![Tiger II (2) Bojo](https://upload.wikimedia.org/wikipedia/commons/e/e8/Tiger_II_%282%29_Bojo.JPG)
The ''Entwicklung'' series (from German ''Entwicklung'', "development"), more commonly known as the E-Series, was a late-
World War II
World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the vast majority of the world's countries—including all of the great powers—forming two opposin ...
attempt by
Nazi Germany
Nazi Germany (lit. "National Socialist State"), ' (lit. "Nazi State") for short; also ' (lit. "National Socialist Germany") (officially known as the German Reich from 1933 until 1943, and the Greater German Reich from 1943 to 1945) was ...
to produce a standardised series of tank designs. There were to be standard designs in five different weight classes (E-10, E-25, E-50, E-75 and E-100) from which several specialised variants were to be developed. This intended to reverse the favor of extremely complex tank designs that had resulted in poor production rates and mechanical unreliability.
The E-series designs were simpler, cheaper to produce and more efficient than their predecessors; however, their design offered only modest improvements in armour and firepower over the designs they were intended to replace, such as the
Jagdpanzer 38(t)
The ''Jagdpanzer'' 38 (Sd.Kfz. 138/2), originally the leichter Panzerjäger 38(t), known mostly post-war as ''Hetzer'', was a German light tank destroyer of the Second World War based on a modified Czechoslovakian Panzer 38(t) chassis.
German ...
,
Panther Ausf. G or
Tiger II
The Tiger II is a German heavy tank of the Second World War. The final official German designation was ''Panzerkampfwagen'' Tiger ''Ausf''. B,'' Panzerkampfwagen'' – abbr: ''Pz.'' or ''Pz.Kfw.'' (English: "armoured fighting vehicle"), ''Ausf.' ...
; and would have represented the final standardization of German armoured vehicle design. Indeed, nearly all of the E-series vehicles — up through and including the E-75 — were intended to use what were essentially the Tiger II's eighty centimeter diameter, steel-rimmed road wheels for their suspension, meant to overlap each other (as on the later production Tiger E and Panther designs that also used them), abandoning the interleaved ''
Schachtellaufwerk''
roadwheel system that first appeared on German military half-tracks in the early 1930s.
''Jagdpanzer'' E-10
![German Entwicklungsfahrzeug E 10 (14628748123)](https://upload.wikimedia.org/wikipedia/commons/4/4e/German_Entwicklungsfahrzeug_E_10_%2814628748123%29.jpg)
Said to have been designed by the Klockner-Humboldt-
Deutz Magirus
Magirus GmbH is a truck manufacturer based in Ulm, Germany, founded by Conrad Dietrich Magirus (1824–1895). It was formerly known as Klöckner Humboldt Deutz AG, maker of the Deutz engines, so the brand commonly used was Magirus Deutz, and for ...
AG firm in Ulm, the E-10 project (development name - "Hetzer") was developed as a replacement for the
Jagdpanzer 38(t)
The ''Jagdpanzer'' 38 (Sd.Kfz. 138/2), originally the leichter Panzerjäger 38(t), known mostly post-war as ''Hetzer'', was a German light tank destroyer of the Second World War based on a modified Czechoslovakian Panzer 38(t) chassis.
German ...
. The name ''Hetzer'' was never officially used for the 38(t).
The designs based on this new chassis would all be in the 10 to 25 tonnes weight class, and using only four Tiger II-style but larger all-steel road wheels per side in an overlapping layout for its main "slack-track" suspension with no return rollers and a rear drive sprocket. Much simplified was the suspension, which was intended to be based on the concept of using conical-spring
Belleville washer
A Belleville washer, also known as a coned-disc spring, conical spring washer, disc spring, Belleville spring or cupped spring washer, is a conical shell which can be loaded along its axis either statically or dynamically. A Belleville washer is ...
s for the E-series AFVs as a whole. These were simply bolted on to the chassis and could be easily removed for repair or replacement. This suspension system was later used on the Swiss
Panzer 61
The Panzer 61 was a Swiss Cold War era medium tank later reclassified as a second-generation main battle tank. The tank had a weight of 36.5 tons and was powered by a 630 hp diesel engine, which gave it a top road speed of . The primary ar ...
. A most interesting aspect was the ability to lower the hull by placing the pivot points of the suspension units higher in respect to the hull bottom; by not having torsion-bars occupying the entire hull planform in the lowermost interior areas of the hull, but via cranks driven by hydraulic actuators on the sides of the hull. This reduced the height of the vehicles from 176 cm to 140 cm.
The intention was to create several new light tank destroyers as a replacement for the
Jagdpanzer 38(t)
The ''Jagdpanzer'' 38 (Sd.Kfz. 138/2), originally the leichter Panzerjäger 38(t), known mostly post-war as ''Hetzer'', was a German light tank destroyer of the Second World War based on a modified Czechoslovakian Panzer 38(t) chassis.
German ...
, as well as a new family of gun platforms (''
Waffenträger'') armed with heavy anti-tank guns. However, from September 1944 the design was abandoned in favour of a redesigned and enlarged Jagdpanzer 38(t), using German parts as opposed to the Czech parts for the Jagdpanzer 38(t). This new design was called Jagdpanzer 38D, and was to use a
Tatra 12-cylinder air-cooled diesel engine similar to the one fitted to the
Sd.Kfz. 234
The Sd.Kfz. 234 (''List of Sd.Kfz. designations, Sonderkraftfahrzeug 234'', Special Purpose Vehicle 234), was a family of Armored car (military), armoured cars designed and built in Nazi Germany, Germany during World War II. The vehicles were li ...
'Puma'. None of these vehicles reached series production.
''Jagdpanzer'' E-25
![E 25 tank destroyer](https://upload.wikimedia.org/wikipedia/commons/f/f1/E_25_tank_destroyer.svg)
The E-25 designs, in the 25-50 tonnes weight class, were to be the replacements of all
Panzer III
The ''Panzerkampfwagen III'', commonly known as the Panzer III, was a medium tank developed in the 1930s by Germany, and was used extensively in World War II. The official German ordnance designation was Sd.Kfz. 141. It was intended to fight oth ...
and
Panzer IV
The ''Panzerkampfwagen'' IV (Pz.Kpfw. IV), commonly known as the ''Panzer'' IV, was a German medium tank developed in the late 1930s and used extensively during the Second World War. Its ordnance inventory designation was Sd.Kfz. 161.
The Panze ...
based designs, with involvement of the
Alkett
Alkett (german: Altmärkische Kettenwerk GmbH, lit=Altmark track works) was a major manufacturer of armored vehicles for the Wehrmacht during World War II. The main factory was located in Berlin-Borsigwalde on the Breitenbachstraße. As more sit ...
, Argus, Adler and
Porsche
Dr. Ing. h.c. F. Porsche AG, usually shortened to Porsche (; see #Pronunciation, below), is a German automobile manufacturer specializing in high-performance sports cars, SUVs and sedans, headquartered in Stuttgart, Baden-Württemberg, Germany ...
firms. This family would include medium reconnaissance vehicles, medium ''
Jagdpanzer
''Jagdpanzer'' (JgPz) is the name given in German to a heavily-armoured, tracked tank destroyer, although it may also be used for other kinds of self-propelled guns. Literally translated from German, ''Jagdpanzer'' is "hunting tank".
It typi ...
'' vehicles and heavy ''Waffenträger'' vehicles. All would use five Tiger II style road wheels but larger per side in a similar overlapping layout to the lighter E-10 suspension, as well as "slack-track" design and a rear drive sprocket.
As main armament, a 75 mm Pak 42 L/70 was planned, with a possible MG in a small turret. Overall, this vehicle would have been similar to the Hetzer tank destroyer. The tank would have been very maneuverable, and due to its low profile, hard to spot on the battlefield.
E-50 ''Standardpanzer''
![Entwicklung 50](https://upload.wikimedia.org/wikipedia/commons/b/b5/Entwicklung_50.svg)
The E-50 ''Standardpanzer'' was intended as a standard medium tank, replacing the
Panther
Panther may refer to:
Large cats
*Pantherinae, the cat subfamily that contains the genera ''Panthera'' and ''Neofelis''
**''Panthera'', the cat genus that contains tigers, lions, jaguars and leopards.
***Jaguar (''Panthera onca''), found in Sout ...
and
Tiger I
The Tiger I () was a German heavy tank of World War II that operated beginning in 1942 in Africa and in the Soviet Union, usually in independent heavy tank battalions. It gave the German Army its first armoured fighting vehicle that mounted ...
and the conversions based on these tanks. The E-50 hull was to be longer than the Panther – in fact it was practically identical to the Königstiger (Tiger II) in overall dimensions except for the upper and lower glacis plate layout. Compared to these earlier designs however, the amount of drilling and machining involved in producing these ''Standardpanzer'' was reduced drastically, which would have made them quicker, easier and cheaper to produce, as would the proposed
conical spring system, replacing their predecessors' torsion bar system which required a special steel alloy.
A new turret was to be designed for the E-50 and E-75, but drawings were never made and the turret was never even conceptualised. Armament is also not confirmed in any sources.
As indicated by its name, the weight of the E-50 would fall between 50 and 75 tonnes. The engine was an improved Maybach HL234 which had 900 hp. Maximum speed was supposed to be 60 km/h.
E-75 ''Standardpanzer''
![Entwicklung 75](https://upload.wikimedia.org/wikipedia/commons/7/76/Entwicklung_75.svg)
The E-75 Standardpanzer was intended to be the standard heavy tank to be used as a replacement of the Tiger II and Jagdtiger. The E-75 would have been built on the same production lines as the E-50 for ease of manufacture, and the two vehicles were to share many components, including the same Maybach HL 234 engine.
The E-75 would have had much thicker armour however, and in fact compared to the Tiger II the E-75 had improved hull armour all round. As its name indicates, the resulting vehicle would have weighed in at over 75 tonnes, reducing its speed to around 40 km/h. To offset the increased weight, the bogies were spaced differently than on the E-50, with an extra pair added on each side, giving the E-75 a slightly improved track to ground contact length. According to some sources, the similarities between the E-50 and the E-75 went further; they were to be equipped with the same turret and 88 mm L/71 or L/100 gun, along with an optical rangefinder for increased long range accuracy (German scientists and engineers had successfully designed a 'schmal' or narrow turret and infra-red lighting and sights for use on the prototype
anther F as the war drew to a close).
Other sources however, indicate that the E-75 was to be fitted with the much larger
Tiger II
The Tiger II is a German heavy tank of the Second World War. The final official German designation was ''Panzerkampfwagen'' Tiger ''Ausf''. B,'' Panzerkampfwagen'' – abbr: ''Pz.'' or ''Pz.Kfw.'' (English: "armoured fighting vehicle"), ''Ausf.' ...
turret, which could be adapted to accommodate an even more powerful high velocity 10.5 cm gun.
E-100
![E100 Model 1](https://upload.wikimedia.org/wikipedia/commons/7/74/E100_Model_1.72_scale.JPG)
The earliest ancestor of the E-100 was the Tiger-Maus. It was supposed to be a simplified Maus. The Tiger-Maus was never built, but it was to use components from the Tiger I Ausf. H and a slightly modified turret from the Maus.
The
E-100 was to be a superheavy combat tank designed to be the replacement for the prototype-only, Porsche-designed
''Maus''. Development and building of a prototype E-100 started in 1944 but was largely abandoned after
Adolf Hitler
Adolf Hitler (; 20 April 188930 April 1945) was an Austrian-born German politician who was dictator of Nazi Germany, Germany from 1933 until Death of Adolf Hitler, his death in 1945. Adolf Hitler's rise to power, He rose to power as the le ...
ordered an end to the development of the ''Maus''.
Only the chassis was finished. It was taken to the
United Kingdom
The United Kingdom of Great Britain and Northern Ireland, commonly known as the United Kingdom (UK) or Britain, is a country in Europe, off the north-western coast of the continental mainland. It comprises England, Scotland, Wales and North ...
for evaluation purposes and eventually scrapped.
During early development the Maus turret was used on the E-100, but later a modified Maus II turret was proposed to have been used. It would have housed 128 mm KwK 44 L/55 (75 rounds) and a 7.5 cm KwK 37 L/24.
According to Panzer Tracts 6-3, there was a proposal for the 15 cm KwK 44 L/38 to be mounted on the E-100 as well. The US military magazine ''
Armor
Armour (British English) or armor (American English; see spelling differences) is a covering used to protect an object, individual, or vehicle from physical injury or damage, especially direct contact weapons or projectiles during combat, or fr ...
'' reported in its
January–February 1959 edition that a 150 mm cannon was considered for the E-100 during the Second World War. This was also reported by Anthony Tucker-Jones. According to Kenneth Estes, a 150 mm or even 170 mm gun was proposed for the E-100 but Estes reports that Dr Karl Jenschke, the Adler works technical director and chief constructor, considered this only possible on an assault gun variant of such a vehicle, because the turret space could not support such weapons.
Estes reports the following specifications for the E-100:
[Kenneth W. Estes, "German Heavy Fighting Vehicles of the Second World War: From Tiger to E-100", 2018, Fonthill Media, ]
* Crew: 6
* Weight: 123.5 ton design
* Power-to-weight ratio: 4.8
* Length: 11.073 m overall (8.733 chassis)
* Width: 4.48 m
* Height: 3.375 m
* Turret basket diameter: N/A
* Engines:
Maybach HL230
The Maybach HL230 was a water-cooled 60° 23 litre V12 petrol engine designed by Maybach. It was used during World War II in heavy German tanks, namely the Panther, Jagdpanther, Tiger II, Jagdtiger (HL230 P30), and later versions of the Tiger I a ...
V-12 gasoline, 700 hp; the theoretical replacement was the experimental fuel-injected
HL234 developing 900 hp, which never reached series production
* Transmission:
ZF Olvar
pre-selector gearbox
A preselector gearbox is a type of manual transmission mostly used on passenger cars and racing cars in the 1930s, in buses from 1940-1960 and in armoured vehicles from the 1930s to the 1970s. The defining characteristic of a preselector gearbox ...
OG 40 12 16B; for the HL234 engine, a Mekydro transmission was specified
* Fuel capacity: 2050 L internal
* Max speed (road): 23 km/h
* Max range: 160 km
* Ground clearance: 0.5 m
* Ground pressure: 1.26 kg/cm2 (17.93 psi)
* Armament: 128 mm KwK 44 L/55, one 75 mm L/24, one MG-34. Elevation -7/+20 degrees. Ammunition stowage unknown.
* Armour (mm/angle in degrees from vertical):
** Hull front: 200/60 upper, 150/50 lower
** Hull sides: 120/0
** Hull rear: 150/30
** Hull top: 40/90 forward
** Hull bottom: 80/90 forward, 40/90 aft
** Turret front: 200/30
** Turret side: 80/29
** Turret rear: 150/15
** Turret roof: 40/90
Post-war development
After the war, the French designed and built the
AMX-50
The AMX 50 (official designation) or AMX-50 was a French heavy tank designed in the immediate post Second World War period. It was proposed as, in succession, the French medium, heavy, and main battle tank, incorporating many advanced features. I ...
series of armoured fighting vehicles, which used a 1000 hp Maybach engine with rear drive, as had been intended for the E-50 and E-75, whilst the idea of external
Belleville washer
A Belleville washer, also known as a coned-disc spring, conical spring washer, disc spring, Belleville spring or cupped spring washer, is a conical shell which can be loaded along its axis either statically or dynamically. A Belleville washer is ...
suspension - which was also developed with the Entwicklung series in mind - resurfaced on the Swiss
Panzer 61
The Panzer 61 was a Swiss Cold War era medium tank later reclassified as a second-generation main battle tank. The tank had a weight of 36.5 tons and was powered by a 630 hp diesel engine, which gave it a top road speed of . The primary ar ...
.
Notes
References
Information about the E-100 at Panzerworld* ''German Tanks of World War II: The Complete Illustrated history of German Armoured Fighting Vehicles 1926-1945'', F. M. von Senger und Etterlin, translated by J. Lucas, Galahad Books, New York, 1969,
* ''Special Panzer Variants: Development . Production . Operations'', Walter J. Spielberger and Hilary L. Doyle, Schiffer Publishing, Atglen PA, 2007,
* ''Panzer Tracts No. 6-3 Schwere-Panzerkampfwagen Maus and E 100 development and production from 1942 to 1945'', Thomas L. Jentz and Hilary L. Doyle, Panzer Pacts, 2008
* {{cite book
, ref= , last1=Jentz , first1=Tom , last2=Doyle , first2=Hilary , title=Paper Panzers: Panzerkampfwagen, Sturmgeschuetz, and Pagdpanzer , series=Panzer Tracts 20-1 , date=2001 , isbn=097084073X , place=Boyds, MD , publisher=Panzer Tracts
External links
TheUntoldPast's video review of the E-series tanks
{{WWIIGermanAFVs
{{DISPLAYTITLE:''Entwicklung'' series
{{DEFAULTSORT:Entwicklung Series
World War II tanks of Germany