The Viribus Unitis Battleship: 1:25 Model; Main Gun Turrets

hey Lezt how have you been?
Sharnhorst was designed like the Mogamis, the Mogamies were designed to easily swap 5 turret of 3X 150mm for 5 turret of 2X 200mm,
was this actually done? (sorry I don't know this :)

the Sharnhorst was designed to swap 3 turret of 3X 280 mm for 3 turret of 2X 380mm guns.
as far as I know, the modification on the Gneisenau started, but was aborted

6 guns is a weak broadside, but then again, Bismark did straddle Hood on the 3rd salvo with the same 380mm gun and similar fire controls.
off top of my head, six times 15" was what the Renown Battlecruisers had, and the Renown was a valuable asset in BOTH Wars (the Repulse was sunk not because of her weak broadside ...)

LOL the Viribus Unitis would've been in trouble if she had met a 15"-guns ship doing 30 knots
 

FORBIN

Lieutenant General
Registered Member
Sharnhorst was designed like the Mogamis, the Mogamies were designed to easily swap 5 turret of 3X 150mm for 5 turret of 2X 200mm, the Sharnhorst was designed to swap 3 turret of 3X 280 mm for 3 turret of 2X 380mm guns.

6 guns is a weak broadside, but then again, Bismark did straddle Hood on the 3rd salvo with the same 380mm gun and similar fire controls.
In the article i have read in practice impossible refit Sharnhorst with 380 mm so difficult, mass matters stability and the mag is excellent !
A turett with 3 x 280 mm about 700 t, Bismark 1000+ t

For the record Yamato ofc 2800 t a turret, a Destroyer ! frontal armor 650 mm waouw ! but don' t forget the radars of the Iowa ... ;)

Come on Jura do 2 threads o_O
- BB/BC WWI
- BB/BC WWII
 
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LOL the Viribus Unitis would've been in trouble if she had met a 15"-guns ship doing 30 knots
also LOL if a Renown-class had met the Squadron:
342c549b09a8.jpg


EDIT
now found the Renown later in her carrier...:
648476c85645.jpg
 
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Come on Jura do 2 threads o_O
- BB/BC WWI
- BB/BC WWII
bro if you set up a WWTwo (most of discussions I saw in Internet just repeated cliches though ... plus there're still fanboish opinions around related to WWTwo), I'll contribute (hope not with cliches and definitely not with fanboism :)
 

Lezt

Junior Member
hey Lezt how have you been?
was this actually done? (sorry I don't know this :)

as far as I know, the modification on the Gneisenau started, but was aborted

off top of my head, six times 15" was what the Renown Battlecruisers had, and the Renown was a valuable asset in BOTH Wars (the Repulse was sunk not because of her weak broadside ...)

LOL the Viribus Unitis would've been in trouble if she had met a 15"-guns ship doing 30 knots

Yes, the Mogami class was refitted in 1939 with 8" guns.

I don't know about the Scharnhorst class, if any upgrades were attemped.

The issue of the Renown class was that the Royal navy post treaty is still massive. The ships of the German navy has to do it all by themselves therefore RN ships are often deployed in quite formidable squadrons, while German navy ships can only go out in pairs with a screen of destroyers.

Thus it is a question of quantity having a quality of its own. Someone is going to hate me if I say that the Bismark can probably take on the Iowa 1v1 but in history the Iowas were screened by multiple squadrons of cruisers and destroyers, when the Bismark would have to fight off aircraft, cruisers, destroyers and battleships by itself.
 
... the Bismark can probably take on the Iowa 1v1 but in history the Iowas were screened by multiple squadrons of cruisers and destroyers, when the Bismark would have to fight off aircraft, cruisers, destroyers and battleships by itself.
technically, you obviously meant Tirpitz, not Bismarck :) and, well, the Iowa (BB-61) had been on "an anti-Tirpitz deployment" at one point (now I quickly checked wiki and it was in August-October of 1943, stationed in Newfoundland) ... could be interesting to see how big was her group there
 

Lezt

Junior Member
I like to classify american battleship design like this: the standard dreadnoughts like the USS texas to the Colorados at 21 knots with 4 turrets so that one blown turret will not affect loss of fire output.

Then you have the fast battleships which sacrificed one turret for more speed, the north carolinas and south dakotas with 27-28 knots.

Afterwards you have the super battlecrusier at Iowa at 32.5 knots and super dreadnaught at montana. 28 knots planned.

I call the Iowa super battle cruisers as their armor is not that great and that her torpedo bulkheads are internal as with most US BBs. These bulkheads do perform worst than the bluges that were use in the Yamato, North carolina refits, planned montana, fuso refit, nagato.

Why this matters is that torpedo bulkheads are internal, bulges are "external" meaning by penetration, you lose a lot more buoyancy. i.e. intetral bulkheads are designed for speed, bulges are designed for survivability.

Iowa had an inclined at around 70 deg 307mm internal belt and a water line armor of 37mm. Weather deck armor was 37mm with a 121mm main deck for a total of 158mm.
file.php

Bismark however had 320mm vertical armor at the waterline, 110mm sloped armor like in a protected crusier at around 40 deg and a 45mm bulkhead. Deck armor is 50 mm weather deck, 35mm inner deck and 80mm main armor deck for a total of 165mm.
440px-Bismarckarmor.svg.png

That means line of sight armor to the protected area of the ship is around 367mm for the Iowa and 537mm for the Bismark. One should note that the Iowa 37mm waterline armor can be penetrated by 100mm guns of destroyers (and secondary guns) and it will cause flooding of torpedo bulkheads. Flooding will only occur in the bismark after the penetration of the 320mm main belt. even 8" shells from the Baltimore at 10 km and at right angles will not penetrate. AP Mark 8 from the 16"/50 Mark 7 on the iowa can only penetrate this at 15K yards (14KM) for 585 (around 16km est). The 38 cm SK C/34 on the bismark can penetrate 393mm at 22 km (so around 24km).

Plunging fire on the Iowa main belt wins due to the incline. then again even if the incline belt is not penetrated, the shell will flood the torpedo bulkhead. But for deck armor, at 35kM the bismark can penetrate 170mm deck armor while at 30K yards (27km) the Iowa can penetate 169mm and 35K yards (32km) 215mm, so around 29 km or more to penetrate the Bismark.

Thus the zone that iowa want to fight bismark is greater than 29 km to 35 km for imunity. While the bismark wants to fight the iowa between 24km to 14km for immunity.

And we all know straddles at that range is rare, Iowa and new jersy straddled nowaki at around 35k yards, no hits. Scharnhorst hit Glorious at 24 km, Warspite hit Guilio Cesare at 24 km, Yamato could have straddled Gambier Bay at 35 km. hood was sunk at around 14 km. i.e. the battle favors the bismark if it is a 1v1. especially, german radar technology is not bad either.

Iowa can dictate the battle due to her speed. but speed will be lost when the torpedo bulkheads gets flooded by the splinter damage of long range gun fire.

my 2 cents.
 

FORBIN

Lieutenant General
Registered Member
All good points fine gents :)

Initialy in 1939/40 German get better optics the best so normaly detect ennemy in first and get the first shot always important but after UK and US get better systems with radars and even if in 1943 Tirpitz get radar i think, normaly UK, US have an advantage for detection, accuracy.
In 12/43 During the the Battle of North Cape King Gorgege V detect in first and fire also.

And we all know straddles at that range is rare, Iowa and new jersy straddled nowaki at around 35k yards, no hits. Scharnhorst hit Glorious at 24 km, Warspite hit Guilio Cesare at 24 km, Yamato could have straddled Gambier Bay at 35 km. hood was sunk at around 14 km. i.e. the battle favors the bismark if it is a 1v1. especially, german radar technology is not bad either.
Remains curious, for history... why Kurita retreat ?

It is a good what if for a wargame :cool:
 
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my 2 cents.

interesting point; in my comfortable chair, imagining myself in the rank of a Commodore (or higher :) I say 'Bring the Tirpitz in!' ... seriously:
indeed the citadel of the Bismarck was pierced through the belt only once (according to the inspection of the wreck), despite receiving from two-miles distance at one point BUT I think we should keep in mind the extent of the damage to the superstructure _always_ caused by large-caliber hits, for example power went briefly off on the Giulio Cesare upon a single hit of basically just a funnel (which activated the fuse, fortunately for the ship) ... I suppose you know about the troubles of the South Dakota off Guadalcanal (if you didn't: Garzke & Dulin at pages 74-76) ... my point is it could've been relatively easy to achieve a mission kill against any WWTwo Battleship if you know what I mean
 

Lezt

Junior Member
interesting point; in my comfortable chair, imagining myself in the rank of a Commodore (or higher :) I say 'Bring the Tirpitz in!' ... seriously:
indeed the citadel of the Bismarck was pierced through the belt only once (according to the inspection of the wreck), despite receiving from two-miles distance at one point BUT I think we should keep in mind the extent of the damage to the superstructure _always_ caused by large-caliber hits, for example power went briefly off on the Giulio Cesare upon a single hit of basically just a funnel (which activated the fuse, fortunately for the ship) ... I suppose you know about the troubles of the South Dakota off Guadalcanal (if you didn't: Garzke & Dulin at pages 74-76) ... my point is it could've been relatively easy to achieve a mission kill against any WWTwo Battleship if you know what I mean

I do,

Needless to say, all superstructure are thin to keep the ship from being top heavy.

This is a toss up thou between the bismark and the iowa. Bismark does have a more finiky fire control system and sub systems that could be easily damaged. but Bismark also throw a load more weight in secondary fire.

There is a question of the german/japanese three tier gun design and the US/UK two tier gun design.

The issue is a question of weight and need. US 5" guns are a bit light for surface work vs crusiers and destroyers. UK 5.25" is a bit to heavy/slow for AA work

German 10.5cm is excellent for AA work and 15cm is excellent for surface work. where as Japanese 5" is mediocre for AA work, while their 6.1" is excellent.

But US and UK ships are meant to be escorted by cruisers....

lets look broadsides...

Bismark have 6x 15cm guns, 8x 10.5cm guns per broadside

8x 10.5cm gun
ROF: 15-18 RPM
Weight of shell: 15.1 kg HE, 15.8 kg AP
Range: 17.7 km

6x 15cm gun
ROF: 10-12 RPM
Weight of shell: 45.3 kg HE, 45.3 kg AP
Range: 23 km

Iowa have 10 5" gun per broadside
10x 5" gun
ROF: 15-22 RPM
Weight of shell: ~25 kg
Range: 16 km

So in a minute of secondary broadside,
Bismark can throw 4.5 tonne - 5.4 tonne of HE shells ti 17.7 km, and 2.7 tonne - 3.26 tonne to 23 km
Iowa can throw 3.7 tonne - 5.5 tonne of HE shell to 16 km

Thus if there are no lucky shots, Iowa would likely have its superstructure (and more importantly, radar, range finders etc) shredded by secondary battery fire before its secondary battery can respond.

There are other limiting factors such as ammunition hoists

Now.. Radar would be another post at another time
 
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