Article by Yuri Pasholok
Putting the PzI Ausf. B into production was the correct decision, albeit a late one. The problem wasn't only that the concept of a light tank with machineguns for armament was obsolete. The 6th Department of the Armament Directorate was disappointed in the chassis developed by Krupp's engineers overall. Even though the power to weight ratio of the PzI grew from 11.1 to 17.2 hp/ton after modernization, there was no drastic improvement in mobility. 40 kph is not what was expected with such a boost. It's not surprising that, instead of developing the PzI Ausf. B further, the German military decided to develop a completely new tank: the PzI Ausf. C.
In halftracks' footsteps
The strange situation with German tank suspensions that happened in the late 1930s didn't just touch the PzI. Only the suspension of the B.W. (future PzIV) was relatively successful. Other tanks had issues in this department, in one way or another. Leaf springs proved less than reliable, and small road wheels experienced issues with rubber rims flaking off.
A number of companies, especially Krupp, completely ignored the military's demands. For example, the request to use torsion bars was ignored several times. Meanwhile, Krupp developed its own torsion bar suspension, which performed poorly on the B.W.II Kp. In Sweden, the torsion bar suspension designed by Porsche K.G. used on the Landsverk L-60 tank performed well.
Eventually, the patience of the 6th Department had worn thin.
It was time for Heinrich Ernst Kniepkamp's finest hour. The talented engineer played an important role in the development of German tanks before, but now he held even greater power. In early 1937, Kniepkamp was put in charge of all prospective tank development.
This is when the letters VK (Vollketten — fully tracked) appeared in the names of prospective German tanks. This designation was applied to all new designs. The letters were followed by numbers, which indicated the weight class.
By 1939, the number was followed by another number indicating the number of the prototype, for example VK 6.01. Later, a code for the company that developed the design was added, for example VK 30.01 (P).
The new type of tank that Kniepkamp evangelized was radically different from what was under development at Krupp and other companies. The new chassis would have to have a torsion bar suspension, which proved itself on Swedish tanks. Another interesting factor is that his suspension design didn't include any return rollers. The large diameter road wheels with rubber rims performed their function. The influence of Kniepkamp's halftracks can be seen here.
Another important addition was the use of track links with lubricated joints, which would allow a high speed of movement. An engine with maximum possible power and minimum dimensions would provide it. A semiautomatic transmission with servos would go with it. The new tank would be fast, but easy to control.
Nobody stopped Krupp from developing their own next generation light tank. In February of 1937, the company received an offer to develop a tank to match Kniepkamp's specifications. Krupp's engineers rebelled against the idea that someone else was choosing what parts they would use to build a tank. Of course, the infamous torsion bar suspension played its part in the conflict.
Kniepkamp replied to Krupp's protests with a mention that the contract could go to any of 10 companies, giving until the 15th to think. It's possible that Krupp relied on their connections to help, but the attempt failed. The contract for an experimental chassis of the 3 ton class (VK 3 t) went to a newcomer: Krauss & Comp.-J. A. Maffei AG from Munich. This company had no experience with building tanks. However, its portfolio included the 8 ton Sd.Kfz. 7 halftrack, the suspension from which served as a starting point for building the new tank.
Third time's the charm
The change of contractors did not mean that the La.S. concept was radically altered. The chassis designed by Krauss-Maffei differed little, conceptually speaking, from the Kleintraktor chassis designed over five years before that. This is not surprising, since both Krupp and the 6th Department had a direct connection to the Kleintraktor.
Development of the VK 3 t chassis began in October of 1937, and it started to take shape by January of 1938. Krauss-Maffei's engineers did not create anything radically new. The chassis that didn't make it off paper was reminiscent of the La.S.138 chassis, further development of the PzII that turned into the PzII Ausf. D. Like MAN's design, the VK 3 t had 4 large road wheels (700 mm in diameter) per side, and its idler and drive sprocket were elevated above the ground. The chassis had the same torsion bar suspension.
The layout of the tank was the same as that of the early PzI. The engine was in the rear, drive sprocket in the front. The engine was also the same as that of the PzI Ausf. B: the Maybach NL 38 Tr. Thanks to its high power to weight ratio and improved suspension, the new tank had an enormous calculated top speed for its time: 80 kph.
The overall chassis concept was approved in April of 1938, after which the VK 3 t chassis turned into the VK 5 to light tank. Overall, the chassis was not changed, just its wheelbase increased a little. According to calculations, the top speed of the tank in 8th gear would be 77 kph.
Meanwhile, further development of the chassis meant that the mass of the tank would grow. Soon, Krauss-Maffei's design was renamed to VK 6. The calculated top speed was reduced to 67.5 kph, and that's with the 115 hp Maybach HL 54 TRM engine, borrowed from the Sd.Kfz. 6 halftrack.
The tracks were taken from another halftrack, the Demag D7 (Sd.Kfz.10). The VK 6 chassis was built in August of 1939, but its trials went poorly, mostly for technical reasons.
Meanwhile, work took another direction in June of 1938. The new tank, indexed VK 6.01, was supposed to receive a 130 hp Maybach HL 61 engine and an 8 speed DSRG 134190 Maybach gearbox. Around the same time, the VK 6.02 was proposed, equipped with the same Maybach HL 61 engine. In October of 1938, a contract was signed between Krauss-Maffei and the 6th Department of the Armament Directorate for production of six experimental VK 6.01 chassis.
The tank underwent serious changes in early 1939, as a result of which very little remained in common between the VK 6 and VK 6.01. The length of the hull was shortened significantly, but the wheelbase remained at 1600 mm. The length of the contact surface decreased from 2295 mm to 1736 mm. The number of road wheels increased to 5 per side, and they were interleaved like on halftracks.
The number of track links dropped to 52 per side from 62, and their width increased from 240 to 260 mm. These were still Kniepkamp's track links, with a lubricated joint and rubber pads.
The 150 hp Maybach HL 45 engine and 8 speed semiautomatic Maybach SRG 15319 transmission were installed to achieve a top speed of 80 kph. Considering the experience gained in Spain, the tank's armour was improved to 30 mm in the front. The sides were still 14.5 mm thick.
While Krauss-Maffei's engineers worked on a new chassis for the light tank, work on its armament proceeded in parallel. The fact that a pair of machineguns was not a correct choice of armament was clear after the first encounter with a T-26 in Spain. At the same time, a 20 mm autocannon was too much for this tank.
As a compromise, a very unusual tank gun was developed, which is associated with a very common misconception. In July of 1938, the Mauser company began working on a tank version of the MG 141 machinegun, which was a derivative of the MG 151.
Like the MG 141, the new design indexed EW 141 (Einbauwaffe, «built in weapon»), used 7.92×95 mm rounds from the Pz.B.38/Pz.B.39 anti-tank rifle. Here is where many researchers are mistaken. They consider the EW 141 a machinegun. In reality, it was a semiautomatic gun, a tank version of an anti-tank rifle.
Thanks to a very powerful round, the EW 141 could penetrate 25 mm of armour sloped at 30 degrees at 100 meters. This was enough to fight lightly armoured targets. The EW 141 would be installed in a one-man turret. The contract for development of a turret platform and its production went to Daimler-Benz.
On September 15th, 1939, a decision was made to build a pilot batch, which included 40 VK 6.01. In April of 1940, the tank received the index Pz.Kpfw.I n.A., or «new type of Pz.Kpfw.I». The first tanks from the pilot batch were expected in March of 1941, and the last ones in September. The appetites of Germany's army were impressive. In case the heavier VK 9.01 reconnaissance tank failed, 1000 Pz.Kpfw.I n.A. would be ordered.
At this time, according to calculations, the tank weighed 6.4 tons.
By the summer of 1941, the situation changed radically. According to a report from July of 1941, the Pz.Kpfw.I n.A. would only be used by airborne troops and expeditionary forces. Looks like the Germany military realized a simple truth: the prospective reconnaissance tank was already obsolete before the first tank came off the assembly line.
In July, Krauss-Maffei finally delivered the first two experimental VK 6.01 chassis. By that point, a decision was made to improve the side armour with 5.5 mm applique plates, increasing the mass of the tank to 7.3 tons. The first chassis were tested with dummies instead of turrets and turret platforms.
The production of the pilot batch of the Pz.Kpfw.I n.A. was delayed to October of 1941, but then this date was shifted further. Daimler-Benz was overloaded with orders for other tanks and could only begin production of turrets and turret platforms by the end of 1941. Work on the chassis at Krauss-Maffei was also behind schedule.
In early 1942, a decision was made to convert two chassis for use in tropical conditions.
Trials continued in the spring, and the sixth experimental VK 6.02 drove from Munich to Dachau without issues on May 21st. It drove on the highway on the way there, but off-road on the way back. Around that time, the tank was subjected to some changes that raised is mass to 8 tons. This weight gain was a death sentence for Kniepkamp's track links. Instead, small tracks without rubber pads were used. The number of track links went up to 89 per side.
On July 1st, 1942, the tank received the index by which it is best known today: Pz.Kpfw.I Ausf. C, Sd.Kfz. 101. Mass production also began around this time. Five years went by between the start of development and mass production, during which the tank's mass increased by more than 1.5 times. But, as they say, what else is new?
High speed training
The new tanks received serial numbers from 150101 to 150140. The production of the pilot batch was delayed, since the companies responsible for production were busy with other tanks. The last tanks were completed in 1943.
That was also the last production of the PzI Ausf. C, since it was clear that such a tank was no longer needed. It was no longer interesting as a reconnaissance tank, since the requirements for this kind of tank changed. The PzI Ausf. C's radio equipment was ill-suited for reconnaissance, and a one-man turret for a reconnaissance tank was also a bad idea.
The Wehrmacht also had no need for ordinary light tanks, since production of those ended in the summer of 1942. The changing conditions of the battlefield left these tanks low odds of survival. SPGs were now being built using the chassis of PzII and Pz38(t) tanks. The PzI Ausf. C's chassis was unsuitable for this purpose, since it was impossible to fit a gun and a crew into the tiny fighting compartment.
The lack of clear direction for these new tanks meant that their fighting career was very short. Two PzI Ausf. C tanks were included into the 2nd Battalion, 1st Tank Regiment, 1st Tank Division in early March of 1943. However, being sent to one of the Wehrmacht's oldest tank units didn't mean that the tanks would see combat. The division was located in Greece, and would not be sent to the Eastern Front until October.
Aside from two PzI Ausf. C tanks, the 2nd Battalion received 8 PzI Ausf. F tanks, the fighting qualities of which were even more suspect. The division fought at Kiev as a part of the 48th Tank Corps, 4th Tank Army. The main enemy of the 1st Tank Division was the 3rd Guards Tank Army, led by General Rybalko. By November 20th, only one of the two PzI Ausf. C tanks remained in service, the first tank with serial number 150101. This tank did not last long either. On December 10th, an order was given to send this tank away for repairs. This was the end of the PzI Ausf. C's career on the Eastern Front.
The fate of the remaining 38 PzI Ausf. C tanks was decided in the summer of 1943. On July 28th, the 58th Reserve Tank Corps was formed in France, which included all reserve and training units. These tanks, with their questionable abilities for the mid war, were sent there. They were spread out among training units. The PzI Ausf. C was a much better training tank than the many captured French vehicles.
The PzI Ausf. C continued its career as a training tank even in June of 1944, which the Western Allies landed in Normandy. In July of 1944, the reformed 58th Tank Corps and some of its PzI Ausf. C tanks did set out for Normandy. These tanks could not influence the course of the battle, since they had no advantages aside from speed. At least one tank was captured and studied. After the war, it was scrapped. This sad fate awaited all PzI Ausf. C tanks.
Krauss-Maffei's design became a victim of late tactical-technical requirements for a new tank. The technical qualities of the vehicles are hard to blame for its failure. The PzI Ausf. C was the fastest German tank, but its combat capabilities mean that it was obsolete before production even started. This was caused by requirements that described effectively the same early PzI, but with slightly more powerful armament and more speed.
Looks like the Wehrmacht was too late to understand that the time of PzI-like tanks was long gone, and attempts to recreate the same tank at a higher technical level were pointless. A program launched by General von Brauchitsch, the commander of German land forces, in November of 1938, serves as more evidence for this thesis. This vehicle, worthy of a separate article, is a competitor for the title of the most useless tank of the war.
Translated by Peter Samsonov. Read more interesting tank articles on his blog Tank Archives.
- National Archives and Records Administration
- Panzer Tracts No.1–2 Panzerkampfwagen 1 (Kl.Pz.Bef.Wg. to VK 18.01), Thomas L. Jentz, Hilary Louis Doyle, Darlington Publication, 2002, ISBN 0–9708407–8–0