Armor schemes: "All or nothing'' vs. ''Incremental"

Warship design and construction, terminology, navigation, hydrodynamics, stability, armor schemes, damage control, etc.
Monitor
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Armor schemes: "All or nothing'' vs. ''Incremental"

Post by Monitor » Mon May 02, 2005 5:47 pm

What are the advantages of the "All or nothing" over the "Incremental" armor scheme and viceversa?

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Javier L.
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Post by Javier L. » Tue May 03, 2005 11:34 pm

This is what I understand.
The "All or Nothing" scheme protects only the most vital places of the ship with heavy armor plates.
The "Incremental" scheme gives protection to more places but the armor plates are lighter.
There must be exceptions but as we say here, "the exception confirms the rule". :D

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Dave Saxton
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Post by Dave Saxton » Wed May 04, 2005 3:00 am

One way to examine the various trade offs is to look at what the Royal Navy did with their later day designs.

Nelson and Rodney incorporated all it's heavy guns into three turrets to shorten the citadel, and while the main armoured deck extended almost to the ships sides, the rather shallow sloped belts were actually inside the shell plating by several feet. No armoured conning tower was used, and there was little protection provided to the steering compartment aft, or the shaft tunnels abaft the citadel. This approach made it possible to provide the vital spaces and the heavy battery turrets and their barbets with heavy plates. This is what the "strict" AoN approach adopted by degree by most navies in the wake of the Washington Treaty was probably all about. The Nelson served as the prototype of how to get a thick main armoured deck on a limited dispacement. However, the amount of total ship that was protected by any armour in the Nelson's case was very low.

Typical of this type of design, the protected length was no more than about 50%. The soft ends of the ships were long and extensive with no splinter protection to protect the water plane there. The internal belts could not protect water planes along the citadel either. The belts actually protected a very narrow window (vertically) from heavy shells, from about the waterline to only about one deck level above the waterline. The side protection system was rather more vulnerable to diving shells, as shells fired from meduim to long ranges could more easily pass beneath the heavily sloped belts peircing the inner hull.

In KGV, the British increased the "coverage" of the citadel by raising the height of the belts and the level of the main armoured deck, one deck level. The volume of the citadel was greatly increased. The belts were now external, and extended below the water line more. Slope was less, except were as it followed the contour of the hull, but it covered a much larger area of the side. The side protection now offered better protection to diving shells, and the water plane over the length of the citadel was now protected. The protected length was increased to about 60% of the overall length.

In Vanguard, we find armour plate being applied to the soft ends of the ship in slight violation of the strict AoN principle, to futher enhance protection of the water plane, and more extensive splinter protection being applied internally. In Vanguard in particular, we find the Royal Navy moving away from the very strict AoN approach to a compromise between the trade offs of different approaches.

Describing a given protection scheme as being either AoN or incremental is rather limiting. I would not describe the systems used by the Germans as either, but a third different type of approach. Many warships that we normally decribe using the term AoN did not follow the principle strictly. For example, US battleships had an additional thin armoured deck over, or under, the main armoured deck, protected steering rooms, and very heavily armoured conning towers. In some aspects I find some strong similarities among German and US battleships.

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Post by Tiornu » Wed May 04, 2005 4:57 am

Vanguard's armor scheme was essentially identical to Howe's. I see no progression.

George Elder
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Look more closely...

Post by George Elder » Thu May 05, 2005 4:22 am

... and you will see both external and internal differences. You can tell us what these are.

George

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Re: Look more closely...

Post by Tiornu » Thu May 05, 2005 9:44 am

Is the shaving of an inch from the belt a progression?

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Re: Armor schemes: "All or nothing'' vs. ''Incremental&

Post by ufo » Fri May 06, 2005 12:40 pm

Monitor wrote:What are the advantages of the "All or nothing" over the "Incremental" armor scheme and viceversa?
I think when you look at a certain armour scheme you also have to think about the context the ship is used in.
For a ship that spends it’s life operating in various task forces as a fast AA platform, as a fire spitting supporter of landing operations or as a hunter of loose raiders, I would say an AoN scheme is the perfect choice. You would want armour that protects the very vitals of the ship as a fighting unit. Once the battle is won, who cares if your bow lays on the ocean floor. There are destroyers to guard you, tugs to pull you, repair ships to nurse you back home.

The story is much different for a ship that is intended to operate as a raider. Here the designer faces the task not only to protect the parts vital for a single fight but also to build in protection to allow for a sustained campaign. A ship intended to spend months alone at sea and survive numerous engagements, cannot do very well with the bow shot off. So in that case you would rather want incremental armour.

I think in most cases there is no answer what particular solution was better or worse. It depends on the intended role of the ship. Only when you take that into account you can judge if the designers got it right.

I think on a general note that is the point that invalidates all these famous battleship rankings. Though they are all members of the Washington Treaty category ‘battleship’ they differ much in purpose. In the Pacific in 1943 a massive light AA is vital. In the Arctic where you sit and wait for a cheeky Panzership to venture out, lots of light AA are more of a fire hazard and a cause of shrapnel when you are hit. So one has to look at the designer’s choice in context of the theatre of war.

Ciao,
Ufo

George Elder
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Richard, you know the differences...

Post by George Elder » Sun May 08, 2005 7:11 am

.... between the KGV armor design and Vanguard, so why be so very disengenuous in stating that these differences amount to little more than the shaving of an inch from the Vanguard's main belt? Look forward and aft of the citadel in the two designs, and the use of more splinter armor in the Vanguard vs the KGV is readily evident. And since this is common knowledge, why ignore the point as it relates to the evolution of the British AoN system? Well, it's back to Mr. T, for you... not that I have time to post much any more.

George

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Re: Richard, you know the differences...

Post by Tiornu » Sun May 08, 2005 10:32 am

George, why bother posting at all? You had an opportunity to say something constructive, but opted instead to offer vague misinformation and false accusation. You apparently do NOT know how Vanguard's protection was different from that of Howe. Give the specifics so I can agree or disagree with you, and keep the hot air for people who enjoy adolescent behavior.

George Elder
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A degree in what?

Post by George Elder » Mon May 09, 2005 3:23 am

Gosh, you have devolved a bit. I am basing my views on the cross-sectional diagrams from D&G and others. Look at the forward frames, about frame 20, see the splinter protection thickness of the Vanguard -- 60+ mm. Compare this with the KGV class. Do the same aft. You know these things. As for Howe, she was a slightly modified KGV, but modified to reflect what was seen as shortcomings in the initial AoN design. Now tell me, why was it seen as neccessary to modify the design? What experience motivated the shift? As for adolescent behavior and hot air, you sure seem to spend an inordinate amount of time on posting boards -- regardless of family, job, etc.. And one can readily find examples of you venting your spleen here and there. Tell me, is such an addiction and rheotorical style the sign of an adult or juvinile disorder? Better yet, it might be best to examine why the British were opting to employ more external and internal splinter armor rather than depend on the AoN citadel armor alone. Now, that would be the adult thing to do.

George

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Post by marty1 » Mon May 09, 2005 6:30 am

Great post Dave...Great post UFO. Thanks for your insights.

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Re: A degree in what?

Post by Tiornu » Mon May 09, 2005 7:37 am

George, this was a discussion about warships until you infected it with your usual personal attacks. This is a repeat of the recent thread which resulting in Jose instructing you to apologize to Bill. I do not believe you are any longer capable of rational discussion. The G&D drawings you are relying on are incorrect on several details of the end armor, and the mind you use to assess information is as hopeless as depicted in your latest post.

George Elder
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How feeble...

Post by George Elder » Mon May 09, 2005 9:36 am

In what sense are the D&G drawings innacurate, because I will surely contact them about your detailed concerns? Their work seems to agree with some other sources to hand (some great quotes from Roberts here), so perhaps a few specifics on your part about exactly where the authors are amiss are in order. That being said, you seems to be evading of the main point here, which is the progression to the increasing use of splinter armor outside the main citidel in British WWII era BB construction -- and thus the abandonment of a "pure" AoN system (if there ever was such a beast). Dave was essentially correct about that. Moreover, this seems like a rational point to discuss, and even the poor pitiful mind I use to access information is stable enough to stick to the point to hand. Ah, but we down in the "bunker," as you put it, what do we know?

George

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Post by Plamen74 » Wed Sep 21, 2005 9:01 am

The American designers compared USS NC and British KGV /Friedman book about USS BB/ and concluded that NC design was more vulnurable to HE and SAP shells because of her "soft" ends.Her speed could be easier reduced.
I wish to mention Musashi loss /AON BB/, which was bombed mainly with General purpose bombs and her speed and manuevarability was reduced
P.V.

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