It might be worth your time to look through Battleship New Jersey's channel, as they have made a number of videos on the implementation of welding into the construction of the ship, and the transition from riveting to welding. As welding was still an experimental process at that time they might have gone overboard with it, and all throughout the ship you can see how all the welds between the armour plates use a unique "scalloped" design, I guess to get as much surface area as possible, as opposed to a welding in a straight line. Perhaps the Germans were trying increase the surface area of the welds with the interlocking plates?
Is it possible that the interlocking of the plates could have been done as an aid to properly fitting and aligning the armor to make the assembly and welding easier and more consistent? I don't what the difference would have been in the factories regarding how the workers fitted the plates in position prior to welding.
Short answer. It was unnecessary. Germans achieve this effect through tactic and proper angling against the target. While having profit of larger internal space. T-34 is heavily overrated and its angled armour was more due to poor quality of Soviet tank crews. Germans start using this effect more with they late tanks (if you ignore that King Tiger have horrible shot trap), where need of space was not so crucial anymore.
Sloped armor or not a small fast and stealthly premium ( pay to win) light tank or TD comes on the battlefield that some how bounces hits from large calibers guns, is armed with a rapid fire small caliber cannon OR a large rocket that always seems to kill your crew, track you or set your tank on fire.
Thank you for this perspective. I've been puzzled that so many people fixate on the idea that the concept of sloped armor began with the T-34. You can see sloped armor on the ironclads CSN Virginia, Arkansas and Albemarle. Also thousands of examples in medieval tournament armor. This principle had been understood and applied for centuries.
The concept of a fort made of wagons is known at least since the first Indo-European nomads begun spreading throughout the Eurasia, but people fixate on the idea of wagenburg being invented by the czech hussites. Why? Because they were the first ones to make it into a system and employ such tactics with significant results against an opponent deemed to be superior in all aspects previously. The same goes to T-34. Germans didn't have all the bright ideas in the world, whatever the wehraboos are imagening to themselves while jerking off on panzers
Only that no other tank made sloped armor so effective and efficient as the T34 prior to that point. That is why it is celebrated so much. And evidently the principle had not been understood and applied for centuries when the T34 applying it basically seemed like a miracle to the Germans
When people think Germany didn't "understand" sloped armour...I always wonder, 'Where do you think their engineers got their degrees?'. Sloped surfaces are basic physics/geometry/material sciences '101' level stuff.
Also, after WW1 Germany had many restriction on what they can and cannot do militarily. Soviet Russia helped educate German military in their war academies. And USSR and Germany where allies it the beggining of the war from 1939 to 1941. So Germans knew very vell what Russians where doing.
And yet somehow these geniuses never applied it anywhere in tank design producing complete trash design one after another until Russians made them laughing stock with T-34. Go figure...
@ Bullshit, if they were allies, nazis wouldn't send arms and men to countries attacking the soviets and soviets would help them with fighting somewhere. Pull the other one, yes I know russophobic revisionists produce endless nonsense today but there was no alliance, mild neutrality at best. And funnily enough soviet designs went completely ignored and laughed by nazis (because these dumb slavs can't produce anything better than us, right?) until they saw T-34 in action and collectively browned their pants...
Also welding had just been adopted for major industrial production. So welding processes were there but structural design had not really been adapted to the process. The interlocking plates are a really good example. They only chose to do so because the structural integrity would be better this way because they did not manufacture full weld penetration on the armour plates. This was a compromise on integrity and welding. The plates support themselves somewhat better by interlocking. But it makes welding even harder. You can tell by the poor weld surface and layers on these joints.
Right, but the interlock keeps the plates better in position. This especially when welding plates in complex angles by less professional staff. So the interlock might simply have been a need for manufacturing. Just a thought - not a fact
@timob3490 True, but most of the welding was used in structural steel, not armour steel. I don't think this is the reason why it is used in armoured components, but in sheetmetal products those battlements are used (usually cause it is a 'free' functionality in a laser cutting process) to both position the individual plates, reduce the amount of weld (not the case in the armour) and to limit deformation due shrinkage of the welded area, actually, the weld shrinkage (in a proper quality weld that doesn't crack!) pulls plates in a stronger connection. I wonder if it was an attempt to limit welding jigs, by having the plates interlock closer together themselves? It feels a bit ungerman lack of Handwerkskunst, but it doesn't really show up til Germany really wants to ramp up production.
Some of the welds look terrible with inadequate penetration. It looks not so much like welds but like they were stitching the plates together with small diameter filler. The weld on the M-10 looks sloppy but adequate. We can’t tell from a video of painted surfaces, but I imagine that the plates had been bonded into a single plate. I find it hard to believe that the Germans didn’t understand the welding process, so I wonder in the “joinery” was to compensate for a shortage of skilled workers on certain production lines. It would have been funny if the used dovetail joints. 😅 Supposedly stronger than finger joints.
“I was [certain] at one point and then I started to ask too many questions.” I think we’ve all been there. Sometimes the more information one has the less clear the answer becomes. I appreciate you being upfront about that.
From an engineering view I want to mention 3 different effects of interlocking plates: 1. Your welding surface is bigger. Welds are a weak point, therefore you want to spread the load over a larger surface. 2. Shear forces between two plates are put onto the much stronger "teeth". (E.g. side view of a shell hitting the front of a panther. The frontal plate is forced inward and up by the impact. The interlocking on the sides of the plate works directly against these forces. 3. Welds handle load in different directions differently well. So interlocks change the direction at which forces act on the weld. (E.g. Frontal view of a shell hitting a panthers' upper plate: Again the plate is forced up and into the tank. A flat weld between upper and lower plate will just get pulled apart and open like a zipper. At interlocks, the weld experiences shear forces, which it can handle better and prevent the whole weld opening up as one.) Thanks for the video about this interesting topic!
Considering welding was quite a new technology and yet to mature, the welds of the time were or at least could often be weaker than after the war. I'd imagine once the welding techniques developed and welds became more reliable and better understood, the need for complicated joints was no longer there (thus interlocking disappeared from use), but it might well have been at the time they were used.
Considering that in order to punch through thick armor like that ,a force of impact of thousands of tonnes-force is required the fact that sometimes the welds don't break is surprising.
All the German tanks still has slopped armour, it just wasn't slopped everywhere because of space problems. Even the front plate of the Tiger was slopped backwards a little 10 degrees I think.
Yes, exactly this. The Panzer III, IV, Tiger, all had sloped armor, just at very shallow angles. Sloping armor is always tradeoff between extra effective thickness, and decreasing interior volume and crew ergonomics. Soviet tanks are infamous for their atrocious crew ergonomics and coffin-like interiors for a reason.
@@_ArsNova Agreed, I thought sloped vs. shallow-sloped armor was just a design and engineering choice. Sloped armor means more metal (the hypothenuse of the triangle) which weighs more (unless made thinner, in which case you lose the benefits somewhat) and covers a larger volume inside the tank. Not all of that volume is useful, and will be used mainly for the driver's and bow gunner's legs.
The problem with sloped armour is that it doesn't actually help as much as people think. Sure you can tilt an armored plate 45 degrees, but in doing so you have to make the plate itself bigger to cover the same space as an unsloped plate. Sloping also creates a lot of space inefficiencies. You can cram more into an After 8 mint box than a Toblerone box.
@@TallDude73 Slopped armor allows ricochets and this is its major advantage over straight armor of similar thickness. Disadvantage is that you have less space inside, i.e. you have cramped tanks (well known fault of Soviet tank design) .
@@mrdojob People also forget that sloped armor is only useful as long as it's sloped. It is rendered worthless if you happen to be caught in a position where that angle is nullified, such as while the tank itself is on an angled slope, or is being fired on from higher ground.
Sloped armor is not a magic bullet (pun intended), a sloped plate will have more effective thickness, but it needs to be longer to cover the same frontal height. Those two effects will exactly offset, the main advantage of sloped armor comes from normalization effects, simpler production of thinner plates and better surface to volume ratio, when designed correctly. For modern APDSFS projectiles with a large degree of positive normalization, sloped homogeneous armor can be worse than a flat plate. Especially in a WW2 context there are definite advantages, but also tradeoffs.
Yes! Thank you! It always drove me nuts to hear that 'sloped armor increases effective thickness for the armor without increasing its actual thickness, so you save weight' when simple geometry shows the increase in length of the armor plate would cancel out any supposed weight loss.
This, 100% I have been writing this for some time as well ... angling a plate doesn't save weight by itself. The weight saving come from decreased surface area you need to cover and less internal volume.
@@quantum340 If a projectile hit's a plate of armor at an angle, it gets deflected. For a normal upwards sloped plate, most basic bullets get deflected upwards, like a ball. They don't penetrate the line of sight thickness, they need to penetrate a longer way, leading to increased effectiveness of sloped armor, this is de-normalization. Specialized armor piercing caps will "bite" into the armor, deform and turn the rest of the projectile downwards.The projectile will now only need to penetrate a shorter distance, closer to the plates actual thickness. This is normalization (the projectile turns towards the normal [perpendicular] to the plate) and this makes sloped armor less effective. Modern armor piercing projectiles and especially APFSDS have positive normalization. Example of WW2 era de-normalization ruclips.net/video/ezf0bX-5R0A/видео.html Example of APFSDS normalization ruclips.net/video/0t-Vi4unTLQ/видео.html
That's why T-34 was supposed to made of high hardness steel to make advantage of the armour angle to deflect shells, but it had side effect of internal cracks hurthing the crew on hit, and Soviets had trouble maintaining any production standard in the first place.
This type of keyed joint is commonly referred to as a "box joint" in English. You may wish to contact the Australian Armor Museum for their opinions about keyed armor joints, their restoration shop has actually welded blown-up German armored vehicles back together. They observed minimal and inconsistent use of armor grade stainless steel welding rods in the late production Stug 3 they are currently restoring, no doubt due to late war shortages,.
I am very curious about the weld penetration the Germans were achieving (or failing to achieve). And I further wonder if this was caused by material shortages (as you suggest), skilled worker shortages, or welding technology lagging plate thickness. If box joints were supposed to improve structural integrity, why not go further and use dovetails? 😂
@@MarcosElMalo2 the box joint is already inefficient compared to a straight line weld. Think about the fact that this would further increase the length of the weld and make the fitting of the armor plate even more difficult than a box joint no doubt does. Man hours are expensive, this might have been a compromise solution.
In manufacturing, interlocking plate would make the jig necessary for hull assembly, simpler, as the locking tabs would insure alignment in two directions. Since these plates were heavy heavy heavy, simplifying the jig would be a goal of any factory engineer for sure. The Soviets may have tried it for the same reason. To simplify alignment for assembly. Thanks Bernhard!
My eyes almost roll a full 360 degrees any time I see someone talk about sloped armor as if it began with the T-34. The Germans had been sloping tank armor since WWI with the A7V. The literal first "tank" concept in Leonardo Da Vinci's drawings from 1487 had sloped armor!
Da Vinci's tank didn't have sloped armor for the purpose of increasing protection, but because of how the armor would be constructed, bound at the top.
Vehicle designers of that time had only a vague knowledge of the effects of shell denormalization, and how to instigate or mitigate it. Their thinking of the efficiency of armor boiled down to mostly sine of the angle from horizontal. What it means is that they said "80mm at 40 degrees from horizontal? That´s just about 125mm. That´s not good enough." Meanwhile the reality is that almost no shell was stable enough in order to "bite" into that angle without major deviation upwards. Modern simulations suggest that Panther II with its 100mm thick front armor would be almost impenetrable even to the mighty Soviet 122mm gun.
125mm is good enough. It is very good. Tiger I was considered almost impossible to knock out and it "only" had 100mm front armor. So personally would I consider 70mm armor with say a 50 degrees slope (or more) to be good enough for a medium tank. Having thicker armor than that would only be wasteful in my opinion and bring extra weigth, slow down the tank, make the tank too heavy to the front, having too much armor at the front so weight have to be saved by cutting down side armor and making the tank weaker and vulnerable to hits from the sides, rear and top. So I think your suggestion is a bad idea. And then it also depends on the type of tank. Hetzer would I consider to be extremely well protected. Its small and easy to hide. And the enemy cannot shot at you if he does not know that you are there. And when he discovers you, then he will have a diffucult time hitting a small target like the Hetzer. And Hetzer in a hull down position its even harder to see and to hit. And if you manage to hit it, then will you probably only hit it where the armor is the strongest - the frontal top of the hull. And there will the thick armor with a sharp sloping give pretty good protection, even against pretty large caliber guns at longer ranges. So its a pretty cost-effective use of armor the Germans had with this little vehicle.
@@sergeyboychuck8872 T-34 and M4 Sherman did have sloped armor and somewhat okayish thickness. So I think they were better designs than the German tanks that either had crappy armor or was too frontally heavy. I guess low quality steel in the russian tanks made their frontal armor not so fully effective as their american counterpart. And bad tank crews and poor ergonomics and other shortcomings could probably explain much of the high soviet tank losses. But the general idea was sound. It had frontal armor of the right thickness. And it had a gun of almost the same calibre as a Tiger I and inside a medium tank.
@@sergeyboychuck8872 But you are comparing apples with oranges I think. Tiger I was an old design. It was very good at its job facing tanks made before its introduction in august 1942. But it was never really meant to be invincible against tanks made after that. And the Soviets also deliberatly armed their tanks with the only guns they had that had been proven effective against the Tiger - such as the 85mm Anti-aircraft gun they put in the turret of T-34. And the 122mm gun they gave IS2. And the 152mm gun on SU-152 and ISU-152. No tank could survive a hit from those guns. Just like no tank today can survive a direct hit from a 155mm or 152mm artillery piece. But it would be stupid to say that armor protection does work because it cannot survive direct hits from high calibre guns.
I'm not sure this makes any sense to me, but as a young man I knew a "tank escort" for the German Army (the guy who walks along side tanks into combat), He served from the beginning of the war to the fall of Paris. Mainly he escorted tiger tanks on the Russian front until losing a kidney and being assigned to guard a tiger during the fall of Paris, where the tank overheated and he got captured still escorting it. So here's the weird part... he told me that the way the Tiger was designed to deflect shells straight upwards. And he claims that's exactly what they did in his actual experience on the Russian Front. He mentioned that Tiger crews preferred to assault or defend from the high ground. and he also added that most Tiger gunners could hit a moving jeep at 1000 meters. While I have to agree that it's unlikely that incoming shells would ever come at a tank straight on I don't quite understand why incoming shells would always ricochet straight upwards. Lastly, at least through quite of a the war, German tankers weren't too concerned with Russian tanks or most other Russian munitions that they were encountering. For the most part they felt that they could outrange the Russians and survive incoming hits. I wish I remembered more of that conversation, but that was nearly 50 years ago.... Perhaps for WW 2 buffs in general, I'll add a couple of fun trivia that he told me: On the offensive towards Moscow the tank guards were usually tasked with capturing meals. For the most part this involved capturing Russian soldiers and confiscating their food. They might capture up to 60 Russians in a morning forage and he said, the Russians didn't necessarily have bullets, but they always had good food. He went on to tell me that things went terribly wrong when the quality of the Russian Food declined and the Russians suddenly became flush with resources and ammo. In his mind the Russians had somehow built a great factory that produced everything they needed and cost Germany the war. He didn't speak Russian or English, but he memorized the name of the factory and he wrote it on the barn wall in pencil.... it read...."Made in USA" which he pronounced as one word in German and I didn't get it until he wrote it. I of course translated the word for him and we both walked away from the conversation having learned something. It's been 50 years and I thought I might share this little story before it's lost to history.
@@2Pzp I spent a summer living on his farm in Germany as a kid. He was my mom's first husband's step brother. He didn't have a son, so he spent time with me teaching me about farming and every once in the while sharing his WW 2 experiences with me. He was a quiet and contemplative man who liked to work with his hands and with animals. He made it all the way to Moscow and ended his military career in Paris. Along the way he earned an Iron Cross with decorations and I suppose is now one of the many that were heroes for a time and have since been lost to history.
@ZaHandle Yup. It's easy for a 21st century English speaker to understand, but can you even imagine how confusing and terrifying it was to a German soldier who grew up a farm boy and neither spoke English nor Russian and only had Nazi propaganda and one clue "Made in USA" to help him understand why his life and the war was going to shite.
From welder's perspective: straight welds are faster and worker doesn't need a lot of experience to make a good weld. Interlocking plates present a challenge because on one hand welder can do his job in such a way that will prevent material/ weld stress ( comparing to straight weld). On other hand interlocking joints will take much more time, effort and weld quality will be often questionable. Look at pictures of knocked out tanks. Very often it's the welds that let go,not armored plates. Want to make welder's life hard? Design welds like those of Churchill tank ( as observed on example in Borden Base Ontario, Canada). What a nightmare.
American examination of German armor, specifically a PzKpfw III gave a low opinion of the choice of welding rod, but a high opinion of the armor plate.
Thank you for being honest. When one speaks plainly about what one knows and one knows not, a new plethora of information is conveyed. It also messes with your intellects in a good way... certainty is a transient state. That fact is often forgotten. Great channel! Cheers.
Tanks in WW1 had sloped armor. Look at the Renault FT. German designs tended to be boxy because of space limitations! They were already using torsion bar suspension in many designs which used a lot of space and the sloped armor further reduced interior space!
Another thing to consider with the interlocking plates is that you get more weld length and it is split across both plates. A simple butt joint leaves the plates subject to flexing along the weld length, while interlocking provides more rigidity. Might help keep welds from failing when a shell hits and flexes it.
The lack of redesign from boxy armor to the slope might also comes from the success of the 39' to 40' campaign. Something in line of "if it ain't broke, don't fix it", well until they were fighting against soviet. I would argue too that the Germans were also misunderstood their post-battle analytics from the earlier campaign by putting their tank's effectiveness factor equal to their war doctrines, as I believe their war doctrines are the true major contributor for their success in the early war.
One important aspect of straight box armour is that you can use the inside surfaces much more efficiently to mount equipment, and it generally gives more room to the inside.
Interlocking armor plates is an interesting but separate topic from sloped armor, because clearly you can do one without doing the other. About the positives and negatives of interlocking armor plates: first off, as you mentioned, thick tank armor is hard to cut (especially with the precision necessary to create interlocking), cutting it into this shape will take more time because the length of material you need to cut is longer than a straight line, the same problem appears with welding. Obviously these are two very expensive, material and time consuming processes, I think that they probably had a reason for them. I think the main benefit to interlocking the plates like this is impact resistance. Welds are generally more brittle than the slabs of armor that they join, when they get hit, they sometimes crack, even more rarely, the entire weld cracks and the structural integrity of the hull is compromised without a full penetration of the armor. I think that this is what they wanted to deal with. If a weld like the one on the Tiger II is impacted, part of the weld might crack, but the crack will only travel down the weld in a straight line, once the crack has to make a 90 degree turn to follow the weld, a lot of the energy will dissipate. This makes the weld tougher even though Germany did not have the best welding technology as you mentioned. This is of course all speculation on my part based on my limited knowledge of armor manufacture, welding, material science and other topics. If I got something wrong please tell me!
Hah! Yesterday I was looking at the pictures I took at the Panzermuseum and wondering why the interlocking plates. Just a few hours later you come up with this video... 😲 Great work, Bernhard!
I really liked the video and highly appreciate your honesty on the level of understanding you have. I was a little bit surprised to see the first part of the video and i think it is rather interesting to think about the connecting mechanisms of armor plates. I personally think it were the drivers vision and the crews and engineers being used to the layout. It is not completely neglecting sloping, it just tries to minimize the size of the visory hatch. Also it might have been an influence that the tank would effectively become a little shorter. As soon as more communication was inteoduced and also no more direct vision was required it was possible to drive without that weakspot. I really wonder if the big hatches of sloped vehicles or the vertically closing hatches of german tanks were seen as a weakspot by the soldiers of that time or as a necessary thing because driving blindly was seen as more dangerous than having a thin weakspot.
Writing this before having seen the video. Look at the turret of the Panzer I and you will see sloped armor. There was sloped armor right from the beginning. Maybe not as much as later, but others didn't have much sloped armor as well. Look e.g. at the british tanks including all the Vickers copies... Also with the early recon cars like SdKfz 222 you find sloped armor.
The interlocking welds/steel plates can also be found in warships like the Iowa class New Jersey. Basically, by increasing the surface you'll get a stronger weld.
That’s not how welding works. It’s very different than wood joinery. In welding, you are bonding two pieces into one solid piece. The weld needs to penetrate the thickness of the metal and you need the proper amperage going through the electrode/filler rod. You are fusing metal together. In a wood joint, increasing the surface gives you more glue surface. That’s what you’re thinking of. The interlocking plates you saw more likely were to aid in more rapid construction-it would allow more rapid positioning of the plates before they were welded.
@@MarcosElMalo2a longer weld means the two metals are joined together over a larger surface, increasing strength The mechanism might be a little different to glue, but in this regard it's no different
The T-34 was a horrible tank to have to fight in. The sloped armor on a relatively small vehicle was a major reason for that. The Germans went to sloped armor as their tanks got bigger (and therefore roomier for crew and ammo, etc.) Better armor protection isn't worth it if your crews can't fight the vehicle well.
Were the Panzer IVF2-J models anything more than adequate stopgap tanks, or were they legitimately excellent designs until the Panthers were fully ready. And by 1944, were they still worthwhile to produce, or were they already outdated?
The main reason why early WWII German tanks did not have sloped armor, is because the trade offs are simply not worth it. While sloped armor does increase the chance of a round bouncing of the plate, and increases the thickness of the armor that has to be penetrated, as the incoming round is hitting at an oblique, what is lost is interior crew space and maintenance ease. That interior crew space allowed German crews to be much less stressed from the travel than a T-34, plus the Germans had much better visibility. In 1941, a T-34 crew would be exhausted from trying to move to the battle, then be blind (lack of vision ports) and deaf (no radio) during the actual combat. That big gun and thick sloped armor required a really well trained crew to make use of it, and that was in short Soviet supply in 1941. Remember, the goal of a German tank in early WII was to not get hit. You can read reports about PzIIIs dodging 76.2 anti-tank rounds, as in actually seeing the muzzle flash, then moving to avoid being hit. Armor was there to only protect against machine gun fire, not to survive a 40mm+ hit. The reason why the Germans used interlocking plate armor, once they began to slope the armor, is to reduce the chance of the weld breaking. You can still see weld breaks on German tanks, but they are much less common than on Allied sloping armor. A tank with a broken weld is essentially a useless tank, and it can't be fixed in the field, if it can be fixed at all. Not only is the armor now compromised, and any additional hit will likely destroy it, but things like the turret ring are affected. Each tank hull was precious to the Germans in late WWII. They expected tanks to get hit and keep fighting, and then go out and fight again without being sent back to a factory for repair. If a Soviet tank had a ruptured weld, well the tank was likely destroyed anyway, but even if the crew survived, just get a new tank. Soviet tank life was SHORT, even if not destroyed in combat. Same with the Americans and British. Late war, tank hulls can be replaced. Crew is way more important than a tank hull. Broken weld, just get a new tank. This doesn't mean the Allies didn't try and salvage hulls or rebuild tanks in the field, but the value of any single hull was of less importance. After the Battle of Stalingrad ended, the Allies were not short of tank hulls. The Germans were ALWAYS short on tank hulls, so they had to engage in practices that increased the longevity of each hull. Early war, that was to use speed and vision to avoid incoming fire, in the latter part of the war, it was to still try to avoid being hit, but rely on armor if hit, and keep relying on that armor until there was a penetration.
Many of the issues with the T-34 stem from design choices, not because of sloped armour. The Soviets and Germans had different philosophies when it came to making a tank, and when you're a country who favours quantity over quality AND are trying to modernize your entire army before its too late, you're going to make sacrifices. Sacrifices, such as radios and vision ports.
@@ASlickNamedPimpbackthe absence of radios and vision ports were a lack of and a flaw respectively, not really sacrifices. When western radios flooded in via lend lease and they had the opportunity to design new turrets, in came radios and vision ports
@@jurassicturtle3666 design choices like “hey, do we have enough radios to supply all our tanks WITH radios” “nope” alright then, don’t bother” and “hey, how’s visibility on 8’o-clock?” “It’s terrible” “how bout we add a gunners port or something?” “We’d have to extend the hull” “don’t bother, it’d take too much time”?
1. All T-34s had the ability to receive radio signals, but not all had the ability to send them (otherwise it would be strange for pragmatic councils to allocate a whole person just to fire a machine gun). The same situation was with German tanks. 2. Unlike the T-34 crew, the Tiger crew’s stress began during field repairs. Almost all German armored vehicles have a terrible protection to weight ratio, due in no small part to a lag in armored vehicle design. The Soviets, having less developed production and a lack of resources (especially human resources), were able to bypass the German tank builders in many aspects, for example - weight, quantity, diesel power plant. You correctly noted that the Germans did not have enough tanks (I explain this by saying that the tank builders of the Reich wanted to make money, not win the war. The story with Zimmerit is indicative in this regard), but personnel, or rather the lack thereof, became no less a problem. You probably know the successes of the Wehrmacht in 41 (although what kind of successes were there, only one of the main intended goals was achieved - the capture of Kyiv), that having less advanced tanks, the Panzerwafe achieved better results than in 43. The basis of this success were skilled soldiers, veterans who had gone through campaigns 39 /40 years. These veterans formed the basis of the German tank forces (the ratio of infantry and tank units is approximately 1/5). It was they who broke through the Polish/French/English/Soviet fortifications/defense lines and it was they who suffered heavy losses in 41, which led to a decline in the combat effectiveness of German tank forces. Now let's sum it up. When German tank units, the basis of the offensive potential of the Wehrmacht, suffered heavy losses, they were sent to the rear for reorganization, where they brought up new recruits to the level of veterans and waited for the arrival of new equipment. All this took a long time, for example 8 months. And while the Wehrmacht elite was in the rear for replenishment, there was no one to attack, because the infantry units remained at the level of development around 1917 due to the fact that almost the entire budget of the Reich was invested in tank units and there was no money left to equip the infantry. And this was during a period when the initiative belonged to the Wehrmacht, when the Soviets began to counterattack, they had to pull away tanks to cover gaps in the defense, which did not allow tank units to be concentrated again for large strikes. This is what we see from the activity of the Wehrmacht - 41 offensives in 3 main directions (center, south, north), 42 only one main direction (south), 43 large-scale offensive on a local section of the front (citadel) and more and more serious offensive actions were not carried out, transition to defense.
One thought about the use of interlocking plates in welded construction. Even before the development of fracture mechanics, it was well known that welds were more brittle than the material that was joined by the weld. Perhaps this interlocking joint design was meant to limit the extent of a weld failure due to impact from a shell.
My guess, If you have good steel quality, you can get some good armor, slope armor is just A factor, not THE factor, not to mention slope armor can limit the space inside your tank if not designed properly
Hi, The German tanks adopted interlocking armor because the steel quality was much lower. The German steel had a much higher carbon content which made the welds subject to cracking along the weld seams. the Interlocking was a way to reduce the weld stress on the joints.
I'd like to see how the hulls were set up in their jigs for welding. I could see it being easier to quickly and cheaply construc hulls without having to build complex forms to hold the plates in place. You cut the plates to size, then interlock them with gauge blocks as spacers then weld it up removing spacers as you go. Note the interlocking shows up on newer designs when more tanks are needed quickly and Armour is thickening. Just a thought.
The thing about German tanks and sloped armor is that German tanks from the PzKpfw III up to the Tiger did have sloped armor, at least on the front of the hull. It's just that it's not set back at a very steep angle, but it is sloped and not sitting at 90 degree vertical. If you look tonkas like the Tiger from the side or a at slight angle, you'll see that the front plate where the bow MG and driver's view port are mounted are sloping back towards the top. And nose of a Tiger is completely sloped.
I am a new viewer of your channel. I have seen your with the Chieftain. Great presentation with facts and interpretations, and indicating when your statement is an opinion. Keep the good work. I appreciate your views based on access to German source material. Thanks
First off great video as always!! I have always supported you guys by purchasing all your books. I have every one in English. Unfortunately my german is extremely rough and out of practice. I see some books that only have german versions. Any chance you guys are working on translations into English for those? Keep up the great work!
Simple answer is submerged welding . Soviets kept their secrets and we forgot about it. Welded joint is weakest part of structure, at least those days, submerged welding provides much stronger joint ,even stronger than plates . I learned that in welding corse. Thank you.
Interlocking (as my original post appears to have disappeared) was an economic measure. Major joints were not plain butt joints. The machining required to rebate joints was expensive in terms of time and tools. Interlocked joints could be gas cut relatively quickly and cheaply. Jigs were still needed for assembly as tolerances were much looser, becoming shocking in some cases later on (joints needing to be packed/shimmed before welding). Chapter and verse: Final Report - Welding Design of German Tank Hulls and Turrets 1948
The Pz-3 snd 4 are relatively small but still considered the best in crew layout and ergonomics in the early years - according to the Chieftain. Sloping costs space and wasnt necessary early on.
This is a very good video that prompted thought about the processes and timelines. The Germans don’t use sloped armor in 1930s because their Panzer generals don’t like it and they are the ones who specified the pre-war designs. It creates ergonomic & storage issues and disrupts team workflow inside a tank, which slows the real rate of fire. If your opponent has his tactics right your armor slope won’t really matter, what they thought was important was firing first. The key point you say about the Panther is “Hitler requested sloped armor” and Hitler was not or never was Panzertruppe. He may have over-ruled those Front Generals, who were now way East preparing Barbarossa, when reviewing lessons from the battle of France with the more sycophantic Generals that he’d begun to gather around him. In 1940 even III & IV Panzers had been successfully ambushed by AT weapons in 1940. This happened in Poland in 1939 too, but German reporting played that down to fit their racist narrative. When you mention the 1939 open- topped armored car (Sd Kfz 222) with its much thinner armor because of the smaller engine, the infantry generals would have been fine with sloped armor, because it was beneficial against 1930s lower caliber AP rounds and doesn’t so badly affect a crew who aren’t trying to work a big, one-shot-kill gun inside a metal box. As for the overlap armor welds, Soviet production replicated the American production lines from the mid-1930s so they looked for the easiest (cheapest) manufacturing process. After they moved their tank manufacture East they did have issues with steel and weld quality and their front plate design change may have been an attempt to account for that reality. Soviet quotas never took account of reality, but you can’t stop engineers from engineering good products. In WWII Germany those same production “lines” are static, craftsman teams who indulged in bespoke part making for each tank. They interlocked front plates because they could and its fundamentally a manufacturing design and not a functional design issue : it doesn’t really change the weight of the tank or its operation. At some point they may have mobilized their “semi-skilled” welders and that may have led to actual or anticipated quality control issues and a redesign of the manufacturing process to correct for that. There maybe something in the records, but it won’t be a very sexy meeting and could be buried in individual factory correspondence? That last statement is just postulation, because I’m not aware of these issues being raised about German tank production before. What I do know is the 1940s post-war top management of VW Wolfsburg were serving British Army officers (Col Charles Radclyffe and Maj Ivan Hirst), so that would certainly be true for places like Kassel too and would have likely adopted British tank production methodology by diktat.
So what's the diffrence for production time in straight welds compared to interlocking armor plate welds? Because cutting the armor plate is only one step, and even then, just cutting straight might still be faster than interlocking. The other question is, what was the maximal thickness that could be welded at the time? Maybe Drachinifel could help with that?
Bernard, take a welding class. You can find a weekend class that will teach you the basics of stick welding. I think you’d enjoy the class. You’d come away with a better understanding of the manufacturing process. And you can ask your welding instructor about the box welds.
As somebody that has to assemble large heavy parts for my day job I have another idea as to why the mortises were there: Ease of assembly. Moving large, heavy, armor plates into exact position for welding is way easier if you had those notches as a guide. This would also explain why germans did this on the "heavies", but not on the 3s and 4s, and why none of the allies really used it. If you're doing well prepared mass production of a tank, you can build welding fixtures that quickly position the plates, regardless of notches, but if youre building them at a lower volume, its easier to cut the plates with notches, instead of building an entire fixture before you can start production
Sloped armor doesn't actually provide an advantage in terms of saving weight. If you expect hits coming from front, you can easily double the armor thickness without doubling the weight with non-sloped armor because you're adding thicker armor to smaller surface area.
@@ФедяКрюков-в6ь Are you suggesting it's impossible for a hypotenuse to be over twice as long than the height of a triangle? An example here. If the length of the triangle is 3x as long as it's height, would the distance traveled between the height and length of the triangle not be longer than that? This is not to say there's no advantage to a sloped armor. Deflection is after all more energy efficient than outright stopping a projectile and against certain ammo types it has an added benefit.
@@strongback6550 well, that's an interesting exercise in geometry, but irc the Panzer III or IV hull shape has the least possible surface, because sloped 'nose' covers the forward wheel shaft and legs of the driver, while the vertical part covers his head in the sitting position. That's how those hulls were designed in the first place. You can build yet another A7V-esque tank with only a vertical armour plate at the front, but in that case the armour surface would be bigger thanks to the unnecessarily enlarged internal volume in front of the driver.
Now I am becoming interested in how exactly they welded those plates together, what did they use for consumables like grinding wheels and electrodes, and how did they procure them? AliExpres wasn't around back in the day, so did they have to produce everything themselves?
I understand there are other earlier vehicles that incorporated sloped armor in their design, but I would argue they are fundamentally different than the approach T-34 took. T-34s are simply, the first ever tank that has a main gun capable of destroying every target it can face whilst also being a good anti infantry weapon, has good mobility in all conditions ,and has enough armor to withstand every single contemporary tank at closer than combat range. Prior examples either used sloped armor for convenience or to save weight to make cheaper/smaller tanks; however the T-34 used sloped armor as a mean to get all three of the firepower-armor-mobility triangle. T-34 basically introduced the world to a brand new class of tanks that later M4 and Panthers falls into, and they are in no way similar in terms of capability and role to their earlier “medium tank” counterparts. That “fast and beat everything whilst remaining reasonable” concept would later be refined with new technology into the MBT concept of T-54/55. And it wouldn’t have been a thing had T-34s been forced to luggage around 80+mm of flat front plate. For that I think its reputation for “pioneering sloped armor” and being “revolutionary” is more than deserved.
Boxy armor can encase more space for the same weight than sloped armor. So the German tanks are roomier and the crews are more comfortable . Also, German tanks had torsion bars and that used a lot of space in the hull. I worked with a guy who was in the US Army in Korea. He was in a M48 tank. That had sloped front armor but was not interlocked. He said in a maneuver a few tanks slid down a long muddy slope into each other. One tank's cast front armor welds broke and fell off exposing the driver.
@@DZGuymed except that's exactly what he did. The narrative was poorly tied together. I'm very confused as to why someone who is known for doing such research and providing such detailed references put this particular product together. I expected to come out of this video understanding why the Germans didn't have sloped armor, and that question was not answered in any way, shape or form. He didn't even acknowledge he didn't know the answer, you just kind of have to piece that together from the way he doesn't answer the question. This would have been a more direct and honest video if he had said up front we don't know. Here are the pieces that go into why it would happen, but none of them makes sense or none of them seem to tie together.
I imagine that interlocking welded plate armor both spreads the stress on a longer weld line, and also the geometry itself also helps to lock the plates in place more strongly also aiding to keep the whole thing together and not relying purely on the welds, i think this was specially important for the germans at that time since their steel lacked components to increade flexibility and reduce overhardness, so with harder plates interlocking is also more effective, but also needed so the plates dont crack at the welding lines or so that the welding lines are stronger
Interlocking might tend to support plates in place during welding, tying up heavy fabrication equipment less. As to flat plate, it seems to me that you don't have to worry so much about shot traps or chaotic deflection. Trying to hit a turret ring would seem to be more challenging.
The question about the interlocking plates is interesting. Given how much extra work involved and waste incurred (where the cutouts create more scrap material) there must have been some clear benefit. I know little about tank design or fabrication specifically but I'd wonder would the interlock allow you to use shallower welds needing fewer passes and less time (using the mechanical interlock to take the stress of the impact rather than having to build up layers of weld to fully fuse the thick plates)? If this is not apparent in sections through the joints then I can't see any saving in manufacturing time and I can only imagine it was purely done for max possible toughness. Perhaps they thought the heat affected zones either sides of the weld would easily shear on impact and they needed the interlock to interrupt the shear line but in practical terms and with the benefit of seeing how others were fine with simple joints it seems mad particularly given the attritional war they ended up in.
Interlocking plates would be able to be assembled and left for welding. Meanwhile the crane can move to next part built tank n place next interlocking armor plate, again n again. Freeing up crane and ensuring plates are in correctly and workers safety. Also by 1943 skilled workers were harder to find , thus interlocking plates may balance structural integrity as weld quality had been reduced.
Probably because they figured it would be easier to add more armor onto the flat designs. It didn't work with the Tiger 1 but Panzer 3 and 4 had quite a few armour thickness upgrades during the war i think. I don't think any German or Soviet designs up armored a sloped hull design during the war. It would probably be similar to the issue that happens when adding ERA to tank that wasn't designed for it.
The interlocking armor has to do with the surface area of the weld. It became necessary as the armor plates became thicker. Depending on the welding technology, and this was hugely different between countries back then, you weld only at the surface of the joint between plates. The interlocking creates more connecting area to weld, and thus stronger weld's. You don't need the interlocking (as much) if there's structural framework underneath or if only one of the plates extremely thick. It's main purpose can also be during construction, to hold something in place so a good weld can be made. That's why you may see it pop up situationally. After the war the hugely thick armor plates disappeared, or were created in different ways. Welding techniques also changed and improved.
My mate is an engineer, he builds and designs trailers. He always uses interlocking where he can. He told me that it provides good strength and shock absorption and stress is distributed equally
@@MarcosElMalo2 Yeah sorry thats what I meant interlocking puts less stress on the welds and distributes pressure evenly. funny enough where the welds have broken (his designing a new trailer for farming) is were the parts cant interlock.
It takes a smart person to assume their right, but to learn more and admit they are unsure. I can always trust this channel to present information in a thought-out and honest way, without letting bias get in the way. And to be fair, the different possibilities presented in this video don't necessarily exclude each other, and more likely, both the structural integrity of welds and the need changes in needs of vision ports contributed to the use of slopped armor.
Didn't the Tiger Handbook advise to angle the tank towards the enemy? By doing this you basically neutralize the disadvantage while still maintaining the benefits.
You are forgetting that German doctrine for PZ III, IV and VI was to take an angled approach to the enemy guns, moving forward by alternating between 10am and 2pm positions. This means the frontal plates ARE angled from the perspective of an opponent at the 12 position. The utility of additional angling in a second plane is questionable in such a position.
There is so much about interlocking... While on pzkpfw 1, 2, 3, 4, 5 there is no interloking and no sloped armor. So why no slopes? The questing is still not answered.
Interlocking will reduce some stress on the weld.normal seam from side all pressure will be on weld.interlocking could get by with less weld at cost of more material preparation.
My guess is that the vision ports and crew comfort/effectivity was prioritized to the point where the engineers thought the slopes would be too much of a negative.
Thanks for a great informative video adressing problems I also asked myself why noone answered them. I love the way you simply state what you know don't yet know and find out later. The hallmark of a trustworthy source. As a former Leopard 1 driver I too noticed the interlocking teeth way of armour wasn't continued. Albeit the phylosophy changed I guess after having lost the war to many Shermans etc. Indeed also what you mention welding techiques and steel quality come into play. As do periscopes we called episcopes due to only mirrors and no optic lenses. I also thought it might have been the room and weight considerations. Sloped armour costs a lot of space inside. The smaller the tank and relative old engines are larger and more awkward old tanks especially British ones had lumps of steel.plate to get it all to fit. So I guess it was a mix of many factors that come into play. Cost, availebility etc. So, the jury is still out on a new line for many video's of choices. And of course talented and less talented engineers or traditions in industry. Anyway, keep up the good work.❤ 16:32 What
The stepped hull is also beneficial for maintenance as it allows for easy access to the transmission. Back in the day the drivetrain was not combined into a dense package that can be lifted out as a single piece instead the components were spaced out more to ease maintenance. The reason why rear engine front transmission was done Is so that both could be placed in a smaller space than what would have been needed if you wanted to put them into a single compartment without compromising maintenance.
Was probably cause experienced welders were in short supply, bet there's a lot of shallow welds on mass produced 4" plates. Bet it helped with assembly too, just lego a hull and leave it, the welders would get to it eventually and they won't need cranes and precise placement
Just a suggestion...the interlocking loooks like a practical assembly idea. Just plonk this plate here...stuff in a spacer for welding gap...weld away...not much training , measuring, thinking ....without being there intimate ..thats posible ? If you had assembly drawings this would establish each asemblg step.
8 месяцев назад+1
That’s the problem with history, it’s so often raised more questions than it answers. Great video as always 👍🏻
I wonder if the interlocking was also to help reduce the warping as well as help line up the plates
8 месяцев назад+1
I recently just cought a massiv error in one of my videos before blasting it out to the world :) The devil really is in the details and unfortunatly most of the time differences arent as clear cut as we simple man would like them to be :) Nice Video
in my mind the interlocking amour joints are a seperate design feature not really connected to sloped or vertical amour, and vision technology again a design feature compromise perhaps led in a direction by better optic development.
I wonder if the mortised weld joints were about getting adequate penetration of the plate. Something like a thick hardened steel plate would be tough to get deep penetration on but interleafing the plates like that would alleviate the problem
I think you have it right. Boxy was easy and it worked given their welding abilities. Evidently, this equation changed for them fire power increased. Really interesting video and topic in general.
I would really consider that halftrack to be "armored". That metal plating is designed to protect from small arms and shrapnel, and imo the sloping is incidental to the shape of the vehicle.
What I had assumed was Germany's tanks were designed for a war that used weaker guns and designed at a time when tanks were novel and so what could/should or could/should not be done with a tank was in question, as well as the fact that a box-like design was easier to design and manufacture.
Betreffend der verzahnten Panzerplatten. Ich war mit meinem Großvater mal im Museum und fragte ihn nach diesen "Zähnen", sah für mich als Kind so aus. Er erklärte mir, diese Verzahnung erleichterte die Herstellung der Wanne, denn die sehr schweren Panzerplatten mussten so nicht per Kran gehalten werden, während sie verschweißt wurden. Nachdem der Kran die Platten so abgelegt hatten, dass sie ineinander gegriffen haben, konnte der Kran anderen Tätigkeiten nachgehen. Es könnte natürlich weitere Gründe geben, aber die Erklärung erschien mir plausibel. Leider kann ich ihn heute nicht mehr fragen.
Wondered about the scene in Pvt. Ryan when someone fires into the "imitation" Tiger's driver port. Wouldn't that be protected by bulletproof glass? Constant rain, snow, bullets coming in might break my spirit.
One of the obvious (maybe oblivious) things to me about sloped armor is it increases the surface area of the armor you need. For heavy designs, and maybe due to efficiencies, the Germans opted for thicker as opposed to bigger. It may also be that when the shell was AP-C, the hardness was expected to defeat the shell. When it got to KEPs or shaped-charge rounds, it concentrated the force enough to defeat hardened armor, and deflection of the penetration path was more a thing. As far as why sloped on early vehicles, bullets on thin armor would dent it, and cause bullet spall up the face. The US was casting hull parts by the end of the war, getting rid of the welds.
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It might be worth your time to look through Battleship New Jersey's channel, as they have made a number of videos on the implementation of welding into the construction of the ship, and the transition from riveting to welding.
As welding was still an experimental process at that time they might have gone overboard with it, and all throughout the ship you can see how all the welds between the armour plates use a unique "scalloped" design, I guess to get as much surface area as possible, as opposed to a welding in a straight line.
Perhaps the Germans were trying increase the surface area of the welds with the interlocking plates?
Is it possible that the interlocking of the plates could have been done as an aid to properly fitting and aligning the armor to make the assembly and welding easier and more consistent? I don't what the difference would have been in the factories regarding how the workers fitted the plates in position prior to welding.
Short answer. It was unnecessary. Germans achieve this effect through tactic and proper angling against the target. While having profit of larger internal space. T-34 is heavily overrated and its angled armour was more due to poor quality of Soviet tank crews. Germans start using this effect more with they late tanks (if you ignore that King Tiger have horrible shot trap), where need of space was not so crucial anymore.
uh the library grew a lot, before there were good works but not of my interest, now it is different!
Germany forgot to buy the WW2 season pass and the sloped armor DLC was only available to non-premium players in '44
Gotta hate pay to win wars
Sloped armor or not a small fast and stealthly premium ( pay to win) light tank or TD comes on the battlefield that some how bounces hits from large calibers guns, is armed with a rapid fire small caliber cannon OR a large rocket that always seems to kill your crew, track you or set your tank on fire.
Understandable, these "service-based" monetarization models suck.
They paid for armored cars DLC though
@@UnfollowYourDreams"War is a pay-to-win game" (c) Giovanni Trivulzio, famous wargame designer of late Middle Ages
Thank you for this perspective. I've been puzzled that so many people fixate on the idea that the concept of sloped armor began with the T-34. You can see sloped armor on the ironclads CSN Virginia, Arkansas and Albemarle. Also thousands of examples in medieval tournament armor. This principle had been understood and applied for centuries.
Can't argue with that one!
The concept of a fort made of wagons is known at least since the first Indo-European nomads begun spreading throughout the Eurasia, but people fixate on the idea of wagenburg being invented by the czech hussites. Why? Because they were the first ones to make it into a system and employ such tactics with significant results against an opponent deemed to be superior in all aspects previously. The same goes to T-34. Germans didn't have all the bright ideas in the world, whatever the wehraboos are imagening to themselves while jerking off on panzers
Leonardo DaVinci tank concept also had sloped armor
@@pex_the_unalivedrunk6785 gErMaN tAnKs hAvE sLopEd aRmoR aT tHe nOsE tOo!!1
Only that no other tank made sloped armor so effective and efficient as the T34 prior to that point. That is why it is celebrated so much. And evidently the principle had not been understood and applied for centuries when the T34 applying it basically seemed like a miracle to the Germans
When people think Germany didn't "understand" sloped armour...I always wonder, 'Where do you think their engineers got their degrees?'. Sloped surfaces are basic physics/geometry/material sciences '101' level stuff.
Somehow German's completely missed the medieval armor period apparently lol
Yes it's Pythagoras law
Also, after WW1 Germany had many restriction on what they can and cannot do militarily. Soviet Russia helped educate German military in their war academies. And USSR and Germany where allies it the beggining of the war from 1939 to 1941. So Germans knew very vell what Russians where doing.
And yet somehow these geniuses never applied it anywhere in tank design producing complete trash design one after another until Russians made them laughing stock with T-34. Go figure...
@ Bullshit, if they were allies, nazis wouldn't send arms and men to countries attacking the soviets and soviets would help them with fighting somewhere. Pull the other one, yes I know russophobic revisionists produce endless nonsense today but there was no alliance, mild neutrality at best. And funnily enough soviet designs went completely ignored and laughed by nazis (because these dumb slavs can't produce anything better than us, right?) until they saw T-34 in action and collectively browned their pants...
Also welding had just been adopted for major industrial production. So welding processes were there but structural design had not really been adapted to the process. The interlocking plates are a really good example. They only chose to do so because the structural integrity would be better this way because they did not manufacture full weld penetration on the armour plates. This was a compromise on integrity and welding. The plates support themselves somewhat better by interlocking. But it makes welding even harder. You can tell by the poor weld surface and layers on these joints.
True. Interlocking increases the length and complexity of the weldseem, which was arguably the weakest part of armor back then.
Right, but the interlock keeps the plates better in position. This especially when welding plates in complex angles by less professional staff.
So the interlock might simply have been a need for manufacturing. Just a thought - not a fact
@timob3490 True, but most of the welding was used in structural steel, not armour steel.
I don't think this is the reason why it is used in armoured components, but in sheetmetal products those battlements are used (usually cause it is a 'free' functionality in a laser cutting process) to both position the individual plates, reduce the amount of weld (not the case in the armour) and to limit deformation due shrinkage of the welded area, actually, the weld shrinkage (in a proper quality weld that doesn't crack!) pulls plates in a stronger connection.
I wonder if it was an attempt to limit welding jigs, by having the plates interlock closer together themselves? It feels a bit ungerman lack of Handwerkskunst, but it doesn't really show up til Germany really wants to ramp up production.
Some of the welds look terrible with inadequate penetration. It looks not so much like welds but like they were stitching the plates together with small diameter filler.
The weld on the M-10 looks sloppy but adequate. We can’t tell from a video of painted surfaces, but I imagine that the plates had been bonded into a single plate.
I find it hard to believe that the Germans didn’t understand the welding process, so I wonder in the “joinery” was to compensate for a shortage of skilled workers on certain production lines.
It would have been funny if the used dovetail joints. 😅 Supposedly stronger than finger joints.
@@carstenlichy-bittendorf3902 - A novice welder will not weld such complex joints well.
“I was [certain] at one point and then I started to ask too many questions.”
I think we’ve all been there. Sometimes the more information one has the less clear the answer becomes. I appreciate you being upfront about that.
From an engineering view I want to mention 3 different effects of interlocking plates:
1. Your welding surface is bigger. Welds are a weak point, therefore you want to spread the load over a larger surface.
2. Shear forces between two plates are put onto the much stronger "teeth". (E.g. side view of a shell hitting the front of a panther. The frontal plate is forced inward and up by the impact. The interlocking on the sides of the plate works directly against these forces.
3. Welds handle load in different directions differently well. So interlocks change the direction at which forces act on the weld. (E.g. Frontal view of a shell hitting a panthers' upper plate: Again the plate is forced up and into the tank. A flat weld between upper and lower plate will just get pulled apart and open like a zipper. At interlocks, the weld experiences shear forces, which it can handle better and prevent the whole weld opening up as one.)
Thanks for the video about this interesting topic!
Considering welding was quite a new technology and yet to mature, the welds of the time were or at least could often be weaker than after the war. I'd imagine once the welding techniques developed and welds became more reliable and better understood, the need for complicated joints was no longer there (thus interlocking disappeared from use), but it might well have been at the time they were used.
Large metal plates warp during welding. To prevent this, one needs to either build massive supporting framework or interlock the plates
Considering that in order to punch through thick armor like that ,a force of impact of thousands of tonnes-force is required the fact that sometimes the welds don't break is surprising.
All the German tanks still has slopped armour, it just wasn't slopped everywhere because of space problems. Even the front plate of the Tiger was slopped backwards a little 10 degrees I think.
Yes, exactly this. The Panzer III, IV, Tiger, all had sloped armor, just at very shallow angles. Sloping armor is always tradeoff between extra effective thickness, and decreasing interior volume and crew ergonomics. Soviet tanks are infamous for their atrocious crew ergonomics and coffin-like interiors for a reason.
@@_ArsNova Agreed, I thought sloped vs. shallow-sloped armor was just a design and engineering choice. Sloped armor means more metal (the hypothenuse of the triangle) which weighs more (unless made thinner, in which case you lose the benefits somewhat) and covers a larger volume inside the tank. Not all of that volume is useful, and will be used mainly for the driver's and bow gunner's legs.
The problem with sloped armour is that it doesn't actually help as much as people think. Sure you can tilt an armored plate 45 degrees, but in doing so you have to make the plate itself bigger to cover the same space as an unsloped plate. Sloping also creates a lot of space inefficiencies. You can cram more into an After 8 mint box than a Toblerone box.
@@TallDude73 Slopped armor allows ricochets and this is its major advantage over straight armor of similar thickness. Disadvantage is that you have less space inside, i.e. you have cramped tanks (well known fault of Soviet tank design) .
@@mrdojob People also forget that sloped armor is only useful as long as it's sloped. It is rendered worthless if you happen to be caught in a position where that angle is nullified, such as while the tank itself is on an angled slope, or is being fired on from higher ground.
Sloped armor is not a magic bullet (pun intended), a sloped plate will have more effective thickness, but it needs to be longer to cover the same frontal height.
Those two effects will exactly offset, the main advantage of sloped armor comes from normalization effects, simpler production of thinner plates and better surface to volume ratio, when designed correctly. For modern APDSFS projectiles with a large degree of positive normalization, sloped homogeneous armor can be worse than a flat plate.
Especially in a WW2 context there are definite advantages, but also tradeoffs.
Yes! Thank you! It always drove me nuts to hear that 'sloped armor increases effective thickness for the armor without increasing its actual thickness, so you save weight' when simple geometry shows the increase in length of the armor plate would cancel out any supposed weight loss.
This, 100%
I have been writing this for some time as well ... angling a plate doesn't save weight by itself. The weight saving come from decreased surface area you need to cover and less internal volume.
But can you explain these 'normalization effects'? What are these and how does it affect flat and sloped armor?
@@quantum340 If a projectile hit's a plate of armor at an angle, it gets deflected. For a normal upwards sloped plate, most basic bullets get deflected upwards, like a ball. They don't penetrate the line of sight thickness, they need to penetrate a longer way, leading to increased effectiveness of sloped armor, this is de-normalization.
Specialized armor piercing caps will "bite" into the armor, deform and turn the rest of the projectile downwards.The projectile will now only need to penetrate a shorter distance, closer to the plates actual thickness. This is normalization (the projectile turns towards the normal [perpendicular] to the plate) and this makes sloped armor less effective.
Modern armor piercing projectiles and especially APFSDS have positive normalization.
Example of WW2 era de-normalization
ruclips.net/video/ezf0bX-5R0A/видео.html
Example of APFSDS normalization
ruclips.net/video/0t-Vi4unTLQ/видео.html
That's why T-34 was supposed to made of high hardness steel to make advantage of the armour angle to deflect shells, but it had side effect of internal cracks hurthing the crew on hit, and Soviets had trouble maintaining any production standard in the first place.
This type of keyed joint is commonly referred to as a "box joint" in English. You may wish to contact the Australian Armor Museum for their opinions about keyed armor joints, their restoration shop has actually welded blown-up German armored vehicles back together. They observed minimal and inconsistent use of armor grade stainless steel welding rods in the late production Stug 3 they are currently restoring, no doubt due to late war shortages,.
I am very curious about the weld penetration the Germans were achieving (or failing to achieve). And I further wonder if this was caused by material shortages (as you suggest), skilled worker shortages, or welding technology lagging plate thickness.
If box joints were supposed to improve structural integrity, why not go further and use dovetails? 😂
@@MarcosElMalo2 the box joint is already inefficient compared to a straight line weld. Think about the fact that this would further increase the length of the weld and make the fitting of the armor plate even more difficult than a box joint no doubt does. Man hours are expensive, this might have been a compromise solution.
In manufacturing, interlocking plate would make the jig necessary for hull assembly, simpler, as the locking tabs would insure alignment in two directions. Since these plates were heavy heavy heavy, simplifying the jig would be a goal of any factory engineer for sure. The Soviets may have tried it for the same reason. To simplify alignment for assembly. Thanks Bernhard!
My eyes almost roll a full 360 degrees any time I see someone talk about sloped armor as if it began with the T-34. The Germans had been sloping tank armor since WWI with the A7V. The literal first "tank" concept in Leonardo Da Vinci's drawings from 1487 had sloped armor!
so what you are saying is that leonardo da vinci was russian?
Da Vinci's tank didn't have sloped armor for the purpose of increasing protection, but because of how the armor would be constructed, bound at the top.
@@josephahner3031 Perhaps, but even back then people understood that cannonballs and other projectiles were more easily deflected by angled surfaces.
Fun fact, Leonardo Da Vinci's tank could withstand a 76.2mm ZiS-3 AT gun at distances of between 600+ meters.
@@Blox117 - Or German LOL
Vehicle designers of that time had only a vague knowledge of the effects of shell denormalization, and how to instigate or mitigate it. Their thinking of the efficiency of armor boiled down to mostly sine of the angle from horizontal. What it means is that they said "80mm at 40 degrees from horizontal? That´s just about 125mm. That´s not good enough." Meanwhile the reality is that almost no shell was stable enough in order to "bite" into that angle without major deviation upwards.
Modern simulations suggest that Panther II with its 100mm thick front armor would be almost impenetrable even to the mighty Soviet 122mm gun.
125mm is good enough. It is very good. Tiger I was considered almost impossible to knock out and it "only" had 100mm front armor. So personally would I consider 70mm armor with say a 50 degrees slope (or more) to be good enough for a medium tank. Having thicker armor than that would only be wasteful in my opinion and bring extra weigth, slow down the tank, make the tank too heavy to the front, having too much armor at the front so weight have to be saved by cutting down side armor and making the tank weaker and vulnerable to hits from the sides, rear and top.
So I think your suggestion is a bad idea.
And then it also depends on the type of tank. Hetzer would I consider to be extremely well protected. Its small and easy to hide. And the enemy cannot shot at you if he does not know that you are there. And when he discovers you, then he will have a diffucult time hitting a small target like the Hetzer. And Hetzer in a hull down position its even harder to see and to hit. And if you manage to hit it, then will you probably only hit it where the armor is the strongest - the frontal top of the hull. And there will the thick armor with a sharp sloping give pretty good protection, even against pretty large caliber guns at longer ranges.
So its a pretty cost-effective use of armor the Germans had with this little vehicle.
reality harsh, IS-2/3 had zero problems with their 122 mm against Tiger's.
@@nattygsbord you just described T-34/85. my congratulations!😁
@@sergeyboychuck8872
T-34 and M4 Sherman did have sloped armor and somewhat okayish thickness. So I think they were better designs than the German tanks that either had crappy armor or was too frontally heavy.
I guess low quality steel in the russian tanks made their frontal armor not so fully effective as their american counterpart. And bad tank crews and poor ergonomics and other shortcomings could probably explain much of the high soviet tank losses.
But the general idea was sound. It had frontal armor of the right thickness. And it had a gun of almost the same calibre as a Tiger I and inside a medium tank.
@@sergeyboychuck8872 But you are comparing apples with oranges I think. Tiger I was an old design. It was very good at its job facing tanks made before its introduction in august 1942. But it was never really meant to be invincible against tanks made after that. And the Soviets also deliberatly armed their tanks with the only guns they had that had been proven effective against the Tiger - such as the 85mm Anti-aircraft gun they put in the turret of T-34. And the 122mm gun they gave IS2. And the 152mm gun on SU-152 and ISU-152.
No tank could survive a hit from those guns. Just like no tank today can survive a direct hit from a 155mm or 152mm artillery piece. But it would be stupid to say that armor protection does work because it cannot survive direct hits from high calibre guns.
Keep on asking questions, they are interesting. Answers are better, but you can't have answers without questions first.
I'm not sure this makes any sense to me, but as a young man I knew a "tank escort" for the German Army (the guy who walks along side tanks into combat), He served from the beginning of the war to the fall of Paris. Mainly he escorted tiger tanks on the Russian front until losing a kidney and being assigned to guard a tiger during the fall of Paris, where the tank overheated and he got captured still escorting it.
So here's the weird part... he told me that the way the Tiger was designed to deflect shells straight upwards. And he claims that's exactly what they did in his actual experience on the Russian Front. He mentioned that Tiger crews preferred to assault or defend from the high ground. and he also added that most Tiger gunners could hit a moving jeep at 1000 meters.
While I have to agree that it's unlikely that incoming shells would ever come at a tank straight on I don't quite understand why incoming shells would always ricochet straight upwards.
Lastly, at least through quite of a the war, German tankers weren't too concerned with Russian tanks or most other Russian munitions that they were encountering. For the most part they felt that they could outrange the Russians and survive incoming hits.
I wish I remembered more of that conversation, but that was nearly 50 years ago....
Perhaps for WW 2 buffs in general, I'll add a couple of fun trivia that he told me:
On the offensive towards Moscow the tank guards were usually tasked with capturing meals. For the most part this involved capturing Russian soldiers and confiscating their food. They might capture up to 60 Russians in a morning forage and he said, the Russians didn't necessarily have bullets, but they always had good food.
He went on to tell me that things went terribly wrong when the quality of the Russian Food declined and the Russians suddenly became flush with resources and ammo. In his mind the Russians had somehow built a great factory that produced everything they needed and cost Germany the war. He didn't speak Russian or English, but he memorized the name of the factory and he wrote it on the barn wall in pencil.... it read...."Made in USA" which he pronounced as one word in German and I didn't get it until he wrote it. I of course translated the word for him and we both walked away from the conversation having learned something.
It's been 50 years and I thought I might share this little story before it's lost to history.
"Madeinusa", thanks for sharing this.
Thanks a lot for sharing this.
Great history! 50 years ago? How did you meet him?
@@2Pzp I spent a summer living on his farm in Germany as a kid. He was my mom's first husband's step brother. He didn't have a son, so he spent time with me teaching me about farming and every once in the while sharing his WW 2 experiences with me.
He was a quiet and contemplative man who liked to work with his hands and with animals. He made it all the way to Moscow and ended his military career in Paris. Along the way he earned an Iron Cross with decorations and I suppose is now one of the many that were heroes for a time and have since been lost to history.
@ZaHandle Yup. It's easy for a 21st century English speaker to understand, but can you even imagine how confusing and terrifying it was to a German soldier who grew up a farm boy and neither spoke English nor Russian and only had Nazi propaganda and one clue "Made in USA" to help him understand why his life and the war was going to shite.
From welder's perspective: straight welds are faster and worker doesn't need a lot of experience to make a good weld. Interlocking plates present a challenge because on one hand welder can do his job in such a way that will prevent material/ weld stress ( comparing to straight weld). On other hand interlocking joints will take much more time, effort and weld quality will be often questionable. Look at pictures of knocked out tanks. Very often it's the welds that let go,not armored plates.
Want to make welder's life hard? Design welds like those of Churchill tank ( as observed on example in Borden Base Ontario, Canada). What a nightmare.
And if it’s the welds blowing out, that means their welders aren’t getting full penetration.
American examination of German armor, specifically a PzKpfw III gave a low opinion of the choice of welding rod, but a high opinion of the armor plate.
Very interesting. Not all research arrives at a neat, interlocking conclusion.
Thank you for being honest. When one speaks plainly about what one knows and one knows not, a new plethora of information is conveyed. It also messes with your intellects in a good way... certainty is a transient state. That fact is often forgotten.
Great channel!
Cheers.
Love the progression of this video as more information comes to light👍
Tanks in WW1 had sloped armor. Look at the Renault FT. German designs tended to be boxy because of space limitations! They were already using torsion bar suspension in many designs which used a lot of space and the sloped armor further reduced interior space!
Another thing to consider with the interlocking plates is that you get more weld length and it is split across both plates. A simple butt joint leaves the plates subject to flexing along the weld length, while interlocking provides more rigidity. Might help keep welds from failing when a shell hits and flexes it.
The lack of redesign from boxy armor to the slope might also comes from the success of the 39' to 40' campaign. Something in line of "if it ain't broke, don't fix it", well until they were fighting against soviet. I would argue too that the Germans were also misunderstood their post-battle analytics from the earlier campaign by putting their tank's effectiveness factor equal to their war doctrines, as I believe their war doctrines are the true major contributor for their success in the early war.
This is a channel with great integrity.
As long as you do not hit his seams.
This video left me with more questions than answers. And I think that's cool, so thank you!
Thanks! Same here :)
One important aspect of straight box armour is that you can use the inside surfaces much more efficiently to mount equipment, and it generally gives more room to the inside.
Interlocking armor plates is an interesting but separate topic from sloped armor, because clearly you can do one without doing the other. About the positives and negatives of interlocking armor plates: first off, as you mentioned, thick tank armor is hard to cut (especially with the precision necessary to create interlocking), cutting it into this shape will take more time because the length of material you need to cut is longer than a straight line, the same problem appears with welding. Obviously these are two very expensive, material and time consuming processes, I think that they probably had a reason for them. I think the main benefit to interlocking the plates like this is impact resistance. Welds are generally more brittle than the slabs of armor that they join, when they get hit, they sometimes crack, even more rarely, the entire weld cracks and the structural integrity of the hull is compromised without a full penetration of the armor. I think that this is what they wanted to deal with. If a weld like the one on the Tiger II is impacted, part of the weld might crack, but the crack will only travel down the weld in a straight line, once the crack has to make a 90 degree turn to follow the weld, a lot of the energy will dissipate. This makes the weld tougher even though Germany did not have the best welding technology as you mentioned. This is of course all speculation on my part based on my limited knowledge of armor manufacture, welding, material science and other topics. If I got something wrong please tell me!
i remember reading from some book that boxy pz was cos sloping reduce space inside the tank
Hah! Yesterday I was looking at the pictures I took at the Panzermuseum and wondering why the interlocking plates. Just a few hours later you come up with this video... 😲 Great work, Bernhard!
SIRI is always listening 🤔🇬🇧
It takes ballz to say "I don't know" in an educational video.
I really liked the video and highly appreciate your honesty on the level of understanding you have. I was a little bit surprised to see the first part of the video and i think it is rather interesting to think about the connecting mechanisms of armor plates. I personally think it were the drivers vision and the crews and engineers being used to the layout. It is not completely neglecting sloping, it just tries to minimize the size of the visory hatch. Also it might have been an influence that the tank would effectively become a little shorter. As soon as more communication was inteoduced and also no more direct vision was required it was possible to drive without that weakspot.
I really wonder if the big hatches of sloped vehicles or the vertically closing hatches of german tanks were seen as a weakspot by the soldiers of that time or as a necessary thing because driving blindly was seen as more dangerous than having a thin weakspot.
Writing this before having seen the video.
Look at the turret of the Panzer I and you will see sloped armor. There was sloped armor right from the beginning. Maybe not as much as later, but others didn't have much sloped armor as well. Look e.g. at the british tanks including all the Vickers copies...
Also with the early recon cars like SdKfz 222 you find sloped armor.
The interlocking welds/steel plates can also be found in warships like the Iowa class New Jersey. Basically, by increasing the surface you'll get a stronger weld.
That’s not how welding works. It’s very different than wood joinery. In welding, you are bonding two pieces into one solid piece. The weld needs to penetrate the thickness of the metal and you need the proper amperage going through the electrode/filler rod. You are fusing metal together.
In a wood joint, increasing the surface gives you more glue surface. That’s what you’re thinking of.
The interlocking plates you saw more likely were to aid in more rapid construction-it would allow more rapid positioning of the plates before they were welded.
@@MarcosElMalo2a longer weld means the two metals are joined together over a larger surface, increasing strength
The mechanism might be a little different to glue, but in this regard it's no different
The T-34 was a horrible tank to have to fight in. The sloped armor on a relatively small vehicle was a major reason for that. The Germans went to sloped armor as their tanks got bigger (and therefore roomier for crew and ammo, etc.) Better armor protection isn't worth it if your crews can't fight the vehicle well.
Were the Panzer IVF2-J models anything more than adequate stopgap tanks, or were they legitimately excellent designs until the Panthers were fully ready. And by 1944, were they still worthwhile to produce, or were they already outdated?
The main reason why early WWII German tanks did not have sloped armor, is because the trade offs are simply not worth it.
While sloped armor does increase the chance of a round bouncing of the plate, and increases the thickness of the armor that has to be penetrated, as the incoming round is hitting at an oblique, what is lost is interior crew space and maintenance ease.
That interior crew space allowed German crews to be much less stressed from the travel than a T-34, plus the Germans had much better visibility. In 1941, a T-34 crew would be exhausted from trying to move to the battle, then be blind (lack of vision ports) and deaf (no radio) during the actual combat. That big gun and thick sloped armor required a really well trained crew to make use of it, and that was in short Soviet supply in 1941.
Remember, the goal of a German tank in early WII was to not get hit. You can read reports about PzIIIs dodging 76.2 anti-tank rounds, as in actually seeing the muzzle flash, then moving to avoid being hit. Armor was there to only protect against machine gun fire, not to survive a 40mm+ hit.
The reason why the Germans used interlocking plate armor, once they began to slope the armor, is to reduce the chance of the weld breaking. You can still see weld breaks on German tanks, but they are much less common than on Allied sloping armor.
A tank with a broken weld is essentially a useless tank, and it can't be fixed in the field, if it can be fixed at all. Not only is the armor now compromised, and any additional hit will likely destroy it, but things like the turret ring are affected.
Each tank hull was precious to the Germans in late WWII. They expected tanks to get hit and keep fighting, and then go out and fight again without being sent back to a factory for repair.
If a Soviet tank had a ruptured weld, well the tank was likely destroyed anyway, but even if the crew survived, just get a new tank. Soviet tank life was SHORT, even if not destroyed in combat.
Same with the Americans and British. Late war, tank hulls can be replaced. Crew is way more important than a tank hull. Broken weld, just get a new tank.
This doesn't mean the Allies didn't try and salvage hulls or rebuild tanks in the field, but the value of any single hull was of less importance. After the Battle of Stalingrad ended, the Allies were not short of tank hulls.
The Germans were ALWAYS short on tank hulls, so they had to engage in practices that increased the longevity of each hull. Early war, that was to use speed and vision to avoid incoming fire, in the latter part of the war, it was to still try to avoid being hit, but rely on armor if hit, and keep relying on that armor until there was a penetration.
Many of the issues with the T-34 stem from design choices, not because of sloped armour. The Soviets and Germans had different philosophies when it came to making a tank, and when you're a country who favours quantity over quality AND are trying to modernize your entire army before its too late, you're going to make sacrifices. Sacrifices, such as radios and vision ports.
@@ASlickNamedPimpbackthe absence of radios and vision ports were a lack of and a flaw respectively, not really sacrifices. When western radios flooded in via lend lease and they had the opportunity to design new turrets, in came radios and vision ports
@@jurassicturtle3666 design choices like “hey, do we have enough radios to supply all our tanks WITH radios” “nope” alright then, don’t bother” and “hey, how’s visibility on 8’o-clock?” “It’s terrible” “how bout we add a gunners port or something?” “We’d have to extend the hull” “don’t bother, it’d take too much time”?
1. All T-34s had the ability to receive radio signals, but not all had the ability to send them (otherwise it would be strange for pragmatic councils to allocate a whole person just to fire a machine gun). The same situation was with German tanks.
2. Unlike the T-34 crew, the Tiger crew’s stress began during field repairs. Almost all German armored vehicles have a terrible protection to weight ratio, due in no small part to a lag in armored vehicle design. The Soviets, having less developed production and a lack of resources (especially human resources), were able to bypass the German tank builders in many aspects, for example - weight, quantity, diesel power plant.
You correctly noted that the Germans did not have enough tanks (I explain this by saying that the tank builders of the Reich wanted to make money, not win the war. The story with Zimmerit is indicative in this regard), but personnel, or rather the lack thereof, became no less a problem.
You probably know the successes of the Wehrmacht in 41 (although what kind of successes were there, only one of the main intended goals was achieved - the capture of Kyiv), that having less advanced tanks, the Panzerwafe achieved better results than in 43. The basis of this success were skilled soldiers, veterans who had gone through campaigns 39 /40 years. These veterans formed the basis of the German tank forces (the ratio of infantry and tank units is approximately 1/5). It was they who broke through the Polish/French/English/Soviet fortifications/defense lines and it was they who suffered heavy losses in 41, which led to a decline in the combat effectiveness of German tank forces.
Now let's sum it up. When German tank units, the basis of the offensive potential of the Wehrmacht, suffered heavy losses, they were sent to the rear for reorganization, where they brought up new recruits to the level of veterans and waited for the arrival of new equipment. All this took a long time, for example 8 months. And while the Wehrmacht elite was in the rear for replenishment, there was no one to attack, because the infantry units remained at the level of development around 1917 due to the fact that almost the entire budget of the Reich was invested in tank units and there was no money left to equip the infantry. And this was during a period when the initiative belonged to the Wehrmacht, when the Soviets began to counterattack, they had to pull away tanks to cover gaps in the defense, which did not allow tank units to be concentrated again for large strikes. This is what we see from the activity of the Wehrmacht - 41 offensives in 3 main directions (center, south, north), 42 only one main direction (south), 43 large-scale offensive on a local section of the front (citadel) and more and more serious offensive actions were not carried out, transition to defense.
One thought about the use of interlocking plates in welded construction. Even before the development of fracture mechanics, it was well known that welds were more brittle than the material that was joined by the weld. Perhaps this interlocking joint design was meant to limit the extent of a weld failure due to impact from a shell.
My guess, If you have good steel quality, you can get some good armor, slope armor is just A factor, not THE factor, not to mention slope armor can limit the space inside your tank if not designed properly
Hi, The German tanks adopted interlocking armor because the steel quality was much lower. The German steel had a much higher carbon content which made the welds subject to cracking along the weld seams. the Interlocking was a way to reduce the weld stress on the joints.
Source?
I'd like to see how the hulls were set up in their jigs for welding. I could see it being easier to quickly and cheaply construc hulls without having to build complex forms to hold the plates in place. You cut the plates to size, then interlock them with gauge blocks as spacers then weld it up removing spacers as you go.
Note the interlocking shows up on newer designs when more tanks are needed quickly and Armour is thickening.
Just a thought.
how do you even weld huge armorplates like this?
would be interesting to see someone explain it
The thing about German tanks and sloped armor is that German tanks from the PzKpfw III up to the Tiger did have sloped armor, at least on the front of the hull. It's just that it's not set back at a very steep angle, but it is sloped and not sitting at 90 degree vertical. If you look tonkas like the Tiger from the side or a at slight angle, you'll see that the front plate where the bow MG and driver's view port are mounted are sloping back towards the top. And nose of a Tiger is completely sloped.
I am a new viewer of your channel. I have seen your with the Chieftain. Great presentation with facts and interpretations, and indicating when your statement is an opinion. Keep the good work. I appreciate your views based on access to German source material. Thanks
I didn't see the answer to the title in the video.
First off great video as always!! I have always supported you guys by purchasing all your books. I have every one in English. Unfortunately my german is extremely rough and out of practice. I see some books that only have german versions. Any chance you guys are working on translations into English for those? Keep up the great work!
Thank you! Stug is being slowly being translated.
Simple answer is submerged welding .
Soviets kept their secrets and we forgot about it.
Welded joint is weakest part of structure, at least those days, submerged welding provides much stronger joint ,even stronger than plates .
I learned that in welding corse.
Thank you.
Course
The US was useing a lot of submerged arc welding to make the liberty ships.
@SuperFunkmachine don't know about that.
However, my comment explains why no interlocking joints.
It wasn't needed as welding technology improved.
Interlocking (as my original post appears to have disappeared) was an economic measure. Major joints were not plain butt joints. The machining required to rebate joints was expensive in terms of time and tools.
Interlocked joints could be gas cut relatively quickly and cheaply. Jigs were still needed for assembly as tolerances were much looser, becoming shocking in some cases later on (joints needing to be packed/shimmed before welding).
Chapter and verse: Final Report - Welding Design of German Tank Hulls and Turrets 1948
The Pz-3 snd 4 are relatively small but still considered the best in crew layout and ergonomics in the early years - according to the Chieftain. Sloping costs space and wasnt necessary early on.
Sloping does not by default reduce spac by default, only in a direct 1 to 1 replacement.
Question: when hit, or when on the move over rough terrain, do the interlocks reduce/prevent crack propagation along the weld lines?
Thank you. Great channel and great video.
This is a very good video that prompted thought about the processes and timelines.
The Germans don’t use sloped armor in 1930s because their Panzer generals don’t like it and they are the ones who specified the pre-war designs. It creates ergonomic & storage issues and disrupts team workflow inside a tank, which slows the real rate of fire. If your opponent has his tactics right your armor slope won’t really matter, what they thought was important was firing first. The key point you say about the Panther is “Hitler requested sloped armor” and Hitler was not or never was Panzertruppe. He may have over-ruled those Front Generals, who were now way East preparing Barbarossa, when reviewing lessons from the battle of France with the more sycophantic Generals that he’d begun to gather around him. In 1940 even III & IV Panzers had been successfully ambushed by AT weapons in 1940.
This happened in Poland in 1939 too, but German reporting played that down to fit their racist narrative.
When you mention the 1939 open- topped armored car (Sd Kfz 222) with its much thinner armor because of the smaller engine, the infantry generals would have been fine with sloped armor, because it was beneficial against 1930s lower caliber AP rounds and doesn’t so badly affect a crew who aren’t trying to work a big, one-shot-kill gun inside a metal box.
As for the overlap armor welds, Soviet production replicated the American production lines from the mid-1930s so they looked for the easiest (cheapest) manufacturing process. After they moved their tank manufacture East they did have issues with steel and weld quality and their front plate design change may have been an attempt to account for that reality. Soviet quotas never took account of reality, but you can’t stop engineers from engineering good products.
In WWII Germany those same production “lines” are static, craftsman teams who indulged in bespoke part making for each tank. They interlocked front plates because they could and its fundamentally a manufacturing design and not a functional design issue : it doesn’t really change the weight of the tank or its operation.
At some point they may have mobilized their “semi-skilled” welders and that may have led to actual or anticipated quality control issues and a redesign of the manufacturing process to correct for that. There maybe something in the records, but it won’t be a very sexy meeting and could be buried in individual factory correspondence?
That last statement is just postulation, because I’m not aware of these issues being raised about German tank production before.
What I do know is the 1940s post-war top management of VW Wolfsburg were serving British Army officers (Col Charles Radclyffe and Maj Ivan Hirst), so that would certainly be true for places like Kassel too and would have likely adopted British tank production methodology by diktat.
So what's the diffrence for production time in straight welds compared to interlocking armor plate welds? Because cutting the armor plate is only one step, and even then, just cutting straight might still be faster than interlocking.
The other question is, what was the maximal thickness that could be welded at the time? Maybe Drachinifel could help with that?
Bernard, take a welding class. You can find a weekend class that will teach you the basics of stick welding.
I think you’d enjoy the class. You’d come away with a better understanding of the manufacturing process. And you can ask your welding instructor about the box welds.
As somebody that has to assemble large heavy parts for my day job I have another idea as to why the mortises were there:
Ease of assembly.
Moving large, heavy, armor plates into exact position for welding is way easier if you had those notches as a guide.
This would also explain why germans did this on the "heavies", but not on the 3s and 4s, and why none of the allies really used it.
If you're doing well prepared mass production of a tank, you can build welding fixtures that quickly position the plates, regardless of notches, but if youre building them at a lower volume, its easier to cut the plates with notches, instead of building an entire fixture before you can start production
Sloped armor doesn't actually provide an advantage in terms of saving weight. If you expect hits coming from front, you can easily double the armor thickness without doubling the weight with non-sloped armor because you're adding thicker armor to smaller surface area.
Nope, you can't physically make non-sloped armour to have twice as little less surface as sloped armour, look at the actual design of tanks
@@ФедяКрюков-в6ь Are you suggesting it's impossible for a hypotenuse to be over twice as long than the height of a triangle? An example here. If the length of the triangle is 3x as long as it's height, would the distance traveled between the height and length of the triangle not be longer than that?
This is not to say there's no advantage to a sloped armor. Deflection is after all more energy efficient than outright stopping a projectile and against certain ammo types it has an added benefit.
@@strongback6550 well, that's an interesting exercise in geometry, but irc the Panzer III or IV hull shape has the least possible surface, because sloped 'nose' covers the forward wheel shaft and legs of the driver, while the vertical part covers his head in the sitting position. That's how those hulls were designed in the first place. You can build yet another A7V-esque tank with only a vertical armour plate at the front, but in that case the armour surface would be bigger thanks to the unnecessarily enlarged internal volume in front of the driver.
Look at warship design decades earlier. Everybody knew about sloped armor.
Now I am becoming interested in how exactly they welded those plates together, what did they use for consumables like grinding wheels and electrodes, and how did they procure them? AliExpres wasn't around back in the day, so did they have to produce everything themselves?
I understand there are other earlier vehicles that incorporated sloped armor in their design, but I would argue they are fundamentally different than the approach T-34 took.
T-34s are simply, the first ever tank that has a main gun capable of destroying every target it can face whilst also being a good anti infantry weapon, has good mobility in all conditions ,and has enough armor to withstand every single contemporary tank at closer than combat range. Prior examples either used sloped armor for convenience or to save weight to make cheaper/smaller tanks; however the T-34 used sloped armor as a mean to get all three of the firepower-armor-mobility triangle.
T-34 basically introduced the world to a brand new class of tanks that later M4 and Panthers falls into, and they are in no way similar in terms of capability and role to their earlier “medium tank” counterparts. That “fast and beat everything whilst remaining reasonable” concept would later be refined with new technology into the MBT concept of T-54/55. And it wouldn’t have been a thing had T-34s been forced to luggage around 80+mm of flat front plate. For that I think its reputation for “pioneering sloped armor” and being “revolutionary” is more than deserved.
There was some mild sloping on the A7V around the main gun wasn't there?
It was to calm natural demons of german designers to overcomplicate everything.
are those stuka sirens im hearing faintly in the background at the beginning?
Boxy armor can encase more space for the same weight than sloped armor. So the German tanks are roomier and the crews are more comfortable . Also, German tanks had torsion bars and that used a lot of space in the hull.
I worked with a guy who was in the US Army in Korea. He was in a M48 tank. That had sloped front armor
but was not interlocked. He said in a maneuver a few tanks slid down a long muddy slope into each other. One tank's cast front armor welds broke and fell off exposing the driver.
M48 hull is single piece casting...
@@jintsuubest9331 You are right. I had assumed it was the welds that failed. Maybe the casting broke.
In Korea were M46 Pattons, not M48s.
@@kot0472 Oh, OK. I heard this around 30 years ago, so....
@@501Mobius M46 is welded so it fits to this story.
Would a shell hit create a shock wave that could break straight welds? Where as the interlocking welded plates would resist this?
This was pretty sloppy. No real analysis. Link between sloped armor and interlocking wasn't made.
This guy is an academic, he’s not going to create a narrative that he can’t support from research.
@@DZGuymed except that's exactly what he did. The narrative was poorly tied together. I'm very confused as to why someone who is known for doing such research and providing such detailed references put this particular product together. I expected to come out of this video understanding why the Germans didn't have sloped armor, and that question was not answered in any way, shape or form. He didn't even acknowledge he didn't know the answer, you just kind of have to piece that together from the way he doesn't answer the question. This would have been a more direct and honest video if he had said up front we don't know. Here are the pieces that go into why it would happen, but none of them makes sense or none of them seem to tie together.
I imagine that interlocking welded plate armor both spreads the stress on a longer weld line, and also the geometry itself also helps to lock the plates in place more strongly also aiding to keep the whole thing together and not relying purely on the welds, i think this was specially important for the germans at that time since their steel lacked components to increade flexibility and reduce overhardness, so with harder plates interlocking is also more effective, but also needed so the plates dont crack at the welding lines or so that the welding lines are stronger
Interlocking might tend to support plates in place during welding, tying up heavy fabrication equipment less. As to flat plate, it seems to me that you don't have to worry so much about shot traps or chaotic deflection. Trying to hit a turret ring would seem to be more challenging.
The question about the interlocking plates is interesting. Given how much extra work involved and waste incurred (where the cutouts create more scrap material) there must have been some clear benefit. I know little about tank design or fabrication specifically but I'd wonder would the interlock allow you to use shallower welds needing fewer passes and less time (using the mechanical interlock to take the stress of the impact rather than having to build up layers of weld to fully fuse the thick plates)? If this is not apparent in sections through the joints then I can't see any saving in manufacturing time and I can only imagine it was purely done for max possible toughness. Perhaps they thought the heat affected zones either sides of the weld would easily shear on impact and they needed the interlock to interrupt the shear line but in practical terms and with the benefit of seeing how others were fine with simple joints it seems mad particularly given the attritional war they ended up in.
Interlocking plates would be able to be assembled and left for welding. Meanwhile the crane can move to next part built tank n place next interlocking armor plate, again n again. Freeing up crane and ensuring plates are in correctly and workers safety.
Also by 1943 skilled workers were harder to find , thus interlocking plates may balance structural integrity as weld quality had been reduced.
Probably because they figured it would be easier to add more armor onto the flat designs. It didn't work with the Tiger 1 but Panzer 3 and 4 had quite a few armour thickness upgrades during the war i think. I don't think any German or Soviet designs up armored a sloped hull design during the war. It would probably be similar to the issue that happens when adding ERA to tank that wasn't designed for it.
The interlocking armor has to do with the surface area of the weld. It became necessary as the armor plates became thicker. Depending on the welding technology, and this was hugely different between countries back then, you weld only at the surface of the joint between plates. The interlocking creates more connecting area to weld, and thus stronger weld's.
You don't need the interlocking (as much) if there's structural framework underneath or if only one of the plates extremely thick.
It's main purpose can also be during construction, to hold something in place so a good weld can be made. That's why you may see it pop up situationally.
After the war the hugely thick armor plates disappeared, or were created in different ways. Welding techniques also changed and improved.
Exactly.
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My mate is an engineer, he builds and designs trailers. He always uses interlocking where he can. He told me that it provides good strength and shock absorption and stress is distributed equally
Ask him about welds.
@@MarcosElMalo2 Yeah sorry thats what I meant interlocking puts less stress on the welds and distributes pressure evenly. funny enough where the welds have broken (his designing a new trailer for farming) is were the parts cant interlock.
It takes a smart person to assume their right, but to learn more and admit they are unsure. I can always trust this channel to present information in a thought-out and honest way, without letting bias get in the way. And to be fair, the different possibilities presented in this video don't necessarily exclude each other, and more likely, both the structural integrity of welds and the need changes in needs of vision ports contributed to the use of slopped armor.
Didn't the Tiger Handbook advise to angle the tank towards the enemy?
By doing this you basically neutralize the disadvantage while still maintaining the benefits.
That is horizontal angling, sloped armor is vertical.
You are forgetting that German doctrine for PZ III, IV and VI was to take an angled approach to the enemy guns, moving forward by alternating between 10am and 2pm positions. This means the frontal plates ARE angled from the perspective of an opponent at the 12 position. The utility of additional angling in a second plane is questionable in such a position.
Didn't the Germans know that guns could be rotated?
@@gore0ru I'm not sure what you mean. The entire point is the tank gun is rotated but the frontal armour remains oblique to the enemy.
@@maryambintghassani2341, yes but what about side armour?
@@СлаваПшеничный-д3й A weakness, obviously, but as it would also be oblique to the enemy, it would also be less vulnerable than it appears.
There is so much about interlocking... While on pzkpfw 1, 2, 3, 4, 5 there is no interloking and no sloped armor. So why no slopes? The questing is still not answered.
Interlocking will reduce some stress on the weld.normal seam from side all pressure will be on weld.interlocking could get by with less weld at cost of more material preparation.
Learned something today thank you
My guess is that the vision ports and crew comfort/effectivity was prioritized to the point where the engineers thought the slopes would be too much of a negative.
An interesting angle to view this through would be as to the reason the Soviets did not employ sloped armor on the KV-1 tank.
Thanks for a great informative video adressing problems I also asked myself why noone answered them.
I love the way you simply state what you know don't yet know and find out later. The hallmark of a trustworthy source.
As a former Leopard 1 driver I too noticed the interlocking teeth way of armour wasn't continued. Albeit the phylosophy changed I guess after having lost the war to many Shermans etc.
Indeed also what you mention welding techiques and steel quality come into play. As do periscopes we called episcopes due to only mirrors and no optic lenses.
I also thought it might have been the room and weight considerations. Sloped armour costs a lot of space inside. The smaller the tank and relative old engines are larger and more awkward old tanks especially British ones had lumps of steel.plate to get it all to fit.
So I guess it was a mix of many factors that come into play. Cost, availebility etc.
So, the jury is still out on a new line for many video's of choices. And of course talented and less talented engineers or traditions in industry.
Anyway, keep up the good work.❤ 16:32
What
The stepped hull is also beneficial for maintenance as it allows for easy access to the transmission.
Back in the day the drivetrain was not combined into a dense package that can be lifted out as a single piece instead the components were spaced out more to ease maintenance.
The reason why rear engine front transmission was done
Is so that both could be placed in a smaller space than what would have been needed if you wanted to put them into a single compartment without compromising maintenance.
Was probably cause experienced welders were in short supply, bet there's a lot of shallow welds on mass produced 4" plates. Bet it helped with assembly too, just lego a hull and leave it, the welders would get to it eventually and they won't need cranes and precise placement
Can you make a video on German casting technology during WW2 and why Germany didn't adopt casting tank turret/hull like US and USSR
Wasn't the interlocking armour plates mainly because of the thickness of the plates?
Just a suggestion...the interlocking loooks like a practical assembly idea. Just plonk this plate here...stuff in a spacer for welding gap...weld away...not much training , measuring, thinking ....without being there intimate ..thats posible ? If you had assembly drawings this would establish each asemblg step.
That’s the problem with history, it’s so often raised more questions than it answers.
Great video as always 👍🏻
I wonder if the interlocking was also to help reduce the warping as well as help line up the plates
I recently just cought a massiv error in one of my videos before blasting it out to the world :) The devil really is in the details and unfortunatly most of the time differences arent as clear cut as we simple man would like them to be :) Nice Video
in my mind the interlocking amour joints are a seperate design feature not really connected to sloped or vertical amour, and vision technology again a design feature compromise perhaps led in a direction by better optic development.
If German steel was weaker later in the war, the extra reinforcement of the plates was probably necessary
I wonder if the mortised weld joints were about getting adequate penetration of the plate. Something like a thick hardened steel plate would be tough to get deep penetration on but interleafing the plates like that would alleviate the problem
I think you have it right. Boxy was easy and it worked given their welding abilities. Evidently, this equation changed for them fire power increased. Really interesting video and topic in general.
I would really consider that halftrack to be "armored". That metal plating is designed to protect from small arms and shrapnel, and imo the sloping is incidental to the shape of the vehicle.
What I had assumed was Germany's tanks were designed for a war that used weaker guns and designed at a time when tanks were novel and so what could/should or could/should not be done with a tank was in question, as well as the fact that a box-like design was easier to design and manufacture.
Betreffend der verzahnten Panzerplatten.
Ich war mit meinem Großvater mal im Museum und fragte ihn nach diesen "Zähnen", sah für mich als Kind so aus. Er erklärte mir, diese Verzahnung erleichterte die Herstellung der Wanne, denn die sehr schweren Panzerplatten mussten so nicht per Kran gehalten werden, während sie verschweißt wurden. Nachdem der Kran die Platten so abgelegt hatten, dass sie ineinander gegriffen haben, konnte der Kran anderen Tätigkeiten nachgehen.
Es könnte natürlich weitere Gründe geben, aber die Erklärung erschien mir plausibel. Leider kann ich ihn heute nicht mehr fragen.
your coment is better than 16+ minutes of this crappy video thank u!
Wondered about the scene in Pvt. Ryan when someone fires into the "imitation" Tiger's driver port. Wouldn't that be protected by bulletproof glass? Constant rain, snow, bullets coming in might break my spirit.
So next video is about the development from direct vision ports to prisma periscopes?
Videos that show the process and challenges of reaching rigorous conclusions are better than videos that present everything as settled and tidy
One of the obvious (maybe oblivious) things to me about sloped armor is it increases the surface area of the armor you need. For heavy designs, and maybe due to efficiencies, the Germans opted for thicker as opposed to bigger. It may also be that when the shell was AP-C, the hardness was expected to defeat the shell. When it got to KEPs or shaped-charge rounds, it concentrated the force enough to defeat hardened armor, and deflection of the penetration path was more a thing.
As far as why sloped on early vehicles, bullets on thin armor would dent it, and cause bullet spall up the face.
The US was casting hull parts by the end of the war, getting rid of the welds.