The VK 30.01 (D) and VK 30.02 (D), also known as VK.3001 (DB) were two tank designs made by Daimler Benz submitted for the VK 30 project for a 30 tonne tank to be used by the German  army.   

The Versuchskonstruktion 30.01 (D) and 30.02 (D), in English "experimental design 30 tonnes Daimler", was intended to counter the Soviet T-34 and replace the Panzer III and  IV medium tanks as a heavy "breakthrough" tank. It had been requested in 1941 by the German Government. The Daimler Benz design was rejected however, and the Maschinenfabrik Augsburg-Nürnberg (MAN) design was selected and entered service as the  Panther tank.

Development 
When Germany invaded the Soviet Union in June 1941, they expected to be facing an inferior opponent. The T-34, with its sloped armor, and the heavily armored KV-1 caught the Wehrmacht off guard. Up until Operation Barbarossa, the Germans had been satisfied with the performance of their early Panzers, even after high losses during the Polish and French campaign, against the French Char B1 heavy tank. Ignoring these incidents, and an incident in spring 1941, when Hitler gave the order for a Soviet military commission to be allowed to see the latest in German tank design. The Soviet delegation refused to believe that they had been shown the latest model of the Panzer IV. Afterwards, because of their insistence, the German Ordnance Office came to the conclusion the Soviets were in possession of better and heavier tanks.

In October 1941, in the aftermath of the 4th Panzer Division's heavy losses of Panzer IVs on the road to Mtsensk, Generaloberst Heinz Guderian called for an investigation into the matter of tank warfare on the Eastern Front. In November German engineers, manufacturers and military procurement officials, including the Waffenamt (Army Weapons Department), were able to inspect and study captured T-34 tanks in order to understand what future German tank development would be needed in the next generation of German tanks. It was initially suggested by Guderian that the quickest way to counter the T-34 would be a direct copy. This was turned down by the Army Weapons Department however, because of the difficulties in producing sufficient numbers of diesel engines and steel alloy.

Initially four companies, Henschel (H), Porsche (P), Maschinenfabrik Augsburg-Nürnberg (MAN), and Daimler Benz (DB), were requested to build prototypes with the requirements for a fast heavy medium tank able to defeat the Soviet T-34 tank on the Eastern front. Henschel's design, the VK 30.01(H), was considered outdated, with only a  Kwk 37 L/24 short howitzer-like gun and resembling an enlarged Panzer IV, but with the overlapping and interleaved Schachtellaufwerk roadwheel system coming from their half-track designs. The Porsche entry, the VK 30.01(P), developed at the same time as the heavy VK 45.01 (P), was withdrawn when the Henschel's Tiger I went into production. This only left MAN and DB as contenders and so they were ordered to construct improved models, VK 30.02 (M) and VK 30.01 (D).

The VK 30.02 (DB) adopted several features of the T-34 over and above those specified by the army (sloped armour, large roadwheels,  and overhanging gun) by using a diesel engine with rear transmission and jettisonable external fuel tanks. The design used leaf springs rather than more expensive torsion bar suspension.

The VK30.02 (DB) was ordered into production with an initial target of 200 vehicles partly due to Hitler favouring the design. Hitler also requested the longer L70 gun rather than the 40-calibre long 75mm. The Waffenprufamt 6 committee however favoured the more conventional - in terms of German design and engineering - VK 30.02 (M) and ordered prototypes of it in May 1942 then quietly rescinded the DB order.

While the VK 30.01(D) could have been cheaper and easier to produce, the German government preferred the roomier turret and more modern suspension of the MAN prototype, which went on to be the production Panther. The VK 30.02(MAN) also shared the same engine as the Tiger, which would help with production and maintenance, it also had larger tracks, which would help with its ground pressure on soft ground. While the Panther was similar to the T-34 in shape, the VK30.01 (DB)'s sloped front was similar, but overall, it was closer to earlier German tanks. Some sources say that one prototype was produced, others say that Daimler Benz produced three slightly different versions.

Specifications 
The VK 30.01(D) was a fast, nimble tank weighing , with a top speed of  and a cruising range of . Its main armament was the  KwK 42 L/70 gun. It had a crew of 5 (driver, commander, gunner, bow gunner/radio operator, and the loader), and its armour ranged between .

Operational use 

One prototype VK 30.01(D) was produced but never saw combat service. The prototype survive the war.

Notes

References

Bibliography
 
 
 

World War II tanks of Germany
World War II medium tanks
Medium tanks of Germany