Tiger II
The Tiger II was a German heavy tank of the Second World War. The final official German designation was Panzerkampfwagen Tiger Ausf. B, often shortened to Tiger B. The ordnance inventory designation was Sd.Kfz. 182.. It was also known informally as the Königstiger. Contemporaneous Allied soldiers often called it the King Tiger or Royal Tiger.
The Tiger II was the successor to the Tiger I, combining the latter's thick armour with the armour sloping used on the Panther medium tank. It was the costliest German tank to produce at the time. The tank weighed almost 70 tonnes and was protected by of armour to the front. It was armed with the long barrelled 8.8 cm KwK 43 anti-tank cannon. The chassis was also the basis for the Jagdtiger turretless Jagdpanzer anti-tank vehicle.
The Tiger II was issued to heavy tank battalions of the Army and the Waffen-SS. It was first used in combat by 503rd Heavy Panzer Battalion during the Allied invasion of Normandy on 11 July 1944; on the Eastern Front, the first unit to be outfitted with the Tiger II was the 501st Heavy Panzer Battalion. Due to heavy Allied bombing, only 492 were produced.
Development
Development started in 1937 with a design contract awarded to Henschel. Another design contract followed in 1939, given to Porsche. Both prototypes used the same turret design from Krupp. The main differences were in the hull, transmission, suspension and automotive features.File:Chambois1.jpg|thumb|left|Supreme commander of the allied forces in Europe General Eisenhower walks by an overturned Tiger II destroyed in Falaise pocket August 1944
The Henschel version used a conventional hull design with sloped armour resembling the layout of the Panther tank. It had a rear-mounted engine and used nine steel-tired, eighty-centimetre-diameter overlapping road wheels per side with internal springing, mounted on transverse torsion bars, in a similar manner to the original Henschel-designed Tiger I. To simplify maintenance, however, the wheels were only overlapping without being interleaved—the full Schachtellaufwerk rubber-rimmed road-wheel system that had been in use on nearly all German half-tracks used the interleaved design, later inherited by the Tiger I and Panther.
The Porsche hull designs included a rear-mounted turret and a mid-mounted engine. The suspension was the same as on the Elefant tank destroyer. This had six road wheels per side mounted in paired bogies sprung with short longitudinal torsion bars that were integral to the wheel pair; this saved internal space and facilitated repairs. One Porsche version had a gasoline-electric drive, similar to a gasoline-electric hybrid but without a storage battery; two separate drivetrains in parallel, one per side of the tank, each consisting of a hybrid drive train; gasoline engine–electric generator–electric motor–drive sprocket. This method of propulsion had been used on the rejected Tiger design, which had been rebuilt as Elefant, and in some US designs and was put into production in the French World War I era Saint-Chamond tank and post-World War I Char 2C. The Porsche suspension components were later used on a few of the later Jagdtiger tank destroyers. Another proposal was to use hydraulic drives; Dr. Porsche's unorthodox designs gathered little favour.
Design
Henschel won the design contract, and all Tiger IIs were produced by the firm. Two turret designs were used in production vehicles. The initial design is often misleadingly called the "Porsche" turret due to the misbelief that it was designed by Porsche for their Tiger II prototype; in fact it was the initial Krupp design for both prototypes. This turret had a rounded front and steeply sloped sides, with a difficult-to-manufacture curved bulge on the turret's left side to accommodate the commander's cupola. Fifty early turrets were mounted to Henschel hulls and used in action. In December 1943 the more common "production" turret, sometimes erroneously called the "Henschel" turret, was simplified with a significantly thicker flat face, and less-steeply sloped sides, which avoided the need for a bulge for the commander's cupola, and added additional room for ammunition storage.File:Bundesarchiv Bild 101I-680-8282A-09, Budapest, Panzersoldaten in Panzer VI.jpg|thumb|right|alt=A tank turret with an almost square, flat, vertical face, the sides are almost vertical, and curve laterally only slightly.|The angular front of the "production turret" designed by Krupp taken during Operation Panzerfaust in Budapest, 15 October 1944. The rough Zimmerit coating is evident, used to prevent magnetic mines from adhering to the tank's armour.
The turrets were designed to mount the 8.8 cm KwK 43 L/71 gun. Combined with the Turmzielfernrohr 9d monocular sight by Leitz, which all but a few early Tiger IIs used, it was a very accurate and deadly weapon. During practice, the estimated probability of a first-round hit on a high, wide target was 100 percent at, 95–97 percent at and 85–87 percent at, depending on ammunition type. Recorded combat performance was lower, but still over 80 percent at 1,000 m, in the 60s at 1,500 m and the 40s at 2,000 m. Penetration of armoured plate inclined at 30 degrees was at and respectively for the Panzergranate 39/43 projectile, and for the PzGr. 40/43 projectile between the same ranges. The Sprenggranate 43 high-explosive round was available for soft targets, or the Hohlgranate or Hohlgeschoss 39 round, which had penetration at any range, could be used as a dual-purpose munition against soft or armoured targets.
Powered turret traverse was provided by the variable speed Boehringer-Sturm L4S hydraulic motor, which was driven from the main engine by a secondary drive shaft. A high and a low speed setting was available to the gunner via a lever on his right. The turret could be rotated 360 degrees at 6º/second in low gear independent of engine rpm, at 19º/second – the same as with the Tiger I – with the high speed setting and engine at 2000 rpm, and over 36º/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, whilst a high torque low speed or low torque high speed final gearing could be selected via a control lever near his left arm. 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 deg/sec, 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. If power was lost, such as when the tank ran out of fuel, the turret could be slowly traversed by hand, assisted by the loader who had an additional wheel, which could manually rotate the turret at a rate of one-half a degree per each revolution of the hand crank; a 20° turret rotation required 40 full cranks of the handwheel, and to turn the turret a full 360° the gunner would be required to crank the handwheel 720 full revolutions.
Like all German tanks, the Tiger II had a petrol engine; in this case the same 700 PS V-12 Maybach HL 230 P30 which powered the much lighter Panther and Tiger I tanks. The Tiger II was under-powered, like many other heavy tanks of World War II, and consumed a lot of fuel, which was in short supply for the Germans. The transmission was the Maybach OLVAR OG 40 12 16 Model B, giving eight forward gears and four reverse, which drove the steering gear. This was the Henschel L 801, a double radius design which proved susceptible to failure. Transverse torsion bar suspension supported the hull on nine axles per side. Overlapped diameter road wheels with rubber cushions and steel tyres rode inside the tracks. Late production Tiger Is received the same wheels, which were one of the few interchangeable parts between the two tanks.
Like the Tiger I, each tank was issued with two sets of tracks: a normal "battle track" and a narrower "transport" version used during rail movement. The transport tracks reduced the overall width of the load and could be used to drive the tank short distances on firm ground. The crew were expected to change to normal battle tracks as soon as the tank was unloaded. Ground pressure was 0.76 kg/cm2.
Command variant
The command variant of the Tiger II was designated Panzerbefehlswagen Tiger Ausf. B. It had two versions, Sd.Kfz. 267 and Sd.Kfz. 268. These had reduced ammunition capacity to provide room for the extra radios and equipment, and had additional armour on the engine compartment. The Sd.Kfz. 267 was to have used FuG 8 and FuG 5 radio sets, with the most notable external changes being a rod antenna mounted on the turret roof and a Sternantenne D, mounted on an insulated base, which was protected by a large armoured cylinder. This equipment was located on the rear decking in a position originally used for deep-wading equipment. The Sd.Kfz. 268 used FuG 7 and FuG 5 radios with a two-metre rod antenna mounted on the turret roof and a 1.4 metre rod antenna mounted on the rear deck.Production
The Tiger II was developed late in the war and built in relatively small numbers. Orders were placed for 1,500 Tiger IIs—slightly more than the 1,347 Tiger I tanks produced—but production was heavily disrupted by Allied bombing raids. Among others, five raids between 22 September and 7 October 1944 destroyed 95 percent of the floor area of the Henschel plant. It is estimated that this caused the loss in production of 657 Tiger IIs. Only 492 units were produced: one in 1943, 379 in 1944, and 112 in 1945. Full production ran from mid-1944 to the end of the war. Each Tiger II cost 321 500 Reichsmark. The vehicle was the costliest German tank to produce at the time.The Tiger II served as the basis for one production variant, the Jagdtiger casemated tank destroyer, and a proposed Grille 17/21/30/42 self-propelled mount for heavy guns which never reached production.