Stielbombe 41 for 3,7cm Pak 36

[pzgr40]

Cutaway model of a 3,7 cm Stielbombe 41, or spigot bomb type 41. It was fired from the barrel of a 3,7 cm pak 36 L/45 anti tank gun. This gun, taken in use in 1936, was a light anti tank gun , using its 0,68 kg heavy Pzgr. 39 APHE projectile, able to penetrate 30 mm of steel at 500 mtrs. at a 90 degrees angle. Until the end of 1940 this was enough to knock out most enemy tanks available. Then came the Russian T34, with thick sloped armour, rendering the 3,7 cm pak 36 obselete and useless in one day. The sarcastic nickname of the Pak 36 became Heeresanklopfgerat , which translates as "the army's little door knocker". However, shortage in production capability and the fact that the pak 36 was used widely on all fronts prevented the gun from being withdrawn from service. German armement designers however came with an ingenoius solution. A rodded , hollow charged bomb, stuck in the fore end of the barrel, and a propelling cartridge, existing of a normal shellcase with a thin wooden dummy warhead, which is used to launch the bomb. This shellcase was loaded in the normal way through the breech. The Stielgranate 41 was able to penetrate 180 mm "(7") of steel plate at an 60 degrees angle. It could be used practically up to 300 mtrs (329 yards), and was able to knock out any existing tank up frontal. It weighed 8,6 kgs (19 Lb) and had a 2,42 kg (5,3Lb) heavy explosive charge. The launching speed of the bomb is 110 mtrs/sec ( 363 fps) The nose fuze is the Az. 5075 (impactfuze), a steel transport and bore safe fuze. After launch, the sudden acceleration throws back the steel arming ring which prevents a rolled up steel strip between the firing pin and firing cap from unroling when in safe position. After firing it unrolls thereby enabeling the firing pin to move into the firing cap of the duplex detonator upon impact. The bottom fuze is a BdZ.5130. A steel made Impact and graze fuze. After firing , the acceleration moves back the detent pin placed upon the detent spring, thereby releasing the ball that blocks the firing pin from moving forward. The firing pin is now released and will be swung forwars at either full hit or graze action. On top of the BdZ.5130 are two back to back placed Boosters type: Kl.Zdlg. C/34 Np, meaning ; small booster C/34 Nitropenta. Inside the booster is a heat ignited detonator, containing 4.6 grains lead azide (blue) and 6 grains of PETN (White), igniting the penthrite (pink) that sets off the main charge of FP02 (TNT). The six fins, stabalizing the stielbombe in flight are spot welded to a steel perforated sleeve.

Regards, DJH

 

[StielGr]

Excellent write up and work as always. The only thing I would question is the blank firing case with a thin wooden dummy warhead. Have you seen this type as I only have noted the cork capped case and a cardboard capped case?

Thanks again.

PC

 

[Bellifortis]

Hallo,
does anybody here have any more detailed literature info on the 2 fuzes used. The AZ 5075 and the BdZ 5130. May be some detailed allied examinations with detailed functioning time info and so on ? This grenade does not seem to have been very precise. From the shape I would assume that this munition would best function in plunging-fire mode, like a topattack round. The cap above the shaped charge is quite short, so not much standoff. Any additional info on the round and the 2 fuzes is very much welcome.
Bellifortis.

 

[StielGr]

A couple of the fuze diagrams.

 

[StielGr]

And the iron sights with adjustable ranges.

 

[pzgr40]

@ StielGr:
Very interesting this iron sight. Was it specially meant for the 3,7cm stielbombe in combination with the Pak 36 only?
The info about the propelling charge I got was that it was a shellcase with a short wooden projectile. But it may have been a misinterpretation

 

[StielGr]

DJH
The Merkblatt for the 3,7 cm Stielgranate 41 H.Dv.g 481/501 has details concerning the sight. From what I can understand the sight was solely for the 3,7cm Pak.

I have also attached a picture of a firing case.

PC