Neubaufahrzeug
The German Neubaufahrzeug (German for "new construction vehicle"—a cover name) series of tank prototypes were a first attempt to create a medium tank for the Wehrmacht after Adolf Hitler had come to power. Multi-turreted, heavy and slow, they were not considered successful, which led to only five being produced. These were primarily used for propaganda purposes and training, though three took part in the Battle of Norway in 1940. Pictures of the "Neubaufahrzeuge" were displayed with different turret models and orientations to fool allied spies; American and Soviet agents independently reported that the Germans had two new heavy  tanks, the Panzer V and VI. In reality, these tanks were far from the Panzer V Panther and the Panzer VI Tiger. Development. Development of the "Neubaufahrzeug" started in 1932 when "Wa Prüf" 6 established design specifications for a new 15 tonne tank to be known as the ""mittlere Traktor"". It had many connections to the previous "Großtraktor", utilizing many of the same components including the engine and transmission. Initially both Krupp and Rheinmetall were asked to submit proposals, but after the end of trials of the "Großtraktor" prototypes, during which Rheinmetall's vehicle proved superior to others, Krupp would  only be awarded a contract for a turret design while Rheinmetall was to design both a chassis and turret. Rheinmetall's turret design had a rounded shape and was armed with a 3.7 cm gun above the 7.5 cm gun, while Krupp's turret was more rectangular and had the 3.7 cm gun mounted beside the 7.5 cm gun. Both turrets were also armed with a co-axial MG-34 machine gun, along with the two sub-turrets at the front and rear of the tank. The "Neubaufahrzeug" went through a series of name changes, including ""Groß Traktor Nachbau"", ""Mittlerer Traktor  Neubau"", and ""Neubau Fahrzeug"" in 1933, and ""Neubau-Panzerkampfwagen IV"" in April 1940. The "Neubaufahrzeug" was never officially named "Panzerkampfwagen" V or VI. Two mild steel trial tanks were built by Rheinmetall in 1934. The first prototype used Rheinmetall's own turret design, while the second prototype used Krupp's turret design, which was mounted in 1935. Three more tanks were built in 1936 with proper armor, all mounting Krupp's turret design. The sub-turrets were also redesigned by a third contractor. The "Neubaufahrzeug" was intended to fulfill the role of a medium tank in Germany's developing armored  force, but it proved to have too many problems with its front drive and aero-engine for this role. But even with all its faults, the "Neubaufahrzeug" provided insight into tank designing that was valuable for the next German medium tank project, the "Begleitwagen" ("accompanying vehicle"), which would enter service as the Panzer IV. Service history. Though these tanks were never placed in production, they provided a propaganda tool for Nazi Germany, for example being shown at the International Automobile Exposition in Berlin in 1939. This propaganda role was extended with the German invasion of Norway, when "Panzer Abteilung z.b .V." 40 (Tank battalion for special purpose 40") was formed for supporting the invasion of Norway, and the three "Neubaufahrzeuge" were assigned to that unit. One vehicle was assigned to "Kampfgruppe Fischer" advancing north through the Østerdalen Valley, while the other two were assigned to "Kampfgruppe Pellengahr" advancing up the Gudbrand Valley. The one assigned to "Kampfgruppe Fischer" was immobilized with mechanical problems on its way to Lillehammer, while one of the two assigned to "Kampfgruppe Pellengahr" also had mechanical problems just north of Lillehammer. Only one tank actually made it to the front; it was immediately put in action  with the German force advancing up the Gudbrand Valley with other elements of "Panzer Abteilung z.b.V." 40. The "Neubaufahrzeuge" first saw combat against British and Norwegian positions on April 22, near the hill Balberg at the far south end of the Gudbrand Valley, 7 km north of Lillehammer. The British Expeditionary Force was equipped with 0.55 inch calibre Boys anti-tank rifles that easily penetrated the "Neubaufahrzeug". After dozens of hits, including one that killed a crew member, the tank retreated and the crew was hesitant to advance further. Other German units pushed further through, flanking the British forces  and forcing them to retreat. It is unclear what happened to the tanks after the Norway campaign, but none of them survived the war. The surviving vehicles were ordered to be scrapped in 1941, and this took place in 1942 according to documents captured by the British in 1945. The dates when the vehicles were scrapped are unclear, but it is thought that the beginning of the construction of the "Sturer Emil" prototypes dates from the same time. According to contemporary German sources, three NbFz were attached to the 1st Panzer Army and destroyed in battle with Soviet BT-7 tanks  in present-day Ukraine in June 1941. The last known surviving "Neubaufahrzeug" was used by a Lehr instruction unit in late 1944 as a target for training the Volkssturm in the use of the "Panzerschreck" "(Raketenpanzerbüchse 54)" and other anti-tank weapons. All that survives of these tanks is a small number of running gear parts, preserved in the "Gudbrandsdal Krigsminnesamling" (Gudbrand Valley War Memorial collection), at Kvam in Norway.