In 1937 Henschel was instructed to design and build a prototype of a 30-33 ton tank to be the successor to the PzKpfw IV. It was initially named the Durchbrüchswagen I (breakthrough vehicle). However, after two prototypes were undergoing trials this project was canceled and development on the original DW 1 resumed. By 1940 Henschel had improved the design that it was designated the DW 2. It originally carried a short 75 mm gun. Trials were carried out until 1941 when an order was placed for a new design that virtually described the DW 2. Porsche, MAN, and Daimler-Benz were asked to submit designs as well.
Henschel built 2 new prototypes in March 1941, and two more in October 1941. It had a superstructure similar to the PzKpfw IV and the suspension had seven interleaved road wheels and three return rollers on each side. It was to carry to 75 mm L/48, however with the invasion of Russia and their T-34/76s, it quickly become obsolete and development was discontinued. Two of these prototypes were lengthened and mounted a 128 mm K 40 gun and were used in Russia in 1942.
One chassis with interleaved road wheels had been built, but in 1938 this was suspended to work on a 65 ton tank, known as the VK.6501 (Vollkettenkraftfahrzeug).
The VK.3001(H) was based on the DW.2. The superstructure was similar to the PzKpfw IV.
The VK3001(P) had longitudinal torsion bar suspension and gasoline-electric drive. MAN and Daimler-Benz made prototypes similar to this design but they were cancelled as being obsolete.
The Weapons Department contracted with Henschel to develop the VK3601. This was to be a vehicle that weighed 36-40 tons and would mount a tapered bore 60 mm or 70 mm gun. It was also to have a speed of 25 mph / 40 kph as directed by Hitler.
The VK3601 was soon abandoned as the taper bored gun required ammunition that used tungsten steel, which was in very short supply.
However, the Germany Army didn't want to abandon all of Henschel's work, so they were awarded a contract that was to be designated the VK4501(H). This was to use the same chassis as the VK3601 but with a 88 mm gun. Specifications were given in May 1941 for a 45 ton tank that would carry an 8.8cm gun. One condition was that the prototype had to be ready by April 20, 1942, Hitler's birthday.
Porsche received a contract to develop the VK4501 that would be a vehicle that weighed 45 tons and mounted an 88 mm gun.
Henschel was able to take the best features from their earlier designs and built two models. The H1 mounted the 88 mm KwK 36 L/56 and a wooden model H2 which had a 75 mm KwK L/70.
Henschel finished a prototype in March 1942.
Standard German railway flatcars couldn't carry the tank as it was too wide. Henschel designed a travel track, which was installed with the outer road wheels being removed. This allowed for it to be transported by train.
Because the Tiger was so heavy, and couldn't cross most European bridges, they were outfitted with wading equipment which allowed it to cross water obstacles by moving along the river bed. Though this only allowed to a depth of 13' 6"/ 4.1 m. The doors and hatches had rubber seals placed around them to make the Tiger water tight. The turret ring had an inflatable rubber tube. The machine gun ports had rubber plugs inserted when the machine guns were removed. The mantlet had a frame that slid with a rubber seal.
A snorkel was placed on the engine compartment which supplied air to the crew and engine. A bilge pump was installed to take out any water that leaked in.
The Tiger could stay submerged for about 2 1/2 hours.
This equipment was expensive to make and also was little used, so after the first 495 tanks that were produced, it was no longer included.
In the front of the hull were two compartments which had the driver and hull gunner. Then there was the central fighting compartment with the turret. At the rear was the engine compartment with the engine.
The floor of the fighting compartment was suspended by 3 steel tubes and rotated with the turret. The sides of the turret were formed by a 82 mm plate that was curved. This was joined in the front by 100 mm plate. Turret was very slow in moving and it took 2 turns of the traversing wheel (one by gunner and one emergency one by commander) to move 1 degree.
Flat sections of armor were used in the hull to help simplify production. The superstructure was welded to the hull, whereas previous PzKpfw models were bolted. The bottom plate was cut from a single piece of 25 mm homogeneous steel that was 5 m long and 1.8 m wide. This would add to the rigidity of the Tiger.
First German tank to have over-lapping road wheels. These were to help distribute the massive weight of the Tiger. The drawback was that the wheels could get packed with snow and mud.
Sometimes the buildup of debris between the wheels caused the track to ride up and over the sprocket teeth and jam. The tension was such that it couldn't be freed by releasing the tension on the idler wheel, or by removing a track pin. It could be possible to tow the disabled Tiger but some choose to place an explosive under the track to blow out a link. This was a last resort if the other alternative was to abandon the tank.
There were eight torsion bar axles on each side that were staggered. The right side trailed to the rear and the left side towards the front.
Steel tires replaced the rubber tires that went around the wheels starting after chassis 250822.
The driver was on the left and used a steering wheel which acted on the differential steering unit.
Emergency steering was provided by two steering levers. A visor was provided in the front vertical plate. Episcopes were located in the escape hatches for the driver and radio operator. There was a gearbox in between them that virtually separated them.
The transmission shaft went from the engine, under the turret cage, to a gearbox next to the driver.
The Tiger originally had a Maybach HL 210 P45 engine that was found to be underpowered. Starting in December the engine that was used was the Maybach HL 230 P45.
The turret was hydraulically powered by a unit that took its power from the rear of the gearbox and was operated by a foot lever at the gunner's right foot. It had a releasing mechanism that allowed for the turret to be easily removed for maintenance.
The front of the turret was joined by two 100 mm thick bars.
Early models had a commander cupola that had five visions slits. Later models had a cupola with six episcopes. These were the same as used on the Panther to help simplify production.
Early models had five "S" mine discharges on top of the superstructure. It would be shot up approximately three to five feet where it would explode sending 360 3/8" steel balls into attacking infantry.
In late 1943 this was replaced by a Nahverteidigungswaffe (close-in defense weapon) which was installed in the turret roof in place of the extractor fan, which moved to the center. It could be loaded from the inside.
The firepower and protection were second to none, however, the Tiger I was underpowered, mechanically unreliable, and consumed mass amounts of fuel. With a trained crew it was a formidable opponent, but as the casualties mounted, so did the loss of the trained crews.
The gunner fired the 8.8cm gun by a foot petal. The gunner controlled the the traverse and elevation by hand wheels. To make one full revolution of the turret took 720 turns of the handwheel.
There was a coil spring in the front of the turret that counter balanced the massive weight of the main gun.
Comparison of Main Tank Armament Performance