Entwicklung series
'development'), more commonly known as the E-Series, was a late-World War II attempt by Nazi Germany to produce a standardised series of tank designs.
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[citation needed] 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.
All would use five Tiger II style road wheels but larger[citation needed] per side in a similar overlapping layout to the lighter E-10 suspension, as well as "slack-track" design and a rear drive sprocket.
The E-50 hull was to be longer than the Panther, it was practically identical to the Tiger II in overall dimensions (except for the upper and lower glacis plate layout).
Compared to those 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.
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 HL234 engine.
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 cannon, along with an optical rangefinder for increased long-range accuracy (as the war drew to a close, German engineers designed the Schmalturm or narrow turret with infra-red lighting and sights for use on the prototype Panther Ausf.
However, other sources indicate that the E-75 was to be fitted with the much larger Tiger II turret, which could be adapted to mount an even more powerful high-velocity 105 mm cannon.
[10] 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 (Sturmgeschütz E100), because the turret space could not support such weapons.
[11] Estes reports the following specifications for the E-100:[12] After the war, the French designed and built the AMX-50 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 suspension - which was also developed with the Entwicklung series in mind - resurfaced on the Swiss Panzer 61.
