Hood v Vittorio Veneto

Historical what if discussions, hypothetical operations, battleship vs. battleship engagements, design your own warship, etc.
Maciej
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Re: Hood v Vittorio Veneto

Post by Maciej » Sun May 22, 2016 8:30 am

alecsandros wrote:
dunmunro wrote:
The RN test did use RM distances,
Source.
ADM 281/31
construction techniques cemented armour on both plates
What materials did they use for the armor plates ?
Class C armorur.
Class C in British therms mean face hardened. For obvious reasons it was British produced plates. I have seen some time ago exact parameters of those plates, but what difference makes it anhyway?
Biger difference is in shell construction.
and the tests were conducted at 30 deg obliquity.
Meaningless - what was the declination of the plates ?
Repeat 30 degree to plate.
It means 30 degree to plate.
Doesn’t mater if plate declined 15 degree and descend of shell 15 degree ( correspond to distance over 20 km ), or if plate is declined 30 degree, and point blank range.
Simple 3d geometry.
The British tests were flawed.
No German tests were flawed. They uses wrong shells!
Yes I know for years that everything British is flawed, and they simply can’t do enything right.
They tested various spaced arrays since 1903.
And through those 40+ years had simply no idea how to do that.
And rest of the world learned in year or so.

Or other possibility is available.

British engineers were equally adequate to imlement various tests ( in 40+ years period, so more than one generation ), but there was some reason why various sides had different conclusions.
Possibilities –
1. very different armour plates with very different capabilities
2. very different shells construction, so decapping works different due to various reasons
3. both above.

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Re: Hood v Vittorio Veneto

Post by alecsandros » Sun May 22, 2016 8:38 am

Maciej wrote: ADM 281/31
What is the distance between plates, Maciej ? And why does it matter, if at all ?
Class C armorur.
Class C in British therms mean face hardened. For obvious reasons it was British produced plates. I have seen some time ago exact parameters of those plates, but what difference makes it anhyway?
Biger difference is in shell construction.
Hardness of face of plate, depth of cimentite, etc, all matter in perforation.
Repeat 30 degree to plate.
It means 30 degree to plate.
Doesn’t mater if plate declined 15 degree and descend of shell 15 degree ( correspond to distance over 20 km ), or if plate is declined 30 degree, and point blank range.
Simple 3d geometry.
NO. Please read the documents, and post afterwards.
Last edited by alecsandros on Sun May 22, 2016 8:40 am, edited 1 time in total.

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Re: Hood v Vittorio Veneto

Post by alecsandros » Sun May 22, 2016 8:40 am

Maciej wrote:
1. very different armour plates with very different capabilities
2. very different shells construction, so decapping works different due to various reasons
3. both above.
4. Inability or un-willingness to replicate any sort of foreign design, on the basis that their own designs were the best in the world.

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Re: Hood v Vittorio Veneto

Post by Maciej » Sun May 22, 2016 8:51 am

What is the distance between plates, Maciej ?
In test of Littorio structure? The same as in Littorio structure. Simple.
Later teste were in different parameters of that distance, but are irrevelant to test of reconstructed Littorio's structure.
Again simple.
alecsandros wrote:
Maciej wrote:
1. very different armour plates with very different capabilities
2. very different shells construction, so decapping works different due to various reasons
3. both above.
4. Inability or un-willingness to replicate any sort of foreign design, on the basis that their own designs were the best in the world.
I waited for that.
Read more primary sources. British constructors were quite with little complexes
If something was clearly better, it was recommendation to simply implement it.
Buy licence to produce it domestically or just copy. There are a lot of such examples.
Again – they tested spaced arrays since 1903, and still in 1948 had no idea how to do that.

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Re: Hood v Vittorio Veneto

Post by Maciej » Sun May 22, 2016 9:46 am

alecsandros wrote:
Maciej wrote: ADM 281/31
What is the distance between plates, Maciej ? And why does it matter, if at all ?
Class C armorur.
Class C in British therms mean face hardened. For obvious reasons it was British produced plates. I have seen some time ago exact parameters of those plates, but what difference makes it anhyway?
Biger difference is in shell construction.
Hardness of face of plate, depth of cimentite, etc, all matter in perforation.
Repeat 30 degree to plate.
It means 30 degree to plate.
Doesn’t mater if plate declined 15 degree and descend of shell 15 degree ( correspond to distance over 20 km ), or if plate is declined 30 degree, and point blank range.
Simple 3d geometry.
NO. Please read the documents, and post afterwards.
To be sure that we are talking about the same thing.
Reconstruction of Littorio structure test. Not later/more early tests
Image

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Re: Hood v Vittorio Veneto

Post by alecsandros » Sun May 22, 2016 10:00 am

Maciej wrote:
Later teste were in different parameters of that distance, but are irrevelant to test of reconstructed Littorio's structure.
Again simple.
What is the influence of spacing of plates in regards of effectiveness of armor array , according to British tests?
Maciej wrote: Read more primary sources.
A perfect advice !
Last edited by alecsandros on Sun May 22, 2016 10:05 am, edited 1 time in total.

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Re: Hood v Vittorio Veneto

Post by alecsandros » Sun May 22, 2016 10:02 am

Maciej wrote:
To be sure that we are talking about the same thing.
No,
Both drawings are incorrect. The projectile exiting the first plate does not follow it's initial angle, but is drawn towards the normal of the first plate.

Also, the interspace was not 7", and the first plate was not 2.75" thick.

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Re: Hood v Vittorio Veneto

Post by Maciej » Sun May 22, 2016 10:40 am

Mistaken post, put in wrong place. I can't delete it,
sorry

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Re: Hood v Vittorio Veneto

Post by kevin32422 » Mon May 23, 2016 6:22 pm

To me the Vittorio Veneto has a few things better than the Hood, it is more modern in almost every way the only thing the Hood has over the Vittorio is the crew seaman ship (knowing what to do and when to do it) and that is a big difference but this match up is still a toss up in my book whoever got the first big hit that cripples the other or slows it down would have the advantage

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Alberto Virtuani
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Re: Hood v Vittorio Veneto

Post by Alberto Virtuani » Tue May 24, 2016 8:01 am

Hi all,
I've been traveling this past week-end, so I'm late with some comments:
Dunmunro, commenting the results of German tests on Littorio's belt, wrote: ".....However the RM used cemented armour on both plates (above document states homogeneous and cemented)...."
RM used homogeneous steel for the decapping plate (the 70mm one) and KC for the resistant plate (280 mm). My mistake when I posted at page 12 of this thread. However, if you look at the graphical armor scheme on the same page, you will see that the "piastra scappucciante" was an homogeneous (OD) one. The German tests were done correctly.


Maciej wrote: ".....So that structure is say the same in protection as say 370 mm plate ( that “sligth” difference ). And inclined 15 degree".....
Even accepting that the British tests are the correct ones, while German and Italians are not (and I would wonder why we should say that.... :think: ), a 370 mm one (and it could easily be 400mm as well, as the result of these tests is quite ambiguous; what does it mean "slightly better" ? 5%, 10% 15% ?.....), is equivalent to almost 400 mm KC (very good Italian quality) vertical belt, followed by heavy bulkheads to the vitals, therefore far better than Hood, QE's, KGV's and Vanguard...... :D


Kevin32422 wrote: "To me the Vittorio Veneto has a few things better than the Hood "
:negative:
Please, please, even discounting the more powerful guns, the far better protection (vertical, horizontal and underwater), the secondary armament, the AA armament, the fact she was 20 years newer and the structural construction (look how Roma's hull reacted to the explosion of the main magazines, having been already severed...) she was at least immune to the German shell that doomed the British battlecruiser....


Bye, Alberto
Last edited by Alberto Virtuani on Tue May 24, 2016 8:33 am, edited 3 times in total.
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Re: Hood v Vittorio Veneto

Post by Maciej » Tue May 24, 2016 8:14 am

Even accepting that the British tests are the correct ones, while German and Italians are not (and I would wonder why we should say that.... ),
Take me right.
I’m sure all tests were “right”
Simply – different shells were used.
The same structure can “perfectly” decap one shell, and not decap/partially decap other shell.
I’m sure engineers on all those sites were quite capable of making tests.
But they used different materials to those tests. British simply had no available armour “made in Itally” and had no shells “made in Itally” ( and Germany ) to reproduce those tests.

That one thing could make difference with conclusions.
And in this particular problem, behavior of such structure against British shells is important.
How well protected is Littorio against Littorio’s shells are unimportant.
Unless we start to analyze some king of Italy civil war, or friendly fire ;)
In most situations she will be shelled by ammo different than own, so protection against such shells is important.
But clearly most reliable data are about protection against own weapons, for obvious reasons.

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Re: Hood v Vittorio Veneto

Post by alecsandros » Tue May 24, 2016 8:45 am

Maciej wrote:
Take me right.
I’m sure all tests were “right”
Simply – different shells were used.
The same structure can “perfectly” decap one shell, and not decap/partially decap other shell.
No, Maciej,
As we discussed above. :cool:

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Alberto Virtuani
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Re: Hood v Vittorio Veneto

Post by Alberto Virtuani » Tue May 24, 2016 8:52 am

Hi Maciej,
just to add that the Italian belt was tested both against Italian 381 and 320 mm shells (the guns available to Italians). The British 356 mm is somehow in between and Italians were possibly confident that the array would have worked against the British shells as well; it could be a wrong assumption, but also the British tests could be totally wrong as they were not using the same materials and did not respect the correct gap distance for the array....

However, as I said, even a 370 mm inclined 15° belt (as per British tests, and "slightly better" could have been 400mm as well....), is equivalent to almost 400 mm KC (very good Italian steel) vertical belt, followed by heavy bulkheads to the vitals, therefore far better than Hood, QE's, KGV's and Vanguard...... :D

If you add the more powerful 15" Italian gun in comparison to the British 14", the advantage of Littorio's against KGV's is quite large in term of IZ.


Bye, Alberto
Last edited by Alberto Virtuani on Tue May 24, 2016 9:02 am, edited 1 time in total.
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"There's always a danger running in the enemy at close range" (Adm.W.F.Wake-Walker)

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Re: Hood v Vittorio Veneto

Post by Maciej » Tue May 24, 2016 9:01 am

(as per British tests, and "slightly better" could have been 400mm as well....)
I checked it now.
It was ~50 feet/s better compared to solid plate of the same thickness ( added actually the same weight. Weight of supporting structure was arbitrally set at 20 lbs: ~0.5 inch, so if total thickness of two plates was say 12", that mens, slighty better resistance than one plate 12.5")
In therms of "critical velocity"
But there were only few shots fired. With a bit "good will" could me dismissed, as "not enough sample to be statistically correct"
or something like that.

Again take me right.
Littorio is many times described very unfairly. She was much better than sometimes stated.
I simply want to avoid moving to "other site"

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Alberto Virtuani
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Re: Hood v Vittorio Veneto

Post by Alberto Virtuani » Tue May 24, 2016 9:12 am

Hi Maciej,
thanks for the data. :clap: I do see your final point and totally agree with you.

Still, the "British" tests were not using the original array materials and, most important, they were not respecting the right gap distance between the 2 plates (that is the very key design feature to ensure the "precession" motion to the shell and its, at least partial, decapping).

My point about the IZ of Littorio's vs KGV's, even accepting the results of the above British tests (therefore "just" 370 mm equivalent inclined belt), still stands.

Bye, Alberto
Last edited by Alberto Virtuani on Tue May 24, 2016 9:29 am, edited 1 time in total.
"It takes three years to build a ship; it takes three centuries to build a tradition" (Adm.A.B.Cunningham)

"There's always a danger running in the enemy at close range" (Adm.W.F.Wake-Walker)

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