The Panzer III was the common name of a medium tank that was developed in the 1930s by Germany and was used extensively in World War II. The official German designation was Panzerkampfwagen III Sd Kfz. 141 (abbreviated to PzKpfw III) translating as "armored fighting vehicle number three".
The Panzer III was purpose designed to create a breakthrough on the battlefield and also to fight other armored fighting vehicles. The performance of the Panzer III was adequate in the early years of the war; however as the Germans came to face faced the formidable T-34 and KV-1 in Russia, it was immediately obvious that a stronger main gun with a considerably enhanced anti-tank capability was now needed. The Panzer IV had a bigger turret ring and was capable of mounting a larger main weapon, the traditional roles were therefore reversed. The Panzer IV mounted the long barreled 7.5 cm KwK 40 gun was detailed to fight in tank-to-tank battles, the Panzer III became obsolete in this role and for most purposes was supplanted by the Panzer IV. From 1942, the last version of Panzer III, Ausf. N, mounted the 7.5 cm KwK 37 L/24 short barelled howitzer better suited for infantry support. Production of the Panzer III ended in 1943. However, the Panzer III's capable chassis provided hulls for the Sturmgeschütz III until the end of the war.
The constantly changing role of the Mark III required close scrutiny from Allied intelligence services in order to keep the front line troops up to speed on the variants which they faced in the field.
This wartime military intelligence report on the German Panzer III was originally published in the US intelligence magazine Tactical and Technical Trends, No. 10, October 22nd, 1942.
A good study of the Panzer III Ausf.E. Note the two machine guns in the turret.
MARK III TANK - THREE BASIC DESIGNS
Close examination of a considerable number of photographs of Mark III tanks, together with those available for examination in the Western Desert, indicates that the Mark III fighting-type tank is found in three basic designs.
Of these, the first has an armor basis of 30 mm (1.18 in) all around. The front sprocket has eight spokes, and the rear idler, though having eight spokes, is almost solid. This type is known originally to have been produced mounting a 37-mm gun and either one or two machine guns coaxially in the turret, with one machine gun firing forward in the hull. Later, however, the 50-mm was substituted for the original principal armament, and this mounting has only one machine gun mounted coaxially in the turret, the hull machine gun being retained. Of the actual specimens examined, all mounted the 50-mm gun (many are now mounting the long-barrelled type), and in these there has invariably been a Variorex gearbox, the steering being hydraulically operated. This basic type, irrespective of armament, has not been found to carry any additional armor, improvised or otherwise.
The second type has an armor basis of 30 mm all around with additional 30-mm plates bolted on. This type has a six-spoke front sprocket, and the rear idler, although having eight spokes, is more open than the first type. An ordinary six-speed gear box and hydraulically operated steering gear are fitted. Neither photographs nor specimens of this type have shown any principal armament other than the 50-mm gun with one coaxial machine gun. Moreover, every individual tank of this type has had similar additional 30-mm plates on the front and rear, this additional armor not having been found on any other type of Mark III fighting tank. The inference is, therefore, that this additional armor is actually part of the design of the tank and probably incorporated during manufacture. There have been no indications that this type originally mounted a 37-mm gun, although this remains a possibility.
The third type has 50-mm armor on the front and rear, with 30-mm armor on the sides. No additional armor has been found on any tanks of this type, and the armament has always been found to be the 50-mm gun with a coaxial machine gun and one machine gun in the hull. The front sprocket and rear idler are similar to those in the second type, and an ordinary six-speed gear box is fitted, the steering being operated by mechanical linkage. The driver's and hull gunner's entrance doors have been changed from the former double doors to single doors hinged at the forward edge. In place of the normal mantlet protecting the hull machine gun, a more hemispherical mantlet is fitted.
A Pz.Kpfw.III Ausf.G captured by the British in North Africa, 1942.
The following minor differences of design between these three basic types have also been noted. Originally on the first type the armor protecting the driver's visor consisted of two plates, one being raised, and the other lowered, to give protection. The third type, and probably the second type as well, have had a single hinged piece of armor which can be lowered to give protection. The third type has also had a slightly different design of the two shields protecting the exhausts from the steering tracks. In the first and second types the air filters were located between the rear bulkhead of the fighting compartment and the engine, air being drawn from the fighting compartment. These filters were believed to be an oil-soaked gauze type. On the third type this arrangement superseded by four oil bath filters, installed over the top of the engine blocks.
The suspension on all these types has been the same, the familiar six small bogie wheels with three return rollers, a front sprocket, and a rear idler. Two early types, however, are known to have had respectively five large bogie wheels and eight small bogie wheels. Both these types mounted a 37-mm gun. Nothing has been heard of either type over a considerable period, and it is probable that they were prototypes only and not produced in significant numbers.
It is known that Mark III fighting tanks have been produced in at least five models designated 'E', 'F', 'G , 'H', and 'J.' These models have consecutive chassis number blocks, and it is logical to assume that they are successive developments. There should therefore be a link with the development shown above, but so far it is not possible definitely to say what each model designation represents. It is, however, known that the first type described above has included Model 'G' tanks, and the third type has included Model 'J' tanks. All three types are known to have been in existence early in 1941, the third type probably being at that time a very new production.
It should be specially noted that, in describing German armor thickness, round numbers are almost invariably given. Careful measurement, has shown that these figures are frequently incorrect. 30-mm, for example, should almost invariably be up to 32-mm.
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The vulnerability of German Tanks was an obvious area for investigation by intelligence gathering services. This article, also taken from from Tactical and Technical Trends, provides an interesting contemporary intelligence report on vulnerability of German tanks to short-range attacks with incendiary grenades. It was originally published in Tactical and Technical Trends, No. 11, November 5th, 1942.
VULNERABILITY OF GERMAN TANKS
When enemy armored force vehicles are attacked at close quarters with incendiary grenades, the air louvres are very vulnerable. It is therefore important that differentiation be made between "inlet" and "outlet "ducts, since obviously a grenade thrown against an exhaust opening will be less effective than one aimed at an inlet, which will draw the inflammable liquid into the vehicle. If the engine is not running, all openings are equally vulnerable.
In general, it may be said that in the Pz Kw II and III tanks the best targets are the flat top-plates of the rear superstructures, since the air intakes are located there. The side louvres in these tanks are invariably protected by a vertical baffle. On the Pz Kw IV, the left side ports are intake and thus more vulnerable than the right-hand exhaust ports.
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The following report on the new armament of the up-gunned German Pz.Kw. III originally appeared in Tactical and Technical Trends, No. 20, on 11th March 1943. This is how Allied troops were informed of the fact that the Panzer III was now operating in a more efficient form. American reports from the period invariably refer to the German tanks using Arabic rather than Roman numerals.
NEW ARMAMENT OF GERMAN PZ.KW. 3
As previously reported in Tactical and Technical Trends (No. 4, p. 15) recent models of two German tanks, the Pz.Kw. 3 and 4, have been fitted with more powerful armament, as shown in the accompanying sketches. These sketches are based on photographs of German tanks captured by the British in North Africa.
Pz.Kw. 3
The principal armament of this tank is a long-barrelled 50-mm gun. It is reported that this gun bears considerable similarity to the 5-cm Pak 38 (50-mm antitank gun), except that there is no muzzle brake and that the mounting is, of course, different. The over-all length from the breech opening to the muzzle is 9 feet, 4 inches. The barrel overhangs the front of the tank by about 3 feet. The ammunition used is that of the 50-mm antitank gun with no adaptation or alteration apart from the fitting of an electric primer, the tank gun being electrically fired. The muzzle velocity of this tank gun has been estimated as a little over 3,000 feet per second. It has been reported that the performance of the tank gun should not be very different from that of the antitank gun, the estimated penetration figures for which are as follows:
•79-mm (3.1 in) homogeneous armor at 300 yds at 30°
•71-mm (2.8 in) homogeneous armor at 600 yds at 30°
•63-mm (2.5 in) homogeneous armor at 850 yds at 30°
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Advice on how to combat the Panzer III was required and the following article, from Tactical and Technical Trends, No. 22, April 8th, 1943, describes areas on German tanks vulnerable to attack with incendiary grenades or Molotov cocktails.
VULNERABLE SPOTS FOR INCENDIARY GRENADES ON GERMAN TANKS
In attacking enemy tanks at close quarters with Molotov cocktails or incendiaries, the air intakes are among the most vulnerable points. It is important, therefore, that the location of these intakes and outlets be known, as the flame and fumes of a grenade thrown against an intake while the engine is running will be sucked inside, but if the grenade lands on an outlet, they will be blown clear of the tank.
The best targets are the flat top-plates behind the turret. Side intakes are invariably protected by a vertical baffle. The accompanying sketches show the "soft spots" on German tanks Pz.Kw.3
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The response to these and other threats was to increase protection on the Panzer III. This U.S. intelligence report on the Panzer III and its increasing armor specification originally appeared in Tactical and Technical Trends, No. 25, May 20th, 1943.
INCREASED PROTECTION ON PZKW 3
The history of the changes in the light medium PzKw 3 demonstrates how fortunate the Germans were in having a basic tank design that could be improved as battle experience indicated, for a basic design can be improved and still remain familiar to the users. Furthermore, the problems of maintenance and supply of parts are greatly reduced and these problems are a major factor in keeping tanks ready for operational use.
(1) General
The Germans seem to be making a gradual increase in thickness of armor-plate as the guns used against it increase in hitting power and range. The PzKw 3 medium tank is illustrative of this trend in tank armor and design, and affords a remarkable example of what can be done to improve the armor protection and fighting efficiency of a tank without changing its basic design. The key of this basic design is the welded main structure which allows heavier plates to be used when desired. Also, operating components of the tank are not hung on the plates, likely to be changed to thicker ones.
(2) Pre-War
The early model PzKw 3 (produced in 1936-38) had basic armor of .59-inch homogeneous plate. At this time there were only 5 bogie wheels on a side instead of the present 6. There is a gap in the formation until 1939, when the tank appeared with 1.18-inch face-hardened armor on the turret and front. This model had 6 bogie wheels on the side. The side armor which forms a great part of the chassis was of softer, machineable-quality plate, due both to necessities of manufacture and to the undesirable weakening effect on hardened plate of the necessary suspension and bracket holes. The model also had improved aperture protection in the form of an external moving mantlet, additional armor around the machine-gun port, and an improved double-flap driver's visor. It appears that these features were added with the modification of but 2 plates on the tank.
A Panzer III packed with fifteen or more grenadiers conveys the impression of just how sturdy these machines were.
(3) 1941 Changes
In 1941, as more powerful guns were being used against tanks, 1.20 inches of additional armor plate was bolted against the plates on the front of the superstructure and on the upper and lower nose-plates. The 1.18-in. basic plates were face-hardened to a Brinell hardness of 600 to 800 and 1.20-in additional plates were the same. About a year later, in January 1942, the tank appeared with a basic armor of 1.96 inches on the front and back, the side-armor thickness remaining unchanged at 1.20 inches. This armor was face-hardened and performed well against monobloc shot, but once the face-hardening was pierced, the shell fragments penetrated the remainder with ease.
(4) 1942
Therefore, in June 1942, a .79-inch additional plate was bolted on the gun mantlet and front superstructure as a means to defeat a shot with a piercing cap. Between this plate and the basic armor was an air gap or space, varying from 4 to 8 inches. The plate conformed roughly to the shape of the section covered. The spaced armor seems to have been a field expedient, resulting undoubtedly from the demonstrated fact that the spare section of track carried on the front of German tanks gave additional protection. This method of adding armor was officially recognized, as later models had brackets fitted for installing spaced armor when desirable.
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Four photographs of German Panzer III tanks captured in North Africa were exhibited in Tactical and Technical Trends, No. 32, August 26th, 1943.
GERMAN PzKw 3
The accompanying photographs show four views of the German medium tank PzKw 3. Figures 2, 3 and 4 is the PzKw 3 with the long-barreled 50-mm gun. Figure 1 is essentially the same tank except that it is equipped with a short-barreled 50-mm gun.
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The intelligence report on the German Panzer III Flammpanzer, entitled “German Flame Thrower on Pz Kw 3 Chassis" was originally published in Tactical and Technical Trends, No. 45, April 1st, 1944. As we have seen some 100 Panzer III were converted to perform this role. The initial report contained some errors and a later report in the July 1944 issue corrected some of the details given in this article.
GERMAN FLAME THROWER ON PZ KW 3 CHASSIS
a. The Tank
German flame-throwing tanks were noted in Tactical and Technical Trends, No. 19, p. 9, and in No. 39, p. 9, a Pz Kw 2 tank was described, mounted with two small flame throwers on the front end of the track guards. At that time, it seemed odd that a more powerful projector should not be installed in the turret. Such a tank has now appeared. Flame-thrower Pz Kw 3 tanks were taken on the Italian front, some in good condition. A front view of this tank is shown in figure 1.
Fig.1: Flame-thrower tank
(1) External Appearance
The flame-throwing tank has a special type of flame thrower mounted on some available chassis. Reports indicate that flame-throwing apparatus is designed to be adaptable to any model of tanks, light as well as heavy. The tank here described is a standard Pz Kw 3 with six bogies and three return rollers. The chassis, hull and turret are identical with the ordinary tank. An additional armor plate 1.18 inch thick has been welded to the front of the chassis and another of like thickness forms the curved shield protecting the front of the turret and the flame gun. This shield is pierced for one coaxially mounted machine gun, and another is mounted in the usual position in the right front of the hull, opposite the driver's vision slit. Smoke projectors of three tubes each are mounted on each side of the front edge of the turret. For comparison see figures 2 and 3. The markings are the standard black-and-white German crosses on the right rear of the chassis, and a little in front of the center roller. Organizational numbers appear on the two sides of the turret directly above the black-and-white cross. Two tanks captured in good condition were marked respectively, F. 23 and F. 24.
(2) Flame Gun
At first sight, the flame gun which projects 5.28 feet beyond the curved shield of the turret, has the identical appearance of the usual 50-mm tank cannon. Even the short reinforcing jacket is simulated. However, the barrel has no taper whatever, and if seen from the muzzle end, is thin-walled, like a shotgun barrel. This "gun" is actually the cover for the flame-projector tube. The muzzle end of the gun is detachable, forming a flame shield designed to facilitate the burning of the flame-oil by having four openings cut in the sides, .4 inch wide and 4.9 inches long, see figure 4. The top and side openings are shielded to prevent the dropping of unburned flame oil on the top of the tank.
Within the turret, a counter-balance weight is attached to the breech of the gun for ease in vertical alignment. Elevation and traverse are controlled by the tank commander through two hand wheels -- the right controlling elevation, the left the swing of the turret. The maximum elevation of the flame gun is about 530 mils (30 degrees); the depression, 180 mils (10 degrees). The indicated horizontal traverse is approximately 800 mils (44 degrees) right and left of center. An indicator with a dial numbered clockwise from 1 to 12 to indicate the position of the turret with reference to the forward motion of the tank is placed near the hand wheels.
Comment: The turret does NOT have an all-round traverse and no machine gun fires rearward. This flame-thrower tank therefore appears to be more vulnerable to attacks of tank-destroyer squads than the gun-carrying model.
(3) Mechanical Operation
Pressure for the flame-thrower fluid is obtained by the operation of an auxiliary two-cylinder motor driving a rotary pump located in the left rear of the tank. Flame-oil pressure is indicated by a pressure gage directly in front of the tank commander, graduated from 0 to 250 units. The flame-oil release is obtained by the dual operation of a right-foot pedal and an electric control mounted above and behind the pressure gage. At the muzzle of the flame gun are two pilot jets; two electric, ground-return igniters, and one opening .394 inch in diameter for the ejection of the flame fluid.
(4) Sighting
Aiming is accomplished by the tank commander sighting through an improvised rear sight, two mm (.08 inch) square and mounted in the turret directly in the rear of the shatter-proof-glass vision slit, and aligning the target with an improvised front sighting device mounted on top of the exterior base of the flame gun (see figure 5). The elevation for estimated target range is obtained by elevating the flame gun so that the line of sight passes over the selected one of three metal horizontal projections, attached to the vertical bar of the front sight. Elevated to range, the gun is kept trained on the target as the tank approaches. As the sights are aligned, the commander presses the electric control and the right-foot pedal. In short bursts the flaming oil is sprayed upon the target, the liquid sticking and burning with intense heat upon the object it touches. The range is normally from 55 to 65 yards; maximum, 84.
(5) Fuel Tanks and Flame Oil
The flame-oil fuel tanks consist of two welded metal containers of approximately 40 to 50 gallons each, mounted beside the tank commander on the right and left of the chassis, set low enough to allow free rotation of the turret, and fitted with meter gages.
The fuel is a thin, black, sticky oil smelling strongly of creosote, which showed upon analysis the following composition by volume:
•Light oils up to 170° - 39.0 percent
•Medium or carbolic oils from 170 to 230° -17.4 percent
•Heavy oils or creosote from 230 to 270° - 4.2 percent
•Medium oils or (coal tar?) oils, 270° - 21.5 percent
•Residual difference at 100 - 17.9 percent
(6) Accessories
(a) Smoke Projectors
Two three-barreled smoke projectors are bolted to the forward sides of the turret and with the center barrel approximately aligned with it, all having an elevation of about 44 degrees. The two outer barrels fire laterally right and left from the center barrel at approximately 20 degrees. These are fired electrically from a lid-covered firing box on the inside of the turret. Each button of the box set is connected with one barrel of the projector. The projectile used is the standard smokepot weighing about five or six pounds, which can be projected an estimated distance of from 150 to 200 yards. The pot produces an opaque, light-gray cloud for about two minutes.
(b) Radio
A pair of radio head sets for intertank or interior communication are supplied to the driver and commander for listening, and connected parallel with the radio operator for inner-phone communication.
(c) Demolition Charge
For the destruction of the tank in case of imminent capture, a demolition charge is provided. The one examined weighed about 8.5 pounds, and was 15 inches long, 3.54 inches in diameter, containing a dense, white solid -- perhaps nitro-starch. A fuze screwed into a booster, and a soft, gray-iron hanging strap for fastening the charge to an object were attached. The charge fitted snugly into a metal carrying case.
(d) Very Pistol
A Very pistol was carried on the right side of the turret behind the commander's right shoulder, with two boxes of 12 colored flares each, one in the rear of the commander's seat, the other beside the turret machine gun. Red, blue or violet, green and white cartridges were provided. Their signal meaning is changed by order of the commanding officer, but it is believed the following apply:
•Red - Enemy attacking
•Blue or violet - Attack by tanks
•Green - Help
•White - We are here
•Flares fired into the enemy's lines - We are withdrawing
(e) Miscellaneous Accessories
Spare multi-layer vision-slit glasses for the commander and driver, totalling 3.34 inches in thickness, were stored in racks. There were also three fire extinguishers, standard gas masks for the crew, and a spare smokepot. In one tank a rack of black egg-grenades 3 inches long by 2 inches in diameter were found. Racks for four fire extinguishers were provided on Pz Kw 3 flame-throwing tanks, two for the tank commander, one for the tank driver and one mounted on the outside of the tank.
(7) Crew
The crew apparently consists of four -- commander, driver, radio operator, and turret machine gunner.
A Flammpanzer III demonstrates the effectiveness of it main armament.
b. Tactical Use
(1) Tank Attack
Two Pz Kw 4's and a Pz Kw 3 flame thrower attacked a platoon position unsupported by AT guns in the following manner: the two Pz Kw 4's opened fire at 400 yards with machine guns from a hull-down position. Still firing, they advanced to about 200 yards where they remained, continuously firing their machine guns.
At the same time, the flame thrower advanced between the two, actually reached the platoon in spite of machine- and Bren-gun fire, and sprayed the men at close range.
Other data indicates that the flame-throwers are usually attached to units of Pz Kw 4 tanks in the ratio of two or three flame throwers to 20 or 25 standard tanks. Their greatest value comes into play when darkness, smoke, or weather conditions make possible a close approach. Against woods, trenches, blockhouses or buildings, flame thrower tanks force defenders into the open where they can be attacked with small-arms fire. Buildings up to four stories in height can be successfully attacked. The Pz Kw 3 was extensively employed at the siege of Stalingrad.
(2) Target Area
The most vulnerable target areas are the vision slits of the tank commander and driver, the area of the center roller on the side, and the right side of the rear end of the chassis. This is also the best target for Molotov cocktails.