Paris Gun

The Paris Gun (German: Paris-Geschütz / Pariser Kanone) was a type of German long-range siege gun, several of which were used to bombard Paris during World War I. They were in service from March to August 1918. When the guns were first employed, Parisians believed they had been bombed by a high-altitude Zeppelin, as the sound of neither an airplane nor a gun could be heard. They were the largest pieces of artillery used during the war by barrel length, and qualify under the (later) formal definition of large-calibre artillery. Also called the "Kaiser Wilhelm Geschütz" ("Kaiser Wilhelm Gun"), they were often confused with Big Bertha, the German howitzer used against Belgian forts in the Battle of Liège in 1914; indeed, the French called them by this name as well. They were also confused with the smaller "Langer Max" (Long Max) cannon, from which they were derived. Although the famous Krupp-family artillery makers produced all these guns, the resemblance ended there.

As military weapons, the Paris Guns were not a great success: the payload was small, the barrel required frequent replacement, and the guns' accuracy was good enough for only city-sized targets. The German objective was to build a psychological weapon to attack the morale of the Parisians, not to destroy the city itself.

Due to the weapon's apparent total destruction by the Germans in the face of the final Entente offensives, its capabilities are not known with full certainty. Figures stated for the weapon's size, range, and performance varied widely depending on the source—not even the number of shells fired is certain. In the 1980s, a long note on the gun was discovered and published. This was written by Dr. Fritz Rausenberger (in German), the Krupp engineer in charge of the gun's development, shortly before his death in 1926. Thanks to this, the details of the gun's design and capabilities were considerably clarified.

The gun was capable of firing a 106-kilogram (234 lb) shell to a range of 130 kilometres (81 mi) and a maximum altitude of 42.3 km (26.3 mi)—the greatest height reached by a human-made projectile until the first successful V-2 flight test in October 1942. At the start of its 182-second flight, each shell from the Paris Gun reached a speed of 1,640 m/s (5,904 km/h; 5,381 ft/s; 3,669 mph).

The distance was so far that the Coriolis effect—the rotation of the Earth—was substantial enough to affect trajectory calculations. The gun was fired at an azimuth of 232 degrees (southwest) from Crépy-en-Laon, which was at a latitude of 49.5 degrees north.^{[citation needed]}

Seven barrels were constructed. They used worn-out 38 cm SK L/45 "Max" 17,130 mm (674 in) long gun barrels that were fitted with an internal tube that reduced the caliber from 380 mm (15 in) to 210 mm (8 in). The tube was 31 metres (102 ft) long and projected 13.9 m (46 ft) out of the end of the gun, so an extension was bolted to the old gun-muzzle to cover and reinforce the lining tube. A further, 6 m (20 ft) long smooth-bore extension was attached to the end of this, giving a total barrel length of 37 m (121 ft). This smooth section was intended to improve accuracy and reduce the dispersion of the shells, as it reduced the slight yaw a shell might have immediately after leaving the gun barrel produced by the gun's rifling. The barrel was braced to counteract barrel drop due to its length and weight, and vibrations while firing; it was mounted on a special rail-transportable carriage and fired from a prepared, concrete emplacement with a turntable. The original breech of the old 38 cm (15 in) gun did not require modification or reinforcement.

Since it was based on a naval weapon, the gun was manned by a crew of 80 Imperial Navy sailors under the command of Vice-Admiral Maximilian Rogge, chief of the Ordnance branch of the Admiralty. It was surrounded by several batteries of standard army artillery to create a "noise-screen" chorus around the big gun so that it could not be located by French and British spotters.

The projectile flew significantly higher than projectiles from previous guns. Writer and journalist Adam Hochschild put it this way: "It took about three minutes for each giant shell to cover the distance to the city, climbing to an altitude of 40 km (25 mi) at the top of its trajectory. This was by far the highest point ever reached by a man-made object, so high that gunners, in calculating where the shells would land, had to take into account the rotation of the Earth. For the first time in warfare, deadly projectiles rained down on civilians from the stratosphere". This reduced drag from air resistance, allowing the shell to achieve a range of over 130 kilometres (81 mi).