The Nebelwerfer (“fog thrower”), initially designed by the Wehrmacht as a mortar for launching smoke shells, was also capable of hurling poison gas and high-explosive rounds, as was the American M2 4.2-inch chemical mortar during World War II. Shortly after the June 1940 fall of France the German army received its first 15cm Nebelwerfer 41s, rocket-propelled weapons likewise capable of delivering all three payloads but primarily used to fire high-explosive rounds. Engineers designed the spin-stabilized rocket with the motor toward the front, thus placing the rear-mounted warhead farther aboveground on impact to optimize the blast effect. The design proved more complicated than it was worth and was abandoned in future versions.
Just before the June 1941 invasion of the Soviet Union, Germany shipped the first 28/32cm Nebelwerfer 41 rockets, in both 280mm high-explosive and 320mm incendiary versions. Nebeltruppen could launch the warheads directly from their packing cases or from wooden or metal frames. A year later came the adaptable 21cm Nebelwerfer 42, a simpler design than the 15cm. Troops could fire its high-explosive warheads from either a five-tube launcher on a towed carriage, or multiple launchers atop armored half-tracks, or single tubes (Werfer-Granate 21) mounted beneath the wings of Luftwaffe aircraft for use against American bomber formations. In 1943 Germany rolled out the final iteration, the 30cm Nebelwerfer 42, with more than twice the range of the 28/32cm models.