The Nebelkerzenabwurfvorrichtung (abbreviated N.K.A.V.) was a rear mounted grenade dispenser used to disperse the Schnellnebelkerze 39 smoke grenade. It was typically found on German tanks from 1939 through 1942.[1]
The device carried five smoke grenades, each grenade being held in position by spring loaded catches. The vehicle commander released the grenades one at a time[1] by wire control which operated a ratchet coupled to a camshaft.
Each pull of the control wire rotated the camshaft one fifth of a turn, releasing a smoke grenade, the pin of which was drawn out by a fixed chain, and the ratchet was returned to its original position by a second spring. Five pulls on the control wire would release all five smoke grenades in succession, enabling the vehicle to reverse out of sight into its own smoke screen[2] with the grenades discharging smoke for about 100 to 200 seconds.[3] Later examples of the Nebelkerzenabwurfvorrichtung were fully enclosed in an armored box (N.K.A.V. mit Schutzmantel).[4] The Nebelkerzenabwurfvorrichtung was discontinued beginning in April 1942 because it had not proven to be effective,[3] the main disadvantage being that the resulting smoke screen built up behind the vehicle.[5] It was succeeded by the turret mounted Nebelwurfgerät launcher.