KGV + PoW

Discussions about the history of the ship, technical details, etc.
alecsandros
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Re: KGV + PoW

Post by alecsandros » Wed Sep 19, 2018 7:38 pm

dunmunro wrote:
Wed Sep 19, 2018 7:24 pm
The KGV class displacement data was carefully recorded by the Admiralty whereas Bismarck's data has not been so conveniently available. Hence the revised figures over the years. I am fully confident in Mr Rico's figures and I'm sure that most board members accept them as correct.
But are you confident that the 2 "standard displacement" were measured in the same way or included the same things ?

That's why I mention G/D - because they actualy did write books on both battleship classes, not only one of them.

dunmunro
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Re: KGV + PoW

Post by dunmunro » Wed Sep 19, 2018 7:56 pm

alecsandros wrote:
Wed Sep 19, 2018 7:38 pm
dunmunro wrote:
Wed Sep 19, 2018 7:24 pm
The KGV class displacement data was carefully recorded by the Admiralty whereas Bismarck's data has not been so conveniently available. Hence the revised figures over the years. I am fully confident in Mr Rico's figures and I'm sure that most board members accept them as correct.
But are you confident that the 2 "standard displacement" were measured in the same way or included the same things ?

That's why I mention G/D - because they actualy did write books on both battleship classes, not only one of them.
Standard displacement has only one definition and was defined by the naval limitation treaties.

You'll have to address any questions about the veracity of his figures to Mr Rico. G&D wrote their books some decades ago, and IIRC much new data has been uncovered in the German archives since then.

Bismarck has a longer main belt (with very similar height) and MAD than KGV and draws the same or more draft. Her machinery is heavier. It would be rather amazing if a 795 x 118ft battleship was only slightly heavier in standard displacement than one that measures 745 x 103ft but, in fact, the difference in std displacement is about what we'd expect, given their different dimensions.

swpz
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Re: KGV + PoW

Post by swpz » Wed Sep 19, 2018 10:20 pm

So I do have a somewhat odd question.

Could Bismarck be considered lightly armed for her size? 8x15" seems kind of few especially when we consider what say the RM or the USN were packing which was 9x15/16" respectively while being nearly 100ft shorter (Veneto class, SD class, North Carolina class, etc).

dunmunro
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Re: KGV + PoW

Post by dunmunro » Wed Sep 19, 2018 11:03 pm

swpz wrote:
Wed Sep 19, 2018 10:20 pm
So I do have a somewhat odd question.

Could Bismarck be considered lightly armed for her size? 8x15" seems kind of few especially when we consider what say the RM or the USN were packing which was 9x15/16" respectively while being nearly 100ft shorter (Veneto class, SD class, North Carolina class, etc).

The RN Lion class which were designed to ~40k tons standard displacement would have had 9 x 16in guns. The RM V.V. class were larger than KGV and more similar in size to Bismarck at ~780 x 108ft and 41k tons std displacement.

The USN ships were more heavily armed but achieved this by reducing hull dimensions and accepting somewhat lower maximum speeds.

alecsandros
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Re: KGV + PoW

Post by alecsandros » Thu Sep 20, 2018 5:27 am

dunmunro wrote:
Wed Sep 19, 2018 7:56 pm
Standard displacement has only one definition and was defined by the naval limitation treaties.
And still here we are, with 3 different displacements for Bismarck, 41663, 41881, 42629 tons at standard displacement.

As far as armor goes, you need to take into account that KGV's belt protected about the same percentage (45%) of ship's hull surface (latteral surface). That is because it had 7.2meters height, versus 4.8meters height for Bismarck. Thus, although KGV's belt was not as long as Bismarck's, it was considerably taller, and thus included a lot of weight.

If you divide displacement to waterline length, you'll find KGV was heavier , per meter, then Bismarck was.

alecsandros
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Re: KGV + PoW

Post by alecsandros » Thu Sep 20, 2018 5:29 am

dunmunro wrote:
Wed Sep 19, 2018 11:03 pm
The RN Lion class which were designed to ~40k tons standard displacement would have had 9 x 16in guns. The RM V.V. class were larger than KGV and more similar in size to Bismarck at ~780 x 108ft and 41k tons std displacement.
That was the design,
In reality, Anson displaced ~40k in 1943, so Lion would displace much more then that.

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Re: KGV + PoW

Post by dunmunro » Thu Sep 20, 2018 7:12 am

alecsandros wrote:
Thu Sep 20, 2018 5:27 am
dunmunro wrote:
Wed Sep 19, 2018 7:56 pm
Standard displacement has only one definition and was defined by the naval limitation treaties.
And still here we are, with 3 different displacements for Bismarck, 41663, 41881, 42629 tons at standard displacement.

As far as armor goes, you need to take into account that KGV's belt protected about the same percentage (45%) of ship's hull surface (latteral surface). That is because it had 7.2meters height, versus 4.8meters height for Bismarck. Thus, although KGV's belt was not as long as Bismarck's, it was considerably taller, and thus included a lot of weight.

If you divide displacement to waterline length, you'll find KGV was heavier , per meter, then Bismarck was.
Bismarck's standard displacement grew over time, which was a natural process for all WW2 battleships. In March of 1941 the KM estimated Bismarck's standard displacement as 43150 tonnes or 42470 tons.
http://www.kbismarck.com/bismarck-riche ... leich.html


You're ignoring Bismarck's 145mm upper belt (~2.4m high) and when we add this to the height of the 4.8m high lower belt we get about the same height as KGV. The main difference being that KGV's belt extends much deeper below the waterline even though the bottom edge tapers in thickness and even a tapered belt thickness is reasonably effective against diving shells.

alecsandros
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Re: KGV + PoW

Post by alecsandros » Thu Sep 20, 2018 8:05 am

dunmunro wrote:
Thu Sep 20, 2018 7:12 am
Bismarck's standard displacement grew over time, which was a natural process for all WW2 battleships. In March of 1941 the KM estimated Bismarck's standard displacement as 43150 tonnes or 42470 tons.
http://www.kbismarck.com/bismarck-riche ... leich.html
Yes, I think this is where we disagreed above: the std disp for KGV is given for 1940. We do not have data for May 1941. A reasonable estimate would include the weight additions of KGV between Oct 1940 and May 1941.

You're ignoring Bismarck's 145mm upper belt (~2.4m high) and when we add this to the height of the 4.8m high lower belt we get about the same height as KGV. The main difference being that KGV's belt extends much deeper below the waterline even though the bottom edge tapers in thickness and even a tapered belt thickness is reasonably effective against diving shells.
There was also a small 170mm lower belt.
But take into consideration that the weight of the 145mm and 170mm portions of the belt were much lighter then the comparable armor belt portions from KGV design. KGV had 7.2m of 374mm belt, whereas Bismarck had about 7meters of 145 to 320mm thick belt.

I don't know what type of hull did Bismarck and KGV had. I.e., how thick and how heavy was the hull itself ?

KGV seems awfully heavy for her size (224m waterline length and ~38000 tons is 169 tons/meter)

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Alberto Virtuani
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Re: KGV + PoW

Post by Alberto Virtuani » Thu Sep 20, 2018 9:21 am

Hi Alec,
I think that the welding technique used for Bismarck and the absence of structural decks when armored ones were present (the armored decks in Bismarck play also a structural role, not sure about KGV, previous British ships did not used this ) helped Bismarck to be not so heavy for her size/protection level, in addition to the smart usage of horizontal /sloped deck to increase also vertical protection.


Bye, Alberto
"It takes three years to build a ship; it takes three centuries to build a tradition" (Adm.A.B.Cunningham)

dunmunro
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Re: KGV + PoW

Post by dunmunro » Thu Sep 20, 2018 10:01 am

alecsandros wrote:
Thu Sep 20, 2018 8:05 am
dunmunro wrote:
Thu Sep 20, 2018 7:12 am
Bismarck's standard displacement grew over time, which was a natural process for all WW2 battleships. In March of 1941 the KM estimated Bismarck's standard displacement as 43150 tonnes or 42470 tons.
http://www.kbismarck.com/bismarck-riche ... leich.html
Yes, I think this is where we disagreed above: the std disp for KGV is given for 1940. We do not have data for May 1941. A reasonable estimate would include the weight additions of KGV between Oct 1940 and May 1941.

You're ignoring Bismarck's 145mm upper belt (~2.4m high) and when we add this to the height of the 4.8m high lower belt we get about the same height as KGV. The main difference being that KGV's belt extends much deeper below the waterline even though the bottom edge tapers in thickness and even a tapered belt thickness is reasonably effective against diving shells.
There was also a small 170mm lower belt.
But take into consideration that the weight of the 145mm and 170mm portions of the belt were much lighter then the comparable armor belt portions from KGV design. KGV had 7.2m of 374mm belt, whereas Bismarck had about 7meters of 145 to 320mm thick belt.

I don't know what type of hull did Bismarck and KGV had. I.e., how thick and how heavy was the hull itself ?

KGV seems awfully heavy for her size (224m waterline length and ~38000 tons is 169 tons/meter)
KGV had 126m x 4.8 meters of 349 (2/3s) or 374mm (1/3) belt armour plus 148m of 2.4m armour that tapered from 349-112mm or 374-137mm and 305-100mm for 20m.

Bismarck was 241.55m WL length and 43283 tons for 179 tons/meter so KGV seems svelte in comparison.
Last edited by dunmunro on Thu Sep 20, 2018 10:10 am, edited 1 time in total.

alecsandros
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Re: KGV + PoW

Post by alecsandros » Thu Sep 20, 2018 10:04 am

dunmunro wrote:
Thu Sep 20, 2018 10:01 am
Bismarck was 224.55m WL length and 43283 tons for 179 tons/meter so KGV seems svelte in comparison.
Bismarck was 242m WL length, not 224.

When Bismarck displaced 43283 metric tons, KGV displaced over 39500 metric tons.

You are using (probably) May 1941 data for Bismarck weight and Oct 1940 data for KGV weight, which is wrong.

dunmunro
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Re: KGV + PoW

Post by dunmunro » Thu Sep 20, 2018 10:08 am

Alberto Virtuani wrote:
Thu Sep 20, 2018 9:21 am
Hi Alec,
I think that the welding technique used for Bismarck and the absence of structural decks when armored ones were present (the armored decks in Bismarck play also a structural role, not sure about KGV, previous British ships did not used this ) helped Bismarck to be not so heavy for her size/protection level, in addition to the smart usage of horizontal /sloped deck to increase also vertical protection.


Bye, Alberto
Bismarck was 43283 tons standard (Mr Rico's data) versus 38030 tons for KGV (G&D). The KM didn't bother to try and design Bismarck to 35k tons and designed a much larger ship than KGV that was also much heavier; this is pretty obvious from her dimensions.

dunmunro
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Re: KGV + PoW

Post by dunmunro » Thu Sep 20, 2018 10:19 am

alecsandros wrote:
Thu Sep 20, 2018 10:04 am
dunmunro wrote:
Thu Sep 20, 2018 10:01 am
Bismarck was 224.55m WL length and 43283 tons for 179 tons/meter so KGV seems svelte in comparison.
Bismarck was 242m WL length, not 224.

When Bismarck displaced 43283 metric tons, KGV displaced over 39500 metric tons.

You are using (probably) May 1941 data for Bismarck weight and Oct 1940 data for KGV weight, which is wrong.
I calculated the weight per meter using 241.55m WL length and 43879 tonnes (Mr Rico) = 43282 tons = 179 tons/m

KGV had no major weight increases from her inclining in Oct 1940.

alecsandros
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Re: KGV + PoW

Post by alecsandros » Thu Sep 20, 2018 10:20 am

dunmunro wrote:
Thu Sep 20, 2018 10:08 am
Bismarck was 43283 tons standard (Mr Rico's data) versus 38030 tons for KGV (G&D). The KM didn't bother to try and design Bismarck to 35k tons and designed a much larger ship than KGV that was also much heavier; this is pretty obvious from her dimensions.
Again you are comparing apples with oranges.
Apples with apples would be Bismarck in Oct 1940 with KGV in Oct 1940, or Bismarck in May 1941 with KGV in May 1941.

dunmunro
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Re: KGV + PoW

Post by dunmunro » Thu Sep 20, 2018 10:32 am

alecsandros wrote:
Thu Sep 20, 2018 10:20 am
dunmunro wrote:
Thu Sep 20, 2018 10:08 am
Bismarck was 43283 tons standard (Mr Rico's data) versus 38030 tons for KGV (G&D). The KM didn't bother to try and design Bismarck to 35k tons and designed a much larger ship than KGV that was also much heavier; this is pretty obvious from her dimensions.
Again you are comparing apples with oranges.
Apples with apples would be Bismarck in Oct 1940 with KGV in Oct 1940, or Bismarck in May 1941 with KGV in May 1941.
KGV didn't gain 1500 tons in std displacement from Oct 1940 to May 1941 and had no major modifications after completion under her post Bismarck refit. Bismarck wasn't even completed in Oct 1940.

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