12.8 cm K.44 Selbstfahrlafette mit gerichtetem Fahrzeug und Feinrichtmaschine

[3.7 cm Flakvierling 43]

While looking through a seemingly random search result, I found a particular drawing that stood out to me as it does not seem to be discussed much outside of this VK thread where I found it...
Here are the details found in said article:

A project for installing the 12.8 cm Kanone 44 gun on a self-propelled lightly armored chassis, dated April 26, 1944. Some of the interesting details of the vehicle were the low profile (2.3 m), impressive elevation angles (+60°) and almost non-existent horizontal angles (2° in both directions) It was not built in metal. Development details are unknown at the time of publication of this article.

There is also a blueprint and a recreation of said blueprint by Andrei Sinyukovich (below), from the aforementioned thread:
Any more information on said project is very much appreciated.
Cheers

 

[World B4]

Would absolutely hate being in it when it shoots

 

[JFC Fuller]

Thanks for posting this, it sent me off on a bit of an online hunt. I turns out this is one of three drawings from Rheinmetall Borsig that have been found in the digitised German archives. The gun is almost certainly Rheinmetall's proposed anti-tank/field gun version of the 12.8cm FlaK 40 that lost to the Krupp Pak 44 for the 12.8cm requirement. Cutting a hole in the floor to allow the gun to depress sufficiently for long range fire, combined with the 72 round ammunition load, suggests field gun performance was an important requirement for the two casemate based versions. I have attached the three plans, in summary they are:

1. Dated 17 June 1944: Basic casemate version
2. Dated 26 June 1944: Casemate version with a fine levelling mechanism (note the addition of the 2 degree left and right gun movement)
3. Dated 7 July 1944: Turreted version with significantly reduced ammunition stowage

The chassis and running gear is intriguing. Six large and slightly overlapping road wheels, based on the given measurements they must be in the 800mm range, up there with the Tigers, Panther and E50/75 designs. The location of the loader and the ammunition stowage implies external suspension though no other clues are present as to the drivetrain. I had originally thought that the Panzer III/IV hybrid would be the logical chassis choice but these designs have roadwheels larger than 660mm, and the overall weight, at 14 tons, is significantly lower. The hull is quite wide at 3.2m and the engine/transmission compartment looks generous in the casemate versions - I am assuming a rear mounted transmission based on the absence of space for a drive shaft running rear to front.

The idea is conceptually interesting but I have to feel for the poor loader, being responsible for manoeuvring those huge 47.4kg fixed rounds into the gun breech in what is a very confined space - all on his own in the versions with the casemate. The task doesn't look any easier on the turreted version but there are at least two crew behind the breech. The second casemate version, had it been designed to 25 tons with space provided for a fourth crew member to support the loader, might have made for an interesting multipurpose self-propelled field/anti-tank gun but this is probably too light.