1:72 "Kugelhetzer" SPAAG, late 1945

Dizzyfugu · November 30, 2020, 11:49:55 PM

The kit and its assembly:
The so-called "Kugelhetzer" was a real German project in late WWII, but it was rather a vague idea, it never it made to the hardware stage. Even from its predecessor, the Panzer IV-based "Kugelblitz", only five tanks were actually built. However, I found the idea interesting, since the combination of existing elements would lead to a very compact SPAAG. And since I had a spare Kugelblitz turret from one of the Modelcollect "Vierfüssler" SF mecha kits at hand, I decided to build a model of this conceptual tank.

1:72 SdKfz. 170, Leichter Flakpanzer 38(t) 3 cm (,,Kugelhetzer"); vehicle ,,23" of the 2. FlakpanzerZug, Pz. Brig. 106 "Feldherrnhalle"; Upper Austria, late 1945 (Heer '46/modified UM Models kit) - WiP by dizzyfugu, on Flickr

1:72 SdKfz. 170, Leichter Flakpanzer 38(t) 3 cm (,,Kugelhetzer"); vehicle ,,23" of the 2. FlakpanzerZug, Pz. Brig. 106 "Feldherrnhalle"; Upper Austria, late 1945 (Heer '46/modified UM Models kit) - WiP by dizzyfugu, on Flickr

The chassis is a Bergepanzer 38(t), a.k.a. "Bergehetzer", from UM Models, an unarmed recovery tank based on the Hetzer hull with an open top. For my conversion plan it offered the benefit of a blank glacis plate and lots of spare parts for future builds. However, upon inspection of the parts-not-intended-to-be-mated I became slightly disillusioned: while the Hetzer's upper original hull offers enough room for the ball turret itself to be inserted into the roof, it could NEVER take the turret bearing and the armored collar ring around it. They already are hard to mount on a Panzer IV hull, but the Hetzer is an even smaller vehicle, despite its casemate layout. I was about to shelf the project again, but then decided to modify and adapt the upper hull to the turret. In real life the engineers would have taken a similar route.

I started to scratch the superstructure from 0.5mm styrene sheet, and work started with the roof that had to be wide enough to carry the turret ring. This was glued into place on top of the hull, and from this benchmark the rest of the "armor plates" was added – starting with the engine bay cover, then adding side walls and finally the more complex corner sections, which actually consist of two triangular plates, but only one of them was actually fitted. The leftover openings were filled with acrylic putty, also in order to fill and stabilize the void between the original hull and the added plates. Later, the necessary space for the ball turret was carved away from the original hull, so that the Kugelblitz turret could be inserted in its new opening. Sounds complicated, but the construction was less complicated than expected, and it looked even better!

1:72 SdKfz. 170, Leichter Flakpanzer 38(t) 3 cm (,,Kugelhetzer"); vehicle ,,23" of the 2. FlakpanzerZug, Pz. Brig. 106 "Feldherrnhalle"; Upper Austria, late 1945 (Heer '46/modified UM Models kit) - WiP by dizzyfugu, on Flickr

1:72 SdKfz. 170, Leichter Flakpanzer 38(t) 3 cm (,,Kugelhetzer"); vehicle ,,23" of the 2. FlakpanzerZug, Pz. Brig. 106 "Feldherrnhalle"; Upper Austria, late 1945 (Heer '46/modified UM Models kit) - WiP by dizzyfugu, on Flickr

Once mated with the lower chassis, some details had to be added to the blank surfaces – e. g. racks with spare barrels for the guns and some tools and stowage boxes. These were taken from the Bergehetzer kit and partly modified to match the different hull.
What really became a challenge was the assembly of the tracks upon the model's completion. Unfortunately, they consist of single elements and even links that have to be glued to the wheels, and since they were not crisply molded (just like the sprocket drive wheels) their installation was a rather tedious affair.

Painting and markings:
This is another variation of the "Hinterhalt" concept, using the three basic tones of Dunkelgelb (RAL 7028), Olivgrün (RAL 6003) and Rotbraun (RAL 8012). In this case – as an autumn scheme with fading light and more red and brown leaves - I used a late-war Panther as reference and gave the vehicle a rather dark basic livery consisting of green and the brown, and on top of that I added counter-colored (green on brown and brown on green) mottles, plus contrast mottles in Dunkelgelb. The tones I used were Humbrol 83, 86 and 113 - the latter is not the standard tone for the Hinterhalt scheme (180 would be appropriate), but it comes close to the typical German red Oxidrot (RAL 3009) primer, which was not only used on bare tank hulls during production but was also integrated into camouflage schemes, frequently stretched and lightened through additives. Effectively the livery is very standard, and since this Kugelhetzer model would depict a standard production vehicle and not a conversion, I extended the camouflage to the turret, too, for a consistent look.
The wheels remained in a single color (just the basic red brown and green), since camouflage was prohibited to be extended onto moving parts of the vehicle: a swirling pattern would have been very obvious and eye-catching when the vehicle was on the move.

1:72 SdKfz. 170, Leichter Flakpanzer 38(t) 3 cm (,,Kugelhetzer"); vehicle ,,23" of the 2. FlakpanzerZug, Pz. Brig. 106 "Feldherrnhalle"; Upper Austria, late 1945 (Heer '46/modified UM Models kit) - WiP by dizzyfugu, on Flickr

1:72 SdKfz. 170, Leichter Flakpanzer 38(t) 3 cm (,,Kugelhetzer"); vehicle ,,23" of the 2. FlakpanzerZug, Pz. Brig. 106 "Feldherrnhalle"; Upper Austria, late 1945 (Heer '46/modified UM Models kit) - WiP by dizzyfugu, on Flickr

A washing with dark red brown, highly thinned acrylic paint followed. The decals – mostly taken from the small OOB sheet – came next, and I settled upon simplified national markings and just white outlines for the tactical code, due to the rather murky camouflage underneath.
The model's main components were sealed with matt acrylic varnish from the rattle can before their final assembly, and some dry-brushing with light grey was done to emphasize details and edges. Finally, a coat of pigment dust was applied to the model's lower areas and used to hide some flaws along the fiddly tracks.

1:72 SdKfz. 170, Leichter Flakpanzer 38(t) 3 cm (,,Kugelhetzer"); vehicle ,,23" of the 2. FlakpanzerZug, Pz. Brig. 106 "Feldherrnhalle"; Upper Austria, late 1945 (Heer '46/modified UM Models kit) - WiP by dizzyfugu, on Flickr

ChernayaAkula · December 01, 2020, 05:46:37 AM

EXTERMINATE!!!

Looking damn nifty.

PR19_Kit · December 01, 2020, 05:49:10 AM

Quote from: ChernayaAkula on December 01, 2020, 05:46:37 AM

EXTERMINATE!!!

Oh yes. I knew it reminded me of something.

NARSES2 · December 01, 2020, 06:00:02 AM

That's looking good Dizzy

chrisonord · December 01, 2020, 09:07:49 AM

Now there's a thought. Flak Daleks,

Very nice Dizzy

Mossie · December 01, 2020, 09:24:43 AM

Great balls of fire(power)!!!

jcf · December 01, 2020, 03:32:20 PM

Yow, even more cramped inside and more of a maintenance nightmare.

This drawing shows a 38(d) based Kugelblitz in the lower left corner, no doubt
completely speculative but it does show the lengthened 38(d) chassis and has
the turret mounted towards the fwd end of the fighting compartment.

buzzbomb · December 01, 2020, 09:25:33 PM

Wow Dizzy, your magic wand of Construction Swiftness is certainly a good one.

Really nice work creating that new superstructure.

Dizzyfugu · December 01, 2020, 11:22:55 PM

Quote from: joncarrfarrelly on December 01, 2020, 03:32:20 PM
Yow, even more cramped inside and more of a maintenance nightmare.

This drawing shows a 38(d) based Kugelblitz in the lower left corner, no doubt
completely speculative but it does show the lengthened 38(d) chassis and has
the turret mounted towards the fwd end of the fighting compartment.

Yup, that's the "Kugelkhetzer" I also found as reference, IIRC I even came across a model of it. But despite the lengthened chassis I do not think that it is realistic. There's still no room for a driver hatch, apparebnrly the extra space was spent on a bigger engine - which was under discussion, though, because the original Hetzer itself was already exhausting the Praga 6 cylinder. But the internal space in front of the ball turret and its huge mount is still minimal (which is the same as for the one with the Panzer IV turret), IMHO, the turret had to be moved backwards. A top view would be nice. And it's funny how "model building archaeology" reveals such flaws through home-made hardware experiments.

Thanks a lot everyone, glad you like this little build. Beauty pics pending...

jcf · December 02, 2020, 01:23:43 PM

I suppose one could lengthen the butt with a new 'box' for a bigger
engine, go for that unbalanced look, like the US Army did with the
M1917A1 variant of their version of the FT-17.

The lengthening was required when they replaced the 42hp I-4 Buda
engine with a 100hp air-cooled Franklin I-6.

Sorry for the fuzzy image, it's the best I could find.

Dizzyfugu · December 03, 2020, 06:16:34 AM

1:72 SdKfz. 170, Leichter Flakpanzer 38(t) 3 cm (,,Kugelhetzer"); vehicle ,,24" of the 2. FlakpanzerZug, Pz. Brig. 106 "Feldherrnhalle"; Upper Austria, late 1945 (Heer '46/modified UM Models kit) by dizzyfugu, on Flickr

Some background:
The need for a specialized self-propelled anti-aircraft gun, capable of keeping up with the armoured divisions, had become increasingly urgent for the German Armed Forces, as from 1943 on the German Air Force was less and less able to protect itself against enemy fighter bombers.
Therefore, a multitude of improvised and specially designed self-propelled anti-aircraft guns were built, many based on the Panzer IV chassis. This development started with the Flakpanzer IV "Möbelwagen", which was only a Kampfpanzer IV with the turret removed and a 20mm Flakvierling installed instead, together with foldable side walls that offered only poor protection for the gun crew. The lineage then progressed through the Wirbelwind and Ostwind models, which had their weapons and the crew protected in fully rotating turrets, but these were still open at the top. This flaw was to be eliminated in the Kugelblitz, the final development of the Flakpanzer IV.

1:72 SdKfz. 170, Leichter Flakpanzer 38(t) 3 cm (,,Kugelhetzer"); vehicle ,,24" of the 2. FlakpanzerZug, Pz. Brig. 106 "Feldherrnhalle"; Upper Austria, late 1945 (Heer '46/modified UM Models kit) by dizzyfugu, on Flickr

1:72 SdKfz. 170, Leichter Flakpanzer 38(t) 3 cm (,,Kugelhetzer"); vehicle ,,24" of the 2. FlakpanzerZug, Pz. Brig. 106 "Feldherrnhalle"; Upper Austria, late 1945 (Heer '46/modified UM Models kit) by dizzyfugu, on Flickr

1:72 SdKfz. 170, Leichter Flakpanzer 38(t) 3 cm (,,Kugelhetzer"); vehicle ,,24" of the 2. FlakpanzerZug, Pz. Brig. 106 "Feldherrnhalle"; Upper Austria, late 1945 (Heer '46/modified UM Models kit) by dizzyfugu, on Flickr

The Kugelblitz used the 30 mm MK 103 cannon in a Zwillingsflak ("twin flak") 103/38 arrangement. The MK 103 was a powerful aircraft weapon that had formerly been fitted in single mounts to such planes as the Henschel Hs 129 or Bf 1110 in a ventral gun pod against tanks, and it was also fitted to the twin-engine Dornier Do 335 heavy fighter and other interceptors against Allied bombers. When used by the army, it received the designation "3 cm Flak 38". It had a weight of only 141 kg (311 lb) and a length of 235 cm (93 in) with muzzle brake. Barrel length was 134 cm (53 in), resulting in caliber L/44.7 (44.7 caliber). The weapon's muzzle velocity was around 900 m/s (3,000 ft/s), allowing an armour penetration for APCR 42–52 mm (1.7–2.0 in)/60°/300 m (980 ft) or 75–95 mm (3.0–3.7 in)/ 90°/ 300 m (980 ft), with an effective maximum firing range of around 5.700 m (18.670 ft). The MK 103 was gas-operated, fully automatic and belt-fed, an innovative feature at that time for AA guns.
In the fully enclosed Kugelblitz turret the weapons could be fired singly or simultaneously, and their theoretical rate of fire was 450 rounds a minute, even though 250 rpm in short bursts was more practical. The total ammunition load for both weapons was 1,200 rounds and the discharged cases fell into canvas bags placed under the guns. The MK 103 cannons produced a lot of powder smoke when operated, so that fume extractors were added, which was another novelty.

The Kugelblitz turret's construction was unique, because its spherical body was hanging in a ring mount, suspended by two spigots – it was effectively an independent capsule that only slightly protruded from the tank's top and kept the profile very low. The turret offered full overhead protection, 360° traverse and space for the crew of three plus weapons and ammunition – even though it was very cramped. Elevation of the weapons (as well as of the crew sitting inside of the turret!) was from -5° to +80°, turning speed was 60°/sec.
The commander/gunner, who had a small observation cupola on top of the turret, was positioned in the middle, behind the main guns. The two gunner assistants were placed on the left and right side in front of him, in a slightly lower position. The assistant situated left of the guns was responsible for the turret's movements, the one on the right side was responsible for loading the guns, and the spare ammunition was located on the right side. Each of these three crew members had separate hatch doors.

However, the Panzer IV-based Kugelblitz SPAAG was ill-fated: A production rate of 30 per month by December 1944 was planned, but never achieved, because tank production had become seriously hampered and production of the Panzer IV was about to be terminated in favor of the new E-series tank family. Therefore, almost all Flakpanzer IV with the Kugelblitz turret were conversions of existing hulls, mostly coming from repair shops.
In parallel, work was under way to adapt the Kugelblitz turret to the Jagdpanzer 38(t) Hetzer hull, too, which was still in production in the former Czechoslovakian Skoda works, and to the new, light E-10 and E-25 tank chassis. Due to this transitional and slightly chaotic situation, production numbers of the Panzer IV-based Kugelblitz remained limited - in early 1945, only around 50 operational vehicles had been built and production already ceased in May.

1:72 SdKfz. 170, Leichter Flakpanzer 38(t) 3 cm (,,Kugelhetzer"); vehicle ,,24" of the 2. FlakpanzerZug, Pz. Brig. 106 "Feldherrnhalle"; Upper Austria, late 1945 (Heer '46/modified UM Models kit) by dizzyfugu, on Flickr

1:72 SdKfz. 170, Leichter Flakpanzer 38(t) 3 cm (,,Kugelhetzer"); vehicle ,,24" of the 2. FlakpanzerZug, Pz. Brig. 106 "Feldherrnhalle"; Upper Austria, late 1945 (Heer '46/modified UM Models kit) by dizzyfugu, on Flickr

1:72 SdKfz. 170, Leichter Flakpanzer 38(t) 3 cm (,,Kugelhetzer"); vehicle ,,24" of the 2. FlakpanzerZug, Pz. Brig. 106 "Feldherrnhalle"; Upper Austria, late 1945 (Heer '46/modified UM Models kit) by dizzyfugu, on Flickr'

By that time, the Kugelblitz turret had been successfully adapted to the Hetzer chassis, even though this had called for major adaptations of the upper hull due to the relatively wide turret ring, which originally came from the Tiger I. The conversion worked and the unique turret could be successfully shoehorned into the Hetzer basis, making it a very compact and relatively light vehicle – it was 5 tons lighter than the Panzer IV-based "Kugelblitz" SPAAG.
In order to carry the turret, the welded upper hull had to be widened and the glacis plate was reinforced with an extra plate, which also covered the Hetzer's original opening for its 75 mm gun. The resulting 60 mm (2.36 in) thick front plate was inclined 60 degrees from the vertical, and therefore offered around 120 mm (4.72 in) of effective protection – much better than the Panzer IV's almost vertical 50 mm (or 80 mm with additional armor on late versions). In this form, the vehicle could withstand direct frontal hits from most medium Allied tanks. The side walls were rather thin, though, only 20 mm, and they became more vertical to make room for the turret mount. The engine cover behind the turret had to be modified, too. Due to the massive changes, the vehicle received a new, separate designation, "Sonderkraftfahrzeug (Sd.Kfz.) 170" and it was officially called "Leichter Flakpanzer 38(t) 3 cm".

However, there were many drawbacks. The interior was cramped: the self-contained Kugelblitz turret itself already lacked internal space, but the driver – the only crew member in the hull – also had little space in front of the turret's mount and he could only access his working place through an opening in the turret at the commander's feet when it was in a level forward position. There was no dedicated hatch for the driver, only an emergency escape scuttle in the floor.
Another issue was the field of view from inside for everyone. As already mentioned, the driver did not have a hatch that could be used for a good view when not driving under fire. He also only had a single panoramic sight, so that he could just see what was going on directly in front of him. There were no side view openings, and especially the right side of the vehicle was literally blind. The crew in the turret also could only rely on forward-facing sights, just the commander had a rotating periscope. But due to its position, the areas directly along the vehicle's flanks and its rear remained wide blind areas that made it very vulnerable to infantry attacks. This flaw was even worsened by the fact that there were no additional light weapons available (or even deployable from the inside) for close range defense – the Panzer IV-based SPAAGs carried a hull-mounted machine gun. And the crew had, due to the open weapon stations a much better field of view or could directly use their own light weapons.

1:72 SdKfz. 170, Leichter Flakpanzer 38(t) 3 cm (,,Kugelhetzer"); vehicle ,,24" of the 2. FlakpanzerZug, Pz. Brig. 106 "Feldherrnhalle"; Upper Austria, late 1945 (Heer '46/modified UM Models kit) by dizzyfugu, on Flickr

1:72 SdKfz. 170, Leichter Flakpanzer 38(t) 3 cm (,,Kugelhetzer"); vehicle ,,24" of the 2. FlakpanzerZug, Pz. Brig. 106 "Feldherrnhalle"; Upper Austria, late 1945 (Heer '46/modified UM Models kit) by dizzyfugu, on Flickr

With the turret's additional weight (the Sd.Kfz. 170 was 3 tons heavier than the Hetzer), and despite a slightly uprated petrol engine, the tank was rather underpowered, especially off road. Another negative side effect of the turret was a considerably raised center of gravity. The original Hetzer was a nimble vehicle with good handling, but the Sd.Kfz. 170 was hard to control, tended to build up and roll even on the road and its off-road capabilities were markedly hampered by the concentration of weight so high above the ground, making it prone to tip over to the side when the driver did not take care of terrain slope angles. This wobbly handling, as well as the turret's shape, gave the vehicle the unofficial nickname "Kugelhetzer".

Nevertheless, all these flaws were accepted, since the Sd.Kfz. 170. was, like its Panzer IV-based predecessors, urgently needed and only regarded as an interim solution until a light E-Series chassis had been adapted to the turret. It was also surmised that the vehicle would not operate independently and rather escort other troops, so that close-range protection was in most cases ensured. Under this premise, about 100 Sd.Kfz. 170s were built until early 1946, when production of the Hetzer and its components were stopped. Operationally, the vehicle was not popular (esp. among drivers), but it was quite successful, not only against aircraft (esp. when used in conjunction with the new mobile radar-based fire direction centers), but also against lightly armored ground targets.
Plans to stretch the hull for more internal space, better field performance and crew comfort as well as replacing the engine with a bigger and more powerful 8 cylinder Tatra engine were never executed, since all resources were allocated to the new E-series tanks.

1:72 SdKfz. 170, Leichter Flakpanzer 38(t) 3 cm (,,Kugelhetzer"); vehicle ,,24" of the 2. FlakpanzerZug, Pz. Brig. 106 "Feldherrnhalle"; Upper Austria, late 1945 (Heer '46/modified UM Models kit) by dizzyfugu, on Flickr

Specifications:
Crew: Four (commander/gunner, 2 assistants incl. radio operator, driver)
Weight: 18 tons (22.000 lb)
Length: 4.61 m (15 ft 1 in)
Width: 2.63 m (8 ft 8 in)
Height: 2.63 m (8 ft 8 in)
Ground clearance: 40 cm (15 ¾ in)
Suspension: Leaf spring
Fuel capacity: 320 litres (85 US gal)

Armor:
10 – 60 mm (0.39 – 2.36 in)

Performance:
Maximum road speed: 42 km/h (26 mph)
Sustained road speed: 36 km/h (22.3 mph)
Off-road speed: 26 km/h (16 mph)
Operational range: 177 km (110 mi)
Power/weight: 10 PS/t

Engine:
Praga 6-cylinder 7.8 liter petrol engine, delivering 180 PS (178 hp, 130 kW) at 2,800 rpm

Transmission:
Praga-Wilson Typ CV with 5 forwards and 1 reverse gears

Armament:
2× 30 mm 3 cm Flak 38 (MK 103/3) with a total of 1.200 rounds

1:72 SdKfz. 170, Leichter Flakpanzer 38(t) 3 cm (,,Kugelhetzer"); vehicle ,,24" of the 2. FlakpanzerZug, Pz. Brig. 106 "Feldherrnhalle"; Upper Austria, late 1945 (Heer '46/modified UM Models kit) by dizzyfugu, on Flickr

1:72 SdKfz. 170, Leichter Flakpanzer 38(t) 3 cm (,,Kugelhetzer"); vehicle ,,24" of the 2. FlakpanzerZug, Pz. Brig. 106 "Feldherrnhalle"; Upper Austria, late 1945 (Heer '46/modified UM Models kit) by dizzyfugu, on Flickr

A conclusive outcome, and a more complex build than obvious at first sight. The re-built upper hull was easier to realize than expected, the true horror came with the assembly of the tracks which consist of tiny, not really crisply molded elements. Why the return track section has to be constructed of five(!) segments - even though it's a straight line - is beyond my comprehension, too.

However, the outcome looks quite good, even though the use of the original Hetzer hull would have created several problems, if the original Kugelblitz turret had had to be integrated. Esp. the lack of space for the driver (and a suitable access hatch!) make this design idea rather unpractical, so that a stretched hull (AFAIK there's a model of such a modified vehicle available) would have made sense.

NARSES2 · December 03, 2020, 06:27:42 AM

I really like the look of that Dizzy

chrisonord · December 03, 2020, 05:58:16 PM

Marvelous

Chris

rickshaw · December 03, 2020, 06:40:56 PM

Desperate measures create desperate solutions. I wonder why you've retained the ARV's lifting jib elements though? A good model. I was surprised by your retention of the Hetze's hull length. From Jon's picture, it was obviously intended to stretch the 38(D) to mount the Kugelblitz turret. I agree that the driver would have had a hatch cut into the Glacis. I doubt they would have retained the thickness of a tank destroyer's Glacis. It wasn't intended to face tanks.

Dizzyfugu · December 04, 2020, 02:43:52 AM

The jib elements pose as spare barrels, or their protective covers. Was the easiest way to add something to the sides, I tend to be pragmatic.

From the sources I have there's also just mention of the attempt to "mount the Kugelblitz turret onto the Hetzer chassis/hull", so that I am not certain about the lengthened chassis as a definitive element of this combo. Given the dire situation, I doubt that neither a new chassis nor the envisioned 8 cylinder engine would have been introduced, and from that point of view I stuck to the standard Hetzer basis - just to see whether the design plan would work at all or not. I am skeptical, even with a potentially bigger vehicle.