In 1935, the best way of destroying the bunker structures and fortifications such as those to be found on the Maginot Line was already under consideration. It was decided that particularly large-calibre artillery should be developed so that such bunker structures could be tackled with brute force. To this end, Krupp offered designs for calibres of 70cm, 80cm, 85cm, and 100cm. In 1937, following Hitler's visit to Krupp in 1936, the Armaments Ministry placed an order for three 80cm guns.
It was not until the 10th of September 1941 that the first test round could be fired from a makeshift gun carriage on the Hillersleben firing range. In November 1941 the barrel was mounted onto its railway gun carriage and taken to Rügenwalde. At the beginning of December 1941, 8 further test firings took place, using a 7,100kg AP shell, to a range of 37,210 metres! For combat, the gun was mounted on a special chassis, which in turn was supported by two special bogies, each with 20 axles and straddling 2 sets of rails. Krupp christened the gun "Schwerer Gustav" (Heavy Gustav), its namesake being the senior director of the firm.
In January 1942, the Heavy (Railway) Artillery Unit 672 was formed, and transferred to the Sevastopol area in April 1942. The transfer required 5 trains with a collective length of 1,653 metres!
On the 5th of June 1942, the time had come: the first shot was fired from the 80cm gun (nicknamed "Dora" by the troops in the meantime) against Sevastopol. Another 47 shots were fired up until the 17th of June, by which time the supply of ammunition had been exhausted. On the right is a photograph of the railway gun "Dora" firing during the battle for Sevastopol. Of the 48 shots fired, only 10 landed within 60 metres of their target. The greatest distance from one of these shots was some 740 metres. Nevertheless, the devastation was enormous. After the battle for Sevastopol ended, another 5 rounds of practice ammunition were fired, and then the gun was dismantled.
There were plans to employ the weapon in Leningrad in September 1942, but due to the Russians breaking the siege ring, the gun was sent to Rügenwalde for an overhaul instead. There a new barrel was constructed and in March 1943, 4 rounds were fired. At this time, Hitler watched 2 rounds being fired on the 19th of March 1943. He was fully impressed, especially because the second HE shell achieved a range of 47km! General of the Panzer Troops Guderian was also present. Dr. Müller of the Krupp works tried to convince Hitler that the gun could be used to fire at tanks! Hitler was fascinated and asked Guderian his opinion of that statement. Guderian simply said: "Fire at, certainly; but hit them? Never!", against which Dr. Müller protested. But Guderian asked what the minimum effective range of the weapon was, which served to make Dr. Müller realise the impossibility of his claim too, considering in addition that it took around 45 minutes just to load the weapon!
The second "Dora" gun was almost completed, but a crew for the weapon was never raised. In April 1945, both weapons were blown up by their crew or destroyed, the remnants being discovered in Saxony and on special railway wagons in Bavaria.
Hitler issued an order that the third ordered gun should also be completed. Yet this was to be equipped with a 52 cm barrel of 48 metres in length (the gun was going to be called "Langer Gustav" (Long Gustav)), which could fire rocket-assisted shells. Such shells were also planned for the 80cm barrel which could then achive firing ranges of up to 160km!
On the left is a picture of one of the standard 7.1 tonne AP shells for the 80cm gun. The shell was 3.6 metres long and carried a charge of 250 kg of explosive. At a muzzle velocity of 720 m/s, a range of 37 km could be achieved. In addition, there was also a 4.8 tonne HE shell, which contained 700 kg of explosive. At a muzzle velocity of 820 m/s, this could be fired to ranges of up to 48 km!
Finally, a few more technical details:
The all-up combat weight of the weapon was 1,350 tonnes. The barrel and breechblock together weighed 400 tonnes, the breechblock on its own weighing in at 110 tonnes! The barrel axis was located 8.6 metres above the ground. The L/40.6 barrel was 32.48 metres long, and the greatest barrel elevation was 53°. Firing the 7.1 tonne shell required a propelling charge weighing 1,850 kg and 4 metres in length! Loading each round took around 45 minutes. Assembly of the weapon required two special cranes and 250 men. The ground preparations needed prior to assembly, plus the other auxiliary tasks, necessitated a team of 4,120 men!
The German technicians did indeed achieve a feat of construction worthy of high praise with this gun, but such a development project would be denied any tactical success!
There are two videoclips of this "Monster", you can view:
Clip #1 shows "Dora" on a presentation where you can see its size when you notice the "small" people!
Clip #2 is of special interest as it shows when the gun is loaded and fired!
