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"Detailed Report on the German "Tiger" PzKw 6"
iz obavještajnog biltena US Army "Tactical and Technical Trends, No. 34, September 23, 1943".
In the early part of 1943 there were repeated reports of a new German heavy tank (Tactical and Technical Trends, No. 18, page 6) and as the campaign in North Africa proceeded, more definite information became available (Tactical and Technical Trends, No. 20, page 7; No. 24, page 6; No. 30, page 7). The following information is taken from a special report compiled in North Africa after extensive tests on one carefully salvaged PzKw 6 and parts of ten others scattered about the battle area.
* * *
a. Structure and Layout
The dimensions are more or less as previously reported, except for the overall width, which is 11 feet 9 inches and not 12 feet 8 inches as has been stated. The hull is entirely welded. The hull dimensions are:
Width to outside of 28 1/2-inch tracks 11 ft 9 in
Width of hull at top 10 ft 3 1/2 in
Width of hull at nose 6 ft 4 in
Length from nose-plate to silencer 20 ft 7 1/2 in
Length track on ground 12 ft 3 in
Height from ground to hull top 5 ft 8 in
Height from ground to highest point on cupola 9 ft 6 1/2 in
Height from ground to top of wading air intake 15 ft 5 1/2 in
Height from ground to sprocket center 2 ft 3 1/2 in
Belly clearance 1 ft 3 in
Height from floor to turret roof 5 ft 2 in
The turret is made up of a horse-shoe-shaped wall with the circular part at the back. The turret bearing is of the vertical type with the stationary race inside and the moving one outside. It is a ball bearing with 1.6 inch balls and no cage. It contains a variety of sealing arrangements; besides the water seals, there is a felt seal. The traverse ring is in one piece and the clear diameter is 6 feet, 2 inches. The turret seems to come off very easily.
The turret platform is 4 feet 9 inches in diameter, connected to the turret by tubular supports. There are no basket sides. The power traverse hydraulic gear sits in the middle of this. There is a trapdoor at the loader's feet, which with the turret at 12 o'clock, gives access to an ammunition bin underneath. The turret dimensions are:
Height from hull top to turret roof 2 ft 8 1/2 in
Height from hull top to trunnion centers 1 ft 3 1/2 in
Diameter of cupola inside 2 ft 4 in
Diameter of cupola hatch 1 ft 6 in
Diameter of turret ring 6 ft 1 in
Diameter of turret platform 4 ft 9 1/2 in
Number of teeth in ring 204
Width of rack (turret ring) 2 1/2 in
The floor surrounding the turret platform is mostly occupied by ammunition bins and kept fairly free of stowage. A total of 92 rounds of 88-mm ammunition is carried, divided between nose-fuze HE and APCBC-HE*.
The layout of the crew space follows the normal German practice of driver and hull gunner-radio operator in the forward compartment, to the rear and offside of the transmission respectively, and a three-man turret, thus making a crew of five.
The 88-mm gun is slightly offset to the right side and its recoil guard extends backwards until it nearly reaches the turret ring, thus dividing the fighting space into two unequal parts. The gunner's seat is well forward and low down on the left side and the commander's seat immediately behind it and higher up; they occupy the larger of the two portions of the chamber, but both are rather cramped.
The loader, having the smaller right side to himself, has more room; the rounds of ammunition are 36 1/2 inches long and nearly 4 1/2 inches in diameter at the rim, so he needs every bit of space. The co-axial machine gun is readily accessible.
b. Armor and Vulnerability
The figures already given for armor thickness are confirmed, but there are still doubts as to the quality. Armor thicknesses are as follows:
Lower nose at 20° 4.02 in Driver's visor at 10° 4.02 in
Rear plate at 20° 3.23 in Upper side 2.44 in
Lower side 2.44 in Glacis 2.44 in
Hull roof 1.02 in Flooring 1.02 in
Belly 1.02 in Turret front 3.93 in
Turret wall 3.23 in Turret roof 1.02 in
Mantlet casting 3.93 in (approx)
The side plating shows surface hardness and brittleness, with a strong tendency to (zabranjeno) and flake. The side plate of the turret also flakes badly on the inside.
The limiting angle for penetration of the 75-mm gun against the 3.23 inch plate is 17°, but it will penetrate the lower 2.44 inch plate at 30°.
The guns used were the 75-mm (M.3) gun in a Sherman tank and a worn 6-pounder (Mk.III-57 mm) in a Churchill tank. It is not possible to give even an estimate of the equivalent full charge. The range for the test was restricted to 100 yards. The cast armor of the mantlet seems to be of good quality, and does not break up or (zabranjeno) under heavy attack. None of those examined had been penetrated. The mantlet covers the entire front of the turret and there is no doubt that it gives far better protection than an internal one.
There is no protection for the turret ring other than that provided by raising the driver's visor plate 2 inches above the hull roof. This is not very effective and an additional weakness is indicated by the penetration of two 75-mm projectiles which were deflected downwards on to the hull roof from the lower edge of the mantlet and turret front.
A trial attempt was made against the front of one of these tanks with PIAT** projectiles but they failed to penetrate either the mantlet or the front 4.02 inch plate. A German "beehive" magnetic hollow charge was tried out on the 3.23 inch side plate and successfully penetrated it.
In general, it seems that the protection afforded by this tank is very good and that for effective AP attack, a gun of the 17-pounder (3-in) class is needed. We have reason to believe, however, that the tracks and bogies, which present a large target area, are liable to damage by HE from field and medium artillery.
c. Armament
The 88-mm (3.46 in) is of the normal type with semi-automatic breech mechanism; it can use antiaircraft ammunition which has been provided with electric primers. The gun has the usual electric safety devices which prevent it from being fired if the breech is not fully closed, or the gun is not entirely back in battery position.
There is also the push button switch for the loader to press when he is ready for the gun to be fired, which completes the firing circuit and lights up a signal light in front of the gunner. The tests disclosed the following pertinent data as to the 88-mm gun:
Length from muzzle to trunnion centers 13 ft 6 1/4 in
Length from trunnion centers to rear of breech 4 ft
Elevation 15°
Depression -8°
Length of HE round 3 ft 1/2 in
Diameter of cartridge rim 4 7/16 in
The gun has semi-automatic gear and recoil guard with deflector bag
The co-axial gun is fired mechanically by means of a pedal near the gunner's right foot. The two machine guns are of the normal type, the hull gun being ball-mounted in the usual fashion. There are three smoke dischargers on each side of the turret. They are fired electrically by three push buttons on each side of the commander's seat.
The smoke generator is lettered No. K.39. It is 3.8 inches in diameter. It is propelled by a charge of powder in a transparent plastic capsule which has a small diameter, threaded extension for screwing into the base of the generator. The charge is fired by a brass electric primer, which is screwed into the base of the discharger from the back.
Up the center of the generator, and held in place by the propellant capsule, is a tube containing some kind of igniter. The loading of these devices cannot easily be done in the heat of battle.
d. Laying and Sighting
The turret is provided with a hydraulic traverse, power driven through a vertical shaft in the center of the base junction. The gunner controls this with a rocking foot plate which gives variable speed in either direction. Maximum rate of traverse appears to be rather slow. The gunner is provided with a hand traverse which can be assisted by a second handwheel operated by the commander.
The degree of traverse of the turret is recorded on a dial in front of the gunner, and there is also the usual traverse ring in the commander's cupola. Both devices are driven off the turret-ring rack through jointed shafts.
Elevation is by handwheel geared with considerable reduction into a toothed sector. The muzzle-heaviness of the gun with its external mantlet is considerable, and a compensating spring, similar to that of PzKw 4 Special is provided.
Maximum elevation if 15° and depression -8°. The gun appears stiff to elevate but depresses quite easily. An elevation lock is provided for travelling, by which the breech can be clamped to the turret roof.
Binocular sighting is provided. This consists of two of the normal jointed telescopes mounted side by side in a frame. The eye pieces are offset from the telescope center lines by the insertion of episcopic prism assemblies, (reflecting lenses) and inter-ocular distance can be adjusted by rotating them in opposite directions. They are geared together, so as to ensure that the motion is shared equally.
e. Lookouts and Hatches
The commander has a raised cupola of the normal type with five slits backed by the usual size triplex blocks. The field of view is good. The front block has sight bars on it for lining up the turret.
There are two lookouts of the same type in the forward parts of the turret, at 10 and 2 o'clock. There are also machine-gun ports at 4 and 8 o'clock, covered by an internal rotary shield.
The driver has the usual long triplex visor-block protected by an adjustable slit. He also has the regulation type episcopic binocular. For vision to his own, the left side, he has a prism episcopic set to look about 30° forward to the side.
The hull gunner has the usual episcopic sighting telescope fitted to the ball mounting of his machine gun. He also has a prism episcope, similar to that of the driver, for looking out to the right. Both these episcopes are fitted in the hatch doors.
The hatch in the cupola and those above the driver and forward gunner are circular, about 18 inches in diameter and spring supported; they can be closed down against a rubber ring so as to be completely water tight.
There is a rectangular hatch above the loader which is also provided with, a rubber sealing ring. The size of this opening is about 20 x 14 inches. In one tank there was a large diameter escape hatch at 4 o'clock in the turret wall, in place of one of the pistol ports.
f. Amphibious Characteristics
The tank has been initially designed for total immersion in water. All the crew's hatches are provided with rubber seals and multiple bolts. The engine compartment can also be sealed off; its cover is normally screwed down on to sealing strips and it can be isolated from the radiator and fan compartments on either side of it, drawing air from a special intake pipe over the engine hatch, the top of which is 3 3/4 inches internal diameter and 15 1/2 feet from the ground, (see sketch).
No attempt is made to plug the cooling air inlets and outlets, so that the radiators run totally submerged, the fans being disconnected by special clutches. The only other aperture required is for the exhaust and this is dealt with by a simple flap-valve on top of the silencer, which is normally held open.
A free translation of an instruction plate inside one of the turrets is as follows:
(1) Lock turret and gun.
(2) Free mantlet sealing frame, push forward and secure by means of locking nuts.
(3) Remove MG and fit in sealing rod.
(4) Draw back telescopes, turn sealing stopper upwards and clamp slide with locking nut.
(5) Plug gun cradle by turning handwheel above the gun.
(6) Pump the sealing hose in the turret race up to 2.5 atmospheres.
(7) Open water-drain tube.
( Tighten the nuts on the vision slit frames.
(9) Open the machine-gun ports and fit sealing stoppers.
(10) Fit water-tight muzzle cap.
(11) Fit sealing cap on the ventilating fan exit in the turret roof.
(12) Close hatches.
(13) Tighten levers in commander's cupola.
(14) In the event of the sealing hose not being tight and letting water through the drain tube, close drain tube and tighten inner sealing ring in the turret.
(15) To lay and fire after emerging, sealings 1 to 6 and 14, at least, must be opened up.
The result of this is to make it possible to immerse the tank completely, drawing air through the long intake pipe. Allowing for a certain amount of free-board and the possibility of having to climb a steeply sloping beach, operation in 14 feet of water should be practicable.
The intake pipe is in three sections, which normally rest inside one another in the hull, but can be fitted together and erected very quickly. There seems no reason why an extra length should not be added if additional depth is required.
Air enters and discharges vertically through a horizontal grating on each side of the radiator block which is isolated from the engine compartment. Inflammable liquids such as from SIP (self-igniting phosphorus) grenades, drawn swiftly through the radiator block, are not likely to do it much injury.
g. Ventilation
The engine breathes from its own compartment and therefore keeps the air circulating through it. There are, in addition, two passages passing through the sidewall on each side into the space between the fans and the radiator block. When engaged in amphibious operations, these passages are closed by butterfly valves actuated by the same lever that disconnects the fan clutches.
It is thought, that when the tank is closed down for amphibious operations, air is drawn down the long tube into the engine room and part of it is diverted through the engine room bulkhead ventilator by the suction of the fan and so ventilates the crew's accommodation before passing to the engine. The only air exit found seems to be through the engine exhaust, and if the engine stops, all ventilation must cease.
For normal evacuation of gun fumes etc., two electric fans are provided, one in the turret roof behind the loader, and one on the center line of the hull roof between the driver and forward gunner. These have ordinary mushroom type outlets, to which waterproof covers can be secured when necessary.
Radiators Fans
Number per tank 2 Number per tank 4
Matrix width 35 in Number of blades 8
Matrix depth 20 in Overall diameter 17 1/2 in
Matrix thickness 7 in Disk diameter 9 1/2 in
Grill spacing 7 per in
Rows of tubes 6
h. Engine
The engine is a V-12, 60°, Maybach gasoline engine developing 650 bhp (brake horsepower). There are four down-draught non-spillable carburetors, each with twin throttle tubes and quadruple floats. Ignition is by two Bosch magnetos of the rotating magnet type, driven off the live end from positions above the rocker gear.
i. Steering and Final Drive
The principal method of steering is by hand wheel, and this operates a fully regenerative system giving geared turns of varying radius with the same sort of "neutral swing" as the Merritt Brown transmission.*** In addition to this there are two skid brake levers.
j. Suspension and Tracks
The interleaved bogies and independent torsion-bar suspensions are substantially as previously reported.
Hydraulic piston-type shock absorbers are provided for the front and rear suspension only. They are mounted inside the hull, the front ones being in the forward compartment. These tanks seem to have a certain amount of trouble with their tracks; the rings securing the track pins seem to be too weak for their job. There are eight torsion bars per side, three bogie wheels are mounted on each bar. This arrangement is for the 28 1/2-inch track. The eight outside wheels are removed when the narrow 21-inch track is used.
k. Performance
It is difficult to assess the performance of this tank. The weight appears to lie between 50 and 60 tons. The maximum speed is estimated at 15 to 18 mph. The cross-country ability is also a matter for conjecture.
l. Conclusions
There is no doubt that the Germans have produced a very formidable tank, and that it must have been conceived with the idea of making beach landings on the shores of Britain. The waterproofing facilities are certainly superior in design and execution to anything that we have hitherto imagined.
*Armor-piercing (projectile) capped with ballistic cap high explosive.
**Projector, infantry antitank.
***One of two types of British transmission.
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