TWMSR

https://www.iwm.org.uk/collections/item/object/1060035213
 




 


 
some khald's, shir's etc, plate which is drilled look like UFP speical amror one, and look like Aluminum

Old Swiss report on the trials of Leopard 2 and M1 Abrams.

2A5/6 sight shutters 

Dunno if it's ever been posted here, but I'll leave these as is - PDFs from Benét Labs, ARDEC and Tank Main Armaments (Picatinny Arsenal) on the ATAC gun project.
 
https://www.docdroid.net/BNPwd3j/20184655mnbt989107254f026170i002-pdf
https://www.docdroid.net/9uIlRZe/20181815mnbt989112214f167098i011-pdf
 
ff6a7899ba6d421e2d9e4bc222fdd340d6d6.pdf (semanticscholar.org) <-- study on barrel vibrations and stabilization; XM291 is featured.
https://archive.org/details/DTIC_ADA320105/mode/2up <-- has a bit on the XM291 testing.

Early French 120 mm smoothbore APFSDS prototypes, the dates on the cartridges show the years 1976 and 1977. They are related to the AMX-30 valorisé program (related to AMX-32 development).
 
Source : The Tank Magazine, December 1978
 

 

 
This can be linked to the gradual evolution of French 120 mm APFSDS throughout their development phase (note the OFL 120 G1 on the far right ) :
 
Source : COMHART, L'armement de gros calibre, 2008
 

Hello guys
Our article about ASCALON,

Any review would be pleased 

https://lasd.online/140-ascalon/

https://below-the-turret-ring.com/history/german-experimental-armor-development-ii-results-of-trial-program-16-21-and-22/

@SH_MM
 
https://drive.google.com/file/d/1nLSVAhNL-6RWqrKljutWH5mJ1K3RMv5s/view?usp=sharing
 
1976-79 german ERA trials 
 

Takes a bit longer than expected. @Wiedzmin, here is the first part. I started with the oldest report, which comes third in the document. At the moment I have only translated the first chapter, further articles will follow for the other chapters  and then for the other reports.
 
https://below-the-turret-ring.com/history/german-experimental-armor-development-part-i-target-arrays-for-trial-program-16-21-and-22/
 
This is also the only report containing performance data (though it is still limited), the other reports only mention that the performance data can be found at other places. In general the report "Bericht über die Erprobungspogramme 16, 21 und 22, durchgeführt in der Zeit vom 9.05 bis 13.05.1977 und vom 14.11 bis 18.11.1977 bei der Erprobungsstelle 91 der Bundeswehr in Meppen; B – TU 1911/00" covers three different test arrays. Two of them were used for tests against 105 mm KE/38 APFSDS rounds. This version of German ERA relied on an external ignition system, as the used explosive material (Dottikon) did not detonate by itself when hit.

Mk3 turrets, left with cast parts, right welded from plates
 

 
mk 1-2 

@TWMSR
 
The KEW-A3 is an update of the KEW-A2 with SCDB propellant:
https://web.archive.org/web/20150813130631/http://defmunintl.com/KEW_A3.html

Sheffield, max speed is for rapid traverse, f.e. when you need to turn turret from 2'oclock to 6 o'clock or TC align turret position with his Peri. Aiming speeds are minis and maxes for responsive aiming, slow for precision 'sensing', fast for target tracking and FCS solution commands (you do not want do wait too long until gun elevates for shooting far-far away targets).

some update

105mm m900 m833 m774 m735


m900 - penetrator length 603 mm, volume 206344,9906mm³ (density 18,6/~3,830kg/real 3,830kg)
m833 - penetrator length 427 mm, volume 196634,2908mm³ (density 18,6/~3,657kg/real 3,668kg)
m774 - penetrator length 345 mm, volume 178942,0578mm³ (density 18,6/~3,328kg/real 3,364kg)
m735 - core length 309,5 mm, volume 119354,6819mm³ (density 18,5/~2,208kg/real 2,210kg)

Leopard 2FK turret

I couldn't find them for free. There is one Google search result pointing to a German FTP server, but the file on the actual server was deleted some time ago. All other sources seem to ask for more money than I am willing to spend on that matter. Could you provide a link to the public available versions?
 
I believe the outcry regarding the use of DEF STAN 95-25 steel (specifically on Twitter by people like Damian) is exaggerated. DEF STAN 95-25 is the successor to IT90G, which covered the same hardness ranges and dates back to WW2. The Chieftain's cast steel turret and hull used steel made according to IT90G and reached an average hardness of 260 to 280 HB, i.e. they remained at the upper spectrum of the standard. I believe that Challenger 2's turret also covers the upper spectrum of hardness specified in DEF STAN 95-25. The difference to DEF STAN 95-26 is just 25 HB, which I would consider negible. The difference in armor protection will be a minimal.
 
However the impact on other aspects such as weldability/manufacturability might be much bigger. You really don't want to heat up a nine tonnes piece of steel every time before and after welding something to it. As RARDE 823/DEF STAN 95-26 steel was only used for the Stillbrew armor (or at least this is the only confirmed usage, whereas Chieftain relied on IT90G steel and Challenger 1 also on DEF STAN 95-25), one has to wonder if there were facilities capable of producing large air-hardened casting of such size,
I also don't think that the quality of DEF STAN 95-25 steel is an issue. The hardness is average for cast steel. US tanks used softer steel (220 HB steel as tested on a M48) until 1978 before switching to 270-280 HB steel. The Soviets also used 260-280 HB cast steel, i.e. roughly comparable in protective qualities to DEF STAN 95-25.
 
My understanding is that the casting of the Challenger 2's turret is quite thick, although I must admit that the informations regarding the exact turret geometry and plate thickness of the Challenger 2 turret remain largely unknown to me. The Challenger 1 also seem to have quite a thick steel casting based on the weight and size of the turret, and this was even increased on the Challenger 2. I believe comparing cast armor grades to the steel grades used for thin RHA plates makes not much sense. DEF STAN 95-24 defines for Class 1 and 2 steel grades with a thickness of above 100 milimeter a hardness of at least 255 HB and UTS of 850. There wouldn't be a noteworthy difference in protection when using a welded steel turret made of such plates, but such a turret might end up heavier (or more complicated to manufacture and more expensive) due to the fact that casting allows using much more variable material thickness.
 
While DEF STAN 95-24 Class 4 high-hardness steel would also be available in the relevant thickness, this is specifically stated to be hardly weldable and thus is not suitable for the inner citadel of a turret to which all sorts of things (including all mounting points for the Dorchester composite armor) need to be attached. American RHA (according to the MIL-1250 standard) at similar thickness also does not seem a better solution, as the hardness range for plates with a thickness of 4 to 6 inches is just 241 to 277; the backplate of the Abrams' hull armor array might not be any better than the turret casting of the Challenger 2.
 
 
The only real alternative - that depending on point of view might be better - is using thinner plates for the turret citadel, i.e. with a thickness of just 40-50 mm and incorporate multiple steel (or alternatively ceramic) layers into the composite armor array.
 
____
 
@Korvette and @BaronTibere regarding Nicholas Drummond: I don't think that calling him senile, a lunatic or assuming that he is a malevolent intent is correct. He makes mistakes, as everyone does. He is just not as involved into the technical aspects of tank development (but rather focuses on the tactical and political side of things, where he acted as witness to the UK parliament's defence committee on different issues). Most likely somebody from Rheinmetall told him that the companies' Challenger 2 LEP offer was based on the MBT Revolution concept and he assumed that this means a Leopard 2 turret is used. IIRC at DSEI 2017 the Leopard 2 Revolution was displayed and Rheinmetall made such comments towards the press (i.e. Jane's, etc.).
 
That doesn't mean that the Leopard 2 turret is used, as the MBT Revolution is a modular upgrade concept (just like the Evolution armor concept on which it is based) using Rheinmetall-made components. There is also the Revolution/Evolution upgrades of the Marder IFV, the SEP 8x8, the Stridfordon 90, the T-72 and many other vehicles, though most of them exist only as prototypes or CAD-based proposals.
 
 
 
That is assuming that the turret ring diameter wasn't reduced on the Challenger 1 or Challenger 2. In case of the Abrams, it was reduced to 83 inches (from 85 inches) during development, but in a later stage of development again increased to 85 inches.
 
  
 
The Leopard 2's turret ring diameter is stated to be 2,200 mm in Paul-Werner Krapke's book. That would be slightly more than 85 inches.
 
 
The MBT Revolution is a modular upgrade suited for a wide variety of vehicles.

On SHARD:
https://www.edrmagazine.eu/nexter-120-mm-shard-towards-tailored-apfsds-solutions
 
Key points:
there will be two SHARD rounds (SHARD Mk. 1 and SHARD Mk 2) SHARD Mk. 1 uses old double-base propellant, SHARD Mk 2 will utilize much higher pressure one SHARD has a longer penetrator than OFL F1 and F1B+ and is made of a new D10 tungsten carbide (this seems like a mistake from the author?) alloy from Plansee the sabot design and the fact that it is seated further down the barrel allows the SHARD catridge to contain more propellant (US did that already earlier...) accuracy is close to 0.2 mil at 1,500 m - much better than OFL F1 overall performance increase (for SHARD Mark 2 over OFL F1B+?) will be 20% SHARD Mk. 1 is to be fully qualified by 2022

EFP vs APFSDS
 
 

Bore size plays it's role, but double-ramp sabots, developed for high elongation penetrators, needs to be long to properly support the rod during firing. Sabot design is not all about reduction of parasitic mass, it should be light enough, but it has other important tasks. Old Soviet 125 mm metal sabots got it's merits, but using ring sabots and full-bore fins and low elongation penetrators today might be considered as suboptimal.
 
Changing sabot material, as in case of M829A1>M829A2, is one way to go (btw. where did you find information that sabot of M829A3 is 30% lighter than one of shorter's M829A2). The other is novel sabot design. And this is the way that Rheinmetall is said to choose in new developments (DM 73 probably not, KE2020Neo probably yes).

The M829A3 sabot mass is 3 kilograms.

Great idea It is so silly to put parasitic mass into design, why do not use zero-mass sabots instead? And why waste so much energy on muzzle blast? All energy should go into penetrator, it must be easy task.



 
 

Great idea It is so silly to put parasitic mass into design, why do not use zero-mass sabots instead? And why waste so much energy on muzzle blast? All energy should go into penetrator, it must be easy task.



 
 

If anyone is interested in the history behind the development of Chinese third generation tanks, I strongly recommend this article (written in Chinese):
Part one
https://weibo.com/ttarticle/x/m/show/id/2309404519105649574380?_wb_client_=1
 
Part two
https://weibo.com/ttarticle/x/m/show/id/2309404531003560690005?_wb_client_=1
 
Part three
https://weibo.com/ttarticle/x/m/show/id/2309404571464467873891?_wb_client_=1
 

Someone do. It is DE102013101423.
https://patentimages.storage.googleapis.com/84/45/e5/ab7a967a9f8dd9/DE102013101423B4.pdf
 
 

RH guy, when asked, stated that A1 got new primer, that meet more strict requirements on electromagnetic radiation hazards.

The latest iteration of Merkava is called Mark 4 Model 400, which has a newer C2 system and enchaned TROPHY (you can tell by the added optical sensor). kinda interesting because although MK 4 had seen many modifications and improvements throughout the years this is IMO the first time that the IDF officially names a new Mark 4 version
 
https://www.idf.il/אתרים/חטיבה-188/2020/טנק-סימן-4-חטיבה-188/