Unrotated Projectile

The Unrotated Projectile (UP) was a British <a href="/facts/Anti-aircraft/fHtGQpLy">anti-aircraft</a> and ground-bombardment <a href="/facts/Rocket_(weapon)/yTtyeLsj">rocket</a> of the Second World War.
The original 7-inch version was developed for the <a href="/facts/Royal_Navy/Xdy8YCH7">Royal Navy</a> by <a href="/facts/Alwyn_Crow/oj9uGMmR">Alwyn Crow</a> of the Projectile Development Establishment of the <a href="/facts/Ministry_of_Supply/9SuX037b">Ministry of Supply</a> at <a href="/facts/Fort_Halstead/LLHtY3YI">Fort Halstead</a>. These were generally similar in layout to contemporary <a href="/facts/Mortar_(weapon)/2vs8xEBx">mortar</a> shells. It proved unreliable and ineffective and was withdrawn from use in 1941.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 but were longer. The UP-3 was used as the basis of the <a href="/facts/Z_Battery/xQULTY8g">Z Battery</a> anti-aircraft weapons and later developed in air-to-ground form as the <a href="/facts/RP-3/Sor5l4MG">RP-3</a>, used against ground forces and shipping by aircraft like the <a href="/facts/Hawker_Typhoon/5gHVSPxA">Hawker Typhoon</a> and the <a href="/facts/Bristol_Beaufighter/oHKx6dQv">Bristol Beaufighter</a>. In 1944–1945 several adaptations for general bombardment were produced, including Sea Mattress, Land Mattress, LILO and Tulip.

Unrotated Projectile open-in-new

Unrotated Projectile