Sturmhaubitze 42, Sd.Kfz 142/2 Late-Production

In October of 1942 Sturmhaubitze 42 was produced by Alkett, its design was based on Stug III Ausf F and F/8's chassis and it was armed with 105mm StuH 42 L/28 (L/30) howitzer. From 1943 onwards StuH 42 was built on Ausf G's chassis. Vehicles of this type were modified in the same way as Ausf Gs were. Early vehicles were fitted with muzzle brakes but since September of 1944, it was decided that it wasn't needed.

In August of 1940, Sturmartillerie units were reorganized into Abteilungen (battalions) with 18 assault guns in three batteries (with 6 assault guns each). In early 1941, the battalions were renamed - Sturmgeschuetz Abteilungen and batteries to Sturmgeschuetz Batteries. In March/April of 1941, all Sturmgeschuetz Batteries had the number of assault guns increased to seven. In 1942, with the introduction of long-barrelled Stug III (75mm L/43 and L/48), Sturmgeschuetz Abteilungen were reformed and number of assault guns was increased to 28 per battalion. Each battalion still had three batteries but number of assault guns in platoons was increased to three. In November of 1942, Sturmgeschuetz Abteilungen were reformed again and number of assault guns was increased to 31 per battalion with three additional assault guns for battery commanders. This type of organization often referred to as Sturmgeschuetz Brigade remained in use until the end of the war. In June of 1944, new organization scheme was introduced - Sturmartillerie Brigade with 45 assault guns, including 33 Stug III/IV (75mm L/48) assault guns and 12 Sturmhaubitze 42 (105mm L/28) assault howitzers. Brigade had three batteries with 2 Stug IIIs for each battery command, while each battery had two platoons of four Stug IIIs and one of four StuH 42s. This organization scheme was used alongside the Sturmgeschuetz Brigade scheme to the end of the war. In practice, these ideals were hardly ever achieved and then only highly favoured formations received the full complement.

Sturmhaubitze 42, Sd.Kfz 142/2 Mid-Production

In 1942, a variant of the StuG III Ausf.F was designed with a 105 mm (4.1 in) howitzer instead of the 7.5 cm StuK 40 L/43 cannon. These new vehicles, designated StuH 42 (Sturmhaubitze 42, Sd.Kfz 142/2), were designed to provide infantry support with the increased number of StuG III Ausf F/8 and Ausf Gs being used in the anti-tank role.

The StuH 42 mounted a variant of the 10.5 cm leFH 18 howitzer, modified to be electrically fired and fitted with a muzzle brake. Later models were built from StuG III Ausf. G chassis as well as StuG III Ausf. F and Ausf. F/8 chassis. The muzzle brake was often omitted due to the scarcity of resources later in the war. 1,211 StuH 42 were produced from October 1942 to 1945.

The early models got the old boxy gun mantlet armor without a machinegun and the machinegun behind the classic shield which had to be operated from the outside. Late models were fitted with the Topfblende (pot mantlet) (often called Saukopf (Pig's head)) gun mantlet without coaxial mount. This cast mantlet with organic shape was more effective at deflecting shots than the original boxy mantlet armor of varying thickness between 45 mm and 50 mm. Lack of large castings meant that boxy mantlet was also produced until the very end.

Coaxial machine gun was added first to boxy mantlets and then to cast Topfblende, in the middle of "Topfblende" mantlet production. With an addition of coaxial, all StuGs carried two MG 42 machine guns from fall of 1944. Later, the Topfblende mantels are be produced without machine gun opening so there are two verions of the late models. The machine gun on the roof, could now be operated via inside. Also a smaller armor plate was provided for the protection of the weapon.

Sturmhaubitze 42, Sd.Kfz 142/2 Initial Production

In 1942, a variant of the StuG III Ausf. F was designed with a 105 mm (4.1 in) howitzer instead of the 7.5 cm StuK 40 L/43 cannon. These new vehicles, designated StuH 42 (Sturmhaubitze 42, Sd.Kfz 142/2), were designed to provide infantry support with the increased number of StuG III Ausf. F/8 and Ausf. Gs being used in the anti-tank role. The StuH 42 mounted a variant of the 10.5 cm leFH 18 howitzer, modified to be electrically fired and fitted with a muzzle brake. Production models were built on StuG III Ausf. G chassis. The muzzle brake was often omitted due to the scarcity of resources later in the war. ~1,299 StuH 42 were produced by Alkett from March 1943 to 1945, the initial 12 vehicles were built on repaired StuG III Ausf. F and F/8 from autumn 1942 to January 1943.

Sturminfanteriegeschütz 33B

The StulG33B was the third attempt at mounting the 15cm slG33 on a Pz Kpfw chassis. Unlike those mounted on the Pz Kpfw I and II chassis, the slG33B was to have a fully-enclosed fighting compartment. In July 1941, Alkett was ordered to furnish twelve chassis which were to be completed by the middle of September. This initial version was completed in December 1941 and January 1942. On 20 September 1942, twelve assault-vehicles mounting a heavy weapon capable of demolishing houses with two or three rounds, were ordered to be completed within 14 days. The original twelve slG33B were rebuilt, and an additional twelve new slG33B were built in October 1942.

The slG338 had the same hull as the StuG, Ausf E and F/8. The superstructure was completely redesigned. The front, sides and rear were extended, and a roof added to form a completely enclosed fighting compartment. The slG33 was mounted in a sliding gun mantlet, offset to the right of the vehicle's centre-line. Secondary armament was provided by an MG34 in a hull mount in the right superstructure front.

All 24 StuIG 33 were rebuilt from normal Stug´s in October and November 1942. 12 were given to the Stug Abteilung 177, who were sent to Stalingrad. The other 12 were sent to the StuIG Batteri of the Lehr Btl. XVII, which were sometimes assumed to the 22. Panzer Division. On 11th April 1943, the 7 left StuIG´s were put to the 23. Panzer Division. The last StuIG were lost in October 1943.
In the beginning, the vehicles were painted in dark grey. Some photos of captured vehicles from Stalingrad show white winter camo. In summer 1943 a three tone camo was applied.

There were 12 pieces of StuIG 33 (Sturminfanteriegeschütz 33 - Assault Infantry Cannon 33) sent to Stalingrad - and all of them lost there. The battle of Stalingrad was finished on 2nd February 1943 - still a couple of days before yellow colour was introduced as an official basic paint, i.e. all of them were grey.

Second batch of 12 pieces came into operation during 1943, they were yellow with dark green snake-like areas.

Panzerkampfwagen III (Pz Kw III) and its Variants I

Development

From 1935 onwards the collective knowledge gained during the development and production of the Pz Kw III at last enabled the German tank building industry to finalise its own design ideas. No longer had it to rely on foreign inspiration, though Germany's ideas did sometimes prove complicated and did not always lend themselves to mass production.

According to General Guderian two types of armoured fighting vehicle were envisaged for Germany's new armoured divisions. The first would be fitted with an armour-piercing gun as well as bow and turret machine guns, and the second type would be a support vehicle, mounting a larger-calibre cannon. It was planned to equip the three light companies of tank battalions with the first of these two types. This was the vehicle later to become well known as the Pz Kw III.

There were certain fundamental differences of opinion on the question of arming the vehicle. The Weapons Department and the Artillery Inspectorate considered the 3.7 cm gun to be sufficient, while the Inspectorate for Mechanised Troops demanded a 5 cm gun. The infantry was already equipped with a 3.7 cm anti-tank gun and, for simplicity's sake, it was thought desirable to standardise on this single armour-piercing weapon. The installation of the more powerful weapon was therefore rejected at this time. But one important concession gained was that the Pz Kw Ill's turret ring would be of a diameter large enough to accommodate a much larger calibre weapon at a future date. The safe loading of German road bridges limited the combat weight of both new types to 24 tons, while a maximum speed of 40 kph was specified. The crew was to consist of five men--commander, gun layer and loader in the turret, with the driver and radio operator in the front of the hull. The commander had a central raised seat between the layer's and the loader's positions, and his own cupola allowing an allround view. Throat microphones were used both for inter-com and also for tank-to-tank communications .in the field.

In 1935 the Weapons Department issued development contracts for the Pz Kw III to MAN, Daimler-Benz, Rheinmetall-Borsig and Krupp.

A 15-ton vehicle was specified with the characteristics already mentioned. The Weapons Department's "concealed-purpose" name was Zugführerwagen/ZW (Platoon Commander's Vehicle). From 1936 onwards the prototypes were thoroughly tested and, as a result of these trials, Daimler-Benz were made responsible for the development and production. In contrast to that of the Pz Kw IV, this machine's suspension system showed the influence of the automobile industry, reflecting the Daimler-Benz tradition, in that torsion-rod springing was standardised in the Pz Kw III, from the fourth development model of the "ZW" vehicles onwards. Krupp's experience of locomotive building led to a coupled bogie suspension with longitudinal leaf springs in the Krupp prototype "MKA", which combined the design features of the "ZW" and the "BW" (Pz Kw IV) tank.

It is noteworthy that the selection of tank building contractors seems to have been made with little regard to experience in mass production on the part of the firms concerned. The conclusion which can be drawn from this is that no mass production of these tanks had been planned at that particular time. The two largest ear manufacturers in Germany at that time-Ford and Opel-were deliberately excluded from the tank programme because of their foreign connections.

Panzerkampfwagen III (Pz Kw III) and its Variants II

Production

In 1936 the first model of the Pz Kw III was produced by Daimler-Benz and ten vehicles designated "1/ZW" underwent troop trials. Eight of these were fitted with the 3.7 cm gun and chassis numbers started at 60,001. Although the hull, superstructure and turret already took the form familiar in the later Pz Kw III models, the suspension consisted of five large double bogies, which were suspended on coil springs, plus a front driving sprocket and a rear idler together with two return rollers. Armour was between 5 and 14'5 mm thick and the overall weight was 15 tons. The power unit was a development of the Maybach DSO 12-cylinder high-performance 108 TR petrol engine of about 11 litres which produced a maximum of 250 hp. Maximum sustained output was however only 230 hp and top speed was 32 kph. Transmission was by a ZF SFG 75 five-speed gearbox. One hundred and fifty rounds were carried for the main armament and 4500 rounds for the three machine guns, two of which were coaxial with the main armament in the turret. This vehicle was known unofficially as the Pz Kw III (3.7 cm) Ausf A.

The marks B and C appeared in 1937. A new suspension was tried, consisting of eight small bogie wheels suspended on longitudinal leaf springs and the number of return rollers was increased to three. Armament remained a 3.7 cm tank gun L/45 in an internal mantlet and two MG 34s, while a third machine gun, mounted beside the driver, was worked by the wireless operator. Fifteen of each of the B (type 2/ZW) and the C (type 3a/ZW) models were constructed. Armour was retained at 14.5 mm all round. The Model D (type 3b/ZW) which finally went into quantity production, appeared at the end of 1938. With the introduction of Model D all previous trial models were redesignated Model D. The various original suspensions were retained, but these vehicles were uparmoured to 30 mm all round, increasing the total weight to about 19 tons. The ZF Aphon SSG 76 transmission was used.

From the Model E onwards the more powerful Maybach 12-cylinder HL 120 TR was fitted, which increased the maximum output to 320 hp by enlarging the bore from 100 to 105 mm and increasing the cylinder capacity to 11.9litres (torque 80 m/kg). The gearbox in this vehicle was the Maybach Variorex pre-selector with 10 forward and one reverse speed. This complicated transmission was intended to make gear changing easier as the change was carried out by a vacuum after the gear had been selected and the release valve activated by depressing the clutch pedal. The 9th and 10th gear positions were overdrives. The speed of 40 kph at 2800 rpm was not to be exceeded. Fifty-five vehicles of this version were produced.

On 27th September 1939 the Army Regulations circular announced "Panzerkampfwagen III (3.7 cm) (Sd Kfz 141), has been adopted as a result of its successful troop trials".

In the mass production which now followed the participating manufacturers were: AItmärkische Kettenfabrik GmbH (Alkett)-Spandau (assembly) and Falkensee (chassis construction); Daimler-Benz ,AG-Berlin-Marienfelde; Fahrzeug- und Motorenbau GmbH (Famo)-Breslau; Henschel & Sohn AG -Werk III, Mittelfeld-Kassel; Maschinenfabrik Augsburg-Nürnberg AG (MAN)-Nuremberg; Mülenbau und Industrie AG (MIAG)-Amme Werk, Brunswick; Waggonfabrik Wegmann AGKassel; and Maschinenfabrik Niedersachsen-Hannover- Hannover-Linden.

The Pz Kw III Ausf E (type 4/Zw) (reference order 652/17 of 23rd April 1940), which appeared in 1939, featured the finalised chassis design of this series. There were now six bogies on each side (bogie size 520 x 95-398, track roller size, 310 x 70-302), mounted on transversely-fitted torsion bars. The vehicle weighed 19.5 tons when fitted with allround armour 30 mm thick and was still equipped with the Maybach HL 120 TR engine. The chassis weighed 13.8 tons. Two coupled machine guns (MG 34s) in the turret had, until now, been coaxial with the main armament, but from this version onward a single coaxial machine gun was fitted. Some Pz Kw III Ausf E versions had the old model D type turrets with an internal mantlet and two turret machine guns however. Transmission was via a main clutch to the Maybach Variorex pre-selector gearbox already described. This gearbox was of the constant-mesh type where sliding gear switch sleeves transferred the drive to the two cog wheels required for the correct gear. The main clutch was hydraulically operated and the bevel gear and the steering gear were flanged to the variable gears. Clutch steering was affected by means of mechanical servo-internal, expanding brakes with hydraulic assistance. Steering and standard brakes were located in the same housing and from these the drive went to the driving sprocket. The rear idler wheel, in this version, consisted of a boss upon which two wheel discs were welded. The 37 mm gun now had an external mantlet. By 1940 100 of these vehicles had been built, intended as the main equipment of tank regiments. The German tank industry could only produce in limited numbers, and this low production capacity became more and more apparent. The Pz Kw III received its baptism office in Poland and there proved itself. For the attack on France on loth May 1940 a total of 349 Pz Kw IIIs was available.