Porche’s X-shaped engine

German tank development followed a very predictable course. This included engine development. After experiments in the 1920s and early 1930s, German tanks settled on the Maybach V-shaped series. These gasoline engines that worked at high RPM (about 3000) were characteristic for German tanks. They were used until the end of the war, although some began to think about an alternative as early as 1941-42. Ferdinand Porsche was among those who had his own idea about what a tank engine needs to look like.

Simmering-Graz-Pauker is best known as a producer of train cars and locomotives.

The first attempt to build a diesel engine was undertaken by Daimler-Benz in 1940. The MB 809 and later MB 507 were unlucky. Work on diesel engines was not abandoned. Porsche K.G. picked up the relay, working closely with Austrian companies. The new team created a brand new engine known as the Simmering-Graz-Pauker Sla 16. This was an X-shaped air cooled diesel engine which opened a whole new direction in development of tank engines. However, Germany did not have time to make use of the fruit of this labour.

The predecessor of the SLa.16 was initially developed for the Typ 205, shown here in its configuration as of October 1942.

Porsche and Militarism

It's no secret that the same people often build tanks and peaceful vehicles. For instance, the Kirovets K-700 tractor was designed by the same people who designed heavy tanks at the Kirov factory (including the IS-7). The same designers also produced the KT-12 skidder immediately after the war, and they were pulled off of military projects to do so. Harry Knox, the creator of American light and medium tank chassis, was a successful car designer before going into tanks. Even the famous John Walter Christie worked on (and drove) race cars as well as fire engines before building his tanks. There are plenty of examples where the same person created military and civilian vehicles.

Ferdinand Porsche reaching to touch his Tiger tank.

Ferdinand Porsche is perhaps the best known German tank designer. He is usually remembered for the Tiger (P), Maus, and other fighting vehicles that never made it into mass production. He is also well known for the "Beetle" (also known as the kDF-Wagen or Porsche Typ 60) and sports cars. While the former category of vehicles was unsuccessful, the latter is tremendously popular. Because of this, some claim that Porsche intentionally sabotaged the Third Reich. Let's take a look at what kind of pacifist Ferdinand Porsche turned out to be.

The Elusive Maus

Great Britain and the USSR actively exchanged information on the enemy during WWII. The USSR even shared its trophies, for instance, Panther and Pz.Kpfw.III Ausf.L tanks captured in the USSR were sent to the UK. However, these relations soured after the end of the war and the exchange of information ceased. As both experimental Maus prototypes ended up in the hands of the Red Army, the British had to collect scraps of information on this tank across their occupation zone. How well did British investigators do and how truthful was the information they collected?

The Final Squeak

The Maus is first mentioned in the DRAC (Director, Royal Armoured Corps) Technical Intelligence Summary for May 1945. The description is rather brief:

“Developments in German tank design appear to have been mainly limited to the super-heavy class. Three equipments falling under this heading have so far been examined as follows:

...

Maus (Mouse). This is a tank with an estimated weight of 200 tons mounting a 12.8 cm Kw.K.82 (L/55) and a co-axial 7.5 cm Kw.K.44 (L/36.5) in a turret with 360° traverse.”

The summary also described the E-100 tank and Grille SPG, but there was likewise little information on those vehicles.

 Officers of the 1st Polish Armoured Division and three sets of Maus armour parts, Krupp proving grounds in Meppen.

The Allies' View of the Maus

VE Day marked not only the defeat of Germany, but the Allies' ability to get their hands on German tank developments. A hunt for trophies and even German arms designers began. Various nations ended up with only pieces of information. This is especially true for the German Pz.Kpfw.Maus superheavy tank.  The USSR may have ended up with both prototypes and some of the documentation that was stored in Kummersdorf and in Berlin, but the British and Americans kept most of the documents, the factories that took part in its production, and the creator of the tank himself, Ferdinand Porsche.

The Elusive Maus

The Maus tank still inspires the imaginations of military history enthusiasts to this day, but the Allies knew nothing about it until after Germany's surrender. In my latest article on Warspot.net I take a look at how the British pieced together scraps of information from documents, interrogations, and inspections of captured materiel to discover the secret of Germany's largest tank.

The Elusive Maus

Stillborn Maus

The Pz.Kpfw. Maus is one of the most famous German tanks. It was the heaviest tank ever built in history. Opinions about the Maus tend to be extreme opposites, some believe that the Maus was the Wehrmacht's last hope, others say that it was the proverbial straw that broke the back of German industry.

As usual, the truth is somewhere in the middle. The Maus was unlikely to save Germany, but it would have been a nasty thorn in the side of the Allies if it ever reached the battlefield. German industry didn't need to apply any kind of heroic effort to produce it. However, the damage dealt to German industry was so severe that the Maus was impossible to produce by the fall of 1943.

Heavyweight

"October 18th, 1945

To the Deputy People's Commissar of Railways, Vice General Director 1st Class comrade Arutyunov

A captured special tank weighing 160 tons (including a removable 40 ton turret) directed to the NIBT proving grounds (Kubinka station, Western railroad) has been stuck at the storage terminal of the cargo base at Brest-East.

The transfer of the special tank is delayed due to the fact that the storage terminal does not have cables necessary for moving the special tank.

I ask for your order to expedite the transfer of the special tank and its delivery to its destination.

I ask you to reply with your decision.

Deputy Chief of the GBTU, Engineer-Major of the Tank Service, Pavlovskiy"

CAMD RF 38-11355-3009 p.82

Mousetrap

The Maus tank that was recovered by Soviet specialists did not sit idle in the Soviet Union. It was picked apart and its components were sent out for study. The armour composition and hull design were carefully studied. It would be a shame to demolish such a rare exhibit, so only the D-25 was allowed to fire on it, with the performance of other tank guns (the Maus' own 128 mm and the Soviet D-10) being only calculated.

Exotic Trophies

"September 15th, 1945

To the commander of the Armoured and Mechanized Forces of the Red Army, comrade Fedorenko

I present to you brief descriptions of the "Maus" superheavy tank, a self propelled AA gun, and a "Tiger-mortar" 380 mm SPG. I report that the aforementioned vehicles, as well as an 88 mm tank destroyer, were sent to Moscow to the Kubinka Scientific Research Tank Proving Grounds.

Superheavy Trophy

The German superheavy Maus tank left a mark in the history of tank building. This was the heaviest tank in the world, developed as an assault tank, practically invincible to enemy fire. In many ways, its fate was the same as the fate of another giant, the French FCM 2C, which holds the title of the world's largest tank to this day. Like the French heavyweight, the German tank never saw combat. In both cases, the tanks were blown up by their own crews. Another similarity was that the tanks became the subject of a careful study.

Maus Intel

"CONCERNING: German tank Pz.Kpfw "MOUSE"

1. The search by Team Number 7 for the "MOUSE" at Böblingen (Germany) was fruitless, however interrogating Karl FROHLICH, Director at the Böblingen complex has revealed that:
1. The tank was built at Stuttgart in 1944
2. A specimen was put together at Stuttgart in October, 1944
3. Specimen was sent to Army Museum in Berlin
4. Hull was built by Krupp
5. Powerplant was an 1000 HP Daimler-Benz aviation engine
6. Transmission built by Z.F. in Friedrichshafen 
7. Electric equipment was from Siemens in Berlin
8. Radio equipment was from Telefunken
9. Miscellaneous equipment was built by F.A. Telekin
10. A wooden model was at Krupp, Essen
11. Assembly was made by F.A. Alkett in Berlin
12. Two models were sent to Böblingen
13. New engines were installed at Böblingen
14. The models were then sent by rail to Berlin Wimsdorf or Kummersdorf
2. All the plans for the "Mouse" were taken by two British Officers prior to Team 7's visit. No "Mouse" type vehicle currently exists at Böblingen.

Signed, Josset [...]"

Credit goes to Florin Moldovan for the document and the translation.

Maus AA Turret

As crazy as the final vehicle turned out, the Maus had the potential to be a whole lot crazier. Compared to the idea of slapping a mini-turret on top of the existing one, the idea of a cupola with an AA machinegun seems downright reasonable. I mean, once you get over the incredibly limited vertical traverse angles that would have made it work quite poorly against aircraft.

Via Yuri Pasholok.

Mauschen: Rat Race

The history of the Pz.Kpfw. Maus is still full of blank spots, despite the popularity of the subject. The beginning of the tank's development from March of 1942 to 1943 is the least studied area. During this time, the project indexed Typ 205 radically changed. Essentially, the only constants were the index and the idea of using an electric transmission. Thanks to new publications and archive research, it is now possible to remove the veil of mystery from many parts of the project.

100 Ton Mouse

After the fall of France in 1940, German designers got access to French developments, including full scale models of superheavy tanks, the FCM F1 and ARL Tracteur C. Compared to these tanks, the German VK 65.01 (Pz.Kpfw. VII) that started development in January of 1939 seemed obsolete. It's possible that this discovery led to the cancellation of the mild steel prototype.

Under the same index, a new, more powerful tank was designed. It seems that this is the tank mentioned in the intelligence report sent to the Red Army General Staff, dated March 11th, 1941. This report triggered work on the KV-3, KV-4, KV-5, A-44, and made serious ripples in other directions. The 90 ton mass fits in with later information about the vehicle known as VK 70.01. It really had a 105 mm gun and the mass was limited to 90 tons (the current limit of German railroad platforms).

Another confirmation that the VK 70.01 started its life before the fall of 1941 is the correspondence with Krupp regarding a new, even more powerful, 149 mm gun, which started no later than April. This same gun, with a length of 40 calibers, pops up again in November of 1941. The "heavy tank type VII" turned out to not be disinformation, fed to Soviet intelligence.

The vehicle that Soviet intelligence discovered wasn't anything like the commonly known VK 70.01. The hull and turret with sloped armour appeared only in late 1941, after the Germans ran into Soviet T-34s. Despite the index suggesting the vehicle was in the 70 ton class, the mass of the vehicle varied from 70 to 90 tons.

The same thing happened to the armament. The "canonical" version of the VK 70.01 is dated late January of 1942, and by early March, the project splintered. The VK 72.01 appeared, with either a 105 mm L/70 gun or 150 mm L/35 gun.

At the same time, Krupp received an order for another vehicle in the 100 ton class "no later than Spring of 1943". This splintering was very arbitrary, as this vehicle was later named Pz.Kpfw. VII (Lowe). In April, its mass returned to 90 tons, and in May, the 15 cm KwK L/40 became the main weapon of this new tank. Krupp was also designing an alternative with a rear turret. Judging by further developments, 90 tons was not enough, and the 100 ton limit was crossed in June of 1942. However, in March, a dangerous opponent for the "Lion" appeared. Here is its story.

In September of 1939, the tank commission (Panzerkomission) was created, which acted independently of the 6th Waffenamt. It was headed by Ferdinand Porsche. A conglomerate headed by Porsche K.G. was in charge of conceptual design. The conglomerate also included Steyr-Daimler-Puch, Friedrich Krupp AG, Siemens-Schuckert AG, Skoda, and Nibelungenwerk, which were responsible for the engine, hull, electronics, suspension, and assembly, respectively. On March 22nd, 1942, this conglomerate was tasked with development of another 100 ton tank. This project was indexed VK 100.01.

The first mention of the VK 100.01 in Krupp's correspondence. The same letter mentions a 128 mm L/50 gun.

According to preliminary classification, the 100 ton class tank would have a 15 cm KwK L/40 gun with a capacity for at least 100 rounds. A part of the ammunition would be stored in the rear of the turret. Initially, the rounds would have been two piece, but a sketch of a one piece round was attached to a letter regarding the turret, dated April 18th, 1942. The overall length of the round was 1.6 meters, and it weighed 57.4 kg, 34 of which were for the shell. This was the lightened variant: initially, the 15 cm K18 round was used, which weighed 43 kg. The muzzle velocity of this shell was 875 m/s, and the rate of fire was an optimistic 4-5 RPM. As an alternative, the 12.8 cm KwK L/50 was proposed, with a 29.3 kg shell and 810 m/s of muzzle velocity. The design of the VK 100.01 was to be done by May 15th.

The first ever mention of the name "Maus" in documentation, dated May 18th, 1942. The gun was also changed on this day, shortened by 3 calibers.

Questionable Innovation

Some changes were made to the tank design. First, the length of the gun was reduced to 37 calibers, dropping the muzzle velocity to 750 m/s. The length of the one-piece round decreased to 1530 mm, while the mass increased to 69 kg due to returning to the K18 shell. Second, the length of the 128 mm gun was deemed insufficient by Hitler, who personally supervised the project. He wanted an L/60 or L/70 gun. Finally, in a meeting on May 13th, Hitler proposed that even the 100 ton limit might not be enough, raising the bar to 120 tons. Hitler tried to accelerate the work on this superheavy tank with all his efforts. According to German intelligence, new Soviet heavy tanks would be ready by spring of 1943.

The change of name also happened around this time. The myth that the tank was initially called Mammut (Mammoth) is connected with this change. The date of this name's appearance was allegedly May 21st, 1942. Documents found in Bundesarchiv dispel this misinformation. By May 18th, the tank was already called Maus, and since summer of 1942, it was called "Mauschen" (little mouse) at least once.

As for the Mammut, this designation does appear elsewhere: in British intelligence reports, dated January 29th, 1945. This information was received from German POWs. Allegedly, two tanks were built under this name. Other tanks "discovered" in such a way include the exotic Adolf Hitler Panzer with two 88 mm guns (one in the turret and one in the hull). In other words, the name Mammut has no relevance to reality.

This is how the Typ 205 was initially: 120 tons, 16 cylinder air cooled diesel, 149 mm L/37 gun

On June 4th, 1942, Porsche K.G. presented Hitler with a draft numbered K.3381. This blueprint, labelled "heavy tank project" contained Porsche's vision for a competitor to the Pz.Kpfw. Lowe. The tank's mass was about 120 tons. The overall view of the tank was defined by a strict railroad transport limit and Porsche's refusal to use transport tracks. The turret was designed by Krupp, which also had a characteristic effect on the tank's looks.

The superheavy tank from Porsche K.G. was similar to the Pz.Kpfw. Lowe. Unlike later redesigns, this was a classically laid out vehicle with a turret in the center of the hull. The length of the hull was slightly longer than the Pz.Kpfw. Lowe in May of 1942 (8331 mm vs 7740 mm), but the overall length was less (10,620 mm vs 10,760 mm). The tank's height was 3.3 meters and width was 3.45 meters.

Seeing this tank, Hitler agreed that it could serve as a "mobile fortress". This was not only because of the tank's size. Porsche K.G. developed a new 16 cylinder V-shaped engine for the new tank. With this engine, the vehicle's maximum speed was rated at 20 kph. The engine was connected to a generator, which transferred the energy to electric motors in the rear of the hull.

Due to the tank's weight, it received a massive suspension. It used two-wheel bogies with a torsion bar suspension from the Typ 101 (VK 45.01), which were attached to the spaced armour and hull sides. Each side would have 6 bogies. It must be said that servicing this arrangement would have been difficult. This dual layer design was made necessary by the fact that the tracks were about a meter wide. As a result, the compartment where the driver and radio operator were placed was very narrow. Porsche's engineers spread the tank's hatches very widely, so climbing into the tank or getting out was not a simple task.

Reconstruction of the overall view of the VK 100.01, June 4th, 1942

Of the tank's 120 tons, 23 were used up in the turret. It had many elements of the Pz.Kpfw. Lowe, down to the gun mantlet that almost perfectly repeated the contours of its lighter competitor. The turret had a 149 mm L/37 gun with a massive muzzle brake. 30 one-piece rounds were stored in the turret. Another 36 were going to be stored in the hull. The question of there they would have gone is an interesting one indeed.

105 mm L/67 gun, proposed by Krupp as a alternative weapon for the Pz.Kpfw. Maus in June of 1942.

Upon seeing the project, Hitler agreed with the general idea, but proposed that Porsche think about thicker armour and protection from enemy infantry. The project had no machinegun. Porsche's engineers thought for a while and came up with draft K.3382 on June 17th, 1942. The name Maus can be seen on this blueprint. On July 23rd, Hitler rejected the idea of infantry protection, suggesting that the tank should be accompanied by separate tanks with short 75 mm guns for support.

This is not surprising, as the new tank resembled a pagoda. Krupp's engineers placed another smaller turret on top of the main one, equipping it with a 75 mm L/24 gun from the PzIV. As a result, the tank grew to almost 4 meters in height. A 105 mm L/70 gun was offered as alternative armament. Hitler preferred it, since it had a higher rate of fire.

Blueprint K.3382, made on June 17th, 1942, in response to Hitler's suggestion to increase the armour thickness and install a gun to protect against enemy infantry.

Hitler approved Porsche's concept, but even the thicker armour did not satisfy him. He wanted more armour, which led to more mass, which led to a complete redesign of the tank. Pz.Kpfw. Lowe couldn't compete and was cancelled on July 20th, 1942.

This is the Song That Never Ends

On June 25th, 1942, Krupp supplied the first draft of a completely reworked turret. Almost a month later, on July 17th, the 6th Waffenamt and Krupp signed contract #SS 006-4467/42 for the development of a turret for the Pz.Kpfw. Maus. The 128 and 105 mm guns were left out, and the designers settled on a 149 mm gun. The length of the barrel was reduced to 31 calibers, which was about the same as the sFH 18 gun family. The gun, indexed 15 cm KwK L/31, had one piece ammunition.

Nevertheless, the 15 cm L/31 gun remained in correspondence until March of 1943. A coaxial 75 mm L/24 gun was meant to fight infantry and lightly armoured targets. The armour thickness of the turret was 250 mm in the front, 200 in the sides and rear, and 80 mm in the roof. Overall, the turret weighed 57 tons, including the weight of 25 149 mm shells and 50 75 mm shells.

Even though the turret was designed for the 15 cm KwK L/31, the Porsche K.G. project supported the guns proposed in June requirements: the 15 cm KwK L/37 or 12.8 cm KwK. Both guns had a portion of their ammunition in the turret and a portion in the sponsons. None of the guns had the 100 rounds that Hitler demanded. By October of 1942, the mass of the turret and armament was estimated at 47 tons.

The redesigned Pz.Kpfw. Maus was presented by Porsche on October 5th, 1942. By October 28th, blueprint K.3384 was ready. The mass of the tank increased only a little bit compared to the late June version, a mere 10 tons. The tank, however, changed beyond all recognition. The new turret had a larger turret ring, so the sloped sides had to go. The hull resembled a box with a sloped rear and front. There was a new feature, a machinegun mount in the hull. Due to the longer and heavier hull, there were now 8 road wheels per side. For ease of service, instead of one wide track, there were now two narrower ones, like on the VK 40.01(P). 

Blueprint K.3384, October 5th, 1942. The Pz.Kpfw. Maus changed beyond recognition.

The project was proposed in two variants. The first, indexed Typ 205A, had a 12 cylinder V-type water cooled 42.4 L Daimler-Benz diesel engine, which produced 1000 hp at 2400 RPM. The second, Typ 205B, had a Typ 141 engine developed by Porsche K.G. This was an 18 cylinder air cooled 41.5 L diesel engine that produced 780 hp at 2400 RPM.

A decision was made to keep it safe and develop both projects in case one engine doesn't work out. In November, the main candidate for installation became the Daimler-Benz 603 aircraft engine. Its power output could be increased to 1500 hp with a compressor.

A wooden model of a turret. Note the somewhat different observation device design.

This increase in power was mandated by the fact that the tank's armour kept growing and it now weighed almost 170 tons. Understanding that this kind of weight will cause trouble, Porsche allowed the turret armour to be decreased by 10%. Thanks to this, the mass of the turret dropped to 43 tons. In early November of 1942, the tank was reworked again. By November 14th, blueprint K.3385 was ready, where the turret moved to the rear of the hull. Similar metamorphoses happened to the Porsche Typ 180 heavy tank (VK 45.01(P)).

This is what the tank looked like in mid-November, 1942.

From December 1st to 3rd, 1942, the redesigned tank was examined by a commission headed by Hitler. The vehicle was finally approved, with a ton of conditions regarding the armament and other features. The 128 mm gun resurfaced. The approval of the Pz.Kpfw. Maus meant the end of the competing Tiger-Maus project developed by Krupp. Work on that vehicle was stopped on December 15th. As for the Maus, its next reincarnation came on January 1st, 1943 (blueprint K.3387). The turret was simplified, the commander's cupola was changed and shifted back. The loader's hatch was removed. The coaxial 75 mm gun was lengthened (later this gun was indexed 7.5 cm KwK 44 L/36). The hull also changed, but negligibly.

Reconstruction of the Pz.Kpfw. Maus as of January 1st, 1943 (blueprint K.3387). These were the last radical changes, and from here on out the tank changed a lot less.

The project changed once again only a week later. By spring of 1943, numerous changes were made. Nevertheless, a tank was built according to K.3387, and it even moved. Of course, this is a 1:5 scale remote controlled model, which was demonstrated to Hitler on May 14th. At the same time, a 1:1 model was shown. This was another tank a much heavier one, very similar to the one that was eventually built in metal.

Demonstration of the Maus tank model to Hitler, "Wolf's Lair" headquarters, May 14th, 1943

Original article by Yuri Pasholok.

Superheavy Paper Tank Destoyers

Fantasies regarding WWII era armour in the areas of technical capabilities and application in combat, both of tanks that existed and those that never made it off paper (or were never even planned at all), are very widespread. A popular category of these fantasies concerns tank destroyers on the chassis of German superheavy tanks. Do any of them actually have a basis in reality?

The Atlantis of German tank design: E-100 Krokodil

The E-100 and Maus superheavy tanks are some of the most worshipped idols among German armour. The fact that the development of both was stopped by a personal order from Hitler in July of 1944 does not stop many from believing that both monsters could make it to mass production. In reality, the fate of the Maus was sealed when the Allies bombed Krupp's factories and there was nowhere left to produce the tank. The E-100 was never fully assembled and never moved under its own power, nor was a contractor determined for its production.

Jagdpanzer E-100 Krokodil with a 173 mm K18 gun. This layout and even the gun have no connection to reality.

Tank destroyers on the chassis of the E-100 and Maus tanks are another topic. Information on these vehicles is quite incomplete which gives fertile soil to wild fantasies. One of the most hyped up examples at present is the imaginary E-100 Krokodil.

Thanks to French artist Hubert Cance who drew this tank destroyer in two variants (149 and 173 mm guns) for the 22nd issue of Batailles & Blindes magazine published in November of 2007, the mythical project took shape. It went as far as the creation of scale models by very serious plastic model companies based on the artist's projections. The fact that the vehicle would break down every 10 kilometers from the strain on the front road wheels clearly did not occur to him.

Superheavy guns for superheavy tank destroyers

Meanwhile, tank destroyers on the E-100 and Maus chassis were indeed planned, but information on them is scarce. Nevertheless, even scraps of archive data allow us to lift the veil off the heaviest and most armoured tank destroyer in the world.

In late March of 1944, the Krupp design bureau developed two guns: the 15 cm StuK L/63 and 17 cm StuK L/53. According to calculations, both could penetrate 200 mm of armour at 4 kilometers. It is not known who the intended target for these monsters was, but both guns appear in Guderian's report detailing potential developments on April 7th, 1944.

The designation of both guns dictated that they were meant for SPGs. These guns could potentially be installed on relatively light Panther or Tiger based vehicles, but in reality only one carrier was built, the 17 cm Kanone 72 (Sfl) Geschuetzwagen Tiger otherwise known as Grille 17. The choice of chassis for gigantic anti-tank guns remained open.

Data from a blueprint of the 17 cm StuK L/53 dated March 23rd, 1944

Sturmgeschutz Maus

Around the same time that Krupp proposed projects for superheavy guns, activity around the superheavy Maus tank resumed, simultaneously with its rival, the E-100, the 140 ton superheavy tank from Adlerwerke. In practice, Adler proposed a redesign of the 1942 Tiger-Maus project, developed by Krupp and cancelled in favour of the Maus. Even the turret used in the blueprint is the Maus turret from January 1st, 1943, also proposed for the Tiger-Maus. This blueprint has notes on two guns, 15 cm and 17 cm. In order to not breed any illusions, let me state that this does not mean anyone had plans to install these guns in this tank.

An American CIOS report sheds light on this note. It states that German engineers did consider the E-100 as a potential platform for 149 mm and 173 mm guns. It also states that the results of their calculations were disappointing: these guns could be squeezed in, but the turret would have to become immobile. The aforementioned turret design was not even considered.

In April of 1944, Krupp started work on a new simplified turret, known as the Maus II turret. The E-100 version had its mass reduced to 35 tons by reducing the thickness of side armour to 80 mm. The 128 mm KwK L/55 would be the main gun on both turrets, with a secondary 75 mm KwK L/24. A rangefinder was also added to both turrets, with the axis of rotation of this pairing directly next to it. It's interesting how a more powerful gun was supposed to fit into such a tight space.

Sketch of an E-100 heavy tank with a 149 or 173 mm gun specified. This sketch became the foundation for many fantasies.

Initially, the E-100 was not a serious option for a superheavy tank destroyer. Its design was not even finished, but the Maus was already undergoing trials, and was a suitable vehicle. Correspondence mentions a draft of an assault gun on the Maus chassis that were delivered to Krupp and Porsche on May 9th, 1944, but sadly, the blueprints did not survive to this day. The 15 cm StuK L/63 was chosen as the main weapon. It was also suggested that a 30 mm automatic AA gun should be added to the top of the Sturmgeschutz Maus, but the idea was rejected on the assumption that the vehicle would be accompanied by SPAAG vehicles.

Sturmgeschutz E-100

The lifetime of the Maus assault gun was not long. While work was being done, it was discovered that the height of the vehicle would exceed the railroad limit. Even if the AA turret was removed, the problem remained. As a result, the Maus project fell apart, and the E-100, whose chassis was much lower, came into play. By the way, the unsolvable problem faced by Krupp and Porsche engineers directly indicates that any fantasies with a Jagdpanther-like fighting compartment are completely unfounded.

Blueprint for a 15 cm StuK L/68 mount in an SPG on the E-100 chassis.

On May 29th, 1944, Krupp requested permission for the development of draft documentation for a 1:5 scale model of 149 mm and 173 mm guns on the E-100 chassis. As with the Maus, the 149 mm gun received higher priority. The gun was redesigned, and its length reached 68 calibers. The blueprint for the 15 cm StuK L/68 on the Sturmgeschutz E-100 was ready on July 4th, 1944. The design of the gun was very similar to that of the 12.8 cm KwK L/55, meant for the Maus and E-100. The guns had an identical recoil mechanism, among other components. As for the vehicle itself, no blueprints remain. However, the slope of the front armour plate on the gun mount blueprint dispel any possibility of a front fighting compartment, same as with the Maus.

Data from the blueprint for a 15 cm StuK L/68 mount in an SPG on the E-100 chassis dated July 4th, 1944

The CIOS report casts a light on this project as well. According to the report, it became obvious that the tank will not meet requirements before the project was done. This fact did not stop the creators, and the tank was partially assembled. In parallel with trying to revive the E-100 as a tank, work continued to convert it to a tank destroyer. The tank would receive a fixed casemate instead of a turret. According to CIOS data, engineers also altered the tank's layout. The transmission, as well as the drive wheels, were moved from the front to the rear. Sadly, no blueprints of the StuG E-100 remain, but based on the conversions, it was likely that it would end up looking like the Ferdinand.

According to available documentation, the StuG E-100 1:5 scale model was finished and shown to Guderian. However, the project was doomed. On July 10th, Hitler ordered the cancellation of all superheavy tanks and SPGs on their chassis. This did not stop Krupp from continuing to work on assembling the E-100 half-legally and, in parallel, preparing 6 hulls and turrets for the Maus, but there was no possibility of further projects. The superheavy tank destroyer died without seeing the light of day.

Original article by Yuri Pasholok. 

Odd Hundred Out

The German E-series tanks (Entwicklung, "project") are especially renowned among German vehicle enthusiasts. The most famous of those is the heaviest of the proposals, the E-100. Alongside the Maus, this tank is often called a wonder weapon which would give the Third Reich a way to change the tide of war. In reality, the abilities of the tank are grossly overestimated. Additionally, the "canonical" history of its creation is omissions and mistakes. Even the external view of the tank, composed by Walther Spielberger, is not the same as what would have been in reality.

Tiger-Maus

In June of 1942, Porsche proposed its superheavy Maus tank. The draft was drastically different from what would eventually end up in metal. Outside, the tank was reminiscent of a larger Lowe, developed by Krupp. The initial design weighed 120 tons and had a 149 mm gun, 37 calibers in length. In June, on Hitler's orders, the armour was thickened, and a secondary turret with a 75 mm gun was added. It was decided that the proposed tank, already at 140 tons, would have to be redesigned. Effectively, it was going to be a whole new tank, with little of the original Tiger-Maus.

Porsche's brainchild had to be altered, but this change of course sealed the fate of Krupp's design. The Lowe, a project in development since 1941, was cancelled in July of 1942. However, Krupp did not lose everything: they were still developing the turret and gun, and the hull production was going to start in Hessen anyway. The company still had hope that they could have their revenge and regain lost profits.

The new round of competition between Krupp and Porsche started on September 11th, 1942. At a meeting between representatives of the 6th Weapons Department and Krupp representatives, the Maus turret was discussed. Lieutenant Colonel Fritz Holzhauer was worried about the many completely new components in Porsche's tank, including the engine. Lieutenant Colonel Felfert, responsible for Krupp's tank building branch, took full advantage of this fear. An alternative to Porsche's design was proposed, a tank that would weigh 150 tons and use as many components from the Tiger as possible. Holzhauer supported the idea and proposed that it be reviewed in a month.

This was not the first time that Krupp made such a move. Six years before these events, Krupp, initially chosen as the producer of a turret for the BW medium tank (future PzIV) managed to get permission to produce two prototypes of an entire tank, and as a result beat out the Rheinmetall design. And now, under the excuse of simplification, Krupp was about to make a tank out of a turret. It is worth noting that the "Tiger" here is the Tiger II. This is clearly indicated by the mass of the "donor" vehicle in question: 65 tons.

By mid-November, the alternative superheavy tank was ready. Unofficially, it was named "Tiger-Maus", but in NARA documents, it's called Krupp-Maus. Unlike Porsche, Krupp's engineers did not cover up the suspension with the hull. A unique solution allowed making the tank both wider than the railroad gauge and narrow enough to fit on a train. Like the Tiger and Tiger II, the tank had special transport tracks. Additionally, the sides were protected by armour plates, which could be removed for transport. The equipment to mount and demount the plates was attached to the turret. There were two versions of this project: blueprint W1671 proposed moving the turret back. This is about the same time as when Porsche's turret was moved (blueprint K3385, November 14th, 1942).

Krupp's revenge did not work out from the beginning. Calculations showed that for a 150 ton Tiger-Maus, even an engine turbo-charged to 1000 hp would not give it a maximum speed over 20 kph. With a stock Maybach 230, the result was even more sad: an effective hp/ton of 4.51. To compare, the British Infantry Tank MkI had an effective power of 5.98 hp/ton, and could go no faster than 13 kph. A similar speed was predicted for the Tiger-Maus with Tiger II components. To summarize, the commission (which, by the way, included Ferdinand Porsche) saw more drawbacks than advantages in Krupp's proposal.

A feverish search for a new engine began. Engines that were planned for the Maus worked, but they were not in mass production, and took away the major feature of the Tiger-Maus, the speed at which it could be put into production. Similar issues arose with the transmission and other components. The problem was compounded by the fact that the tank's mass grew month after month, reaching 170 tons in November.

On November 30th, 1942, a draft of the 170 ton Tiger-Maus was made (blueprint W1674). The mass of the chassis was 122 tons, 82 of which were for the hull. The proposed engine was the MB.507, the same as on the Maus. The removable side armour concept remained. The road wheels were planned to be 650 mm in diameter, less than on the Tiger II.

The result of the project review on December 1st, 1942, led by a key figure of the 6th Weapons Department, Heinrich Kniepkamp, was not promising. This Tiger-Maus was simply unnecessary, as it could not be rapidly put into production. With a mass of 170 tons, one could forget about using the engine, turning mechanism, transmission, or any other elements of the Tiger II. Only the reduction of mass by reducing side armour thickness was met with approval.

One week later, on December 7th, Krupp proposed a new version of the project (blueprint W1677). The mass of the Tiger-Maus dropped to 130 tons, the wheels were increased to the same 800 mm diameter as on the Tiger II. According to calculations, the top speed of the tank would be 23 kph, but considering the effective power of 5.4 hp/ton, this was overly optimistic. At the same time, an alternative variant (W1681) was prepared with a rear turret.

The commission that reviewed the project on December 8th immediately rejected the rear turret. The main variant was met with approval, as it reused many Tiger II components. The tank's suspension was to be torsion bar based, and a prototype was expected for fall of 1943.

Kniepkamp and Krupp's joy was not meant to last. On December 15th, Holzhauer decided to keep only one Maus after consultation with the OKH. Hitler himself decided that Porsche's tank was more promising, and the Tiger-Maus was forgotten, only to later return under a different name.

Aryan Rebranding

In early March of 1944, Adlerwerke company from Frankfurt auf Main submitted blueprint 021A38300 for a super-heavy tank called E-100. This project would be the heaviest tank of the E-series, the idea of which was proposed by Kniepkamp in April of 1943 (in other sources, the E-100 project was started in June of 1943). The concept was for a series of vehicles with external suspension elements. The Adlerwerke team, headed by Karl Jenschke, would only work for the suspension, not only of the E-100, but of the E-75 and E-50. This is worth noting, as Adlerwerke is often credited with the E-50, E-75, and E-100 entirely, which is not correct.

According to the blueprints, the 140 ton tank would be armed with a 149 mm gun and a 75 mm gun. Two types of engines were proposed: one was a 700 hp Maybach 230, with a transmission and turning mechanism borrowed from the Tiger II. The estimated top speed was 23 kph. The second variant would have a new 1200 hp Maybach engine. Nothing specific was said about its transmission or turning mechanism. The top speed of 40 kph, at 8.57 hp/ton, was also very optimistic. The tank's main feature was the already familiar removable side armour and transport tracks to reduce width.

A maximum speed of 23 kph, removable armour, engine, transmission, and turning mechanism from the Tiger II? This seems very familiar. No, there was no mistake, this is almost an identical copy of the Tiger-Maus with a suspension from Adlerwerke. Instead of a torsion bar suspension, springs were proposed, and new 900 mm road wheels. The blueprint's authors did not even design a new turret: the Maus had an identical one on blueprint K3387, dated January 1st, 1943. The turret lasted for two weeks, after which it was replaced with a nearly year-old design: a 15 cm L/37 gun, one that was rejected in March of 1943.

Kniepkamp did not try very hard conceal the fact that his "new" tank was a year-old project pulled out of the dusty closet. Initially, he tried to convince Holzhauer that this was a new tank developed by a new company. In reality, Krupp was behind this project, and the Tiger-Maus was resurrected due to the restart of the Maus program. Kniepkamp's logic was sound: the E-100 was a simpler and lighter superheavy tank.

The tank would certainly not have received the same turret as in blueprint 021A38300. The 149 mm gun was rejected in March of 1943, and the turret itself changed significantly since then. In March of 1944, Krupp started work on a new turret, known as Maus II. The curved front was removed, the turret became easier to produce, and the guns (128 mm KwK L/55 and 75 mm KwK L/36) were placed on top of each other. Another important addition was a rangefinder. The E-100 was supposed to receive the same turret, but with a reduced mass to 35 tons. This was achieved by reducing the thickness of the side armour to 80 mm.

Despite Kniepkamp and Krupp's enthusiasm, the E-100 was not seen as a magic solution to all problems. By spring of 1944, an experimental Maus prototype was driving around Boeblingen, and work on the second prototype already started. All components for Porsche's tank were more or less finalized. The idea of rapidly building a competitive tank based on Tiger II components became impossible. The difference in mass between 140 and 189 tons was not that much, as in either case, specialized train platforms would have to be used. Finally, the armour of the Maus, especially on the sides, was greater than that of its competitor. There was little necessity in the E-100.

All that E-100 lobbyists managed was to receive permission to build one prototype with a dummy turret. This permission was given based on the potential use of the E-100 as a tank destroyer with either a 15 cm StuK L/63 or 17 cm StuK L/53 gun. It's evident that the first proposal was to install these guns in a rotating turret, but that trick would not fly. The Maus was not suitable as a chassis, as its hull was too tall. As a result, it was approved as a chassis for the StuG E-100. This was the purpose for which the chassis was being built, but Kniepkamp and Krupp retained hope that they could still push their tank through to replace the Maus.

On July 10th, 1944, Hitler gave an order to stop work on all superheavy tanks and SPGs. The orders were followed, partially. Changes were still made to the Maus, to the point of replacing the gasoline engine with a diesel one. These changes only stopped when both prototypes were moved to Kummersdorf, where Porsche could no longer tinker with his "children". The situation with the E-100 was even more comical: while Porsche was secretly tuning his creation, its competitor was still secretly being assembled.

The site of assembly was a Henschel proving ground in Haustenbeck, not far from Paderborn. This choice was not a coincidence: the project used Tiger II components, so Henschel was an interested party. Due to the critical situation on the front and overloaded production, assembly went slowly. By January 1945, the hull and engine compartment were mostly ready. The suspension was also partially assembled, but since Adlerwerke could only spare three men, and the springs were lost in the mail, it was not ready. Judging by the state of the tank after the war, the springs were never found.

In May of 1945, the unfinished chassis fell into the hands of the Allies. The Americans limited themselves to examining the vehicles at Haustenbeck. The British had other plans. By the time the E-100 was captured, it was partially disassembled by Germans. It seems that the British managed to find the missing springs, since in the summer of 1945, the suspension was completed and the tank was pulled out of its garage.

All available E-100 parts were loaded on a superheavy trailer, and the tank began its journey towards the home islands, along with many other vehicles from the test site. Tracks were not installed on the vehicle until it reached England. There are rumours that the tank underwent trials, but they are unwarranted. The tank remained at the Bovington school until the 1950s when it was sold for scrap metal, along with most vehicles that arrived from Haustenbeck.

You may note that this story differs from the "canonial" one. Turns out, the perfect wonder-weapon was a rejected design that lobbyists tried to push through a second time. It had no advantages over the Maus. The E-100, as with the whole E-series, is one big question mark. As of March 1945, not a single E-series tank was listed in a production proposal, which speaks volumes.

Original article by Yuri Pasholok.

Biggest Shell, Best Shell

Three years before the Soviets were experimenting with a single piece 122 mm shell, the Germans were already working on arming their wonder-weapons with a 150 mm cannon. They decided to use a single piece shell.

Via Yuri Pasholok

This is a one piece shell designed for use in the 15 cm L/40 cannon in the VK 70.01. The length of the shell is a whopping 1.6 meters, and the mass is an optimistically estimated 57.4 kg. Trying to load one of these would be like grabbing a short person and trying to shove them into the breech of a gun. Compare this to the Soviet 1210 mm shell with a 40 kg mass that was deemed too big and heavy, and the common idea that the Soviets did not care about their tank crews' well being disappears.

Here is a similar shell, drawn up a month later for the 15 cm L/37 cannon.

The length is somewhat reduced to 1530 mm, but the mass calculations are more realistic, up to 69 kg. No person could sling these kinds of shells for the duration of a battle. There was an automatic loader for the 150 mm AA gun, but as a scale sketch by LiveJournal user torsus_sd illustrates, it does not exactly fit into a tank.

Kummersdorf and Ardelt

The close relationship between British and Soviet technical branches outlived the war. For instance, the British were allowed to investigate the Kummersdorf proving grounds, which were in the Soviet occupation zone. 

SVAG Archive

"Report on the technical research executed by English command to investigate German armament in the Soviet zone.

1. Kummersdorf proving grounds.

The Kummersdorf artillery proving grounds was built in 1873, and is the oldest proving grounds in Germany. The proving grounds is a scientific research organization tasked with studying new cannons, small arms, and gunpowders.

Since 1937, Kummersdorf tested small arms, small caliber cannons, and gunpowders. Testing of larger caliber artillery was moved to the main German proving grounds, Hillersleben (near Magdeburg).

The proving grounds consists of about 250 buildings, including laboratories, workshops, warehouses, etc.

Presently, all equipment from the proving grounds has been removed by GAU KA and prepared for shipment to the Leningrad Artillery Proving Grounds and Moscow small arms proving grounds. The following remains on the territory of the proving grounds:

1. Artillery that is of no interest or value: 150 units.
2. Ammunition: 40 train cars.
3. All structures, including 65 reinforced concrete pillboxes.

2. Kummersdorf tank proving grounds

The tank proving grounds is a scientific research organization tasked with studying tanks. Presently, the equipment from the proving grounds has been removed by the Red Army armour directorate.

3. The new Mauschen (German name) or Maus (English name) tank

In 1944-45, the German Mauschen tank was tested at the tank proving grounds. Only two were built. 

Brief information:

• Length: 8.5 meters
• Width: 3.5 meters
• Track width: 1.0 meters
• Front hull armour: 210 mm
• Front turret armour: 300 mm
• Side hull armour: 150 mm

Mass: 180 tons. Engineer Mani claims that the actual weight is only 120 tons.

Armament: two guns, 128 and 75 mm.

One tank was destroyed by the Germans at Stammlager, the other remained at the proving grounds, where it was also disabled.

Presently, the Red Army armour directorate has built one tank out of the two broken ones and has shipped it to Moscow for study (loaded to ship from the Kummersdorf station on August 15th, 1945)

4. No one who directed these trials remained at the proving grounds, and it is not known where they can be found.

According to locals, the chief of the department of tank and engine testing, Colonel Esser, surrendered to the Americans.

5. Ardelt factory and new "Leichter Waffentrager" vehicle

The factory was owned by four Ardelt brothers, who, according to engineer Renke Wilhem, are presently on Allied occupied territory. Presently, the factory is being dismantled by the Commissariats of Shipbuilding, Heavy Machinebuilding, and Armament.

Before the Second World War, the factory made cranes. During the war, it had a torpedo launcher plant, two munitions plants, and opened a plant to build light tracked SPGs with 360 degree turrets and 88 mm guns in the end of 1944. They were designed to fight enemy tanks. This SPG was called "Leichter Waffentrager".

Ardelt had to choose a design from two Leichter Waffentrager proposals (Krupp and Ardelt), and produce the best one (both designs are attached). According to the assembly foreman, the factory was building Ardelt SPGs.

Only 4 Leichter Waffentragers were built, one was destroyed by the Germans, and three were sent to fight against the Red Army.

All blueprints of the Leichter Waffentrager were collected by a representative of the People's Commissariat of Armament, Major Sudakov, and sent to the Commissariat. According to a representative of the People's Commissariat of Shipbuilding, Colonel Ishenko, a full set of Leichter Waffentrager components was given to Major-General Zernov, a representative of GOKO.

Presently, the Ardelt factory has 6 Leichter Waffentrager hulls, one 88 mm gun, and 6 engines. Some data can be obtained by external inspection:

• Length: 5.5 meters
• Width: 2.8 meters
• Armour thickness: approximately 10 mm
• Armament: 88 mm gun with 360 degree range
• Engine: gasoline, 6 cylinder

Conclusions:

1. Equipment from the Kummersdorf proving grounds has been removed, and is being shipped to the USSR.
2. The Mauschen tank is being sent to Moscow, to the Red Army armoured directorate.
3. The Leichter Waffentrager is an SPG with a small size, weak armour, and weak, relative to the armament, engine. It is of little interest to the Red Army."

E-100 Flop

A report from the Combined Intelligence Objective Sub-Committee #19, file XXXII-35 briefly recalls the sad fate of the German super-heavy E-100 tank.

Inside the Maus

Out of the two prototypes the Soviets recovered, they were able to assemble one "full" tank (hull from the turretless prototype, turret from the turreted prototype) and put it on display at Kubinka. This enterprising gentleman managed his way inside, and took some photos to demonstrate exactly how much exists in the exhibit. Let's take a look.

Here is the Maus from the outside, in case someone didn't know what it looks like.

Driver's compartment. Vodka bottle can be used for scale :)

Spare road wheels inside the tank. The article author theorizes that these came from the other Maus, since this one has all of its wheels accounted for.

A lone road wheel in the engine compartment.

Oil tank bay. The tank itself is gone. 

Inside of the fighting compartment. This was supposed to fit a commander, a gunner, both loaders, most of the ammunition, battery charger, and a power supply for the turret turning mechanism. A snug fit, by any measure. 

Closer view of the turret ring and ammunition storage.

Floor to the rear. The pipes lead to the electric motors. 

Gun breech.

Another view of the gun and the turret ceiling. The hatches and observation devices have been removed.

Gun and turret front.

Grille on top of the engine compartment.

Left side of the turret.

As you can see, there isn't much left inside. What wasn't damaged by the explosion and fire was removed prior to the tank being put on display.