Unrotated Projectile

Common card · No. 462278

The Unrotated Projectile (UP) was a British anti-aircraft and ground-bombardment rocket of the Second World War. The original 7-inch version was developed for the Royal Navy by Alwyn Crow of the Projectile Development Establishment of the Ministry of Supply at Fort Halstead. These were generally similar in layout to contemporary mortar bombs. It proved unreliable and ineffective and was withdrawn from use in 1941. Further development of the concept led to the UP-2 and UP-3, which had diameters of 2-inch and 3-inch respectively and were longer. The UP-3 was used as the basis of the Z Battery anti-aircraft weapons and later developed in air-to-ground form as the RP-3, used against ground forces and shipping by aircraft like the Typhoon and the Beaufighter. In 1944–1945 several adaptations for general bombardment were produced, including Sea Mattress, Land Mattress, LILO and Tulip.

Read on Wikipedia · Image Beadell, S J (Lt), Royal Navy official photographer, Public domain