KGV article on wikipedia

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Bill Jurens
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Re: KGV article on wikipedia

Post by Bill Jurens »

To Dunmunro:

I have just pulled out my set of 'As Fitted' plans for HMS KGV and compared it directly to the Booklet of General Plans for North Carolina. This inspection has led me to conclude that your idea that somehow the KGV design had non-essential 'venting' spaces above the SPS whereas North Carolina did not, is basically incorrect. To be honest with you, I don't see any significant difference in the allocation of spaces above the side protection system in either of these designs. In both cases, the spaces above the SPS are primarily store-rooms, etc. If anything, I would say that the KGV design has more occupied spaces above the side protection system than the North Carolina does. In North Carolina most of the spaces are labelled as some sort of store-room. In KGV most are labelled as Seamen's Wash Places and Dressing Rooms, etc.

Further, I can find no justification for a claim that "...In both [British?] designs the magazines are surrounded by non-essential spaces in-board of the holding bulkhead.", along with the implication that this is not true in North Carolina as well. Abreast the forward turrets, KGV has a four layer system, loaded Void, Liquid, Void, Void from the shell working inboard. On North Carolina, the system is also four layers, Void, Liquid, Liquid, Void, again proceeding inboard. In both cases the magazines are immediately adjacent to the innermost void space, KGV carrying her heavy bulkhead ouboard of the innermost void, while North Carolina carries her heavy bulkhead inboard of the innermost void. The total width of the system, at least adjacent to "A" turret would appear to be nearly the same, so these systems would appear -- at least to me -- to be nearly equivalent, at least geometrically. Perhaps I'm misreading something important, and in that regard, would invite other readers (certainly not excluding Dunmunro) who might have both plan sets available to comment upon this as well.

I have read the North Carolina War Damage Report again. There was no ignition of propellant whatsoever. Although a bit of flash did apparently penetrate to one handling room, there was no propellant in there because the ship was not at General Quarters when she was hit. Buships felt that ignition would have been improbable in any case.

I am glad to read your comments about the Garzke/Dulin series. It is hard to picture a series matching them in overall accurate coverage even today.

Bill Jurens
dunmunro
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Re: KGV article on wikipedia

Post by dunmunro »

I don't have access to original plans for KGV or NC, but for example here is a low res schematic of a SPS cross section for both ships:

Image

The deck above the KGV SPS is 7mm thick. It appears to me to be very thin to allow for easy upward venting of the V-L-V layer below. On NC, the equivalent deck is 30mm thick, which would indicate, at least to me, that it is not intended to allow for upward venting, although this may happen regardless, but the pressure required would be considerably greater.

now here is a machinery schematic for KGV and NC:

Image

The SPS armoured bulkhead is shown on KGV by the bolded line and the additional void from it to the forward 14" magazine is shown. On NC the magazines are located directly inboard of the final TDS bulkhead, which I believe is the armoured bulkhead, at least according to G&D's US Battleships, p66. My PDF plans of New Jersey show her magazines directly inboard of the final TDS holding bulkhead, which again.

Here is a higher res image of KGV's SPS crosssection and several other BBs:

Image

Again, the 7mm deck over the KGV SPS V-L-V layer is quite apparent, in contrast to the much thicker decks capping the Bismarck's and Richelieu's SPS.

Note, you may have to open some of these images in their own windows to see the entire image.
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Re: KGV article on wikipedia

Post by Bgile »

It appears to me that the KGV system isn't as deep as in contemporaries, and the forward engine rooms are particularly vulnerable.

Isn't it also true that US powder is less volatile than the cordite used in British ships, so less likely to explode even if there is flash in the powder magazine?
dunmunro
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Re: KGV article on wikipedia

Post by dunmunro »

Bgile wrote:It appears to me that the KGV system isn't as deep as in contemporaries, and the forward engine rooms are particularly vulnerable.

Isn't it also true that US powder is less volatile than the cordite used in British ships, so less likely to explode even if there is flash in the powder magazine?

The forward engine rooms are certainly no more vulnerable than any other design.An extra void space is provided for them after the armoured bulkhead, in lieu of the auxiliary machinery spaces. At least one USN BBs had a serious propellant fire that led to the loss of an entire turret crew, during WW2.
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Re: KGV article on wikipedia

Post by Bgile »

dunmunro wrote: The forward engine rooms are certainly no more vulnerable than any other design.An extra void space is provided for them after the armoured bulkhead, in lieu of the auxiliary machinery spaces. At least one USN BBs had a serious propellant fire that led to the loss of an entire turret crew, during WW2.
The forward engine rooms on the KGV are closer to the hull than on contemporary BBs.

I just noticed something else. The spaces over the side protective system on the KGV are not as heavily subdivided as the SPS is. That means that any time you have an explosion which breaches this deck (which you indicate is deliberately weak) over the SPS, you have flooding over the entire top of your SPS of a space larger than the space below it. That's not a good thing, is it? In the case of the US system, the actual SPS void goes up about as high as the additional space on the KGV, but has the same subdivision as the SPS. The US system provides about as much space for "venting", but retains the subdivision and doesn't have any doors in it.

Did British battleships have turret fires with the same result? Were there even any fires? I think the US ships fired (on average) a lot more main battery rounds than British ships, didn't they? So statistically that would make them more likely to have turret fires.
dunmunro
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Re: KGV article on wikipedia

Post by dunmunro »

Bgile wrote:

The forward engine rooms on the KGV are closer to the hull than on contemporary BBs.

I just noticed something else. The spaces over the side protective system on the KGV are not as heavily subdivided as the SPS is. That means that any time you have an explosion which breaches this deck (which you indicate is deliberately weak) over the SPS, you have flooding over the entire top of your SPS of a space larger than the space below it. That's not a good thing, is it? In the case of the US system, the actual SPS void goes up about as high as the additional space on the KGV, but has the same subdivision as the SPS. The US system provides about as much space for "venting", but retains the subdivision and doesn't have any doors in it.

Did British battleships have turret fires with the same result? Were there even any fires? I think the US ships fired (on average) a lot more main battery rounds than British ships, didn't they? So statistically that would make them more likely to have turret fires.
The total width of KGV's SPS abreast the forward engine room is ~16 ft. NC's TDS width is ~18ft at approximately the same area. Bismarck has about 19ft of width, yet Bismarck has the lowest rated SPS in terms of charge weight. Clearly, design is important, not just width.

I don't know the design (from primary sources) specifics of either design in terms of how it was meant to operate, but I think we can infer from the cross sectional drawings that the space above the KGV SPS was to allow for venting. Again the RN design was tested full scale and defeated a 1000lb charge, which is a larger charge than the other designs could defend against, so that simple dimensional comparisons are likely to be very misleading. The partially external bulged design of NC represents a very different design from KGV's SPS.

AFAIK, there were no turret fires in RN BBs during WW2. Again, the point is that while USN propellant was quite stable, it was not perfectly so, and could certainly ignite to deadly effect under the correct conditions.

One of the historical problems when studying the KGV SPS is that many analysis of the SPS design have been tainted by the possibility that a torpedo with a 330lb charge may have defeated the SPS on PoW at frame 206 - which we now know did not happen. DK Brown In Nelson to Vanguard, for example, is quite skeptical about the ability of the KGV SPS to defeat a 1000lb charge because of it's supposed failure on PoW, although Brown does state that the RN reached the conclusion that the SPS could defeat a 1000lb charge after extensive sub and full scale testing.
Thorsten Wahl
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Re: KGV article on wikipedia

Post by Thorsten Wahl »

@ dunmunro
Did you have an report about Job 74 or even some secondary material
I read about the report only at Middlebrook Mahoney "Battleships" but it was without description in depth
did the Ark Royal use the same TDSdesign tested by job 74

Thank you
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Re: KGV article on wikipedia

Post by dunmunro »

Thorsten Wahl wrote:@ dunmunro
Did you have an report about Job 74 or even some secondary material
I read about the report only at Middlebrook Mahoney "Battleships" but it was without description in depth
did the Ark Royal use the same TDSdesign tested by job 74

Thank you
Allied Battleships and Nelson to Vanguard have brief descriptions of the Job 74 trials while British BBs provides some data on previous testing.

Ark Royal's SPS was based upon the Job 74 trials, and shared the same general features and width as the KGV SPS, but there are important differences due to the narrower beam of the Ark Royal and the Illustrious class. The Ark Royal design has a much a much larger liquid layer and smaller void spaces, and IIRC a welded rather than riveted holding bulkhead. The SPS is not surrounded, in-board, by non-essential spaces as in KGV but there does appear to be provision for non-essential spaces above the SPS.
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Re: KGV article on wikipedia

Post by Bill Jurens »

I have the complete Job 74 original report here (less photographs, as I recall, as these were difficult to xerox properly...) When making the sorts of analyses were are trying to do here, it is, I think, important to work from primary rather than secondary sources. When one condenses a 30 or 40 page original document, including drawings, into one or two sentences -- or perhaps even a single phrase -- then one is bound to leave a lot of (potentially very relevant) material out. In addition, we must remember that (with notable exceptions) many of the authors of secondary sources are unqualified to interpret the original material anyway, and many are really just rephrasing something from a secondary source to begin with, making theirs a tertiary statement.

The complete North Carolina War Damage Report (which I also have here) alone is probably 80 pages in length, and includes about 50 photographs which are difficult to interpret without at least a full set of General Arrangement plans and a Damage Control Book at hand. Just absorbing this one item alone could easily consume ten or twelve man-hours. And you really do need the primary sources at hand if you are even begin to make valid assessments.

One of the reasons I haven't commented in more depth on this thread is that I don't have the time to adequately go over the original source material, e.g. the Job 74 report(s) and/or the General Arrangment Drawings of the ships themselves and make any sort of meaningful summary, particularly when it is often not clear exactly what question is being asked (or answered). Relatively simple straightforward questions, e.g. "Did the propellant aboard North Carolina ignite or not?" are susceptible to a quick word search and an unambiguous response, which I have provided when possible. Other more amorphous questions and problems, e.g. exactly what constitutes an "expansion space" and precisely how such a space might be expected to behave after a torpedo explosion are, in reality, so complex that it would take a long time to even begin to answer them coherently.

There are, unfortunately no simple answers, nor any easy ways to get at the complex ones...

Bill Jurens
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Re: KGV article on wikipedia

Post by dunmunro »

Bill Jurens wrote:I have the complete Job 74 original report here (less photographs, as I recall, as these were difficult to xerox properly...) When making the sorts of analyses were are trying to do here, it is, I think, important to work from primary rather than secondary sources...
Bill Jurens
Bill, thanks for the reply. How long is the Job74 report? Maybe I can order it from the UK archives.
Bill Jurens
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Re: KGV article on wikipedia

Post by Bill Jurens »

Here are the Job 74 files as listed at the National Archives in Kew:

ADM 116/3594
"Vulnerability of British warships to torpedoes and bombs: Job 74 experiments 1935-1937
ADM 324/4
"Trials carried out during the period 1935-1937 using full scale experimental floating structure known as Job 74” 1937 Jan 01-1937 Dec 31
ADM 226/50
"Job 74" 1944 Nov 2
ADM 226/50
“Job 74: further towing experiments” 1944 Nov 11
ADM 226/50
"Job 74: further towing experiments model CC” 1944 Nov 16
ADM 253/102
"Job 74 trials: "B" bomb shot; bullhead and deck accelerations” 1935
ADM 253/103
“Job 74 trials:"B" bomb trials: gauge measurements below target” 1936
ADM 253/118
"Job 74 trial: 1000lb contact charge against starboard bulge” 1936
ADM 253/119
"Job 74 trial: 1000lb charge against starboard bulge” 1936
ADM 253/130
"Job 74 trial: Second1000lb charge against starboard bulge” 1937

The best summary, I think, is in the first document, i.e. ADM116/3594.

If you do decide to chase these down, please let me know what you come up with, as I might like to add a few of the totally missing reports to my own files, and touch up a few of my existing files that are missing various pages. Copying technology has come a long way since 1980 or so...

Bill Jurens
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Re: KGV article on wikipedia

Post by lwd »

Bill Jurens wrote:...
There are, unfortunately no simple answers, nor any easy ways to get at the complex ones...
I'm reminded of the old saying: "To any complex question there is at least one simple answer .... That is wrong." :D
Thorsten Wahl
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Re: KGV article on wikipedia

Post by Thorsten Wahl »

I could ask a friend from the UK for a cost estimate like this
recently we made a inquiry at Kew with2 friends of the German Forum Marinearchiv
at least we decide to purchase the ninty pound piece SUPP 6/910

http://forum-marinearchiv.de/smf/index. ... #msg126639

DEFE 15/474 Variation in penetrative performance of AP (steel) capped projectiles of varying head shapes, against armour
DEFE 15/474 £13.50
A3 Mono. copies (from original documents) 30 x £0.45 = £13.50

DEFE 15/454 Performance of AP projectiles against armour protected by skirting plates
DEFE 15/454 £25.65
A3 Mono. copies (from original documents) 57 x £0.45 = £25.65

SUPP 22/41 Performance and prediction formulae armour piercing projectiles
SUPP 22/41 £16.65
A3 Mono. copies (from original documents) 37 x £0.45 = £16.65


SUPP 22/42 Vulnerable area diagrams armour plate versus AP projectiles
SUPP 22/42 £6.75
A3 Mono. copies (from original documents) 15 x £0.45 = £6.75

DEFE 15/1693 German 40.6cm armour piercing projectile capped with ballistic cap
DEFE 15/1693 £16.95
A3 Mono. copies (from original documents) 5 x £0.45 = £2.25 +
A1 Mono. prints (from digital scans) 1 x £14.70 = £14.70

DEFE 15/200 Part C: armour piercing projectiles
DEFE 15/200 £5.40
A3 Mono. copies (from original documents) 12 x £0.45 = £5.40

ADM 213/726 Admiralty Mining Establishment: report on underwater pressures set up by the impact of 6 inch S.R. projectile fired near the critical angle of ricochet (a) with water and (b) with an armoured steel plate when travelling underwater
ADM 213/726 £6.30
A3 Mono. copies (from original documents) 14 x £0.45 = £6.30

DEFE 15/452 Fundamental investigation into optimum hardness for capped armour piercing shot: part II
DEFE 15/452 £13.50
A3 Mono. copies (from original documents) 30 x £0.45 = £13.50

SUPP 6/910 The penetration of armour plate (compiled by the co-ordinating sub-committee)
1950 Jan 01-1950 Dec 31
SUPP 6/910 £90.90
A3 Mono. copies (from original documents) 202 x £0.45 = £90.90
Meine Herren, es kann ein siebenjähriger, es kann ein dreißigjähriger Krieg werden – und wehe dem, der zuerst die Lunte in das Pulverfaß schleudert!
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Re: KGV article on wikipedia

Post by dunmunro »

I attempted to purchase ADM 116/3594, but the document was too long for the Digital express service. I will try and order a copy via their regular service next week.
Bill Jurens
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Re: KGV article on wikipedia

Post by Bill Jurens »

So far as I know, the National Archives still allows you to take in a digital camera and photograph documents on site, so that if you have someone who can go down there in person and photograph the original file for you, that's a LOT cheaper than having the Archives staff do it. The quality often isn't quite as good, but the content is still there.

But you have to find someone...

Bill Jurens
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