In April of 1944, plans were laid for the design that would be an effective defense against Allied fighter bombers, which proved to be very effective against German ground targets. It was proposed to build such vehicle based on Panzer IV Ausf H's proven chassis and armed with twin 30mm MK (MK - Maschinenkanon) 303 "Doppelflak" / "Brunn" guns (developed by Rheinmetall for Type XXI U-Boot to be installed on coning towers) mounted in fully closed sphere-like turret.Development of this project was given to both Rheinmetall and Daimler-Benz and production was planned to start in September 1944.

First improvised prototype by Daimler-Benz was mounted with modified U-Boot turret armed with two 30mm MK303 guns. It was tested but it didn't perform as expected and further development was to be continued. The additonal problem was that entire production of 30mm MK303 guns and turrets was reserved for the Kriegsmarine. Designers then decided to utilize older 30mm MK103/38 guns, which were used as armament for Henschel Hs 129 and Dornier Do 335 Pfeil (Arrow) airplanes. The weapon was known to the Luftwaffe as the Jaboschreck (Fighter-bomber terror). In November of 1944, first real prototype was produced at Marienfelde and was tested and eventually production was to start in March of 1945 with 30 being produced monthly. Only five chassis were obtained due to shortages by Daimler-Benz with sub-contractor Stahlindustrie. Daimler-Benz produced three and Stahlindustrie two were produced in February/March of 1945. Due to the war situation and cancellation of Panzer IV's production, only 2 to 5 prototypes were delivered in February/March of 1945 and assigned to Panzerflak Ersatz und Ausbildungs Abteilung (Anti-Aircraft Tank Training and Replacement Battalion) at Ohrdruf, but it is not knownif they saw any combat. Although, some sources state that all took part in the Battle for Berlin in April of 1945, where they were all lost.Kugelblitz was intended for use exclusively on the Western Front, where Allied Air Force was the biggest threat to the German Army.

Kugelblitz was operated by the crew of 5, protected by the armor thickness varying from 10mm to 80mm. The turret housed 3 men crew consisting of two gun operator (each sitting alongside the gun) and commander (sitting in the middle). The 3500kg turret had one entry/exit hatch (commander was last to enter and first to exit) and two smaller hatches for observation. It had manual traverse by hand of 14 degrees per second. Armored protection of the turret was only 20mm. The size and weight of the turret demanded that hulls were fitted with larger 1900mm rings from Tiger I.

With its low silhouette, high mobility (with maximum speed of 38km/h), great rate of fire (400 to 650 rounds per minute) and gun range (up to 5700 meters), Flakpanzer IV Kugelblitz would prove deadly to any enemy plane. Both guns were coupled together, but could be fired independently. The ammunition, known as Minengeschoss was belt-fed and more powerful than standard 30mm round, only three to four rounds were needed to shotdown any enemy plane. Its main drawback was its small ammunition storage allowing it to continue firing for only 90 seconds, while afterwards more ammunition was to be supplied by other vehicles.

Also, version armed with two 30mm MK and two 20mm MK cannons was planned. 20mm cannons were to be used to "get on target", while 30mm cannons were to fired on it. In addition, tests were carried to equip future models with radar and infra-red equipment. In November of 1944, it was accepted to utilize Hetzer's chassis as a base for Flakpanzer 38(t) Hetzer mounted with Kugelblitz's turret, but it was never materialized due to the war situation. In mid 1945, it was planned to mount Kugelblitz's turret on PzKpfw 38(d) chassis. It was also proposed to mounted Kugelblitz's turret on Panther's chassis, but it was never done.Its design was revolutionary for the time and served as an example until late 1950s. There is even some similarity between Kugelblitz and post-war American M42 "Duster" anti-aircraft system.

Turret of Kugelblitz on display in England.

Specifications