Battlecruisers: Flawed or not?

General naval discussions that don't fit within any specific time period or cover several issues.
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Dave Saxton
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Re: Battlecruisers: Flawed or not?

Post by Dave Saxton »

Hindsight is a wonderful thing, but perhaps the RN would have been better advised to build three fast 15" battleships (28 -30 knots) instead of Hood, Renown and Repulse.
Hood had better protection than the QEs and the Rs. Hood was a fast battleship as built. It was built with the Hindsight of Jutland. After Jutland, Hood's design had the armour increased 50%, increasing the displacement 5000 tons. The main belt was already 12" and sloped 15*. Turrets had 15" face plates (curved) with 5" roofs.
Entering a night sea battle is an awesome business.The enveloping darkness, hiding the enemy's.. seems a living thing, malignant and oppressive.Swishing water at the bow and stern mark an inexorable advance toward an unknown destiny.
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Re: Battlecruisers: Flawed or not?

Post by Steve-M »

Dave Saxton wrote:One question I have: is why those three? Was the ammunition and the handling fundamentally different from the other British capital ships at the time?
Ammo/powder handling practices are reputed to have been aimed at higher rate of fire at the expense of safety in Beatty's squadron, though I don't know how true that is. Didn't HMS Malaya also suffer a near catastrophic hit to her secondaries at Jutland?
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Alberto Virtuani
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Re: Battlecruisers: Flawed or not?

Post by Alberto Virtuani »

Dave Saxton wrote: "Hood was a fast battleship as built."
Hi Dave, she was, but only according to standards of WWI, to which Hood was anyway not ready in time to contribute.
Unfortunately for Hood, by WWII, the fast battleships were far better protected, with much more powerful guns.....

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VoidSamukai
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Re: Battlecruisers: Flawed or not?

Post by VoidSamukai »

Alberto Virtuani wrote:
Dave Saxton wrote: "Hood was a fast battleship as built."
Hi Dave, she was, but only according to standards of WWI, to which Hood was anyway not ready in time to contribute.
Unfortunately for Hood, by WWII, the fast battleships were far better protected, with much more powerful guns.....

Bye, Alberto
Well of course. Hood was built by WW1 standards. Comparing her to a WW2 ship like the Bismarck is like comparing the Kongo to North Carolina. Over the time to two ships were built, new technologies and design features were discovered and implimented. So of course by WW2 standard, Hood was rather weak.

If they got around to refitting her though with better deck armour, AA and just maybe a new model of 15inch guns, she might've still been a massive threat. As it was, Britain instead used her for tours and visits without refitting her in any major fashion.
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Dave Saxton
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Re: Battlecruisers: Flawed or not?

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Alberto Virtuani wrote:
Dave Saxton wrote: "Hood was a fast battleship as built."
Hi Dave, she was, but only according to standards of WWI, to which Hood was anyway not ready in time to contribute.
Unfortunately for Hood, by WWII, the fast battleships were far better protected, with much more powerful guns.....

Bye, Alberto
I agree. Although Hood was built post Jutland it was built before the 1920's test of a full scale Hood section demonstrated that the new 1920 "Green Boy" shells could defeat all the Hood's protective decks at 25,000 yards. The newer German 15" guns and shells designed during the 30's were much more deadly. Although if we just look at total inches of Hood's armour it compares favorably with North Carolina and Washington (12" sloped belt and ~5 " horizontal), the arrangements and materials of the protective decks certainly did not equate. The Hood's deck armour was merely high tensile "protective plating", not exactly high quality homogenous armour like STS, Wh, and such. Plus it was laid atop the structural decks which do not count much toward effective thickness. I have estimated that Hood's effective deck protection was about 70mm. Nonetheless, it is still better deck protection than the "battleships" of its generation*, and goes without saying it was better than the battle cruisers.

In terms of belt protection, the quality of the 12" sloped belt was good but it only protected a relatively small area above and below the waterline. Above the 12" belt were 7" and 5" strakes. Some have presented the theory; that it was 15" shell passing through the 7" section and then it was fairly easy passage through the thin remaining decks to the 4" magazine. I presented the theory of a below the belt passage into the magazine many years ago, but most others didn't think much of that theory at the time. Maybe they still don't?

* The deck protection level of early generation battleships is exemplified by the main deck of the USN battleships even up to the West Virginia class. It was only 1.5" STS laid over 1.5" of mild steel (tensile strength of only 60,000 psi) comprising the main armoured deck. That only calculates to about 45mm effective.
Entering a night sea battle is an awesome business.The enveloping darkness, hiding the enemy's.. seems a living thing, malignant and oppressive.Swishing water at the bow and stern mark an inexorable advance toward an unknown destiny.
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Re: Battlecruisers: Flawed or not?

Post by Byron Angel »

What really made WW1 era horizontal protection schemes obsolete was the development of a reliable delay-action fuze for AP projectiles.

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Re: Battlecruisers: Flawed or not?

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Dave Saxton wrote:
Hindsight is a wonderful thing, but perhaps the RN would have been better advised to build three fast 15" battleships (28 -30 knots) instead of Hood, Renown and Repulse.
Hood had better protection than the QEs and the Rs. Hood was a fast battleship as built. It was built with the Hindsight of Jutland. After Jutland, Hood's design had the armour increased 50%, increasing the displacement 5000 tons. The main belt was already 12" and sloped 15*. Turrets had 15" face plates (curved) with 5" roofs.
Obviously not enough, i wonder how Hood would have stood up to the battering that Warspite took at Jutland?
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Re: Battlecruisers: Flawed or not?

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That, and bombs that could be reliably dropped onto them XD

Oh, and time traveling JMSDF DDs, cuz why not XD
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Re: Battlecruisers: Flawed or not?

Post by 1T6VDTYX »

Dave Saxton wrote:
Hindsight is a wonderful thing, but perhaps the RN would have been better advised to build three fast 15" battleships (28 -30 knots) instead of Hood, Renown and Repulse.
Hood had better protection than the QEs and the Rs. Hood was a fast battleship as built. It was built with the Hindsight of Jutland. After Jutland, Hood's design had the armour increased 50%, increasing the displacement 5000 tons. The main belt was already 12" and sloped 15*. Turrets had 15" face plates (curved) with 5" roofs.
Dave,
Of course you are correct about Hood's armour, but it wasn't good enough to save her against Bismarck.
I must admit that I have never understood the thinking of the RN after WW1, they already had 15" gunned ships so they must have known that other nations would follow and they also must have known the capabilities of the 15" (and the 16") shell, so why not increase the armour in vital areas? Obviously any hit from a large calibre shell is going to do some damage, but Warspite took a fearful battering at Jutland without blowing up or sinking and I do wonder if Hood would have done the same if she was there instead of Warspite.
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Re: Battlecruisers: Flawed or not?

Post by paul.mercer »

Dave Saxton wrote:
Hindsight is a wonderful thing, but perhaps the RN would have been better advised to build three fast 15" battleships (28 -30 knots) instead of Hood, Renown and Repulse.
Hood had better protection than the QEs and the Rs. Hood was a fast battleship as built. It was built with the Hindsight of Jutland. After Jutland, Hood's design had the armour increased 50%, increasing the displacement 5000 tons. The main belt was already 12" and sloped 15*. Turrets had 15" face plates (curved) with 5" roofs.
The Hood may have had better protection than the QE's or R's but when she met Bismarck it was not enough.
I have to say that I have never understood the RN policy on armour, they pioneered the original Dreadnought and the 15" ships so they must have known that other nations would follow building something similar in firepower. They also must have known the capabilities of the 15" & 16" shell, so why built a ship that is only slightly better protected that the R's and QE's? Obviously any hit from a large calibre shell is going to do some damage, but I wonder if Hood would have stood up to the tremendous battering that Warspite took at Jutland without sinking or blowing up. I realise that the later Washington Treaty made later battleship building difficult but again the RN built Rodney and Nelson with a pathetic speed that was even slower than the QE's, did the RN designers go to sleep between the wars or were they so complacent that they thought that no one would dare challenge them?
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Re: Battlecruisers: Flawed or not?

Post by Dave Saxton »

paul.mercer wrote:
The Hood may have had better protection than the QE's or R's but when she met Bismarck it was not enough.
I have to say that I have never understood the RN policy on armour, they pioneered the original Dreadnought and the 15" ships so they must have known that other nations would follow building something similar in firepower. They also must have known the capabilities of the 15" & 16" shell, so why built a ship that is only slightly better protected that the R's and QE's? Obviously any hit from a large calibre shell is going to do some damage, but I wonder if Hood would have stood up to the tremendous battering that Warspite took at Jutland without sinking or blowing up. I realise that the later Washington Treaty made later battleship building difficult but again the RN built Rodney and Nelson with a pathetic speed that was even slower than the QE's, did the RN designers go to sleep between the wars or were they so complacent that they thought that no one would dare challenge them?
There are several issues at play here.

One is the typical capabilities of battleship caliber AP shells at the time these warships were designed. As Byron alluded to, pre-Greenboy British shells performed poorly. They often went off on contact if they went off at all. If they struck very far from the normal they often were rendered inert or they broke up. The relatively soft caps fitted over the heads of the shells often failed to do its intended functions. These were to stress the face hardened armour to enable the shell to penetrate the armour, and to protect the shell from being broken up by the face hardened armour. At that time a typical AP shell may not penetrate intact a face hardened belt of armour at any range.

The Greenboy shell changed the game. It could penetrate 14" of high quality face hardened armour intact at 16,000 yards, and it still worked given a more oblique impact. Nonetheless, as a practical matter the typical maximum a shell like a Greenboy could penetrate was about its own caliber.


Another factor at the time these ships were designed was the practical battle ranges of combat. At that time 20,000 yards was the maximum range that battle could be expected and the angle of fall of incoming rounds were less than 20*. This fact meant that horizontal protection schemes were made up of a series of protected decks intended to mainly contain splinters rather than "keep projectiles out", because shells would be fused by the upper belts and upper decks and explode before they reached the vitals.This was the function of the Hood's upper belts for example. Deck hits would be at such shallow angles that the shell would most likely scoop and the trajectory would carry it across the beam of the target until it exploded if it didn't scoop.

These facts meant that the vertical protection of a design could provide protection at just about all practical battle ranges if it was about as thick as the caliber of shell it was intended to defeat. 15" belt vs 15" shells was good. (or in the case of the Hood 12" sloped). A series of thin protected decks was good to 20,000 yards. By the late 30s 15" shells were far advanced over the Greenboy. The German 38cm had about 5" more belt penetration than that of the 15" Greenboy of 1920, for example (actually it had more belt penetration than North Carolina's new 16" gun). It still penetrated intact even when striking at angles up to 60* from the normal. It was not prone to scooping. It was difficult to remove the cap. Advances in weaponary had rendered the old generation of capital ship dangerously obsolete, even with modernization. It was lucky that warships like the Warspite, and the West Virginia, and the Nagato, were not put to the test by a modern opponent like the Hood was.

Given the Great Depression, navies could not really afford to replace old warships with new construction.

Another issue was that the Washington Treaty not only stopped new construction but also effectively stopped research and development of guns, armour, and shells . The Germans still conducted R&D secretly the entire time through Krupp, however.
Entering a night sea battle is an awesome business.The enveloping darkness, hiding the enemy's.. seems a living thing, malignant and oppressive.Swishing water at the bow and stern mark an inexorable advance toward an unknown destiny.
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Re: Battlecruisers: Flawed or not?

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Gentlemen,
Having read all your posts I have come to the conclusion that the BC was good at what it was designed for, basically keeping enemy armoured cruisers out of the way and keeping the vast British Empire secure by the presence of a large heavily armed ship sent to deter any interference with our trade in far away waters the Falklands battle being a typical example -these were the days when Britannia ruled the world and there was little to challenge them. However as technology got better and other countries built similar or more powerful ships the role of the BC declined and they were dangerously exposed to the threat of heavy calibre shells as was proved at Jutland and of course with Hood. I often wonder what would have happened it conditions had been better and the Twins had decided to really fight when they met up with Renown, I suspect that she might have been either badly damaged, blown up or sunk.
As for the twins, there has been discussions on what their role in WW2 was supposed to be. They were in all but name battleships, fairly heavily armoured but fitted with too small an armament to take on a modern 14/15/16" battleship. Had they been given the proposed 6
x 15" they would have been a match for the older RN ships and a dangerous opponent for the KGv's. All of this leads me to think that the BC had its day even before WW1 and that if the Germans had wanted to upset the trade routes with ships they would have been better advised to build more Admiral Sheer class ships which, as Captain Langsdorff said was fast enough to avoid most of the RN heavy ships and powerful enough to deal with an enemy cruiser. My conclusions are that neither Hood,Renown,Repulse or the Twins were ever really fit for purpose.
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Re: Battlecruisers: Flawed or not?

Post by VoidSamukai »

Well Hood could've had the role of making sure that german cruisers dont go into the Atlantic and disrupt the convoys, as well as Renown, with speed and firepower. Hood was just placed in a situation she should never have been in the first place: pitting in line of battle against a battleship 20 years more advance. The twins proved deadly as commerce raiders and could've done a better job if Hitler wasnt such a chicken with his navy. They might've also been good at destroying escorting cruisers as well.
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Re: Battlecruisers: Flawed or not?

Post by paul.mercer »

VoidSamukai wrote:Well Hood could've had the role of making sure that german cruisers dont go into the Atlantic and disrupt the convoys, as well as Renown, with speed and firepower. Hood was just placed in a situation she should never have been in the first place: pitting in line of battle against a battleship 20 years more advance. The twins proved deadly as commerce raiders and could've done a better job if Hitler wasnt such a chicken with his navy. They might've also been good at destroying escorting cruisers as well.

That is true of course,but the German cruisers, although very fine ships never achieved very much and the twins were under orders not to engage if a battleship was in the convoy, so although they did fairly well they really did not achieve what they could have done, but I still think that any of the RN BC's would have had a problem if confronted with both twins had they been allowed to attack. My point about building more 'Sheer' class ships would mean that most of the convoys would have had to be accompanied by a heavy ship or at least two 8x8"" cruisers, then of course the RN BC's would be doing what they were designed for.
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Re: Battlecruisers: Flawed or not?

Post by VoidSamukai »

Make that D class. The Duetsch class had one problem that might hiner their performance. The speed. 28 knots means that they could be caught up by fast BBs and BCs. The D class with better speed would solve this problem. Then there is the O Class BCs which were, in my theory, actualy designed by the British due to such low armour.
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