CAP vs NO CAP | APCBC vs APBC | Armour Piercing Developments Vol. 1 

APCR vs angle

i wonder if you'll show the 1939/1940 Brandt APDS (37/25, 75/57) then, while being a no-show for the BoF, the tech package was sent to the UK and served as some of the basis to the development of the British APDS

Is there a way to make a shell "turn towards" the armor? Inverted cone shape for the AP cap maybe?

@@abelw16 The cap as is does that. Albeit very slightly. Carefully watch the first impact and you can see the effect around 14 seconds. Edit: maybe not quite visible, but the simulation results show the effectiveness. Edit: Not the ballistic (pointed) cap. The flatter one is the armor piercing cap.

@@abelw16 No, it is fiction. Best case scenario you get no deflecting like rod or scj.

He’s cappin, they gotta be the same projectile but with different drip

@@jross1269 stop the cap

beat me to it

This whole video is cap

*generic witty reply about your "capping" joke*

IT would usually also explode after penetration.. its not simulated

@@JaM-R2TR4 im sure they dont have explosive filler unless they have he in the name, like apbc-he or something like that

@@loganwalker8537 Why are you sure of that when it's literally specified at the very beginning of the video you're commenting under that the explosive filler has been omitted for simulation purpose? What did you think that cavity in the rear was for? Just there as a joke?

@@Narcan885 no the hole at the back is for goal

Just like the German skirt armour wasn't designed to defeat bazooka's, but it does :-)

@@ddbb4962 It does reduce damage though - air itself and standoff contributes little to no effect, but striking the plate causes jet to lose the focal point. Both HEAT and APFSDS are weak against "porous" materials with uneven density, such setups interfere with shockwave conductivity and strip the self-forming friction cap formed by armor already destroyed. That's why modern tanks use mix of plates and rubber pads/resin fillers, all combined with air gaps. for their frontal armor block.

​@@notsureyou Penicillin was an accident. So does Viagra

It doesn't have any advantage against sloped armor really. Americans specifically developed uncapped T33 shot against sloped armor, it could easily go through panther upper plate when m62 capped shell couldn't

Fr

That is probably also because it is a German cap. See, Krupp was arguably the first to figure out that a fairly blunt cap like you can see here, has little to no loss of penetration characteristics against flat armour, but it does have superior penetrating performance against sloped armour. Basically the edge of the cap "bites" into the sloped plate and transfers a lot of the energy into the plate, causing it to fail. The Germans started deploying this type of shells in the early 1930s on their new 203, 283 and 380mm naval guns. Most navies never fielded such shells during WW2. Only the USN would independently also figure this out later in the 1930s and adopt such shells for their new 152, 203, 305 and 406mm guns. The difference there was that the USN figured it out after they had already completed designing or even started building ships like the North Carolina, South Dakota, Iowa, Cleveland or Baltimore classes. Basically they knew that the vertical armour protection on their latest ships, was utterly insufficient against their own shells, but nothing could be done about it any more. These shells also seem to have been a large contributing factor in the German naval armouring system that they developed. Because the Germans correctly deduced that no single plate stands much of a chance of stopping such shells in realistic battle conditions. Thus the Germans effectively abandoned the heaviest plating in favour of a two layerd decapping system. The Germans figured out that you needed about 0.2 calibres effective thickness of the shell in question, to decap such a shell. Thus for 380mm shell you would need around 76mm effective thickness. So either such a flat plate, or a slightly thinner plate at an angle also worked. Further the Germans also learned that around 0.5 calibres, a now decapped shell would shatter. The Germans also experimented with deliberate yawing plates to offer just enough resistance to get a shell to curve upwards like you can see with these heavily sloped plates, but now on flat plates. Finally they introduced a very shallow angled, sloped deck that would be able to stop just about any decapped shell up to 406mm at even point blank ranges. They did this in combination with the deceleration of a shell penetrating a 300mm+ thick main belt. And this all came together in Bismarck. It is no coincidence that Bismarck its barbettes below the main deck or main cable duct where 220mm thick to ensure 0.5 calibres against the expected 380mm or 406mm shells. Both also have an additional layer of armour around them for decapping. Either the belt or 50mm weather deck armour or a second 60mm thick ring around the main cable duct. Neither is the 145mm upper belt an accident. It will pretty much stop any 203mm SAP or HE, offer at least some protection against 203mm AP and also offer very good protection against 152mm AP while stopping 152mm SAP or HE. Further that 145mm would cause yaw when struck by 380 or 406mm AP shells and that seems to have been its main intent. And for the armoured decks they where banking on the often quite shallow angles to decap 380mm or 406mm AP with a 50mm deck. Then the main deck would stop such shells. And just as with the upper belt, such a deck also offers decent protection against HE shells, but also HE bombs. SAP or AP bombs would penetrate, but that is again where the main armoured deck was for.

@@DanielWW2 thats some pretty interesting stuff thanks for sharing it!

@@DanielWW2 I think the improvement mainly comes down to the 88mm Pzgr. being both quite short and pointy or that the cap helps when overmatching the armor. In general, capped shells only provide an advantage against armor sloped between 0-45° but blunt shells are known for being more efficent when overmatching armor. So in this instance the cap might have increased the range of penetration but generally resulted in less armor penetration ability.

@@kimjanek646 Being short was already part of what the Germans figured out in the early 1930s. They deliberately kept AP shells to a limited length to with ratio because they where concerned about shell integrity. That is for example the reason why Bismarck its 380mm guns where "only 800kg". It has nothing to do with the Germans giving preference for lighter shells as often repeated. Anybody who would compare the German 128mm, 203mm or 406mm off the same SK C/34 line to their contemporaries would realise this. The 128mm and 203mm shells are on the heavier side and the 406mm is very slightly below average. Italian, French or British 380mm shells where simply longer and in the French or British case also contained a larger explosive cavity. Those however didn't have such caps nor the ultimate structural integrity. The Italian shell is really thick walled and has very little actual explosive content. The Italians went for very high velocity and mass and paid the price in terms of after penetration effect. But even then, the main point is the flat cap. And the Germans took what they learned from their naval experiments straight to the army when they started needing ever larger guns. Because in the end, Krupp basically designed most German AP shells for all services. The cap what contributed to this level of oblique impact performance and that came on top of having a fairly good shell concept to begin with. Because that piece of extremely hardened steel is what is impacting the armour. And to prove my point a part of the British post WW2 document about German shells, ADM213/951. The full document is floating on the internet and has a lot more information. But this one covers the caps. 🙂 imgur.com/qQMaKft

bro this is cap

anyone else want to be part of an experiment, we think there is a survival rate

Crapy quality of the capped version? Version without the cap was more fault tolerant. And if you have capped version that is crooked then you have much bigger chance that your projectile gonna miss the target... 92,000 of German artillery projectiles got built-in flaws thx to the Polish slave workers that were also part of the Polish resistance(but i think the built-in flaws were in the detonator so they were making duds out of them).

@@Bialy_1 I'd imagine the US had time to keep up quality, especially after the war. Either way, capped shells weren't completely replaced and there was considerable effort in making the AP work as well as it could against angled armor even when it meant worse performance against flat plates. I guess it was acceptable since their HVAP was ridiculously strong in that department.

The 90mm T33 is one of the best examples of late war APBC. Unfortunately, they wanted to match German nose hardness, but could not, which in turn caused the T33 shot to have major shatter issues (165mm at 100m). Though for some reason the shell had incredible angled penetration performance. Probably because of the shatter, but I’m not sure.

US late war and post war APBC had a really blunt ogive under the cap. That was meant to help against sloped armor.

US AP and APBC shells aren’t as sharp tipped as the 88mm Pzgr., which is also sharper than the 75mm Pzgr. If the nose stays intact, a sharper nose probably results in greater amounts of KE getting deflected from the plate. Just a speculation but a cap might improve the shells performance, if the nose is as sharp tipped as the 88mm Pzgr. British trials showed that capped shells required around the same or more KE to defeat sloped armor plates as uncapped shells.

Cap

Oh btw i love your vids i think i watched all of them, a lot even twice :D

Yes there is a way to show it but I dont normally. Thanks though

Both

uh what

Ah yes, the APFSDS is the circumcised version of tank warheads

kinda sus..

Thank you so much!

The spalling isn't modeled in the simulation, and this is against a test plate that both would go right through when face on. If the armor were thicker, you would see much better results from the BC against the angle.

@buffalo wt not quite. The bigger chunks are rendered as spalling, but you also have sand sized bits and sparks coming off that steel.

You've got a great site going on there. Full of very good stuff to read, investigations and plenty of calculators too.

Wow Nathan Okun himself makes an appearance! I've been visiting Navweaps on and off for more than 20 years, and the amount of information there is amazing, with specifications of naval weapons (pre-WW1 to modern though of course, I was mostly interested in the WW2 ones ;) ) and also articles and treatises. I was also able to contribute a tiny bit to the site, in the translation of a postcard of the Japanese battleship Mikasa :) I had read that back in the day of traditional AP rounds vs RHA, the d/T ratio (diameter of AP round vs thickness of armour) was a very important (if not dominant) factor in determining penetration. So, for example, an 88mm PzGr39 round so overmatched the 45-47mm glacis plate of the T-34 that it hardly mattered that the plate was angled at 60 deg - contemporaneous accounts speak of rounds penning the glacis and ending up in the T-34's engine block. This simulation seems to bear that out as well, even against a thicker (60mm) plate.

Attack the D point!

@@forsakenplant "Affirmative!"

@@xneri772 ATTENTION TO THE DESIGNATED GRID SQUARE!

I agree

@@thonalanbatchelor5030 GRAMERCY!

Then you get modern day APDSFS lol

apfsds

Yes i do plan to, but the model still needs some refinement. I doubt much will change but the visual result will be more realistic

here the explosive effect isn't modelled, so i wonder if it had any influence on the final penetration result

@@quentintin1 No, it doesn't. You need 6 inch class projectile for explosive to change the result in any real way. Even then, it is still minimal.

I'd imagine its because these are right on the critical angle/thickness which rarely occurs irl; increasing/decreasing thickness/angle slightly leads to impact results you more commonly see

Well these shells always hit straight , like shot point blank . At range you got a balistic curve , so the angle is better .

Check out the XYZ video on armour that was posted lately you'll see some 16lb hits that tumble slightly like that and not too many of them penned.

There’s no way that’s accurate.88mm KwK 43 could penetrate Panther’s frontal plate up to 2,000 meters.It had better armor piercing performance at 2,000 meters than regular 88 had at point blank.What a load of BS.Literally the best performing traditional AT gun of WW2 only could penetrate Panther’s UFP till 600 meters??I wonder where did you get that source imo.

If the simulation works, it should show an improvement in low oblique penetration for sharp nosed shells compared to less sharp or blunt shells against armor that isn’t overmatched by the shell. Basically increasing nose sharpness increases low oblique penetration as long as the nose stays intact.

@@kimjanek646 Interesting. What do you think the effect of an inverted ogive penetrator would be in order to help penetrate extremely sloped armor? (Think if the shell had a hollow point but was not designed to expand like a lead one)

@@Boomchacle I imagine it would result in very poor penetration performance compared to either flat or sharp pointed shell. Such shell would probably require the least amount of energy to defeat a heavily overmatched armor plate at low obliquity, kinda like a cockie cutter, compared to other designs. But when is that a realistic scenario? Maybe a 40mm low velocity grenade launcher would be able to defeat a 15-20mm armor plate that way, at close range, but then you could just use a HEAT projectile to penetrate much more armor.

@@kimjanek646 I was thinking about for something like a battleship shell where you're expecting to hit extremely angled armor

The idea of a cap projectile tilting towards the plate has been over exaggerated; the cap will just reduce the amount it is deflected away

I'm insuring of that

Probably. Base fuzes are triggered by the rapid deceleration of the projectile as it hits the armour, and especially in the non-ricochet cases you likely still have enough deceleration to do that - after all, the fuze had to trigger for armour thicknesses significantly thinner than the penetration capability of the shell. So especially in the non-ricochet cases, I imagine the shell's detonation would also send a shower of fragments into the tank, in addition to the spalling.

He compensates for this effect by reducing the speed of the heavier round so they have equivalent kinetic energy

K.E. = 1/2 m v^2

Because long rod projectiles erode as they penetrate, preventing them from being turned away