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WW2 Czechoslovak-related weapon development


Beer
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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. 

AH7As5d.jpg

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.

mNHdwOk.jpg

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. 

 

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  • 2 weeks later...

Some time ago I stumbled uppon this. I knew there were secret comparison tests of LT vz.38 (aka Pz.35(t)) against T-26 held in Kubinka in the fall of 1938 but I didn't know that the Soviets built a variant of T-26 with a suspension copied from the LT vz.35 and wider tracks. Just like the comparison test the prototype T-26-5 (or T-26M) also showed that it was way faster in terrain than the one with the original Vickers suspension and narrow tracks, more reliable and less prone to loosing tracks (in the comparison test the original T-26 was basically unable to turn sharply on a slope higher than 8°). However the tank was never built is series. The article also mentions that a planetary gearbox for KV-1 designed by N.F. Shashmurin (not used in the final vehicle) was based on the LT vz.35 semi-automatic gearbox. 

http://www.tankarchives.ca/2020/06/courtesy-visit.html

ltvz35ussr17-a6a9695e3ab0e2847b43756ad58

 

In the Kubinka comparison testing the measured speed was:

Top speed: LT vz.35 - 36,0 km/h; T-26 mod.37 - 38,4 km/h 

Cobblestone highway average: LT vz.35 - 29,09 km/h; T-26 mod.37 - 23,8 km/h

Dirt road average: LT vz.35 - 20,66 km/h; T-26 mod.37 - 15,5 km/h

Off-road average: LT vz.35 - 16,25 km/h; T-26 mod.37 - 10,0 km/h

 

The T-26-5 compared to the regular T-26:

Cobblestone highway average: T-26-5 - 26,74 km/h; T-26 mod.37 - 19 km/h

Combined dirt, icy road average: T-26-5 - 21,4 km/h; T-26 mod.37 - 15,2 km/h

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Partial replica of Jagdpanzer 38(t) Hetzer Starr is now on display in the muzeum called "On the demarkation line" in Rokycany near Pilsen, Western Bohemia. It's built of a damaged original chassis found on a waste dump in 1994 (overall there are two more Hetzers in Czechia, both in Lešany muzeum, one of them is original makeshift combat vehicle without gun used by Prague insurgents, the other is a vehicle used by Czechoslovak army post-war). 

https://www.czdefence.cz/clanek/hetzer-starr-v-muzeu-na-demarkacni-linii

 

Hetzer Starr was a simplified late-war variant of Hetzer with no recoil device on the 75 mm L48 gun and a new Tatra V8 diesel engine. Although only 14 vehicles were built, they actually saw combat in and around Prague in May 1945 (4 prototypes and 10 preproduction ones with most of them still equipped with petrol Praga NR engine were built). Four vehicles including one powered by diesel engine were used by SS tank school Milovice (partially manned by staff from S. Abt. 507) and few more vehicles were used by other units. It is known that they were engaged in figting against Czech insurgents in Břevnov (part of western Prague today) and it is possible that they were involved in the only armoured engagement during Prague uprising on 9th May when the first coming Soviet scout platoon of three T-34/85 was ambushed by four Hetzers in Klárov (directly under the Prague castle, basically at today's Malostranská underground station). Leading T-34/85 driving with opened hatches and even a civilian sitting on it (a man from liberated concentration camp) was hit and a ricochet shell hit a house behind. A brick from the house somehow struck the tank commander lieutenant Goncharenko in the head and killed him. He was a veteran fighting from the very first day of the war on the eastern front and he died on May 9 1945 from a brick, shit happens... After that the combat went pretty bad for the Germans. Two Hetzers were destroyed (one with catastrophic ammo explosion) and two more were abandoned by the crews and left in place. The Soviets lost one dead and two wounded, the civilian was also wounded (lost leg). At least two other Hetzer Starr vehicles managed to retreat to the Americans in Rokycany. In the post-war account of the Czechoslovak army there are 8 Hetzer Starr vehicles but they were re-equipped with recoil mechanism. More information about Hetzer Starr including wartime photos from Prague fighting or serial numbers can be found here

 

Hetzer%202020%20010.jpg

Hetzer Starr replica. Source of the image is the linked article. 

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Let's switch to small arms for a moment with a very special SMG which actually saw some combat during WW2 - the ZK-383 which is a particularly interesting weapon of a kind of its own... 

 

I have added some more info bellow which adds to what Ian said (most of his information is correct aside of mixing ČZ and ZB companies). 

 

It's a product of Zbrojovka Brno (ZB) designed by Josef Koucký in 1938. The weapon was first tested in September 1938 too late for being addopted by the Czechoslovak army and moreover at the time when MOD already addopted much cheaper and simpler competitor SMG vz.38 from Česká Zbrojovka Strakonice. In the end it was the first weapon from Brno which was produced in series, although small ones while the second one, while formally addopted, was never produced due to the historical events. 

 

Why is ZK-383 special? Because it has a quick-exchangeable barrel, selectable ROF and an integral bipod while it is still a relatively lightweight SMG in 9x19 Prabellum (4,3 kg without ammo). The reason for this very unusual layout is in the original army requirement which considered SMG to be a good option for replacing more expensive LMG vz.26 in some fortification objects which were close to each other (that was rather usual in difficult terrain where lines of fire were very short - and that was pretty common on our borders). The result was an (ultra)light squad automatic weapon - sort of. 

 

Originally it was developed in .380 ACP which was the standard pistol ammo in Czechoslovak pre-war army (as 9 mm vz. 22), later it was modified and produced in 9x19 Prabellum and a sample in .45 ACP was built for Argentina. The weapon got its final shape in 1941 (shown on the video) and as such entered limited production. 

 

It's a recoil operated weapon firing from open bolt equipped with a removable ballast from the bolt, by which the ROF can be switched between 500 and 700 RPM. It can fire also in semi-auto mode. It had either 30 or 100 rounds magazine but I haven't seen any photo or drawing of the large one and I think that it was never produced. It's all machined in rather ridiculous quality for a WW2 weapon (which probably explains why so few were built). In fact it is not known how many were built. Some were built for SS but nobody knows how many. 4000 were delivered to Bulgaria and 190 to Slovakia (used as SMG vz.42). Others were ordered by Ustasha forces from Croatia and again from Bulgaria but nothing was delivered (that was rather common because Czechoslovak factories had to give priority to German orders and the other countries often got nothing but a promise). Some weapons somehow got to Yugoslav partizans where they were very higly regarded. Those were probably captured from SS units or delivered from Bulgaria after it switched sides in September 1944. 

 

Two weapons are preserved in Prague Žižkov museum of the Military History Institute. 

 

One from Slovak order (drawing included): http://www.vhu.cz/samopal-zk-383/ 

Prototype of Bolivian police variant from 1939 (without bipod but with a foregrip) in nice original package with spare barrel etc.: http://www.vhu.cz/exhibit/ceskoslovensky-vyvojovy-samopal-zk-383-p/  

Preserved JIG for filling the magazine: http://www.vhu.cz/exhibit/plnicka-zasobniku-pro-samopal-zk-383/

 

 

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2 hours ago, Beer said:

/.../

Why is ZK-383 special? Because it has a quick-exchangeable barrel, selectable ROF and an integral bipod while it is still a relatively lightweight SMG in 9x19 Prabellum (4,3 kg without ammo). The reason for this very unusual layout is in the original army requirement which considered SMG to be a good option for replacing more expensive LMG vz.26

/.../

   Soviet Union developed an LMG in 7.62x25 Tokarev catridge, it was deisgned to produce high volume of fire at short ranges, where suppression fire was critical. So this concept of pistol caliber LMG had it's merits at short range. Low weight of catridge, very good control over a weapon in full auto, pretty deadly, easier to mass produce, eat less resources to make and so on.

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4 hours ago, LoooSeR said:

   Soviet Union developed an LMG in 7.62x25 Tokarev catridge, it was deisgned to produce high volume of fire at short ranges, where suppression fire was critical. So this concept of pistol caliber LMG had it's merits at short range. Low weight of catridge, very good control over a weapon in full auto, pretty deadly, easier to mass produce, eat less resources to make and so on.


This just sounds like a PPsh, with extra steps. 

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