Beer

Soviet evaluation of Pershing in summer 1945 gives some light to the previously discussed terrain speed of Panther and Pershing. The result didn't favour Panther... 

http://www.tankarchives.ca/2018/03/pershing-heavy-by-necessity.html

This is the measured average speed in comparison with other tanks on the same terrain track. Pershing was the fastest of them in this test mainly thanks to its torque converter. 

T26E3 - 18,9 km/h

T-44 - 17,5 km/h

M4A4 - 16,5 km/h

Panther - 15,8 km/h

IS-3 - 14,6 km/h

Fuel consumption on the same track however showed that the torque converter made it also very thirsty, basically same as Panther. 

IS-3 - 373 l/100 km

T-44 - 378 l/100 km

M4A4 - 503 l/100 km

T26E3 - 585 l/ 100 km

Panther - 595 l/100 km

http://fofanov.armor.kiev.ua/Tanks/ARM/2a46.html

310 mm hard stop for 2A46 family but 700 mm for low-recoil variant 2A75 used in Sprut-SD/SDM. 

IMHO You can judge by naked eye that the center of gravity must be indeed very high.

As for the performance I think that Turkish or Israeli heavy use of EW and decoys and a stand-alone use outside of well integrated layered AD network is the reason for its somewhat questionable performance. On the other hand we haven't seen other systems performing better in comparable environment (although there are such claims about Tor). We have seen number of proofs that Pantsir clearly is capable to take out drones and PGMs but we have also seen a lot of them being taken out, however majority of them (not all) were clearly switched off (radar in transport mode, stored in hangars etc.). I dare to say that the combat record is more about limits of SHORAD platforms overall than about Pantsir alone. One particular problem of such systems is the short range which allows the striking platforms to attack it without getting inside the engagement envelope. 

Post-Kursk penetration trials of Ferdinand dated september 1943. The most interesting perhaps is that a non-penetration close-distance frontal hit from 85 mm 52-K AA gun tore off the screws of the front armor and destroyed radio and some other internal equipment. Non-penetration 122 mm A-19 HE hit caused cracking of the whole casemate along the weld seems. 

http://www.tankarchives.ca/2021/04/elephant-hunters.html

If someone hasn't read that yet, in this older post there is a breakdown of known Ferdinandd losses (over 50 documented cases from Kursk or Italy). Very few were lost to gunfire (not a single one in Italy) but as expected many were lost due to mechanical breakdowns, being stuck in terrain or by mines... 

http://www.tankarchives.ca/2013/12/ferdinand-losses.html

Something new regarding Czech IFV tender. After several months of internal disputes about MoD financing vis-a-vis covid situation there is now a request from the ministry of industry and trade to enlarge the required value of the offsets. At the moment it is expected that by late April the trials of the vehicles shall finally restart and by early May the competitors shall receive the conditions for their final bid. The size of the order stays on 210 vehicles. 

https://www.irozhlas.cz/zpravy-domov/bvp-bojova-vozidla-pechoty-tendr-ministerstvo-prumyslu-ministerstvo-obrany_2104141347_ako

10 minutes ago, Lord_James said:

I’ve been meaning to ask, what is that big cylinder thing on the back of the T-80’s? 

Training snorkel I guess. 

2 minutes ago, Toxn said:

I think the big lesson here is "don't fight on your own soil", which explains a lot of their planning and conduct. 

Ironically in reality they conducted exactly opposite. By September 1938 there were 7 German divisions on the entire western front and by September 1939 it was 23 divisions. The French even without the British had gigantic numerical advantage but in 1938 they decided to do nothing and in 1939 they advanced 8 km into Germany and retreated... 

14 minutes ago, Toxn said:

Ya, but part of the reason for that is because the Char B1 was sucking up all of the resources that should have gone into making more modern medium designs.

Tend to disagree here. Up to the very last moment the military kept buying literally thousands of 2-men tanks both for the infantry support and cavalry eqipped with the same vintage gun as the FT-17 (R-35, H-35, H-38, FCM-36). That means that by may 1940 the military had close to 3000 2-men tanks with useless guns which were by large majority produced during late 30'. That's a looot of resources vasted. 

2 hours ago, Toxn said:

Indeed. Not a good bet, as it turned out.

 

But you can't blame them for at least hedging. The French, at least, went into WW1 adamant that it would a war of offensive manoeuvre (based on their previous experience with the Prussians), and it was for a month or two. And then it wasn't and they lost a generation of young men.

 

If I'd been bled white and had chunks of my country rendered permanently uninhabitable because I didn't put money on the defensive being dominant in the last war...

I think that it's a bit of misconception. The French certainly saw that tanks and airforce were very important in the modern warfare, after all they had the largest tank force in the world by 1940 and their airforce was pretty well equipped. The issue was that for various reasons they mostly stayed basically with FT-17 and its more modern clones and on top of that had completely disfunctional command and communication chain. 

24 minutes ago, Lord_James said:

True, but from my understanding, the Renault FT had a better showing than the British Marks and Saint Chamond: being faster, cheaper, requiring fewer crew, and generally more reliable. 

FT was for sure the best tank of WW1 but by may 1940 there were still 1300 of them in French army service, of that roughly 530 in frontline units facing the German invasion...  

Not being a pro at all, just building some paper stuff for fun from time to time. 

Here a couple of 1:35 (T-30 and LT vz.38) and a couple of 1:50 (T-50 and P-26/40). 

I haven't found an appropriate thread where to put some interesting rare stuff related to WW2 development, be it industrial one or makeshift field modifications. 

Let's start with two things. The first one is a relatively recently found rarity from Swedish archives - a drawing of ČKD/BMM V8H-Sv tank. The drawing and a letter was found by WoT enthusiasts in Swedish archives in 2014 (the original announcement and the drawing source is here). The drawing is from a message dated 8th September 1941. One of the reasons why this drawing was not known before may be that the Czech archives were partially destroyed by floods in 2002. Anyway it is an export modification of the V-8-H tank accepted into Czechoslovak service as ST vz.39 but never produced due to the cancelation of all orders after Münich 1938 (for the same reason negotiations about licence production in Britain failed). Also later attempt to sell the tank to Romania failed due to BMM being fully busy with Wehrmacht priority orders. The negotiations with Sweden about licence production of V8H-Sv lasted till 1942, at least in May 1942 Swedish commission was present in Prague for negotiations. The tank differed compared to the base ST vz.39 in thicker armor with different front hull shape (armor 60 mm @ 30° on the hull front and also 60 mm on the turret; all sides were 40 mm thick). The tank was heavier (20 tons) and had the LT vz.38 style suspension with probably even larger wheels. The engine was still the same Praga NR V8 (240-250 Hp per source). The armament was unchanged with 47 mm Škoda A11 gun and two vz.37 HMG. The commander's cupola was of the simple small rotating type similar to those used on AH-IV-Sv tankettes. It is known that the Swedes officially asked to arm the tank with 75 mm gun, replace the engine with Volvo V12 and adding third HMG to the back of the turret. In the end the Swedes decided to prefer their own Strv/m42. 

Source of the drawing

The second is makeshift field modification found on Balkans. It appears Ustasha forces (and possibly some SS anti-partizan units) used several Italian M15/42 medium tanks with turrets from Pz.38(t). There are several photos of such hybrids but little more is known. On one photo it is possible to see Ustasha registration number U.O. 139.

Few more photos of such hybrid.

It appears that the source of all those photos to be found on the internet is this book, Armoured units of the Axis forces in southeastern Europe in WW2 by Dinko Predoevic. 

57 minutes ago, LoooSeR said:

   Soviet attack UAV - Korshun-V

 

 

 

Wasn's the Korshun-V designed only during 90'? The base UAV is Soviet but I think the strike variant is newer. 

Anyway, do you have an idea where it was combat used? Chechnya? 

Since we got to the topic of the fortiffication cast elements in another topic I'm giving here what thickness of what in which resistance class was used and what those were supposed to withstand (by mid 1930' technology). I'm listing only what could be hit from enemy side. 

As mentioned elsewhere the known requirement for the steel was 550-700 MPa tensile stregth and ductility 14-17%. Per recent analysis of one cupola the hardness was 177 HV 30, i.e. 169 HB. The required compressive strength of the concrete was 450 kg/cm2, i.e. 44 MPa. Early object had less, some only around 30 MPa, later had often more, usually around 50 MPa. 

Light objects vz.36 were meant for frontal MG fire, vz.37 mostly for side fire but rarely also for frontal fire MG. Only one light object vz.37 for AT gun was built before Münich in Bratislava. Heavy objects mostly only for side direct fire and for indirect fire excluding cupolas and turrets which were to be used for frontal fire too (never installed). 

Light objects vz.36: To withstand 75 mm artillery 

- frontal walls: 50-60 cm of reinforced concrete 

- roof: 40-50 cm of reinforced concrete

- firing ports: 3 cm armoured steel shutter (I think that when this was designed Germany didn't have yet 75 mm AP shells) 

Light objects vz.37: To withstand 105 mm artillery or up to 155 mm in reinforced variant (quite numerous)

- frontal walls: 80 (120 reinforced variant) cm of reinforced concrete + 1 meter of stone wall + earth berm

Heavy objects (classes 1-III for isolated objects, IV for fortresses with more objects connected via underground network):

Class 1: To withstand frontal fire of 155 mm artillery

- frontal walls - 120 cm of reinforced concrete + 3 meters of stone wall + earth berm

- roof - 100 cm of reinforced concrete

Class 2: To withstand frontal fire of 180 mm artillery

- frontal walls - 175 cm of reinforced concrete + 3 meters of stone wall + earth berm

- roof - 150 cm of reinforced concrete

- armoured cupolas (usually observation with LMG) - 15 cm of steel 

Class I: To withstand frontal fire of 210 mm artillery

- frontal walls - 175 cm of reinforced concrete + 3 meters of stone wall + earth berm

- roof - 150 cm of reinforced concrete

- armoured cupolas (usually observation with LMG) - 15 cm of steel 

Class II: To withstand frontal fire of 280 mm artillery (most numerous variant), however the test object allegedly survived a direct hit of 305 mm on the roof

- frontal walls - 225 cm of reinforced concrete + 4 meters of stone wall + earth berm

- roof - 200 cm of reinforced concrete

- armoured cupolas (usually observation with LMG) - 20 cm of steel 

Class III: To withstand frontal fire of 305 mm artillery 

- frontal walls - 275 cm of reinforced concrete + 4 meters of stone wall + earth berm

- roof - 250 cm of reinforced concrete

- armoured cupolas (observation with LMG, single or twin HMG) - 30 cm of steel 

Class IV: To withstand frontal fire of 420 mm artillery 

- frontal walls - 350 cm of reinforced concrete + 4 meters of stone wall + earth berm

- roof - 350 cm of reinforced concrete

- armoured cupolas (observation with LMG, single or twin HMG) - 30 cm of steel (deeper and placed upon steel base)

- artillery retractable turret - 30-35 cm of steel for the movable part and up to 45 cm for solid armour around (never installed)

11 minutes ago, N-L-M said:

A hardness of 169 BHN corresponds to around 570 MPa yield, which is indeed fairly soft and weak for armor steel, but that's somewhat typical for fortifications where weight was less of an issue than the ability to take multiple repeated hits.

Would you know what was typical for French fortification elemenets of the time? Škoda was part of Schneider group after all and France was the main ally of Czechoslovakia in 1930' and our fortiffication system in general was inspired by the French one albeit the result was somewhat different. 

Interestingly the tank school went completely different way than the French one. 

2 minutes ago, Collimatrix said:

Ah, yeah, that's not great metallurgy for tank armor by postwar standards, but it definitely sounds like they had big enough foundries to make the parts.  I did not realize that the Czech T-72 turrets were domestically produced!

Sure, the fortification parts from pre-war period don't tell the whole story. We know that the fortiffications caused a great burden on the state budget and the steel used on these massive pieces quite sure wasn't the best available but a compromise driven by cost and reuired quantity. Since a static fortiffication doesn't move it is possible to make things thicker and heavier but from cheaper steel. I guess that it was the case here as well but that's all I have for this period. 

7 hours ago, Collimatrix said:

What was the state of Czech casting foundries at the time?  IIRC, the big cat mantlets were the biggest armor castings the Germans could make.

Already before WW2 Czechoslovak industry rutinely produced heavy extremely thick armoured cast pieces, especially observation cupolas and firing posts for the fortifications. To my knowledge at least three companies were supplying them in hundreds (Steel works in Vítkovice, Třinec and Škoda in Plzeň). They had a lot of experience from working on armoured parts for Austro-Hungarian fortresses and navy (basically all heavy machinery of A-H Empire was enherited by Czechoslovakia). 

The mass-produced armoured cupolas for Czechoslovak interwar fortiffication had 150-300 mm thickness (per object resistance class), the weight was 20-65,5 tons (300 mm heavy cupola for twin-HMG). They were later largely removed and reused on Atlantic wall by the Germans. 

Due to Münich treaty this thing was never installed but parts were built by Škoda including at least one turret. The Armor of the turret was 300-350 mm, the fixed armor around the turret is 175-450 mm thick. The weight is roughly 120 tons for the retractable turret and 180 tons for the surrounding armor (there are two full-size semi-automatic 105 mm howitzers inside hence why the size). 

Source of the pixture is book of Eduard Stehlík: Lexikon tvrzí československého opevnění z let 1935–1938

Here is something from a recent research done with one of one of the cupolas produced in Třinec in 1937 (200 mm thickness): 

Chemical: C 0,28; Mn 1,15; Si 0,44; P 0,026; S 0,023; Cr 0,35; Cu 0,27; Al 0,01 

Ferrite-pearlite structure with measured hardness 177 HV 30 which shall be equivalent to 169 HB, i.e. rather soft. It is not much known about the original requirements, incomplete sources say the steel had to have tensile strength between 550-700 MPa and ductility 14-17%. Based on that the steel used on this cupola was probably close to the lower strength limit. 

Source is here.

Anyway starting with early 50' the new armory in Martin, Slovakia was producing quality cas turrets for T-34/85 and later T-55 and T-72 in thousands. 

7 hours ago, delete013 said:

> this is the final vehicle (https://www.valka.cz/Kaetzchen-38t-t12141)

"Napriek podpore Heeres Waffenamtu a WaPrüf 6 projektu obrneného transportéru firmy Auto Union známeho pod krycím názvom Kätzchen, existovala ešte i snaha využiť podvozok tanku Pz.Kpfw.38(t)"

 

Here is the answer to your mistery. Germans wanted to use the BMM production capacity and the 38(t) platform.

My source is book of Vladimír Francev and Charles Ch. Kliment. 

6 minutes ago, SH_MM said:

NGP vs MMP

You are right. Are MMP values available somewhere? 

2 hours ago, N-L-M said:

This statement is entirely false. The overlapping wheels offer reduced ground pressure, at the cost of a whole host of other deficiencies, which are the reason nobody uses them any more.

A quick search gives us these ground pressure values. 

Panther 0,09 MPa

Königstiger 0,102 MPa with combat tracks and 0,123 MPa with transport tracks

Tiger 0,104 MPa with combat tracks and 0,142 MPa with transport tracks (the need to use different tracks for move via rail is another retarded feature btw.)

To compare 

KV-1 0,77 MPa 

IS-2 0,0785 MPa

T-34/85 0,0824 MPa

T-44 0,083

IS-3 0,0853 MPa

A41 Centurion Mk.I 0,07 MPa

T30 Heavy 0,08 MPa

M26 0,09 MPa

Sherman VC Firefly 0,09 MPa

M4A2 (76W) 0,1 MPa

A22F Churchill VII 0,094 MPa

A34 Comet 0,095 MPa

A27 Cromwell IV 0,101 MPa

In my list of main late war tanks (and some early post war) the interleaved wheels helped Königstiger and Tiger to achieve the last two places in terms of the ground pressure which further underlines how crazy overweight the vehicles were. Panther with its interleaved wheels has same ground pressure as M26, ended behind all soviet vehicles in the list and faaaaaar behind Centurion which happened to be the best in my list (a surprise for me). 

4 minutes ago, delete013 said:

Count the road wheels and check the length of the hulls. Then think why Soviets (at least mediums) and Germans both wanted very short vehicles. Turning radius of these things has to be half of Texas. Some "theory" for you:

The image shows the forces that have to be overcome to turn the vehicle. Each hull extension increases them and extends the possible turn radius, decreasing the agility of the vehicle. Sure, for heavy tanks that might not be essential but it requires more powerful engine at already increased weight.

IS-7 hull is shorter than Königstiger. T30 hull is only 23 cm longer. How about if you checked that first yourself before writing? 

4 minutes ago, delete013 said:

They stated that the Kniepkamp's designes will be dropped?

It states that all future light vehicles shall be built with Surin's suspension. What you don't understand? I won't repeat the same sentence for the fifth time. 

8 minutes ago, delete013 said:

What can be wrongly interpreted in that simple statement? It wasn't either-or. It was the combination of both.

The double torsion bars were used to fulfill the required suspension travel because there was no other chance to achieve it regardless of material available at the time (anywhere). 

8 minutes ago, delete013 said:

Tiger 2 was a heavy tank. This distinction makes to majority here problems.

That changes nothing. 

8 minutes ago, delete013 said:

Then Pershing becomes medium when discussing armour and suddenly heavy tank when mobility. IS-2 has torsion bars, hence the same mobility as panther?

You don't make sense at all. 

8 minutes ago, delete013 said:

Read my answer to collimatrix. It is the combination that works, not separate parts.

He knows. You believe. 

42 minutes ago, delete013 said:

Then I am sure you will be able to dismantle my arguments on a scientific level.

First you have to bring some. 

1 minute ago, delete013 said:

English is not my first language, nor am I a mechanical engineer. It's a direct translation.

Where do you get the arrogance to argue about things you have no clue about? 

3 hours ago, delete013 said:

Really? Even your source claims it is based on hetzer. And Jagdpanzer 38 is based on Pz.38.

What my source? Vehicle you posted is second Auto-Union prototype. The hull has nothing to do with Pz.38(t) aside of the externally mounted 38(t) suspension for comparison testing. This vehicle was built before ČKD even knew that it was being developed. Picture I posted is different vehicle designed later by ČKD and only that one is based on 38(t). Period. 

3 hours ago, delete013 said:

That is not how it works. The concept of interleaved wheels was a solution for the limitations of the time. The only other suspension able to carry such weight were compound solutions with limited suspension travel. Today's arrangement would never work with ww2 tech.

3 hours ago, delete013 said:

Because they were designed 30 years later. If vehicles needed to exceed 70 tonnes then interleaved wheels would likely come back into play.

That's only your and all wrong interpretation and ignorance. There are countless examples that interleaved wheels are not needed for heavy vehicles and it was like that in WW2 just like it is today. Two examples of many many more. 

1945, 86 tons, single torsion bars

1945, 68 tons, single torsion bars

3 hours ago, delete013 said:

You interpret it in your own way. So far the only clear thing is that Hetzer's chassis was standardised for several vehicle types. Nothing on wanting or not the interleaved arrangement. Neither did you provide a proof that single line was considered better.

I'm not interpreting anything. I'm telling what the October 1944 decision stated. There is nothing ambiguous about that. 

3 hours ago, delete013 said:

Lets see what German professional literature says:

You interpret the article wrong.  The use of double torsion bars was not a measure to overcome material issues but a measure to achieve double travel with existing materials. You can clearly see that on Königstiger which didn't have double torsion bars (by your logic it would absolutely had to have them). 510 mm is insane value for the time, nearly double to the other vehicles of the period and it was possible only through double length of the springs. Double travel over double length means that twisting of the spring is same.

And this crazy suspension travel is the reason why Panther was good in terrain and absolutely not the fact it had interleaved wheels. 

3 hours ago, delete013 said:

You literally confirm my statements. Germans had material limitations and had to improvise.

No. If you knew something about the subject you would have known that it is impossible to build springs without certain alloying elements. Even for somewhat worse spring steel you still need them. 

22 minutes ago, Collimatrix said:

I had heard vaguely that a design concept for the Czech post-war TVP project was mocked up with interleaved road wheels, but that this was rejected.  I never saw a picture or anything.

So, yeah, a napkin drawing of a napkin drawing, according to rumor.

Post-war, most designers seem to have been content with other ways of reducing the MMP of their tanks.

To my knowledge none of the known drawings shows interleaved wheels. All had standard torsion bars, some trailing, some leading. One of the drawings had one pair of torsion bars leading and the rest trailing to create space for turret basket. All had also rear drive sprocket. Even the Surin's suspension was quickly abandoned (it survived in an attempt to create cheap export tank on the basis of LT vz.38 but there was so much cheap armor around the Globe that time that it didn't get anywhere past test chassis). 

What was taken from German tanks was the gun mantlet in Topfblende style which in combination with the later cast IS-3 style turret looked very interesting. Generally the earlier concepts were looking a bit more German, the later took a lot of insipration from IS-3 but the vehicles were planned to be smaller, lighter, much less armoured and a lot faster and all were to be equipped with autoloader.. I will post some drawings later in the history section. 

An interesting new radar from Retia. ReGUARD is light portable AESA 3D radar for guarding important objects or venues. The radar has only 66 kg weight. It is able of automatic classification of target (classes are fixed wing, rotary wing, drone, bird, ground object) at the distance up to 18 km and altitude up to 3 km. For example it is able to detect and classify the DJI Phantom at 6,5 km distance. It has a standardized ASTERIX output and can be therefore easily linked to a wider network. It can be placed stationary, on a vehicle or on a on a rotating mast.  

More here.