Czechoslovak interwar bits

[Beer]

Very rare original tankette MU-4 from Lešany museum which was by some miracle preserved and after the war used as a tractor in Škoda factory. Only one piece was built by Škoda as a late-competitor to ČKD tankette which became the standard Tč vz.33. Both vehicles were modification of Carden-Lloyed Mk.VI. The Škoda one was better but it was late for the competition. In 1933 it won a tender of Yugoslav army but the it never materialized in an order. Yugoslavia ordered Škoda tankettes of later types though (including gun-armed which could be considered a sort of light assault guns). Unfortunately when I was in lešany last time, this tankette was not on display. The vehicle was 2,2 tons heavy, had up to 10 mm thick armor, two men crew and two LMG vz.26 armament. Thanks to the 40 Hp engine the top speed was rather good 40 km/h. The most interesting thing is that the vehicle was fully welded which is very unusual for pre-war Czechoslovak AFVs which were usually rivetted.  

 

[Beer]

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)

 

[Beer]

Video compilation from the Military Historical Intitute related to the 1938. You can see a lot of shots mainly from 1938 including May partial and September full mobilization. You can see a lot of weapons such as tanks LT vz.35, tankettes Tč vz.33, Avia B-534, Avia/Fokker F-IX, Aero/Bloch MB-200 planes, light howitzers vz.30 and heavy ones vz.37, light field guns vz.17 and vz.30, AT guns vz.37, mountain guns vz.15, AA guns vz.22, heavy mortar vz.16,  mortar vz.17, HMG vz.24, LMG vz.26, some fortifications and of course rifles vz.24 (Mauser). The troops use mainly helmets vz.30 but some still have the old vz.20 (similar to WW1 German and 1917 Austro-Hungarian ones). From what is being said in the video the most interesting things are probably this - by 1938 Czechoslovakia had the 5th highest defence spending (in relation to GDP) in the world behind USSR, Germany, Japan and Italy. The peace army size was roughly 200 thousand men (60% infantry including armoured units, 20% artillery, 6% airfoce including AA units, 6% cavalry and 6% engineering). After the partial mobilization in May 1938 it had 370 thousand men, by the late September 1938 the number crossed one million due to the succesfully finished full-size mobilization (35 divisions including 4 of gendarmerie if I am not mistaken). The airfoce had 55 squadrons of which 38% were recon units, 38% fighter units and 24% bomber units.

 

Not said in the video but added by myself for the overal picture. The armoured units had 298 tanks LT vz.35, 50 tanks LT vz.34, 70 tankettes Tč. vz.33, 50 armoured cars vz.30 and several dozens of other armoured vehicles such as 15 armoured cars vz.27, 8 training Renault FT tanks, 6 armoured cars vz.23 etc. (not counting temporarily seized export vehicles), trains, armoured trolleys and river boats. Most of the armor was concentrated in 3 fully-motorized so called fast divisions which were mainly concentrated in Brno-Opava area where a flanking attack was expected. The fortifications shall have given the field army a time to move and regroup for counter attack where necessary. 

 

Another video taken from 1937 movie showing Czechoslovak army during military excercise. Quite interesting footage because it captures a lot of rare equipment. Mainly LT vz.34 tank which was the first serially produced Czechoslovak tank and even ancient Renault FT armed with HMG vz.24. Other than that there is field and heavy artillery, some airforce (Avia/Fokker F-IX bombers and Avia B-534 fighters) and a very funny concealed HMG nest at 2:06  What is also interesting is that quite a lot of the soldiers don't wear helmets vz.30 but older vz.20 or vz.28. Considering that those were stopped being used in 1936 it gives an idea that the video was taken probably in 1935-1936.