Laviduce

1 hour ago, Wiedzmin said:

CR2 have lower KE protection than M1A1HA which have 600mm vs KE, so CR1 can't have 620 or 550, and if take some numbers from some british reports about CR1, it's hull front for example have less protection than Shir2 with it's "325mm"

 

but again, all this numbers useless if you don't know which round was used, on which striking velocity etc...

I also read that the CR2 was expected to have a KE resistance lower than that of the M1A1 HA. I think this came from a British assessment document.   Yet there is a problem , the British were aware of the threats posed by the 125 mm guns. There is little reason to believe that the British were not successful of reaching a protection level of 500 mm RHAe in the 60 frontal arc. This would translate to about 580 mm RHAe from the front. The M1A1 HA KE protection in the frontal 60 degree arc was stated to be around 600 mm RHAe. This would translate to a KE resistance of up to 690 mm directly from the front.

What we know:

CR1 - Armed Forces Journal estimate: 580 mm RHAe

CR1 -  Engineer Rumor:  620 mm RHAe

Average between the sources: 600 mm RHAe

M1A1 HA - multiple sources - up to 690 mm RHAe

CR2 - British document projection - below M1A1 HA level

This would give us:     600 mm RHAe < CR2 KE resistance < 690 mm RHAe      -> reasonable middle ground for the CR2 turret cheek armor from the front 650 mm RHAe

This would satisfy the requirement of the CR2 offering marginally inferior KE resistance compared  to the M1A1 HA but marginally superior KE protection compared to the CR1. Now 50 mm is not much of an improvement but it could still be true. 

The jump in KE resistance from the M1 to the M1A1 was also around 50 mm if we follow the given sources.  The increase in CE resistance was more significant, from 700 mm RHAe all  the way up to 1000 mm RHAe for the frontal 60 degree protection arc.

The CR2 could have followed the same idea, where an increase in CE protection was emphasized over an increase in KE protection.

16 hours ago, Collimatrix said:

And now that the rebels are getting the shit kicked out of them, they have alleged another chemical weapons attack.

 

In fact, the New York Times had a leaked conversation explaining exactly how this happened:

 

Bashar al-Assad:  It looks like the ceasefire and busing agreement in Douma has broken down.  I guess we'll have to go in their and kick their asses.  Oh well, we were about to win anyway, it will just take a bit longer this way.  Continue with the original plan of preparing the area with artillery before assaulting with ground troops!

Darth Putin:  I have a much better idea.

 

Bashar al-Assad:  What is that, my master?

 

Darth Putin:  Gas them.

Bashar al-Assad:  I... I suppose that would be faster and more effective if we just gassed everyone in Douma.  Thy ruthless will be done, my master!

 

Darth Putin:  No, don't gas everyone.  Just gas like, a few dozen people.

 

Bashar al-Assad:  I... suppose we could use chemical weapons to ensure the elimination of key points of resistance within the city, and it would expedite the capture of the area.  Truly you are a tactical genius, my master!

 

Darth Putin:  No, I want you to gas a few dozen random civilians just to remind the world that we are, in fact, completely evil.  I want you to give the opposing foreign powers a convenient excuse to intervene just as their precious rebellion is about to be crushed.  Because we are evil.  We do these things because we just hate people and enjoy suffering and don't care that it would be enormously convenient to the rebels on the balance.

 

Bashar al-Assad:  Oh, OK.  Just like the last several times where we were about to win, and then decided to gas a few dozen random civilians for no strategically coherent reason.  I understand, my master.

 

Darth Putin:  Gooooooooodddd.  You are now my second-favorite minion, after Trump.

Those evil Russians ! Why are they so evil ?   Why is Putin so evil ?   Why does he gas people and invade countries in Europe and the middle east ? This is so confusing. Thank goodness i have the BBC, Fox News, CNN, MSNBC, etc. to keep me informed !

The following diagram seems to show some old "weldlines" on the hull of a Leclerc prototype concept. Given the dimensions of the hull, nothing much seems to have changed between this prototype concept and the Leclerc Serie 1 hull.  This would give the front hull a LOS thickness of 600-620 640 mm, which conveniently falls within the limits of the earlier diagram:

here is some info dealing with the protection requirement of the Chieftain of the 1980s:

This also makes me believe that the turret "cheek" armor protection of the Challenger 1 is 500+ mm RHAe against subcalibre KE threats. The Armed Forces Journal estimate of 580 mm RHAe and the British CR1 engineer "rumor" of 620 mm RHAe seem indeed plausible.

2 minutes ago, Mighty_Zuk said:

I am leaning towards thinking they might be wrong.

that sucks!  Are they any viable estimates on the protection level of the early Merkava I , II and III ?

I am getting the impression that a lot of the general  estimates of many MBTs out there are overestimates.  The  Leopard 2A5 turret cheeks having a KE resistance of 1300 mm RHAem is a good example of these overly "optimistic" estimates.

48 minutes ago, Mighty_Zuk said:

There may be some validity if they only refer to certain areas of the tank. The sketch of the Mark 3's armor thickness values, however, was proven to be wrong.

What about the general protection levels? Are they wrong ?

Is there any validity left in those Chinese protection values for the early Merkava III ?

Hello guys, i need your wisdom and insight!

would you guys know the approximate LOS thickness of the Leclerc front hull "beak" ?

Im looking for the LOS thickness of the special armor in front of the fuel cell.

Here is my preliminary estimate:

37 minutes ago, Mighty_Zuk said:

Quite likely that none of them are true.

but but why not ? I like to "believe"...

In summary , how valid are these chinese protection diagrams ?

16 minutes ago, Mighty_Zuk said:

It's been in progress for a long time. This will definitely add some depth to it, but I still need info on the Mark 1 and 2 tanks. 

 

 

@Molotav_DIGITANK

Is there anything on the physical thickness of the armor, rather than just protection values?

 

Also, there's a photo of the up-armored Mark 3 there, in a configuration that didnt enter service. Does it say anything special about it? Purpose and such. Thanks.

How far along are you with your Merkava I and II study ?

But how valid is this information on the Merkava III ?   

On 29.3.2018 at 11:39 PM, Xoon said:

Would you mind translating the name of the colors?

 

Also, thank you very much!

Hello Xoon !

Here are the translations:

red -   Operational Pressure

orange - Control Pressure/Actuators

yellow - Pre-control pressure

green - Recoil

white - N₂

white -  Air

These should be about right.

On 24.3.2018 at 11:33 AM, Xoon said:

Does anyone know what type of motors and controllers used in the elevation/traverse mechanism, as well as the fire control system in the Leopard 2? 

 

- For example, does the electric version use a stepper motor, BLDC, PM, Induction or synchronized motor?

- Do they employ dynamic or DC injection breaks?

     - If mechanical breaks are used,  are they spring-loaded? Do they run on AC or DC? 

     -Is regenerative breaks used?

     -Is the controller a simple on/off, soft starter, transformer or solid state controller? 

 

-Does the hydraulic system require breaks?

-Does the fire control system directly control the motors, or through the controls of the operator?

Hi Xoon,

I do not have all the information you requested but this might be of interest. According to Krapke:  For the Leopard 2(A0-A4) the gun laying system or Waffennachführanlage (WNA) is known as H22.  It is a electric-hydraulic retarder control eqipped hydrostatic motor where an electric motor powers a coaxial piston pump which pumps the hydraulic fluid out of the reservoir into hydro storage cell.

Here is the diagram of the WNA H22:

2 hours ago, Mighty_Zuk said:

Mockup of the Merkava 4 hull:

we need more !!!!! We need ....https://media.giphy.com/media/wLXo0vTZSM7GU/giphy.gif  !!!!!!!

14 hours ago, SH_MM said:

Your drawing is missing some parts of the armor, you are looking at the tank from the front, but ignore that a large part of the sloped roof visible from the front actually belongs to the armor modules; therefore it should have a higher protection level. On the right side of the turret, the thicker roof armor would extend up to the commander's PERI R17, on the left side it is a bit shorter. Furthermore the steel elements used to mount the gun trunions are not part of your armor scheme. Here illustrated with your old CAD drawing:

 

  Hide contents

 

 

 

 

That would reduce the vulnerable area of the roof and slightly reduce the size of the weakened zone of the gun mantlet.

 

As for the Swiss trials, I don't think they said anything about the protection level of the Leopard 2. Spielberger just wrote that the protection of the Abrams was better, the official report does clarify this by using different, more exact wording: the protection of the M1 Abrams was found to be "umfassender" ("wider", "more comprehensive"), which is probably a statement made in relation to the different armor coverage (Leopard 2 has shorter heavy ballistic skirts, no composite armor at the turret bustle, etc.). 

 

You also write that the protection level is achieved against 1970s ammunition, yet the Swedish documents do not mention what type of ammunition was used to establish the protection level. Given that the values are taken from a comparison with more modern Leopard 2 variants, it seems rather unlikely that they reference 1970s ammo (if you want to compare the protection values of various tanks, it makes most sense to use the same ammo for all tanks).

 

Regarding the hull side armor, it seems that the crew compartment is better protected (thicker side armor) than the rear section of the hull. In case of the Leopard 2K and Experimentalentwicklung Keiler, the frontal section was quite a bit thicker. Keiler had 40 mm side armor at the crew compartment (lower section) and 29 mm at the engine compartment. The Leopard 2K had 39 mm at the crew compartment and 29 mm at the engine compartment. The lowermost section that you have labeled with 25 mm steel-equivalent protection against KE ammo is highly sloped (just compare it to the front view), which IMO suggests that it should be a bit thicker when hit from the side.

 

1)      Yes, i simplified the diagrams to show the approximate areas of vulnerability.  Here is a more detailed breakdown of the  roof area of the model:

Overall, i would still consider this roof area to be a weakened zone given the quickly decreasing LOS thickness of the special armor and thinness of the roof plate.

The trunnion area follows the same example. I assumed that this zone belongs to the 500+ mm RHAe areas in the diagram. I  set this value to 5% of the total surface.

2)   Spielberger said the following about the Leopard 2 vs. M1 Abrams Swiss tank trials  (1981-1984):

3)  I agree

4) Concerning the sponson. I am not that sure about the KE and CE protective properties of a 10 mm steel plate + 490 mm diesel fuel cell + 50 mm of steel.   How would you estimate it ?

Also, the angled lower front hull section seems to be about 20 -25 mm thick. According to the diagram below, the side plates are angled at about 51-52 degrees from the horizontal giving us a LOS thickness of 25-32 mm:

2 minutes ago, DrunkenMaster said:

So the whole gun assembly behind the mantlet made out of titanium is actually thin air, or cardboard maybe? Good to know, thx! 

Leopard 1:

Leopard 2K:

These images made me believe that the Leopard 2 trunnion interior is "...actually thin air, or cardboard..."

2 hours ago, SH_MM said:

 

From the article "Antiarmor - what you don't know could kill you" by US Army Reserve Major Michael R. Jacobson. There are some errors in the data (M60A1 protection level, muzzle velocity of the M829A1 APFSDS, etc.), but it seems overall to be quite interesting.

 

 

Probably spaced in front of the reference plate. Normal NERA achieves an even higher "thickness efficiency" if you include the empty space...

But how valid is this chart ?  Do you think the values really correspond to the actual protection values ?

2 minutes ago, DrunkenMaster said:

 

You should update your drawing then. I don't get how you are arriving at the 280mm protection vs KE.

 

If the mantlet is using the same armor makeup  as the turret cheeks with the same thickness efficiency  we have =>  mantlet composite array (KE resistance of = ~220 mm) +  25 mm steel+ ~180-230 mm air gap + 25 mm steel = ~270-280 mm KE resistance against APFSDS rounds.

22 hours ago, Militarysta said:

 

Whit KE I can agree - IMHO it's more or less correct.

But IMHO - CE value is mistaken. I will explain why - even erly Burlington armour give protection circa as 1 (in compare to the same weight) RHA block agains APDS and after APFSDS and 2 (in compare to the same weight) RHA block agains HEAT. Of cource we can discuss it this ratio is insluding backplate and frontplate or for same "special armour" itself but more or less - HEAT protectio will be mucht bigger then you marked.

I propose to not break open door and just copied KE/CE ratio from well known M1 Abrams from 1982 - the same armour orgins, teh same year itp:

 

400mm vs KE

750mm vs CE

ratio: 1,875

 

And finnal it should looks like this:

 

 

Thank you very much for the feedback. I will make the changes! In the meantime, could you take a look at this and tell me what you think:

The sponson and track areas gave me the greatest problems.    Explanation:

Sponson (outside->inside):

Section around the turret ring: 10 mm steel (angled) + 490 mm Fuel Cell (diesel) + 10 mm steel.  Total LOS: 510 mm

Section around the heavy side skirts: 50 mm steel (angled) + 490 mm Fuel Cell (diesel)+ 10 mm steel.  Total LOS: 550 mm

Section around the powerpack: 10 mm steel (angled) + 490 mm Batteries/empty space/NBC system + 10 mm steel.  Total LOS: 510 mm

Side skirts (outside->inside):

Heavy side skirts:  100-110 mm (steel/spaced) heavy side skirts + 680 mm air gap + 30-35 or 50 mm of steel.  Total LOS: 810-845 mm

Side skirts:   20-25 mm ruberized perforated steel plates + 680 mm air gap + 30 or 50 mm of steel. Total LOS: 730-755 mm

Turret bustle:   Construction depth of around 80 mm at most. Seems to be spaced. Possible make up: 45 mm Steel + 20 air gap + 15 mm  steel. Total LOS: 80 mm

Ammunition hatch: Hatch seems to be mostly composed of "thin and light elements". Possible basic construction:  10 mm steel cover plate + 280 mm air gap/spacer + 20 mm steel cover plate. Total LOS : 310 mm

Lower side hull:  angled bottom side hull seems to be 20 mm thick steel at around 45 degrees. Side hull seems to alternate between 30-35 mm and 50 mm.

Updated CE resistance disgram:

I adjusted the values according to 1) Militarysta's feedback and 2) the respective LOS thicknesses. 

I would be grateful for any feedback!

7 hours ago, DrunkenMaster said:

How are you getting 280mm for the gun mantlet? Isn't the gun shield alone 200mm thick? Or is it just the raw armor value of the gun mantlet without the gun shield?

The mantlet seems to be 420 mm thick. This is followed by  the hollow trunnion block giving a total LOS thickness of 680 to 730 mm.

Update with corrections:

23 minutes ago, Militarysta said:

 

IMHO there is no need to use draws ;-)

I had masured it by my own hands:

Hatch:

 

Upper glastic plate is the same.

So 30mm at 8 = 215mm RHA

 

The bigger problem is whit turret roof but it's propably  the same.

 

Yes !   Using the drawings, the forward turret roof comes to about 45 mm at around 7 degrees , whereas the level turret roof comes to about 30 mm. This gives me a LOS thickness of aroudn 350 mm. I will make that change to the diagrams.

49 minutes ago, Militarysta said:

Very nice job, but IMHO there is one small mistake:

Upper hull plate is no lees then 30mm RHA - the same as turret roof. So both have the same protection.

Thank you for the feedback, Militarysta. Using the Hilmes drawings i came to about 30 mm at around 8 degrees from the horizontal. Looking at the Leopard 2K drawings , i see that the plate is 35 mm thick at 8 degrees from the horizontal. I think quite a few things were taken over from those early prototypes and i think this might be one of those features. Given this, i will adjust the estimate for this area to around 215 - 250 mm.  

Hello everyone!  i would need some feedback on my latest estimates on the Leopard 2(A0-A4 early):

My proposed protection solution could potentially satisfy the plot depicted in the Lindström presentation:

As we know, the center plot is of particular interest. It seems to depict the various armor solutions (packages). I used the magenta colored plot line (B-type armor tech?) for my solution: