Like many other realized utopian ideas, an unenviable fate awaited the supergun: the Germans destroyed all the guns and technical documentation immediately after the conclusion of peace, which automatically transferred it to the category of legends.
The difficult birth of the Colossal gun began in 1916, when Professor Eberhardt came to the design headquarters of the Krupp plant with a proposal to create a cannon that could fire at 100 km. Theoretically, the professor's calculations showed that the enemy should be hit with 100-kilogram shells with an initial speed of 1600 m / s. The unpleasant air resistance was supposed to be overcome by sending the projectile to the heights of the upper boundary of the stratosphere (about 40 km), where the rarefaction of the air envelope increased the firing range. Three-quarters of the projectile's flight to the target had to take place just in the stratosphere - for this, Eberhardt suggested raising the gun barrel by an angle of at least 500. It is noteworthy that the professor even took into account in his project a correction for the Earth's rotation, which is vital for artillerymen, taking into account the time of the projectile's arrival to goals. The German elite, together with the industrialists of Krupp, believed Eberhardt and set him 14 months to make a cannon for the destruction of Paris. It is worth making a small patriotic digression and pointing out the project of an ultra-long-range weapon (more than 100 km), proposed by the Russian military engineer V. M. Trofimov back in 1911, which, as happened more than once, was rejected.
Colossal ultra-long-range cannon. Source: secrethistory.su
The Krupp plant in Essen (under the direction of director Rausenberg) was engaged in the practical embodiment of the German ultra-long-range gun, and at the very beginning of the project, the choice was made in favor of ready-made barrels of 35-cm naval guns, which, with minor modifications, were to become the basis of the future Parisian cannon of Kaiser Wilhelm. However, while the prototype was being designed, by 1916 the Germans planned to retreat to the Siegfried Line at a distance of 110 km from Paris. Ludendorff eventually demanded that the range of the gun be increased to 128 km. Of course, a 35-centimeter barrel was not enough for such a range, and the Kruppists turned their attention to the 38 cm battleship. Such powerful guns under the SK L / 45 index were originally planned for battleships such as Bayern, Sachsen and Wurtemberg. In the field performance, the gun was named Langer Max (Long Max) and distinguished itself when shelling Dunkirk at a record range of 47.5 km. "Long Max" fired a projectile weighing 213.5 kg with a muzzle velocity of 1040 m / s, which made it an excellent base for the future "Colossal". Rausenberg intended to increase the length of the barrel and thereby accelerate the projectile for Paris to the required 1600 m / s, however, a technological problem arose. Krupp machines at that time were unable to cut threads in trunks longer than 18 m, so the connecting flange came to the rescue. With its help, smooth-walled extension attachments of two dimensions - 3, 6 and 12 meters - were attached to the Long Max's rifled barrel. Such a super-barrel in the basic version reached 34 meters in length, of which 1 m fell to the breech, 3 m to the charging chamber, 18 m to a rifled barrel and the rest to an innovative attachment. Of course, the trunk was bent under its own gravity - this sharply reduced the chances of getting into the French capital, so they developed a special cable support system like a bridge. Eyewitnesses claimed that the barrel vibrations lasted two to three minutes after each shot. Due to the use of a replaceable liner (a threaded pipe inserted into the barrel of large-caliber artillery guns), which keeps the gun from extreme pressures and temperatures, the Colossal's caliber was 21 cm.
One of the few "lifetime" photos of the gun. Source: zonwar.ru
The gun fired its first shots in the summer of 1917 in the city of Mappen - the shells flew towards the sea, but only reached a 90-kilometer range. The engineers identified the reason in the weak obturation of the projectile in the smoothbore nozzle and went to Essen to revise the gun. As a result, they introduced new projectiles with 64 ready-made protrusions on two leading belts, which ensure good projectile guidance along the grooves. The problem of weak obturation on the smooth part of the barrel was solved by the constructional "highlight" of the leading belts, which, coming out of the rifled part, turned under the action of a moment of force and locked the barrel bore. Each projectile was very expensive, so the Germans decided to guarantee its operation on target by installing two fuses at once - bottom and diaphragm. And, indeed, all the shells from the Colossal, fired on French territory, exploded, but some did not completely. Diligently collected large fragments made it possible to get an idea of the design of the super-gun projectile. It is noteworthy that the Germans took into account the degree of wear of the Colossal liner and all the shells had a different caliber - from 21 cm to 23, 2 cm. Also, each of them had its own serial numbers and the latest (and, accordingly, the largest) went already into the reamed liner after 50-70 shots.
21-cm Colossal projectile with ready-made protrusions. Source: Izvestia of the Russian Academy of Missile and Artillery Sciences
Due to the peculiarities of firing from a gun, the mass of the charge was variable: the main part of 70 kg, enclosed in a brass sleeve; in a silk cap there was 75 kg of gunpowder in the middle part of the charge and, finally, the front part - it was its mass that was selected based on specific conditions. For example, on the cool day of the debut shelling of Paris, 50.5 kg were immediately dispatched to the front of the charge, based on calculations for a higher air density. In total, for each shot, the gunners spent under 200 kg of high-grade gunpowder with a projectile mass of 104 kg. The gunpowder was a special grade RPC / 12 and was distinguished by a relatively slow burning in order to increase the survivability of the barrel.
The shell is a projectile with a serial number. Source: Izvestia of the Russian Academy of Missile and Artillery Sciences
Rough calculations of the Kolossal's external ballistics, carried out at the Russian Academy of Missile and Artillery Sciences, show that the maximum flight height of the projectile was 37.4 km, which it climbed in 84.2 seconds. At a muzzle velocity of 1600 m / s, further climb went with a flight deceleration, however, on the descending part of the trajectory, the projectile accelerated to a second maximum speed of 910 m / s. Then it again slowed down from friction against the dense layers of the atmosphere and flew towards the French at an angle of 54, 10 at a speed of 790 ms / s. The time from the shot to the fall of the shell was an agonizing 175 seconds.
Shooting table for a 21 cm projectile. Source: Izvestia of the Russian Academy of Missile and Artillery Sciences
The Germans beat Paris in the First World War, setting the Colossal on a circular rail track, allowing the gun to be guided in azimuth. The total weight of the installation exceeded 750 tons, and for the concrete base of the carriage it took over 100 tons of cement, 200 tons of gravel and a couple of tons of reinforcement. Before servicing such a monster, the "land" artillerymen were not allowed, but dispatched 60 gunners of the naval and coastal artillery, who had experience working with such "toys". We placed the batteries of guns at three points - at a distance of 122, 100 and 80 km from Paris. The first to rumble was the most distant battery, disguised in a dense forest near the town of Laon, and did so with the support of sound-camouflaging cannons. The latter were supposed to fire synchronously with the Colossals to mislead the French sound-metric reconnaissance stations. The Germans approached the artillery raid on Paris very thoroughly - the agent network in the French capital monitored the effectiveness of the strikes, and the aerial bombardment of the city was stopped altogether for the sake of the purity of the experiment. The Kaiser's super-guns fired at the target for 44 days from March 23, 1918, firing 303 shells and killing 256 people - less than one Parisian for one 100-kilogram piece of steel with explosives. Moreover, only 183 shells flew into the city limits, the rest exploded in the vicinity of Paris. The statistics would be even less optimistic if the shell had not hit St. Gervais, carrying away 88 people and crippling 68. There was also a certain psychological effect from the Colossal - several thousand Frenchmen left the city, not feeling protected from an accidental arrival. Realizing the uselessness of such expensive weapons, the Germans took them out of the occupied territory, dismantled them, and destroyed all the documentation. It is not known whether they did it out of shame or for reasons of secrecy, but after a while the concept of ultra-long-range guns again took possession of the brains of German designers. And they implemented it on a much larger scale.
