively light, mid velocity 40mm weapon just ain't gonna cut it against a Panzer that's about to rain all over your parade. `Bout the only thing the Brits had going for them was the fact that the Matilda II tank that carried the 2pdr was almost impenetrable by the German's main guns. The only safe way to stop a rampaging Matilda was to to call up the Luftwaffe and have them use one of their dual purpose 88's on them. The French 47mm guns were quite effective, that's why, after the French defeat, there were so many used on the early Panzerjagers.

Hipshot,

The competition of round vs. armor is a longstanding one. Your statement about the 2 pdr is correct after the Germans upgraded the armor on the Pz III H (mid-late 1941) to include the extra 30mm of armor. Before they did that, the British 2 pdr could penetrate 40mm of armor at a range of 1 km and 30 degree impact and the Pz III had only 30mm...when the Germans upgraded their armor, the British upgraded with the 6 pdr which could penetrate 74mm of armor with a standard AP round at range of 1 km and a 30 degree impact...more than enough to penetrate the cumulative 60mm of armor on the Pz III.

After 1941 the 2 pdr was no longer effective due to advances in armor and other weapons platforms, but then the same is true of the Pz II and yet it was still in service. Wartime needs produce unusual circumstances to say the least. But at the start of the war, it was just as effective as the German 37mm AT or the American 37mm AT which, at the time, were both considered the main AT guns for their respective services.

If I recall correctly the British were forced to rely on the 2 pdr. for longer then they wanted, because of their retreat from France left them with almost no tanks and that they had to go with what was available to them. Thanks to lend lease, the campaign in the Desert may have ended differently. Always wondered what percentage of armor was supplied to them in that theatre. The Grant wasn't a great tank, but it's 75mm was a vast improvement over the 2 pdr. and could easily destory a Panzer III.

Eric,

You are right about the Brits having to rely on the 2 pdr longer than they wanted to..and why their tanks continued to be armed with the 2 pdr until the advent of the Crusader III with the 6 pdr gun.

One thing to keep in mind about the 75mm on the Grant/Lee...it was a short-barrelled pack howitzer with a low muzzle velocity. Combine that with the fact that it was sponson mounted instead of in a turret and it made very a poor AT gun. Compare it's muzzle velocity to the 2 pdr, (1,860 ft/sec vs. 2800 ft/sec), and it's penetration using standard AP at 1km was only 53mm at 30 degrees. The Pz III H and later could survive a one-on-one encounter with the Grant and win.

I don't know the ratios of the Grants/Lees in the Brit NA forces, but it's interesting to note how widespread it was used by them and the Russians as well. The Russians used them right up throug Kursk (4 brigades 1/3-2/3 equipped with them, the rest T34s) but their nickname of "Grave for 6 Brothers" doesn't speak well to it's operational performance...

Yah, I didn't think it had the best muzzle velocity, but could deal with the MK II's, early MK III's and the Italian armor.

QUOTE: Originally posted by tigerman Yah, I didn't think it had the best muzzle velocity, but could deal with the MK II's and, early MK III's and the Italian armor.

It was better than throwing rocks, that's for sure! Beggars couldn't be choosers at that point in time so they took what they had...Even the American tankers who used them hated them...when you compare it to the Sherman they are light years apart so those who always knock the Sherman should realize things were a lot worse before they got better.