Question Regarding Panzerfaust Fuze.

[marty_01]

Question Regarding Panzerfaust Fuze.

Hallo

Can anyone explain to me the details of how the fuze to activate the shaped charge explosive on a Panzerfaust worked? Was it a simple inertia base detonating fuze with a creep spring? Or something completely different?

In addition did the fuze evolve between the Pzf30 and Pzf60?

Vielen Dank

[greif]

From a british handbook.

[marty_01]

Thanks very much Greif. That is exactly what I was looking for.

Best Regards
Marty

[mag]

Heres the FpZ 8003. On the left Save and on the right Armed.

There are 3 more Types, the 8001, 8002 and the 8003umg. The 8003umg. contains a self destruct feature. The 8001 and 8002 where used for the 30k and 30 (weaker springs) the others for the 60,100 and 150 (harder springs). The 8003umg. was specialy designed for the Pzf150 with frag sleve, so the projectile could burst in the air for a better fragmentation efect. The self destruct device was ignited by the propelant charge and detonated the warhead after 3 seconds. The 8003umg. worked as a impact type too!

[marty_01]

Sehr gut Mag! Danke.

It looks to my untrained eye like the base fuze on a panzerfaust was very similar to the creep spring and firing pin arrangment used on a 2.36" Bazooka rocket.

Best Regards
Marty

[mag]

From the general working sheme yes but technicaly no. :D The safety on the 2,36" bazooka rocket is released by hand before firing, on the FpZ the safety is released by the shock of firing. (inertia) The bazooka Rocket is a very dangerous thing to handle once the safety Pin is released, you could even throw it and it would work.

[marty_01]

Yes – that makes sense. There is a snippet in another portion of the Tech-Manual from which I scanned the Bazooka fuze picture which indicates that the bazookas shaped charge would be expected to function if the rocket were dropped from a height of 48-inches. That is after the safety pin was removed.

I have read that this sort of fuze system – spring and firing pin -- often had difficulty activating on highly sloping armor – or from high obliquity impacts. At a minimum the fuze was slower to activate, such that the shaped charge jet was much less effective. I am not sure I understand why this sort of fuze might react slower or not at all when the projectile impacts its target at an angle. Do you have any thoughts or opinions on the matter?

[PzGr40]

Hi Marty, I'll try to explain on the hand of two drawings. In picture one you can see the difference between hitting an object at 90 degrees impact or at 45 degrees. By simply sloping armour , you increase the amount of armour to be pierced by 1,41 times. So the 5 cm thick frontal armour of the M4a1 Sherman , that was placed under a about 45 degree slope, was in fact 1,41 x5cm=7,05 cm thick for any type of armour piercing shell that wanted to pass it. I also drew the force generated on the firing pin at a 90 degree impact, when the full inertia force moves it forward. At a 45 degree anle impact, the force will be devided into a force forward and a negative inertia force downward, pressing the firing pin down in it's housing. This causes a friction between the firing pin and it's housing, resulting in a time lapse at an angled impact. For this reason, inertia firing pin blocks and their housings do always have a very smooth surface finish, this to reduce friction between the moving parts. During this time lapse (picture 2), the rocket moves forward, climbing up (deflecting) the sloped armour, the angle for the firing pin becomes even worse; it now has to climb uphill, while moving forward). It also means the amount of armour to be pierced has increased to 174,5 mm, thereby reducing the effect of the hollow charge even more. With regards, Pzgr40

[marty_01]

Sehr gut Pzgr40! Danke für das Sprechen mit mir auf Englisch. Mein Deutsch ist nicht gut.

Your explanation makes sense both physically and intuitively. I had assumed that oblique impact force acting on the fuse would be dived into x and y components. And that the y-component would not be helping the weighted firing pin in overcoming the resisting force of the creep spring. However I had neglected to consider the frictional force from this downward y-compnent force and the resultant frictional force acting upon the weighted firing pin and its housing. Very good eye on your part.

I have an unrelated question -- also regarding HEAT ammunition fuzes – but in this case when the shaped charge is activated by a nose or stand-off probe mounted piezoelectric fuze. I have also noted in various sets of firing trial data that these types of fuzes also have difficulty activating properly (or they don’t activate at all) vs. highly sloping armor or during high obliquity impacts. I understand the relation of equivalent armor thickness vs. slope armor and the path a HEAT jet has to travel when penetrating sloping armor. I guess I am more interested on your -- or anyone elses -- impression of the forces that maybe acting on either the HEAT projectile or its piezo-electric fuze such that sloping armor would interfere with proper fuze action.

mit freundlichen Grüssen
Marty

[marty_01]

Sorry -- one more question on the creep spring and weighted firing pin in a bazooka or panzerfaust:

Any thoughts on a reasonable range of friction coefficients acting between the weighted firing pin and its housing. Smooth steel on steel. Would the surfaces have been lubricated in any way -- or is this a no-no for a fuze?

I am thinking the spring constant for the creep-spring of the bazooka could be resolved based upon the height at which the projectile can be dropped that will result in activation of the shaped charge.

Sorry -- just thinking out loud as to how one might resolve critical attack angles at which the forces acting on the firing pin might result in improper fuze action.

[x]

Heres the FpZ 8003. On the left Save and on the right Armed.

There are 3 more Types, the 8001, 8002 and the 8003umg. The 8003umg. contains a self destruct feature. The 8001 and 8002 where used for the 30k and 30 (weaker springs) the others for the 60,100 and 150 (harder springs). The 8003umg. was specialy designed for the Pzf150 with frag sleve, so the projectile could burst in the air for a better fragmentation efect. The self destruct device was ignited by the propelant charge and detonated the warhead after 3 seconds. The 8003umg. worked as a impact type too!

Do you have any info on the FpZ 8003 umg with the SD device actually installed? The fuzes themselfes are found (on PzF 60 or 100) but the space for the SD device is always empty and has never been documented in a drawing or photo.

[mag]

Nein, habe leider auch nichts genaueres darüber als das was ich geschrieben habe. Habe nur ein Dokument und da ist auch nichts genaueres eingezeichnet nur halt geschrieben das es durch die Treibladung gezündet wird und nach 3 sec umsetzt.

[x]

Schade, dachte schon das endlich mal wer was gefunden hat.

[marty_01]

I was watching a US-Army Ordnance video on the RPG. The film was made during the Vietnam War – 1967’ish. Apparently the RPG of that period had some sort of timed fuze in addition to the piezoelectric impact fuze. The time fuze would automatically detonate the warhead after a certain length of time even if the RPG wasn’t activated by impact.

I have had problems finding precise dimensions for the Panzerfaust warhead (Pzf30, Pzf60 or Pzf100). Specifically I am trying to determine the diameter of the shaped charge cone at the base of the cone, as well as the distance from the cone base opening to the nose of the projectile. If you look at the attached image, the dimensions I am trying to determine are shown as "A" and "B". I have found one source showing dimension “B” that looks like 11.5cm. But as you can see from the attached the image is very poor so I can’t be sure if this is actually 11.5cm or not. Does anyone know what these dimensions might be?

Thanks for any additional assistance.

Marty

[mag]

Hi, Cone diameter schould be 11,5cm and Standoff is 10cm for the Pzf 60 and 100.

[marty_01]

Wow...that was a quick reply. Thanks again Mag. You have been very helpful.

Best Regards
Marty

[Munibob]

Any thoughts on a reasonable range of friction coefficients acting between the weighted firing pin and its housing. Smooth steel on steel. Would the surfaces have been lubricated in any way -- or is this a no-no for a fuze?


Hi, Marty
I'm not shure about the lubrication in the Fuze, I think, there will be a thin lubrication left from the production of the parts, but no additionell grease or so. The fuzes for the Panzerfaust were designed for "rapid consumption" against the allied tanks attacking at all fronts, so there was - as I think - no thought on long-time storage and problems with corrosion.

During my training for EOD at the "Sprengschule Dresden" some years ago I had an Panzerfaust fuze in the hand. The fuze was armed (aktivated by acceleration, the arming collar had moved to the back end and was locked by the wire locking spring). Whenever I turned my hand, I could hear the hole inner part move from one end to the other.
I won’t claim, that this would be enough to ignite the detonator, but it was a very good (and still remaining) „feeling“ about the very low friction coefficient and of course the danger of a dud Panzerfaust when you have to move it.

Greetings
Bob

[x]

I was watching a US-Army Ordnance video on the RPG. The film was made during the Vietnam War – 1967’ish. Apparently the RPG of that period had some sort of timed fuze in addition to the piezoelectric impact fuze. The time fuze would automatically detonate the warhead after a certain length of time even if the RPG wasn’t activated by impact.


Marty


The RPG with self destruct feature would mean then the PG-7 rocket for the RPG-7 launcher. Just not to drop the fact that Chinese made ones exist without self destruct (SD) feature and they likely have been used in Vietnam a swell.
The other RPG variant (the earlier) being used in Vietnam was the Russian PG-2 grenade for the RPG-2 launcher and was used with a "mechanical impact only" fuze without SD (the DK-2 fuze).
There existed a fuze named DK-4 which had a SD but I have never seen one nor I met one who did - probably because most people do not look at them since the outer appearance is the same and only markings are different and most people do not read cyrillic anyway.
The Chinese used a different mechanical fuze for the same round which also looks like the DK-2 but has a different interior and is made of bakelite (a kind of plastic).

[Przemek]

Hello
If fuze in picture presented by MAG (previous site) is expected to be FPZ 8003, there is a question: How primer can be striked if firing pin is enclosed (with locking spring holder)? It can't be seen in picture, but maybe firing pin isn't completly covered? Could you show this fuze in parts (or depict this detail)? In opposite case it can be FPZ 8002 with misakely inverted detonator holder.

[Bombdefender]

hat denn jemand genaue infos zum FPZ 8003 umg?....meines wissen nach ist der baugleich mit dem FPZ 8003 bis auf eine öffnung im boden, im zündnadelträger und verzögerungssatz 3sek. der wohl über die treibladung gezündet wurde....vieleicht lieg ich ja daneben...hab ich mir aus den endlosen inoffizellen infos so zurecht gelegt

[genkideskan]

Beschreibung,Maßzeichnung und Einzelteile des Zünders sowie die Panzerfaust 150 findet man umfassend abgehandelt in der Waffen Revue 111.

[Bombdefender]

hab heut ein nachdruck der nr.111 waffenrevue erhalten.....leider keine angaben über aufbau und funktion der zeitzündeinrichtung beim FpZ8003 umg.

[mag]

Meines wissens nach gibt es über den 8003umg keine angaben, nur die äußere form ist bekannt. innerer aufbau jedoch nicht.

[rigby]

@mag

über den FPZ8003 ist alles bekannt der große unbekannte ist der FPZ8003umg

[mag]

den meine ich ja auch... *lol*