V-3 Cannon, the London Gun (1944 to 1945):
The ‘V-3 cannon’ was a German WWII Supergun working on the principle of multi-charge along the barrel’s length where to add the velocity of a projectile, secondary propellant charges are fired as soon as the projectile passed them. V stands for Vergeltungswaffe which means retaliatory weapons. Germans used to call it HDP (Hochdruckpumpe) gun that meant High Pressure Pump.
In retaliation to the German cities pounded to rubble by the Allied bombers, this supergun was developed as ‘vengeance’ weapon by the Germans. A 130m (430 ft) long V-3 Cannon with 165km range was almost fully constructed at bunkers at Pas-de-Calais region in Northern France. The shells inside the cannon had the ability to achieve a muzzle velocity of 1,500m/s (4,900 ft/s) and fire 300 shells per hour. Weight of each shell was 140kg (310 lb). It was planned to be used to strike back at London by October 1, 1944 but was disable by Allied bombing raid before completion of construction. The Allied forces used the deep-penetrating Tallboy bombs, each of which was 5,400kg (11,900 lb).
However, two more V-3 Cannons with shorter barrels of 50m (160ft) were constructed at Trier city in Germany in late 1944. These were used against Luxemburg which was 43km (27mi) away from the V-3 cannons and had been liberated in September 1944. Muzzle velocity of this shortened barrel V-3 cannons was 935m/s (3,070 ft/s).
The first gun was ready by December 30, 1944 but only 7 shells were fired with it. The second gun tube was operational by January 11, 1945 and till February 22, 1945, it fired some 183 rounds, 44 of which hitting the urban targets. 142 of the fired shells struck Luxembourg. 10 people were dead and 35 wounded. Due to such small number of casualties, the V-3 cannons were not considered as very effective. On February 22, 1943, when American soldiers advanced within 3 kilometers of the cannon site, all was quiet on the western front.
Two US Army soldiers with a captured Sprenggranate 4481 projectile, which would have been used in the V-3 cannon.
