Panzerkampfwagen Neubaufahrzeug V / VI
During the 1920s and 1930s, a number of countries experimented with very large, multi-turreted tanks. The British built a single example of the Vickers A1E1 Independent in 1926. This inspired the Soviet T-35, which was built in limited numbers from 1933. Likewise, in Germany development of the Neubaufahrzeug (German for “new construction vehicle”) started in 1933 when the then Reichswehr gave a contract for the development of a Großtraktor (“heavy tractor”) to both Rheinmetall and Krupp. Großtraktor was a codename for the development of a heavy tank, Germany being still forbidden to develop tanks under the terms of the Treaty of Versailles. The Rheinmetall and Krupp designs resembled each other to a great extent, the main difference being the weapons placement. The original design had a main turret armed with a 75 mm KwK L/24 main gun and secondary 37 mm KwK L/45. Rheinmetall’s design mounted the second gun above the 75 mm KwK L/24, while the Krupp design had it mounted next to the 75 mm KwK L/24. Both designs had a secondary turret mounted to the front and the rear of the main turret.
Rheinmetall’s design was designated the PzKpfw NbFz V (PanzerKampfwagen NeubauFahrzeug V), and the Krupp design the PzKpfw NbFz VI. It was intended that these designs would fulfill the role of heavy tank in the armored forces, but the design proved to be too complex and unreliable for this role. Nevertheless, development continued in order for the nascent German military to gain experience with multi-turreted tanks. In 1934 Rheinmetall built two mild steel prototypes with a partially welded hull, both with their own turret design. Three more prototypes were built with proper armor and the Krupp turret in 1935 and 1936. The first prototype had the original Rheinmetall turret with tandem guns (the 37mm Tankkanone L/45 was installed over a 75mm KwK L/24), and a horse-shoe FuG turret antenna. The other four were given the Krupp turret (with coaxial guns).
The two secondary turret were mounted in a lozenge configuration, one on the front left and the other one the right rear. The driver’s compartment was next to the front turret, with the main fighting compartment behind. There were two rear hatches for the original BMW engine (Type A), replaced with four hatches for the more powerful, gasoline Maybach HL 108 TR of 120rpm, both fed by a 457 liter capacity fuel tank. Transmission was with a crash gearbox, 5 speed forward, no reverse. The modified coil (leaf) spring suspension system was composed of a set of five paired road wheels bogies pivoted to Christie type torsion arms and two front single road wheels suspended independently (similar to the British A1E1 and Russian T28). They were protected by side skirts with mud chutes in échelon (under each return roller), with two access doors to the suspension. The Turrets were also provided with large, one piece side hatches for access. The commander’s cupola was at the rear end of the turret. Provision for ammunition was 80 rounds for the main gun, 50 for the coaxial 37mm, and around 6000 for the two Mg.34 Mgs. Armour was no thicker than other Panzers of the time, – in other words it was just enough to provide minimal protection against infantry weapons, light AT guns and shrapnel.
Soon after delivery, the three late prototypes were extensively tested at the proving grounds at Putloss while the two earlier versions took part in army manoeuvers. However, by the end of 1936, it was decided to cancel all further development of the series, with priority being given to the construction of the light and medium Panzer I, II, II and IV. Nevertheless, they were displayed in propaganda events, shows and on newsreels, including the International Automobile Exposition in Berlin in 1939.
They were deployed in Norway, being landed at Oslo harbour on 19 April, 19 1940 and taking part in local operations. Although handicapped by their slow speed, they were still an impressive sight, and by far the most heavily armed German tank ever fielded in operations, combining the firepower of a Panzer III and IV and two Panzer I’s in a single package. This unit was later posted to Akershus Fortress (Oslo) in Norway in 1941 and their eventual fate is unclear, although they were captured in Norway by 1945 and apparently scrapped afterwards. The two others may have taken part in operations in Ukraine and Rumania.
