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GERMAN Y'S PANTHEH TANK

was almost completed. A model of the motor was complete and was to be sent to Berlm-Marienfelde for studying mount-mg m the chassis. The motor had a continuous power rating of 350 mętne horsepower, mereasmg up to 400 without fuel mjectors With the mechamcally dnven fuel injector that had already been developed, power could be further inereased to 450 mętne horsepower. The motor needed to be redesigned to reduce the length and width, lower the weight, and lower fuel consumption in order to merease the weight available for mereased armor protection Design of a diesel motor was necessary to utilize the strategie fuel specifically demanded by Hitler. Ifgasoline was required, it was possible to convert the motor to fuel mjection.

The design for the MB 809 diesel motor was completed m June 1940 The first motor ran on a test stand in February 1941. followed by its acceptance test on 12 March 1941. On 21 March 1941. this motor arrived in Berlin-Marienfelde to be mstalled in the experimental chassis. Drivmg tests were eon* ducted at the assembly plant and in Kummersdorf.

On 1 August 1941. the VK 20.01 (D) was reported as weighmg 22.25 mętne tons with a maximum speed of 40 to 50 km/hr. The leaf spring suspension cushioned 700 mm di* ameter roadwheels which ran on 440 mm wide Kgs 62/440/ 120 track

On 22 December 1941, a report to the directors of Daimler-Benz stated: Based on experience in the Russian campaign, the new tank just developed by Daimler-Benz was now obsolete. Utihzing the already developed tank, studies were being conducted to develop a new design with thicker armor and heavier a rmam en t.

was extraordmanly unstable. and therefore the accuracy ot the weapons suffered

d No shock absorber had been found to satisfactonly dampen this unstable platform

The above di$advantages were not present with leaf spring suspensions Therefore. a leaf spring design was to be mstalled m the new GB % Roadwheels of 680 mm diam-eter (Drawmg No 021 B 10814) were imtially considered for the GBk project

Since the hydrauhc assisted steenng m the PzKpfw III Ausf E had not functioned as planned, a different steenng mechamsm was planned for the GBr An engmeer was to report on the current status of Dr Porsches hydraulic drive design and whether a steenng gear could eventually be de-veioped from it. In parallel. a Daimler-Benz engmeer was comp/etmg a totally new steenng gear design. As long as nothmg better was availabie, steering was to be performed usmg mechamcal levers mstead of the hydraulic system.

The followmg status report on tank design by Daimler-Benz was presented at the board ofdirectors meetmg on 16 August 1940 It was still the understandmg of the directors that only Daimler-Benz had been given liberty to design a new tank. It was therefore an affair of honor for Daimler-Benz to create every specification for the tank without interference It was also noted that instead of Direktor Panten from Alkett, Direktor Oberlaender from Daimler-Benz was to head up the Panzerwagenkommlsslon being created by Dr Todt.

The tank design was to be completedin Decem ber 1940.

If the MB 809 diesel engine could be delivered m February 1941. completion o fan experimental chassis was to directly follow. The design for the 12 cylinder MB 809 diesel motor

Designed by Daimler-Benz for a maximum speed of 50 km/hr. the VK 20.01 (D) had a leaf spring suspension cushioning 700 mm diameter roadwheels on a 440 mm wide track.

CHAPTER 1: DESIGN ANO DEVELOPMENT

At a meetmg on 15 September 1939, Baurat Kniepkamp (Wa Pruef 6) and Direktor Woelfert (chief engineer of the panzer design department for Krupp) discussed the design of a new chassis, the VK 20.01 (IV). for further development of the Pz.Kpfw.IV series: The motor compartment and the Maybach HL 116 motor were to be adopted from the VK 20.01 (III). Maximum speed was to be 42 kilometers per hour. the same as the Pz Kpfw.IVAusf.C The suspension was to be selected to maintain a vehicle weight o120 metric tons with a hull width of 1620 mm and an overall width of 2900 to 2950 mm The Schachtellaufwerk (interloaved roadwheel suspension) from the VK 20.01 (III) couldn't be used, sińce it resulted in an overall width of about 3040 mm and exceeded the weight specification. Krupp proposed a six wheel suspension with leaf springs. When compared to a suspension with torsion bars mounted across the bottom of the hull. the leaf spring suspension allowed easier installation of the auxiliary generator and ammumtion stowage for the 7.5 cm Kw K. In addi-tion, the shock absorbers. absolutely necessary with torsion bars, were not needed with the self-damping leaf spring suspension. The six roadwheel suspension could be constructed utilizing components from the normal eight roadwheel suspension for the Pz.Kpfw IV

At a meetmg on 28 October 1939 with Wa Pruef 6. a diameter of 630 mm was set for six roadwheel suspension for the VK 20.01 (IV) New Kgs 61 /400/120 tracks were to be utilized.

The designation for VK 20.01 (IV) evolved to VK 20.01 (BW) in November and then changedto B.W.40 in Decem-ber 1939.

On 15 November 1939. Zahnradfabrik Friedrichshafen reported that they were prepared to produce SSG 76 trans-missions for the VK 20.01 (BW) experimental chassis.

On 13 December 1939. the frontal armor for the B.W.40 was increased from 30 mm to 50 mm thick. The basie hull shape for the B.W.40 was the same as the Pz.Kpfw.IV Ausf.D. On 4 January 1940, Wa Pruef 6 notified Krupp that two armor hulls and one soft Steel hull were to be produced for the three B.W.40 experimental chassis. Three superstruc-tures and rear decks were to be madę from soft Steel.

On 15 February 1940. Woelfert presented Oberbaurat Kniepkamp (Wa Pruef 6) with a proposal describing the en* tire layout of the B.W.40 with independent two*stage steer-ing gear, six roadwheel leaf spring suspension. the Maybach HL 116 Motor and transverse mounted radiators. Kniepkamp was in basie agreement with this layout. Since finał clarifica-tion of the entire design had just been completed and the detailed design was just beginning. the earliest possible de-livery of the first experimental chassis would be at the end of 1940.

On 16 May 1940, Wa Pruef 6 informed Krupp that in con-sideration of the wartime situation. the B.W.40 project was to be shelved.

In May 1940. in coordination with Wa Pruef 6. Krupp mi-tiated their design of a VK 20.01 (K), creating sketches of a chassis that could mount either the Maybach HL 116 or HL 115 motors As reported in Krupp’s business report for fiscal year 1939/1940. preliminary proposals had been completed for the VK 20.01 (K) with 5 cm armament and heavier armor.

A fuli scalę wooden model was being completed and a de-tailed design had been started The experimental turret for the VK 20.01 was being designed by Krupp with 5 cm Kw.K.

L/42 armament Frontal armor was to be 50 mm thick. side and rear armor 30 mm thick

By 24 October 1940. Krupp had received contracts for three VK 20.01 (K) developmental chassis and by 12 No-vember 1940 a contract for production of a 0-Serłe of 12 VK 20.01 (K) complete with 5 cm gun turrets Wa Pruef 6 had awarded contracts for the design of new tanks with 7.5 cm gun turrets in the 20 ton class to M A N and Daimler-Benz

In March 1941. Woelfert remarked that Kniepkamp only concerned himself with development work at M.A.N and not with the other compames. To merease Kniepkamp’s mterest m design work from Krupp. Woelfert proposed that Krupp complete three developmental VK 23.01 (K) chassis and six experimental VK 23.01 (K) with torsion bars. The VK 23.01 (K) was to have the power train components designed by Kniepkamp and developed by M A N. which met the require-ment for component standardization strived for by Wa Pruef 6.

On 18 Apnl 1941. Wa Pruef 6 informed Krupp that they were to concentrate on development of a new submersible turret with a 5 cm Kw.K. L/60 gun for the VK 20.01 (K) The experimental turret for the new VK 20.01 (K) was to be completed by 1 February 1942 directly followed by production of 12 turrets for the 0-Serle

By July 1941. an additional contract had also been awarded to Krupp for three developmental VK 23.01 (K) chassis in soft Steel without turrets The previous contract for the 0-Serie of 12 VK 20.01 (K) was revised to specify two rede-signed variants; six VK 20.02 (K) and six VK 23.01 (K)

In July 1941. Krupp still had a contract to complete three developmental VK 20.01 (K) chassis (without turrets) with soft Steel hulls and leaf spring suspensions. The first VK 20.01 (K) was to be ready for testmg by Wa Pruef 6 in November 1941 This first developmental VK 20.01 (K) could not serve as the basis for series production because:

•    It was to be delivered without a turret

•    Correct stowage of ammunition and military equipment

was not possible (shorter length and narrower width)

•    It was not designed for tropical use (only 35 instead of

42 degrees outer temperaturę)

•    It did not possess the deeper fording depth now required

These specifications were to be met by the experimental series of six armored VK 20.02 (K) with 5 cm Kw.K. L/60 guns in their turrets.

Both the VK 20.01 (K) and VK 20.02 (K). designed for a maximum speed of 56 km/hr. had the same leaf spring suspension with six roadwheels (700 mm diameter) running on 450 mm wide Kgs 62/450/120 track. The total weight of a complete VK 20.01 (K) including a turret was calculated to be 21.5 metric tons compared to the VK 20.02 (K) at 23 metric tons.

To meet the requirement for standardization demanded by Kniepkamp. the VK 23.01 (K) was to have a Schachtellaufwerk designed by M.A.N. with six 880 mm diameter roadwheels. a torsion bar suspension. and 474 mm wide Kgs 63/474/110 tracks. The earliest that M.A.N. could

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