Early development prototype hulls for the Henschel heavy tank programme which ultimately produced the Tiger I.
Henschel & Sohn began development of the vehicle that eventually became the Tiger I in January 1937 when the Waffenamt requested Henschel to develop a Durchbruchwagen (breakthrough vehicle) in the 30 metric ton range (see DW 1 hulk opposite). Only one prototype hull was ever built and it never was mounted with a turret. The general configuration and suspension of the Durchbruchwagen prototype in many respects resembled the Panzer III. The proposed turret also bore similarities to existing machines and,had it been completed, it would have greatly resembled the early Panzer IV C turret which sported the short barrelled 7.5cm L/24 cannon.
Before Durchbruchwagen I was completed, however, a new request was issued for a heavier 30 tonne class vehicle with thicker armour; this was known as the Durchbruchwagen II (see VK 6501 opposite). This tank would have carried 50mm of frontal armour and have mounted a Panzer IV turret with the standard 7.5cm L/24 cannon. Overall weight would also have been approximately 36 metric tons. Again only one hull was ever built and a turret was never actually fitted. Development of this vehicle was cancelled in the autumn of 1938 in favour of the more advanced VK3001(H) and VK3601(H) designs. However, both the Durchbruchwagen I and II prototype hulls were used as test vehicles until 1941.
On 9th September 1939, with the invasion of Poland underway, Henschel & Sohn received permission to continue development of a VK3001(H) medium tank and a VK3601(H) heavy tank, both of which apparently pioneered the overlapping and interleaved main road wheel concept as adapted for tank chassis use. Interleaved road wheels were already being used on German military half-tracked vehicles such as the SdKfz 7 although there was very little comparison with regard to the weight of a heavily armoured tank compared to a lightweight half track.
The War Office commissioned this illustration on the basis of a photograph from the German newspaper above published in December 1942. Note the lack of muzzle brake on the gun.
The VK3001(H) was intended be produced in three main variants the first of which was to mount a 7.5cm L/24 low velocity infantry support gun, the second was intended to carry a 7.5cm L/40 dual purpose anti-tank gun, and the third a 10.5cm L/28 artillery piece in a Krupp turret. Overall weight was to be 33 metric tons. The armour was designed to be 50mm on frontal surfaces and 30mm on the side surfaces. Four prototype hulls were completed for testing. Two of these were later used to create the 12.8cm Selbstfahrlafette L/61, also known as Sturer Emil.
The VK3601(H) was intended to weigh 40 metric tons, and carry 100mm of armour on its frontal surfaces, 80mm on turret sides and 60mm on hull sides. The VK3601(H) was also intended to appear in four variants adapted to house a 7.5cm L/24, or a 7.5cm L/43, or a 7.5cm L/70, or a 12.8cm L/28 cannon in a Krupp turret that looked very similar to an enlarged Panzer IVC turret. One prototype hull was built, followed later by five more prototype hulls. The six turrets intended for the prototype hulls were built but never actually fitted and ended their working lives as static defences mounted the Atlantic Wall. The development of the VK3601(H) project was discontinued in early 1942 in favour of the VK4501 project. German combat experience with the French Somua S35 cavalry tank and Char B1 heavy tank, and the British Matilda I and Matilda II infantry tanks in June 1940 showed that the German Army needed better armed and armoured tanks. In 1940 superior tactics had overcome superior enemy armour, but Rommel had endured a nasty shock on the form of a successful British counter attack at Arras. The German tank designers however, took notice of the lessons from the battlefield. Accordingly on 26th May 1941, at an armaments meeting, Henschel and Porsche were asked to submit designs for a 45 tonne heavy tank, to be ready by June 1942. Porsche worked hard and fast to submit an updated version of their VK3001(P) Leopard tank prototype while Henschel worked to develop an improved VK3601(H)tank. Henschel built two prototypes. A VK4501(H) H1 which used the 88mm L/56 cannon and a VK4501(H) H2 which used the 75mm L/70 cannon.
Prototype drawing for the Porsche version of the Tiger I. There were many problems with this design including forward location of the turret made manoevering difficult. There were also many mechancical breakdowns during testing.