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CHAPTER 1

DESIGN AND DE1/EL0PMENT

The search for a replacement tank for the P2.KpKv.lll and Pz. Kpfw IV began in 1938. This new series oftanks were designated as VK 20.01. The VK stood for Vollketten (fully tracked). the 20 for the weight class m tons. and the 01 for the first model in the series. The first contract for a detailed design was given to Daimler-Benz. In October 1939. Daimler-Benz started to design their own tank after receivmg permission to prepare designs without outside in-terference At the beginning of the War in September 1939. Krupp embarked on designing an improved Pz.Kpfw.IV. This project was canceled in May 1940 and Krupp began detailed designs on a new tank in the 20 ton class. Engineers at both Daimler-Benz and Krupp favored leaf springs suspensions and were opposed to torsion bar suspensions. Therefore. Maschinenfabrik Augsburg-Nuernberg (M.A.N.) was pulled into the competition to design a pew tank in the 20 ton class with a torsion bar suspension.

By November 1941. designs for new tanks in the 20 ton class had almost been completed when frontline troops de-manded a better tank to defeat the Russian T 34 and KW i tanks. In December 1941. the decision was madę to abandon the previous designs andcreate new tanks in the 30 ton class. Krupp was dropped from the competition, leavino Daimler-Benz and M.A.N. to fight it out. In March 1942, the politicians decided in favor of producing the Panther thathad been independently designed by Daimler-Benz. However. a special commission formed to review both designs ruled in favor of the M.A N. design in May 1942. Hitler agreed with their recommendation and the M.A.N. Panther was selected for series production.

DESIGN EVOLUTION

DAIMLER-BENZ KRUPP    M.A.N.

CHAPTER 1: DESIGN AND DEVELOPMENT

Chassis and turret designs were the responsibility of two speed overdrive gear fitted to German tanks, which appar-completely separate offices in Wa Pruef 6 (the department ently could be used only under very favorab!e conditions. was responsible for tank design). The officers and engmeers withm a General Staff requirement It was not used for high speed Wa Pruef 6 created conceptual design specifications and then troop movements on roads. sińce tanks were transported contracted private design firms (Daimler-Benz. Krupp, M.A.N., mostly by raił Kmepkamp had no elear idea of the tactical Rheinmetall) to complete the detailed designs. Normally. the use of such a gear, but a speed of 65 km/hr had been ob-contract for detailed design of the tank chassis was awarded tained on an Autobahn. to one firm and the contract for detailed design of the turret to another. Thus. the development history of a tank chassis does

not coincide with the development history of the turret. In fact. 1.1.1 VK 20 SERIES FROM PAIMLER-BENZ many tank chassis designs were created independent of turret designs and in some cases multiple turrets were designed In the search for a potential Pz.Kpfw.lll replacement, Daimler-for the same chassis    Benz was awarded a contract for creating the detailed de-

Monthly meetings were held between the contractors and sign for a new tank chassis in the 20 ton class. known as the representatives from Wa Pruef 6 to make decisions and to VK 20.01 (III) Unlikethe Daimler-Benz Z.W.40 project which discuss the progress of the designs. The surviving records of was based on modifying a normal Pz.Kpfw.lll chassis, the these meetings provide the basis for this development his- VK 20.01 (III) was a complete departure from previous de-tory. In many cases we are fortunate to be left with a few brief signs By 14 December 1938. Daimler-Benz had completed glimpses of rare variants whose existence and correct posi- a design project with the 6 cylinder Maybach HL 116 motor tlon in the evolutionary cham have not been previously rec- developing 300 metric horsepower at 3300 rpm The VK 20.01 ognized.    (III) was one of the first tanks designed with a Schacht-

ellaufwerk (interleaved roadwheel suspension) with torsion bars. The advantage of the Schachtellaufwerk was a shorter 1.1 PREPECESSORS    ground contact length for improved steering with the tank's

weight distributed over larger diameter roadwheels Larger Based on his previous success with half-tracks, Baurat Dipl.- diameter roadwheels lasted longer and provided a smoother Ing. Ernest Kniepkamp (Wa Pruef 6) embarked on designing ride over rough terrain.

a series of tank chassis known as VK (Vollketten - fully Durmg the campaign in Poland major problems were tracked) in 1937. Unlike the earlier Pz.Kpfw.l, II. III and IV. encountered with the suspension and transmission of the whose design specifications were controlled by In 6 Pz.Kpfw.lll Ausf.E. Daimler-Benz complained that. against (Inspektorate 6 - responsible for tank and automotive pro- the advice of their designers. Wa Pruef 6 had forced Daimler-curement). no specific requirement or reguests from the troops Benz to accept these untested components This damaged existed for this new series of vehicles. As Kniepkamp stated Daimler-Benz reputation as the leader in providmg reliable when interrogated after the war; The engineer is the only automotivevehicles. In October 1939. Daimler-Benz received person who knows the engineeringpossibilities. His duty was permission from the Generalbevollmaechtlgen (a commis-to discuss with the General Staff their requirements, interpret sion with the power to enforce standardization of automotive these requirements into suitabte designs and finally to sub- designs) to independently design a tank without mterference mit his proposals to the General Staff. His policy was to pre- from Wa Pruef 6. The new tank was initially designated by parę three, and if possible morę, alternative designs. all of Daimler-Benz as the GBk (Kampfwagen des General-which he submitted to the General Staff, who then would se- bevollmaechtigen) and only later as the VK 20.01 (D). lect what they regarded as a suitable solution.    On 15 November 1939. engineers and directors from

Without the control of governing specifications that were Daimler-Benz met to discuss the following specific design founded on sound tactical need. Kniepkamp was free to cre- features for the GBk The following problems had been dis-ate "state-of-the-art" tank chassis. In Kniepkamp's opmion: covered in the 20 ton tank (Pz.Kpfw.lll Ausf.E) currently in The main task ofan armored fighting vehicle was to bring the production: transmission failure. excessive rubber tire wear, highest firepower up to the enemy at the hlghest possible poorly performing Delbag air filter, armor somewhat too weak speed and with the best possible protection. The importance and the hydraulic assisted steering not functioning as planned. of the different factors bemg in the order stated.    Solutions to these problems were to be found and corrected

In his drive to create tanks with speed. speed. and morę m the new GBk (Kampfwagen des Generalbevoll-speed, the tank chassis designed for Kniepkamp’s VK series maechtlgen) designed by Daimler-Benz. shared the following characteristics:    A Wilson transmission was to be designed by CKD. Prag.

As a backup, a manually shifted transmission similar to the

•    Large roadwheels usually without return rollers    Zahnradfabrik SSG 77, but adapted to the higher torque of

•    Torsion bar suspensions    the Daimler-Benz MB 809 diesel engine, was to be devel-

•    The latest motor design, packing inereased horsepower oped by Daimler-Benz.

in the smallest space    The Pz.Kpfw.lll Ausf.E suspension design with six

• Power assisted semi-automatic transmissions    roadwheels per side each separately sprung by a torsion bar

•    Advanced steering gear designs    had the following disadvantages:

a. Wasted space inside the vehicle.

When interrogated after the war about the requirement    b. Poor access to repair or replace the torsion bars.

for speed. Kniepkamp’s response was recorded as; The top    c. With separately sprung wheels, the weapons platform

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