At the very beginning of the XXth century, the German Army yet showed some interest to the anti-aircraft artillery, and required the development of specic equipments. However the experience of the first months of the war demonstrated a lack of Flak 77mm 1914 guns (36 guns only...), so numerous improvisations were made to reinforce the numbers, awaiting for the design of new materials.

The fieldgun 7.7cm FK 96 n/A was then converted into an anti-aircraft equipment by using it on the top of a tall wooden scaffold. The first 'Koebe-Protze' system introduced in 1915 was replaced in 1916 by the Schnetzler system.

That solution was far from being perfect because of that scaffold instability, as well as the unsactisfactory operation of the recuperator in a quasi-vertical axis. This latter issue was partially solved by the adjunction of an additional spring linking the breech block and the carriage.

Moreover, the rather low initial speed of the projectile probably limited its use to the fight against airships ('Bak' = Ballon-Abwehr Kanone).

Main specifications :

• Weight in firing position : 1138 kg
• Calibre : 77 mm
• Tube length : 27 calibres
• Projectile weight : 6.2 kg
• Initial velocity : 460 m/s
• Maximum range : 8025 m (maximum altitude unknown)