V 3's how successful if completed

Discussions on alternate history, including events up to 20 years before today. Hosted by Terry Duncan.
von Rundstedt
Member
Posts: 70
Joined: 19 Jan 2008, 04:00
Location: Australia

Re: V 3's how successful if completed

#16

Post by von Rundstedt » 07 Apr 2008, 06:01

JonS wrote:I take it you've not heard of the "Paris Gun" then?

Granted it was 210mm rather than 150mm, but it was also an utterly conventional design, and a quarter-century older.

Which is not to say that I think the V3 would have been particularly effective as a weapon. But it is technically plausible.
Calais to Dover is one thing, Calais to London is another, even rocket assist that is one hell of a trajectory, also by way how much weight of the rocket powered shell is warhead.

v.R.

User avatar
phylo_roadking
Member
Posts: 17488
Joined: 01 May 2006, 00:31
Location: Belfast

Re: V 3's how successful if completed

#17

Post by phylo_roadking » 07 Apr 2008, 15:36

also by way how much weight of the rocket powered shell is warhead.
...scratches head...ALL of it - it was a cannon, a "supergun", not a tube-launched missile system. Google under "Gerald Bull" and "Supergun"


User avatar
LWD
Member
Posts: 8618
Joined: 21 Sep 2005, 22:46
Location: Michigan

Re: V 3's how successful if completed

#18

Post by LWD » 07 Apr 2008, 15:47

Well they did mention rocket assist. But I'm wondering just how much explosive would be in each round. Also for the Paris gun didn't they have to fire the rounds in order? Or was that another long range piece? Weren't the rocket fuels of the time rather corrosive? Barrel errosion whether by fricition or corrosion whould defintily be a consideration. At these ranges the projectiles are going exoatmospheric I believe. Means there's considerable room for accuracy problems due to exterior ballistics. Over all an interesting concept but I'm not sure that it was practicle at the time or even now especially with unguided rounds.

User avatar
phylo_roadking
Member
Posts: 17488
Joined: 01 May 2006, 00:31
Location: Belfast

Re: V 3's how successful if completed

#19

Post by phylo_roadking » 07 Apr 2008, 16:53

Not "rocket-asisted" in the sense you mean.
The V-3 cannon used multiple propelling charges placed along the barrels' length and timed to explode as soon as the projectile passed them by, to provide an additional boost. Due to their higher suitability and ease of use, rocket boosters were used instead of explosive charges, arranged in symmetrical pairs, attached to the barrel with a low (below 30º) angle. This layout spawned the German codenames Hochdruckpumpe ("high-pressure-pump") and Tausendfüßler ("millipede"). Unlike conventional rifled weapons of the day, the smooth-bore gun ejected a fin-stablized shell, dependent upon aerodynamic (rather than gyroscopic) forces to prevent tumbling and consequent high drag.
It was packaged rockets in the side tubes like RATO packs that were to provide the extra oompf behind the shell as it shot up the "barrel".

Only the C-stoff/T-stoff mix was corrosive in the way you mean; a whole variety of rocket fuels are available, C-stoff/T-stoff was only used in the Me-163 for its "specific impulse", the power to be got out of each gram of the combination. That particular combination had a VERY high "specific impulse", and therefore in a small aircraft was the best available, and the other problems were the necessary trade-off for higher power.

As for accuracy...don't let any artilleryman hear you say that LMAO Take a look at these...

http://www.astronautix.com/lvfam/gunnched.htm

...particularly this... :wink:

http://www.astronautix.com/lvs/babongun.htm

User avatar
Auseklis
Member
Posts: 710
Joined: 20 May 2005, 11:26
Location: Heart of the Ruhr-Valley

Re: V 3's how successful if completed

#20

Post by Auseklis » 07 Apr 2008, 17:01

LWD wrote:Well they did mention rocket assist. But I'm wondering just how much explosive would be in each round. Also for the Paris gun didn't they have to fire the rounds in order? Or was that another long range piece? Weren't the rocket fuels of the time rather corrosive? Barrel errosion whether by fricition or corrosion whould defintily be a consideration. At these ranges the projectiles are going exoatmospheric I believe. Means there's considerable room for accuracy problems due to exterior ballistics. Over all an interesting concept but I'm not sure that it was practicle at the time or even now especially with unguided rounds.
You did understand, that the rocket propelant was not attached to the shell but was distributed in a series of chambers along the whole lenght on both sides of the projectors barrel? Just asking...
The Hochdruckpumpe was neither a rocket-launcher nor a bull-Style long range gun.
If I should tell sombody with modern day military knowledge, how to imagin the Hochdruckpumpe, I would say: "Like a gauss-rifle but chemical driven..."

User avatar
LWD
Member
Posts: 8618
Joined: 21 Sep 2005, 22:46
Location: Michigan

Re: V 3's how successful if completed

#21

Post by LWD » 07 Apr 2008, 17:10

I tried to post this earlier and it appeats to have vanished. Hope it doesn't get posted twice.
Ok I missed the fact that the rockets weren't attached to the shell. Saw rocket assist and thought modern version of it.

However a couple of points. Hot gasses in general are corrosive. Even some older propelents such as black powder can be chemiclally as well as thermally corrosive. How much of a problem it would be in these guns I don't know but it could be a factor.

I didn't see anything in the two referances you gave that would indicate how accurate the big guns would be vs a terrestial target.

If you look at the info from the US 16" gun at:
http://www.navweaps.com/Weapons/WNUS_16-50_mk7.htm
it states
For example, during test shoots off Crete in 1987, fifteen shells were fired from 34,000 yards (31,900 m), five from the right gun of each turret. The pattern size was 220 yards (200 m), 0.64% of the total range. 14 out of the 15 landed within 250 yards (230 m) of the center of the pattern and 8 were within 150 yards (140 m). Shell-to-shell dispersion was 123 yards (112 m), 0.36% of total range.
Now given that it looks like the CEP for that shoot was around 150 yards at 17 nm, I'm guessing the lighter higher projectile mentioned here would be lucky to have a CEP less than 1 nm when fired on London.

User avatar
phylo_roadking
Member
Posts: 17488
Joined: 01 May 2006, 00:31
Location: Belfast

Re: V 3's how successful if completed

#22

Post by phylo_roadking » 07 Apr 2008, 17:42

Like the V-1 and V-3, it was a strategic bombardment weapon...even in 1944, London was some 55 miles across....from one side of 1930's "Metroland" to the other.

User avatar
LWD
Member
Posts: 8618
Joined: 21 Sep 2005, 22:46
Location: Michigan

Re: V 3's how successful if completed

#23

Post by LWD » 07 Apr 2008, 18:03

Well accroding to:
http://www.navweaps.com/Weapons/WNUS_6-47_mk16.htm
The bursting charge on a US naval 6" round was 6kg. Even if the burster is 2 or 3 times as much you are still talking about less than 20 kg of explosive. http://www.vectorsite.net/twbomb_01.html states that for "normal" bombs ~ half the weight of the bomb is explosive so this is the equivalant of scattering 50kg or 100lb bombs around the whole of London. Sounds to me like a pretty inefficient weapon to me.

User avatar
phylo_roadking
Member
Posts: 17488
Joined: 01 May 2006, 00:31
Location: Belfast

Re: V 3's how successful if completed

#24

Post by phylo_roadking » 07 Apr 2008, 18:12

It's enough to deroof slate-roofed houses, drive people into shelters at night OR day or out of the city entirely, and stop them going to work while they try to look after their families etc....and eventually have them marching down Whitehall with "No More War" posters. Hopefully...

Which was exactly what the RAF had been doing to Germany for three years, with the addition of incendiaries and a stiff wind....

German thought on "strategic bombardment" was still firmly wedged in the pages of Douhet...

User avatar
LWD
Member
Posts: 8618
Joined: 21 Sep 2005, 22:46
Location: Michigan

Re: V 3's how successful if completed

#25

Post by LWD » 07 Apr 2008, 19:13

I did a bit more research and apparently was overly generous with a few assumptions.
Looking at:
http://en.wikipedia.org/wiki/V-3_cannon
It gives a shell weight of 140 kg. US 6" shells were a bit under 50kg so we're almost assuredly looking at under 18 kg of explosive. The big thing is accuarcy. Since these shells were fin stabalized they would be very vulnerable to atmospheric effects (winds) and the errors due to inclination at pitch over could also be magnified. Also consider the Paris gun which was firing at a range approximatly equal to these guns required that the barrel be repaced after 85 rounds and that the rounds had to be fired in a definite numerical sequence. With a smooth bore unless you have some sort of sabot you are going to get even more problematic barrel wear (ie it may not be uniform). Based on what I see they probably could hit London but ....
(Some of the above from: http://en.wikipedia.org/wiki/Paris_Gun)

Of course the lack of practicallity wasn't always a big impediment to weapons development in the Third Reich.

User avatar
phylo_roadking
Member
Posts: 17488
Joined: 01 May 2006, 00:31
Location: Belfast

Re: V 3's how successful if completed

#26

Post by phylo_roadking » 07 Apr 2008, 19:43

LWD, all of that is only important if you're looking to use the weapon to hit ONE specific target. It was the CITY of London at random that was the target, a "vengence" weapon for the "terror raids" on Germany.

Regarding
With a smooth bore unless you have some sort of sabot you are going to get even more problematic barrel wear
...you missed
The angled lateral combustion chambers were spaced every 3.65 m along the bore. The modular weapon could have the lateral chamber sections replaced as they wore out (they would burst after only a few firings
The entire gun was modular and could be replaced by sections - given that like Gerald Bull's Iraq supergun it could only be machined in sections of a given length.

Image

Image

User avatar
LWD
Member
Posts: 8618
Joined: 21 Sep 2005, 22:46
Location: Michigan

Re: V 3's how successful if completed

#27

Post by LWD » 07 Apr 2008, 20:09

Well let's see if I replace a section then it's going to be smaller than the one on either side of it. Doesn't sound like a good idea to me. Also the wear will tend to be on the bottom of the barrel (due to gravity pressure) so it's not going to wear "round". Any significant out of round wear means even hitting London is problematic. Given the nature of the understanding of high altitidue weather and arodymamics I'm not even sure that hitting London would have been all that easy for these guns. Once they had them calibrated on a given day maybe as long as they all had similar wear. But calibration is going to be real pain. And if the British place some deceptive news paper articles they would have a good chance of adjusting the rounds where they wanted or at least didn't mind them. If the Germans had air superiority this might have worked but as it is I'm far from convinced.

User avatar
phylo_roadking
Member
Posts: 17488
Joined: 01 May 2006, 00:31
Location: Belfast

Re: V 3's how successful if completed

#28

Post by phylo_roadking » 07 Apr 2008, 20:17

And if the British place some deceptive news paper articles they would have a good chance of adjusting the rounds where they wanted or at least didn't mind them
Not an "if" - that among other options was how they kindly "adjusted" the aim of the V2s for the Germans.
Any significant out of round wear means even hitting London is problematic
Not if your target is 50 miles across. Its maximum range was 165 Km; 50 miles is, what, 70 Km? So it can't hit a target 70 Km across from only @160 Km away???

User avatar
LWD
Member
Posts: 8618
Joined: 21 Sep 2005, 22:46
Location: Michigan

Re: V 3's how successful if completed

#29

Post by LWD » 07 Apr 2008, 20:36

phylo_roadking wrote:Not an "if" - that among other options was how they kindly "adjusted" the aim of the V2s for the Germans.
Thought I remembered something like that.
Any significant out of round wear means even hitting London is problematic
Not if your target is 50 miles across. Its maximum range was 165 Km; 50 miles is, what, 70 Km? So it can't hit a target 70 Km across from only @160 Km away???
With high velicity guns range errors tend to predominate. If you have much out of round you can get problems like projectile tilt as it leaves the barrel or gas leakage around the projectile. Either of these can have very serious (and in some cases unpredictable) effects on range errors. Remember also this projectile is going up to altitudes that are likely going to be higher than 40km. At that point will the fins stabalize it? If not then when it reinters the thicker atmosphere it could be at a number of orientations that could really mess up it's trajectory or even cause it to break up. The Germans really don't have a chance to test this gun under any sort of controled circumstances. They could even get some significant effects due to exaust gasses on the tail of the projectile and it might not be obvsious. Now if they could test or at least accuratly observe the fall of shot then they could probably get it to work well enough to hit London with most of the rounds. In the absence of that, particularly if the British were engaged in a campaign of deception as noted, it might become problematic even hitting London.

JonS
Member
Posts: 3935
Joined: 23 Jul 2004, 02:39
Location: New Zealand
Contact:

Re: V 3's how successful if completed

#30

Post by JonS » 07 Apr 2008, 20:58

LWD,
that's all true if you're trying to hit a particular building in London. It's not so much of an issue if you're trying to hit any building in London.

Jon

Post Reply

Return to “What if”