Tiger I
The Tiger I was a German heavy tank of World War II that began operational duty in 1942 in Africa and in the Soviet Union, usually in independent heavy tank battalions. It gave the German Army its first armoured fighting vehicle that mounted the KwK 36 gun. 1,347 were built between August 1942 and August 1944. After August 1944, production of the Tiger I was phased out in favour of the Tiger II.
While the Tiger I has been called an outstanding design for its time, it has also been criticized for being overengineered, and for using expensive materials and labour-intensive production methods. In the early period, the Tiger was prone to certain types of track failures and breakdowns. It was expensive to maintain, but generally mechanically reliable. It was difficult to transport and vulnerable to immobilisation when mud, ice, and snow froze between its overlapping and interleaved Schachtellaufwerk-pattern road wheels, often jamming them solid.
The tank was given its nickname "Tiger" by the ministry for armament and ammunition by 7 August 1941, and the Roman numeral was added after the Tiger II entered production. It was classified with ordnance inventory designation Sd.Kfz. 182. The tank was later re-designated as Panzerkampfwagen VI Ausführung E in March 1943, with ordnance inventory designation Sd.Kfz. 181.
Today, only nine Tiger I tanks survive in museums and private collections worldwide., Tiger 131 at the UK's Tank Museum is the only example restored to running order.
Design history
Earlier designs
Henschel & Sohn began the development of a large tank design in January 1937 when the Waffenamt requested Henschel to develop a Durchbruchwagen in the 30–33 tonne range. Only one prototype hull was ever built, and it was never fitted with a turret. The Durchbruchwagen I's general shape and suspension resembled the Panzer III, while the turret resembled the early Panzer IV C turret with the short-barrelled L/24 cannon.Before Durchbruchwagen I was completed, a request was issued for a heavier 30-tonne class vehicle with thicker armour, the Durchbruchwagen II, which would have had of frontal armour and mounted a Panzer IV turret with a short-barrelled 7.5 cm KwK 37 gun. The overall weight would have been 36 tonnes. Only one hull was built, and no turret was fitted. Further development of the Durchbruchwagen was dropped in 1938 in favour of the larger and better-armoured VK 30.01 and VK 36.01 designs. Both the Durchbruchwagen I and II prototype hulls were used as test vehicles until 1941.
Further attempts
The VK 30.01 medium tank and the VK 36.01 heavy tank designs pioneered the use of the complex Schachtellaufwerk track suspension system of torsion bar-sprung, overlapped and interleaved main road wheels for tank use. This concept was already standard on German half-tracks such as the Sd. Kfz. 7. The VK 30.01 was intended to mount a low-velocity 7.5 cm L/24 infantry support gun, a 7.5 cm L/40 dual-purpose anti-tank gun, or a L/28 field gun in a Krupp turret. Overall weight was to be 33 tonnes. The armour was designed to be on frontal surfaces and on the side surfaces. Four prototype hulls were completed for testing. Two of these were later modified to build the "Sturer Emil" self-propelled anti-tank gun.The VK 36.01 was intended to weigh 40 tonnes, with of armour on front surfaces, on turret sides and on the hull sides. The VK 36.01 was intended to carry a 7.5 cm L/24, a 7.5 cm L/43, or a 7.5 cm L/70, or a 12.8 cm L/28 cannon in a Krupp turret that looked similar to an enlarged Panzer IV Ausf. C turret. The hull for one prototype was built, followed later by five more. The six turrets built were never fitted and were used as part of the Atlantic Wall. The VK 36.01 project was discontinued in early 1942 in favour of the VK 45.01 project.
Further improvements
Combat experience against the French SOMUA S35 cavalry tank and Char B1 heavy tank, and the British Matilda II infantry tanks during the Battle of France in June 1940 showed that the German Army needed better armed and armoured tanks.On 26 May 1941, Henschel and Ferdinand Porsche were asked to submit designs for a 45-tonne heavy tank, to be ready by June 1942. Porsche worked on an updated version of their VK 30.01 Leopard tank prototype while Henschel worked on an improved VK 36.01 tank. Henschel built two prototypes: a VK 45.01 H1 with an 8.8 cm L/56 cannon, and a VK 45.01 H2 with a 7.5 cm L/70 cannon.
Final designs
On 22 June 1941, Germany launched Operation Barbarossa, the invasion of the Soviet Union. The Germans encountered large numbers of Soviet T-34 medium and KV-1 heavy tanks. According to Henschel designer Erwin Aders, "There was great consternation when it was discovered that the Soviet tanks were superior to anything available to the Heer."Weight increase to 45 tonnes and an increase in gun calibre to were ordered for it on 26 May 1941. The due date for the new prototypes was set for 20 April 1942, Adolf Hitler's 53rd birthday. Unlike the Panther tank, the designs did not incorporate sloped armour.
Porsche and Henschel submitted prototype designs, each making use of the Krupp-designed turret. They were demonstrated at Rastenburg in front of Hitler. The Henschel design was accepted, mainly because the Porsche VK 4501 prototype design used a troubled petrol-electric transmission system which needed large quantities of copper for the manufacture of its electrical drivetrain components, a strategic war material of which Germany had limited supplies with acceptable electrical properties for such uses. Production of the Panzerkampfwagen VI Ausf. H began in August 1942. Expecting an order for his tank, Porsche built 100 chassis. After the contract was awarded to Henschel, they were used for a new turretless, casemate-style tank destroyer; 91 hulls were converted into the Panzerjäger Tiger in early 1943.
The Tiger was still at the prototype stage when it was first hurried into service, and therefore changes both large and small were made throughout the production run. A redesigned turret with a lower cupola was the most significant change. The river-fording submersion capability and an external air-filtration system were dropped to cut costs.
Design
The Tiger differed from earlier German tanks principally in its design philosophy. Its predecessors balanced mobility, armour and firepower and were sometimes outgunned by their opponents.While heavy, this tank was not slower than the best of its opponents. Although the general design and layout were broadly similar to the Panzer IV medium tank, the Tiger weighed more than twice as much. This was due to its substantially thicker armour, the larger main gun, greater volume of fuel and ammunition storage, larger engine, and a more solidly built transmission and suspension.
Armour
The Tiger I had frontal hull armour thick, frontal turret of 100 mm and gun mantlet with a varying thickness of. The Tiger had thick hull side plates and armour on the side superstructure/sponsons, while turret sides and rear were 80 mm. The top and bottom armour was thick; from March 1944, the turret roof was thickened to. Armour plates were mostly flat, with interlocking construction. This flat construction encouraged angling the Tiger hull roughly 30-45° when firing in order to increase effective thickness.Gun
The 56-calibre long 8.8 cm KwK 36 was chosen for the Tiger. A combination of a flat trajectory from the high muzzle velocity and precision from the Leitz Turmzielfernrohr TZF 9b sight made it very accurate. In British wartime firing trials, five successive hits were scored on a target at a range of. Compared with the other contemporary German tank guns, the 8.8 cm KwK 36 had superior penetration to the 7.5 cm KwK 40 on the Sturmgeschütz III and Panzer IV but inferior to the 7.5 cm KwK 42 on the Panther tank under ranges of 2,500 metres. At greater ranges, the 8.8 cm KwK 36 was superior in penetration and accuracy. British trials found the gun took from 6 to 16 seconds to reload varying on turret position and consequently which storage bin was being used.The ammunition for the Tiger had electrically fired primers. Four types of ammunition were available but not all were fully available; the PzGr 40 shell used tungsten, which was in short supply as the war progressed.
- PzGr. 39
- PzGr. 40
- Hl. Gr. 39
- sch. Sprgr. Patr. L/4.5
Engine and drive
The 501st Heavy Panzer Battalion reported in May 1943:
The engine drove the front sprockets through a drivetrain connecting to a transmission in the front portion of the lower hull; the front sprockets had to be mounted relatively low as a result. The Krupp-designed 11-tonne turret had a hydraulic motor whose pump was powered by mechanical drive from the engine. A full rotation took about a minute.
Another new feature was the Maybach-Olvar hydraulically controlled semi-automatic pre-selector gearbox. The extreme weight of the tank also required a new steering system. Germany's Argus Motoren, where Hermann Klaue had invented a ring brake in 1940, supplied them for the Arado Ar 96 and also supplied the disc. Klaue was acknowledged in the patent application that he had improved, it can even be traced back to British designs dating to 1904. It is unclear whether Klaue's patent ring brake was used in the Tiger brake design.
The clutch-and-brake system, typical for lighter vehicles, was retained only for emergencies. Normally, steering depended on a double differential, Henschel's development of the British Merritt-Brown system first encountered in the Churchill tank. The vehicle had an eight-speed gearbox, and the steering offered two fixed radii of turns on each gear, thus the Tiger had sixteen different radii of turn. In first gear, at a speed of a few km/h, the minimal turning radius was. In neutral gear, the tracks could be turned in opposite directions, so the Tiger I pivoted in place. There was a steering wheel instead of either a tiller – or, as most tanks had at that time, twin braking levers – making the Tiger I's steering system easy to use, and ahead of its time.
Powered turret traverse was provided by the variable speed Boehringer-Sturm L4 hydraulic motor, which was driven from the main engine by a secondary drive shaft. On early production versions of the Tiger maximum turret traverse was limited to 6 degrees per second, whilst on later versions a selectable high speed traverse gear was added. Thus, the turret could be rotated 360 degrees at up to 6 degrees per second in low gear independent of engine rpm, or up to 19 degrees per second with the high-speed setting and engine at 2,000 rpm, and at over 36 degrees per second at the maximum allowable engine speed of 3,000 rpm. The direction and speed of traverse was controlled by the gunner through foot pedals, the speed of traverse corresponding to the level of depression the gunner applied to the foot pedal. This system allowed for very precise control of powered traverse, a light touch on the pedal resulting in a minimum traverse speed of 0.1 degrees per second, unlike in most other tanks of the time this allowed for fine laying of the gun without the gunner needing to use his traverse handwheel.