Thank you WT for having this goofy SPAA in the game. Would have never found it if I never saw a video about it. As the German Luftwaffe (German Air Force) lost control over the skies of Germany in the second half of the Second World War; it could no longer provide sufficient protection against Allied aircraft. Panzer divisions were especially affected by the lack of cover from fighter aircraft because they were always at the center of the most intense fighting. While the Germans already had copious amounts of half-tracked Self-Propelled Anti-Aircraft Guns of different calibers and weights (Sd.Kfz.10/4, Sd.Kfz.6/2, Sd.Kfz.7/1, etc), these had the significant flaw of being vulnerable to the planes they themselves were meant to protect against. A tank-based anti-aircraft vehicle (German: Flakpanzer) could solve this problem, but little effort was done in this direction. The first attempt was the Flakpanzer I, which was built only in limited numbers and was more an improvisation of an existing design rather than a purpose-built vehicle. The later 20 mm armed Flakpanzer models (Flakpanzer 38(t)) and the Wirbelwind, goated AA) were built in some numbers but were considered unsuccessful, mostly due to the weak fire power of the 2cm Flak 38 by this late stage of the war. Larger caliber 37 mm (Möbelwagen and the Ostwind, based on the Panzer IV) armed models proved to be somewhat better vehicles but were not without flaws. The Mobelwagen required a long time to prepare for action, and the Ostwind was built in limited numbers and too late to have any influence on the War. Even the famous 88 mm anti-aircraft guns were installed on some fully-tracked and tank chassis’, but again only in very limited number. These anti-aircraft vehicles’ main problem was the lack of a fully enclosed crew compartment. This issue was to be solved by the production of a new vehicle with a fully enclosed turret, the Leichte Flakpanzer IV 3 cm but mostly known by as ‘Kugelblitz’.
The maximum armor of the lower frontal glacis was 80 mm thick, the sides were 30 mm, the rear 20 mm and the bottom armor was only 10 mm. Most parts of the upper tank hull were unchanged from the original Panzer IV. The driver’s front observation hatch and the ball-mounted hull machine gun remained. The turret ring was replaced with a one taken from the Tiger I with a diameter of 1900 mm. This was necessary because of the wider size of the newly designed turret. Because of this, the two hull crew hatch doors for the driver and radio operator were repositioned so as to not disturb this new installation. The front hull, directly above the driver and radio operator positions, was totally straight and level with engine deck. This differs substantially from standard Panzer IV hull as this part was slightly sloped. The front armor of the upper hull was 80 mm, the sides were 30 mm, and the rear armor that protected engine compartment was only 20 mm. The biggest change in the design was the newly enclosed oblate spheroid turret with a fully 360° traverse armed with two 3 cm cannons. Some sources (Marcus Hoch and Walter J. Spielberger) describes it as spherically (or simply as ball-shaped) shaped, but due to flattened sides and irregular top shape, the oblate spheroid is a more convenient designation. This newly designed turret was fully enclosed (suspended by using gimbals) and protected by a rounded protective mantlet which had a shape like a shortened cone.