German Pibrans rocket program

[Wurger]

Hi,

reading Günter Nagel`s "Himmlerswaffenforscher" (Helios Verlag, Aachen, 2011) there are quite a handfull of rocket projects in development by Pibrans stated in page 219.
Pibrans was a firm integrated in "Waffen Union" with Skoda and other companies, more or less under the aegis of the SS.
On the familiar side there were: V-101, Rochen, Püppchen, Panzerfaust, Panzerschrek, Taifun P/F, Luftfaust and Panzerblitz.

These are the mentioned programs which are unknown to me:

Zugspitze;
"PAR" (probably stands for Panzerabwehrrakete) rocket series (two are noted, II and V);
Regenschirm project, in experimental stage;
"7-Kreiser"

Is there someone who can shed light on this subjects? Maybe our "resident rocket scientist", Grzesio?

 

[Grzesio]

No idea, sadly. :-\
Is Günter Nagel a reliable author? Wouldn't you like to write something about the book?

 

[Foxglove]

A Polish writer, Igor Witkowski, implies that the Pilzen-based Skoda works were involved in research(manufacture?) into the electrogravitic engine.
Would this '7- Kreiser' be related?

 

[Wurger]

Hi,

the author is reliable, stating throughly all sources, in this particular case (Pibrans) some steming from the private files of one of the engineers involved with Pibrans (some pictures too). I will write a small recension on the book next week (I`m not at home), but I could say that it came as a surprise to me. Herr Nagel`s intention was to provide a general view of the scientific branches of the SS. His work hasn`t much graphic documents (I will post an interesting item soon), but it is well researched, and an excellent starting point for more in-depht investigations relating to some of my personal interests (radar and artillery fire control) undertaken by the dreaded SS.
The author is about to publish "Wissenschaft für den Krieg. Die geheimen Arbeiten der Forschungsabteilung des Heereswaffenamtes", which only by its title suggests much. I will get in touch with Herr Nagel and try to get more on this subject. Afterwards I will post in our forum. `till then!

 

[Michel Van]

Hi,

These are the mentioned programs which are unknown to me:
Zugspitze;
"PAR" (probably stands for Panzerabwehrrakete) rocket series (two are noted, II and V);
Regenschirm project, in experimental stage;
"7-Kreiser"

Is there someone who can shed light on this subjects? Maybe our "resident rocket scientist", Grzesio?

PAR could be acronym for Panzer Abwehr Rakete
but in Third reich used the official therm "Reaktive Panzerbüchse" means reactive anti-tank rifle
later in end of WW2 they used the Therm "Panzerfaust" means Tank fist

7-Kreiser is not German word, it could be typing error
eider it mean 7-Kreisel (gyro) or 7-Kaiser (Emperor )

 

[Grzesio]

Thanks, Wurger! I'd be great!

A Polish writer, Igor Witkowski, implies that the Pilzen-based Skoda works were involved in research(manufacture?) into the electrogravitic engine.
Would this '7- Kreiser' be related?

There was a well researched book published in Poland just last year, "The last secret of the Wunderwaffe vol. 3", a step by step analysis of the V-7 myth development since the war, which apparently proves (I havent read it yet) that the whole Chronos Project, die Glocke etc. is a private invention of Mr. Witkowski of late 1990s, intended for making money with his books "researching" this topic.

but in Third reich used the official therm "Reaktive Panzerbüchse" means reactive anti-tank rifle
later in end of WW2 they used the Therm "Panzerfaust" means Tank fist

But there was a PAW - Panzer Abwehr Werfer - developed in 1944.

Regards

Grzesio

 

[Wasp]

7-Kreiser is not German word, it could be typing error
eider it mean 7-Kreisel (gyro) or 7-Kaiser (Emperor )

I have to disagree that 7-Kreiser is not a german word.

Although not a regularly word "Kreiser" is simply a nounform of "kreisen", which isn't necessarily "das Kreisen" if it is meant to describe someone doing it. You probably wouldn't find "Kreiser" in a dictionary, still it would be a legitimate word to name something. A "Kreiser" would generally translated mean "someone or something who/that circles". Another possibility would be that 7-Kreiser describes a craft/thing with 7 circles (whatever kind of circles that may be). Like Bicycle, Tricycle etc. in german we could say "ein 7-Kreis" or "ein 7-Kreiser", of course I admit as there is no generally known 7-Kreiser, the word feels even for german tongues unusual.
At least I think 7-circler sounds still more technical sound than 7-emperors.

As for the "Regenschirm". Possibly it could have something to do with the Project Just Miranda described as Planet Project (s.h. Rheinkind thread)?
At least one of the schematic drawings showing a surface launched clusterrocket, looks a bit like an umbrella covering the place beneath...

 

[Wurger]

Please see our own (where else?) thread:
http://www.secretprojects.co.uk/forum/index.php/topic,6806.msg57919.html#msg57919
On the Regenschirm, Wasp, I really do not know.
At this moment I could add nothing more to this quest. Lets hope Herr Nagel discloses something on this.
Stay tuned in the Army Secret Projects. Next monday! Fancy a rocket-propelled land mine? Yes, german WW2!!!

 

[Grzesio]

And here are the answers:
http://library2.lawschool.cornell.edu/donovan/pdf/Batch_13/Vol_XCIX_46.pdf

Zugspitze is a12 cm AA rocket.
PAR V is a rocket assisted 88 mm shell for AT guns. PAR II is not described in detail.
Regenschirm is an air brake intended for rocket assisted bombs.
7-Kreiser is a RATO unit made of six 8 cm RSprgr engines.

I think, Fritz-X is misidentified in the report. The description clearly applies to rocket assisted AP bombs, although the mention about shutting the engine off remotely from the carrier aircraft is strange enough, as solid fuel is used (ok, it is possible in certain way, basically blowing the engine open, but...). I cannot also imagine the idea behind the Regenschirm device - equipping a rocket assisted bomb with an airbrake to slow it down again makes completely no sense for me.

I also don't like the Zugspitze data - they make no sense at all.

 

[Jemiba]

I cannot also imagine the idea behind the Regenschirm device - equipping a rocket assisted bomb with an airbrake to slow it down again makes completely no sense for me.
I also don't like the Zugspitze data - they make no sense at all.

Maybe it was a way to slow a bomb down to zero speed above ground and then acceleraet it vertically downwards ?

 

[Grzesio]

Maybe it was a way to slow a bomb down to zero speed above ground and then acceleraet it vertically downwards ?

Yest, this method would be reasonable and is used in rocket bombs indeed. But the report says:
A parachute opens at the moment a certain acceleration of the bomb is reached; the falling time of the bomb is thereby increased, allowing the fuel combustion to be shut off at the proper moment. This increasedbombing accuracy.
The Regenschirm seems to be deployed after the engine is ignited, to slow the bomb down... There's something strange in the report, some misinformation or misinterpretation about shutting the engines down in rocket propelled bombs.

And how do you like the Zugspitze?

 

[Jemiba]

Ok, now I could open/download the full report, it failed after two or three pages during my
first attempt.

An explanation for "Regenschirm" could be, that it wasn't intended to slow down the bomb, but
just to stop further acceleration and so to bring the bomb to a constant speed ? This would still
coincide with the statement, that "falling time of the bomb is thereby increased" and maybe with
"This increased bombing accuracy", too. The Fritz-X was guided optically by eye view. A constantly
accelerating weapon may have been more difficult to steer, as commands would have to be given the
faster, the more it reached its target, probably no mean task for the bomb aimer. So the rocket just
secured a speed greater, than that of a free falling bomb and the parachute limited it to a manageable
amount ?

But you're right, I think, about the misidentification/misinterpretation of "Fritz-X". In the list all weapons
are listed by its names, most weapons are described in general (or not at all), e.g. "Rheintochter" or "Rochen".
But under "Fritz-X" just the additional rocket motor is mentioned, not standard to the usual "Fritz-X". So, probably
just an additional device was regarded as the whole thing, maybe indicating, that the interrogators had no knowledge
before of this gliding bomb.

About "Zugspitze":
To me, the text describes a single stage unguided ground-to-air rocket, about 4m long and with a diameter
of maybe 15 cm, depending on the thickness of the casing. The overall diameter would have hardly been the same,
as for the propelling charges. "The was placed in a one-tube arrangement ...sections of decreasing diameter" maybe
was a kind of booster-sustainer arrangement ?
But considering the dispersion of unguided rockets, it would have needed really masses of those rockets, to hit anything
in 10 km distance, I think.

 

[Grzesio]

Wow, a drawing!

So the rocket just secured a speed greater, than that of a free falling bomb and the parachute limited it to a manageable amount ?

You may be right! For example the Hs 293 could be equipped with fixed drag bodies to limit its max velocity - the Regenschirm could be intended for the same purpose, but opening only when necessary.

Well, I cannot see a lot of sense in the Zugspitze concept - at all.
It appears to be designed - to some degree - to the same idea as Taifun and Tornado were, i.e. to rise rate of fire of heavy Flak and thus increasing statistical hit probability when firing at an area target (bomber formation) in a given period of time. But both those rockets were intended as highly cost efficient projectiles, lightweight and fast. Zugspitze seems to be more traditional - time fused (= heavy warhead), big and rather slow. Also the whole concept behind the impact fused AA rocket with demolition warhead was rejected.
There's a lot of conflicting data in the report. First of all, this capacity of German solid propellant is only some 35 kg heavy, not 70 kg. But the latter value is reasonable for the complete engine (although the charging factor, or whatever it is called in English, is rather low).
Reaching 10 000 m range in 6 s would require 1667 m/s medium speed - this is fairly impossible. It may be a wrong value given by Larsson, translation error or simply a typing mistake.
I tried to recreate the Zugspitze too, with pretty similar results.
I ended up with a rocket just over 4.5 m long (warhead with 7.5 kg of HE inside a shell 1 cm thick), some 13.5 cm in diameter. The launch weight is 100 kg (maybe a few kg more), including 35 kg of propellant.
Calculated max velocity (with my very simple method, but still giving approx. 5% accuracy) is only 750-800 m/s, while burning time for average propellant can be expected as some 2.5 s, average thrust 2800 kp, total impulse 7000 kps and so on.
Time of climbing to 10 000 m is hard to assess easily, but by comparison to the Taifun, I'd say it would be obviously under 20 s - but I'm not sure if it could be as short as 16 s (if we assume there should be the digit "6" somewhere in this value ).
Generally, the Zugspitze seems to display a little bit traditional way of thinking about AA rocket - delivering twice as much of HE as a 12.8 cm Flak shell, but utilizing 3.5 times more propellant and much more raw material.

I tried to figure out the reason for adopting such a 'stepped' propellant charge - I think it was done due to its extreme diameter-to-length ratio (burning area to chamber cross section area). I'd place the thinner segments towards the rear though, making place for combustion gases to move towards the nozzle. Such a charge would also produce degressive, gradually decreasing thrust.

 

[Grzesio]

Just one thing came to my mind, when I was reading this caption again...

A parachute opens at the moment a certain acceleration of the bomb is reached; the falling time of the bomb is thereby increased, allowing the fuel combustion to be shut off at the proper moment. This increased bombing accuracy.

... maybe it is unprecisely described and the translation is even worse, but could the Regenshirm be just a kind of automatic airbrake indeed, limiting maximum velocity of the bomb to a certain (but still appropriately high) value? This could possibly produce a more predictable trajectory and increase accuracy to some degree indeed... ??? Jemiba was right, I think!