Help please,
Can any of my learned friends out there tell mw what type off ammunition the siege guns used. The type pendraken make. Did they use a shell with a brass cartridge or a shell with a bagged charge. Like the big naval guns.
Thanks in anticipation.
Sorry forgot to say 1870 siege guns.
Best I can find so far - 24 pounders at the siege of Paris.
(https://c8.alamy.com/comp/CP1A6B/events-franco-prussian-war-1870-1871-siege-of-paris-1991870-2811871-CP1A6B.jpg)
2 gunners at the right are carrying what looks like a shell.
That suggests that bagged propellant would be poked in behind.
No actual pictures of the propellant - and can we really trust a woodcut?
No spent brass either, which adds to your supposition that the charge is bagged.
But ....but.... the Germans had problems with obturation, and used brass cases on much larger weapons than other armies. That said the engraving does look like bagged charge weapons.
IanS
So, either or then. 🤔🤔
FRaid so
The ammunition was not fixed, it comprised a separate projectile and charge.
Quote from: ianrs54 on 28 March 2019, 07:55:46 AM
But ....but.... the Germans had problems with obturation, and used brass cases on much larger weapons than other armies. That said the engraving does look like bagged charge weapons.
IanS
I read about the obturation problems and also Krupp's steel pieces bursting on account of a faulty cooling process.
I got the impression that the obturation wasn't resolved until De Bange's device in 1871.
PS: isn't De Bange a fantastic name for an artillery officer?
Come on then.
Tell Mr Thicky what obturation means with regards* to a siege gun. :-[
It gets 'blocked' ??
Cheers - Phil
*Or should that be regard ? :-\
Obturation - "In the field of firearms and airguns, obturation denotes necessary barrel blockage or fit by a deformed soft projectile. A bullet or pellet, made of soft material and often with a concave base, will flare under the heat and pressure of firing, filling the bore and engaging the barrel's rifling." Wikipedia
Apologies for the large size*, but is this the same gun? What is that on the bottom right? Looks like a shell and a small arty coffee table.
(https://c8.alamy.com/comp/CP8K7F/historical-illustration-from-the-19th-century-depiction-of-a-german-CP8K7F.jpg)
*Yup, I've said that before
Quote from: Ithoriel on 29 March 2019, 06:02:13 PM
Obturation - "In the field of firearms and airguns, obturation denotes necessary barrel blockage or fit by a deformed soft projectile. A bullet or pellet, made of soft material and often with a concave base, will flare under the heat and pressure of firing, filling the bore and engaging the barrel's rifling." Wikipedia
Thanks, Mike !! :)
Cheers - Phil
Quote from: fsn on 29 March 2019, 08:36:37 PM
Apologies for the large size*, but is this the same gun? What is that on the bottom right? Looks like a shell and a small arty coffee table.
(https://c8.alamy.com/comp/CP8K7F/historical-illustration-from-the-19th-century-depiction-of-a-german-CP8K7F.jpg)
*Yup, I've said that before
The last image looks like the Krupp 9cm C/1873 . The field gun of the Prussian army. The shell is alongside and is the small arty coffee table the metallic cartridge case holding the bagged charge. When the shell was inserted in the rifling, the charge was removed from its cartridge and rammed into the breech.
The big siege gun is the Krupp 21cm- Same principle - just on steroids. :)
Ah!
Thank you.
The items in the picture comprise the projectile, the separate charge and, I think, the two crossed objects might be the tools for setting the fuse, but I'm not entirely certain.
Quote from: John Cook on 30 March 2019, 06:06:44 PM
The items in the picture comprise the projectile, the separate charge and, I think, the two crossed objects might be the tools for setting the fuse, but I'm not entirely certain.
Probably correct. The 1870 Krupp guns had no firing pin.
Thanks guys,
Never surprised by the depth of knowledge on here.
Quote from: Ithoriel on 29 March 2019, 06:02:13 PM
Obturation - "In the field of firearms and airguns, obturation denotes necessary barrel blockage or fit by a deformed soft projectile. A bullet or pellet, made of soft material and often with a concave base, will flare under the heat and pressure of firing, filling the bore and engaging the barrel's rifling." Wikipedia
I may have been getting it wrong.
In the context of a breechloader I understood obturation as preventing gas and flash escaping through the breech mechanism.
Quote from: steve_holmes_11 on 31 March 2019, 08:07:18 PM
I may have been getting it wrong.
In the context of a breechloader I understood obturation as preventing gas and flash escaping through the breech mechanism.
No, Steve, you have got it right - exactly.
Early first-generation Krupp breechloaders required an obduration ring, usually made of soft lead or similar material, to help prevent the escape of gas through the breech. This was not entirely effective and the more gas that escaped, clearly the less that remained to push the projectile out of the gun. They also used a separate charge and a friction primer, requiring a vent in the breech which further reduced efficiency and, in addition, weakened the piece, hence the sometimes failures of Prussian guns during the war.
The solution to this was the brass case with an integral primer ignited by a firing pin. The case not only prevented obduration but also removed the need for a vent. It was a post war development though pioneered, ironically, by the French who lost all their artillery during the war, either in action or confiscated, and had to start from scratch. It culminated in the legendary 75mm Model 1897.