German POWs captured by British troops, north of Anzio, Italy; 31 January 1944. 

German POWs

HMS Nelson equipped with UP Launchers on her main turrets. Photo shows a UP launcher and its operator.

UP or "Unrotated Projectile" Launchers were 20 round rocket launchers designed to form a protective barrier against attacking aircraft.

Rockets were fired 10 at a time. Once they reached a preset distance from the ship they would deploy a mine suspended from three parachutes via a length of wire. Aircraft that flew into the wires would detonate the mine. The idea was that that launchers could create a aerial minefield around the ship.

However, the minefield was rarely dense enough to provide an obstacle to attacking aircraft. In addition, the slightest wind could disperse the mines over a wide area, even onto friendly ships and even back onto the ship that launched them. Last but not least, the supply of rockets stashed aboard a ship posed a significant fire hazard. During her final battle, HMS Hood took a hit on her boat deck that ignited her UP rockets, causing a large fire.

Though an interesting concept, the weapon was largely ineffective and quickly removed from British ships in 1941 in favor of additional AA guns.

IWM - A 1995/taken from fb

UP set-up

M4A2 "Sherman" tanks (first and third tank) of the British 4th Tank Brigade on Via Giuseppe Garibaldi in the Sicilian city of Catania. Second tank is an M5 "Stuart".
In the background - the Cathedral of St. Agatha.  