The Pz Kpfw Tiger Ausf B heavy tank (also called the Sd Kfz 182 "special purpose fighting vehicle type 182," according to unified designation system used by the Germans), was developed by "Henschel" under the leadership of its chief designer Erwin Anders. It was in mass production from January 1944 up to May 1945. The tank weighed 69.4 tons, and had a power-to-weight ratio of 10.08 h.p. per ton. The hull and turret were made of rolled homogenous armor plate with low to medium hardness. 487 vehicles were produced in total.
The first "Tiger-B" tanks captured by Soviet forces were sent to the GABTU NIIBT at Kubinka for comprehensive study. There were vehicles numbered 102 and 502. The very movement of these tanks to the loading station under their own power revealed numerous defects. At 86 kilometers, the left idler wheel went out of commission (when the bearings failed), as well as the left drive sprocket (when all the mounting bolts sheared). The high temperatures at the time, which reached 30 degrees Celsius (86 F), turned out to be too much for the cooling system. This led the right engine block to overheat and to continual overheating in the gearbox. The tank was repaired, but after that the right side running gear had completely failed. It was replaced with one scavenged from another tank, but this one almost immediately went out of commission again when the drive shaft roller bearings failed. Besides this, time and again it was necessary to change the track's elements, which were constantly breaking (cracking) due to the tank's colossal weight, especially when the vehicle was turning. The design of the track tensioning mechanism hadn't been completely perfected. As a result, the tension had to be adjusted after every 10-15 km of travel.
In the end, both captured vehicles were delivered to the NIIBT proving ground, where vehicle #102 underwent further maneuverability tests. This testing encountered severe obstacles connected with the extremely low reliability of the chassis elements, engine, and transmission. It was determined that 860 liters of fuel was sufficient for 90 km of movement over an dirt road, even though the vehicle's manual indicated that this amount of fuel should have been sufficient for 120 km. Fuel consumption per 100 km was 970 liters instead of the 700 liters according to this same (captured) manual. Average rate of movement along the highway was 25-30 km/h, 13.4-15 km/h along an dirt road. The average speed when moving over rough terrain was even worse: 6-7 km/h. The maximum speed, given as 41.5 km/h in the tank's technical documentation, was never even once achieved in the maneuverability tests.
In order to obtain an objective evaluation of the tank's armor protection, it was decided to subject to shell fire the hull and turret of the captured vehicle with turret number 502. Most of the systems and assemblies were removed for further study. The tank's armament was sent to the ANIOP for study.
The live fire tests were conducted in the fall of 1944 at Kubinka, during the course of which the following results were obtained:
"1. The quality of armor on the "Tiger-B" tank, in comparison with the armor on the "Tiger-I," and "Panther," tanks, as well as early production "Ferdinand" self-propelled gun, has sharply deteriorated. The first individual impacts caused cracks and spalling in the armor of the "Tiger-B" tank. Groups of shell impacts (3-4 shells) caused large-scale spalling and fractures in the armor.
2. Weak weld seams appeared characteristic of all hull and turret joints. Despite careful workmanship, the seams held up to shell impacts significantly worse than they did in analogous constructions on the "Tiger-I," and "Panther," tanks, as well as the "Ferdinand" self-propelled gun.
3. Impacts of 3-4 armor-piercing or high-explosive fragmentation shells from 152, 122, or 100 mm artillery pieces caused cracks, spalling and destruction of the weld seams in the tank's 100-190 mm thick frontal armor plates at ranges of 500-1000 metres. The impacts disrupted the operation of the transmission and took the tank out of service as an irrevocable loss.
4. Armor-piercing projectiles from the BS-3 (100 mm) and A-19 (122 mm) gun completely penetrated when impacting the edges or joints of the "Tiger-B" tank's front hull plates at ranges of 500-600 metres.
5. Armor-piercing projectiles from the BS-3 (100 mm) and A-19 (122 mm) gun completely penetrated the "Tiger-B" tank's front turret plate at ranges of 1000-1500 metres.
6. 85 mm armor-piercing projectiles from the D-5 and S-53 gun failed to penetrate the tank's front hull plates or cause any structural damage at distances of 300 metres.
7. The tank's side armor plates were notable for their sharply unequal durability in comparison with the frontal plates and appeared to be the most vulnerable part of the tank's hull and turret.
8. The tank's hull and turret side plates were penetrated by armor-piercing projectiles from the domestic 85 mm and American 76 mm guns at ranges of 800-2000 metres.
9. The tank's hull and turret side plates were not penetrated by armor-piercing projectiles from the domestic 76 mm guns (ZJS-3 and F-34).
10. American 76 mm armor-piercing projectiles penetrated the "Tiger-B" tank's side plates at ranges 1.5 to 2 times greater the domestic 85 mm armor-piercing projectiles."
Here, for fans of the "King Tiger", it should be said that the 122 mm D-25 tank gun mounted on the JS-2 tank was the direct descendent of the A-19 gun-howitzer. Basically, these guns were different in their breech blocks (the D-25's was semi-automatic) and in a few technical details not affecting their ballistics. Consequently, the armor penetration capabilities of both guns were the same. In addition, the 100 mm BS-3 field gun and the D-10 tank gun, mounted on the SU-100, also had the same armor penetration capabilities.
During lab tests of the "Tiger-B" tank's armor, conducted at TsNII-48, it was noted that there had been an "evident gradual decline in the quantity of molybdenum (M) in the German T-VI and T-V tanks, and a complete absence in the T-VIB. The reason for replacing one element (M) with another (V, vanadium) must obviously be sought in the exhaustion of their on-hand reserves and the loss of those bases supplying Germany with molybdenum. Low malleability appears to be characteristic of the "Tiger-B's" armor. An advantage of domestic armor, as is well-known, is its high malleability; German armor has fewer alloys and is therefore significantly less malleably."
A comment should also be made here. More malleably armor results in a smaller number of secondary fragments when penetrated (these fragments intended to kill crew and to damage tank controls), and, besides this, the armor has a smaller chance of cracking.
During testing of the weapon, the German KwK 43 tank gun gave good results in both armor penetration and accuracy, practically the same as the Soviet 122 mm D-25 gun on the JS-2 tank. At a range of 1000 metres, the following projectile impact deviations from the aiming point were observed: 260 mm in the vertical, and 210 mm in the horizontal. In comparison, for the JS-2 tank's D-25 gun the average projectile deviation from the aiming point did not exceed 170 mm in the vertical and 270 mm in the horizontal during stationary firing at a range of 1000 metres. The penetration capability of the 71-caliber long 88 mm KwK 43 gun, with its muzzle velocity of 1000 m/s for its armor-piercing projectiles, was 165 mm at a 30 degree impact angle at 1000 metres. In particular, the "Tiger-B" projectile went completely through the turret of its "colleague" at a range of 400 m. But in high-explosive power, the 88 mm projectile was 1.39 times inferior to the 122 mm high-explosive fragmentation projectile.
The final report of 16 February 1945 on the "Tiger-B" tests, stated the following:
"The frontal hull and turret armor is low quality. Non-penetrating damage (dents) in the armor caused cracking through the armor and large scale interior spalling. The side plates were notable for their sharply unequal durability in comparison with the frontal plates and appeared to be the most vulnerable part of the tank's hull and turret.
Shortcomings: The chassis is complex and is not durable. The steering mechanism is complex and expensive. The side running gear is extremely unreliable. The radius of action is 25% inferior to the "IS"-tanks. The ammunition (except in the turret recess) is awkwardly located. The excessive size and weight of the tank do not correspond to the tank's armor protection and firepower."
Source: "Tankomaster" #6 1999.