Projectile DM105 (HC Smoke)

155 mm projectile Smoke DM 105 HCis one of three projectiles developed as a result of the trilateral agreement concluded by Germany, Italy and the United Kingdom on the development of the 155 mm FH-70 towed howitzer and its associated ammunition. The Smoke DM 105 was developed by Rheinmetall W & M GmbH and is produced by Buck Werke GmbH & Co, Bad Reichenhall and Simmel Difesa SpA (Italy).

The DM 105 is a carrier projectile with a body made of high-quality forged steel, usually equipped with a mechanical clockwork fuze, containing (in the nose) a powder booster, an ejection mechanism and four smoke canisters located inside the projectile body.

In operation, the flash from the fuze initiates ignition, which is passed to the 6.5 g black powder booster. The booster triggers the ejection mechanism, which ignites a 15 g powder bag inside a cylindrical metal casing. Under the pressure, the four smoke canisters are pushed out. The flash from the ejection mechanism charge also ignites the four smoke canisters.

The canisters scatter under the action of centrifugal force. 4.5 s is the time after which the smoke canister is fully ignited, and it is also the time of flight to the ground. The descent speed is approximately 30 m/s, depending on weather conditions.

Each canister contains a white hexachloroethane/zinc (HC) smoke composition in a cylindrical metal casing and burns for 3 to 3.5 minutes (depending on conditions), creating a smoke screen that can reach 200 by 50 m in area and 10–15 m in height, provided the projectile bursts at a distance of 150 m above the ground (under normal atmospheric conditions).