Battleship for Freedonia

Historical what if discussions, hypothetical operations, battleship vs. battleship engagements, design your own warship, etc.
Mostlyharmless
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Battleship for Freedonia

Post by Mostlyharmless » Wed Jun 20, 2018 5:14 pm

It is around 1936 and I have been appointed as Navy Minister by Freedonia. We are planning to build a battleship or class of battleships. As Freedonia has reasonably good relations with all the World's major naval powers, we are able to use technology from any country. We even have a few engineers who can test, modify or develop technologies although they don't have too many original ideas. I need your advice on what sort of ships we should build. Unfortunately, for reasons of security, I have to be vague about our strategic plans, the extent of our budget, the size of our dry docks and even the maximum draft of ships that can use our naval bases.

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Re: Battleship for Freedonia

Post by Dave Saxton » Thu Jun 21, 2018 3:38 pm

In 1936, the ten years moratorium of battleship construction has just ended one year before. One of the important aspects of the moratorium was that it not only suspended new construction, but also largely suspended research and development of guns and armour-at least among those who honored their treaty obligations. Indeed, the office responsible for armour research within the USN Bureau of Ordinance has consisted of only a few people headed by a junior officer and is just getting started again. Midvale Steel has just sent a delegation to Krupps to get a handle on how to proceed. Actually, Freedonia probably doesn’t want to deal with USN BruOrd at all, as the next years will reveal it is an arrogant rouge agency that is very difficult to work with, wrong on a lot of technical issues, according to the British Royal Navy and also USN critics.

An overarching question, is Freedonia a party to the treaties and if so is Freedonia going to abide by those treaties? How much hindsight on technical innovations should be allowed here?

In 1936, naval radar is largely unknown except among a cloistered community of a few scientists and engineers throughout most of the world. The exception is in Germany where it is quietly becoming an operational reality. Their radar is, however, highly secret. The technical innovations and resulting tactical considerations circa 1925 still hold sway. Jutland, is still the standard to what kind of battle will be fought and what type of battle to design for. The main considerations post Jutland were that greater ranges were thought possible and the advent and progress of naval aviation.

Is Freedonia going to design ships to meet those requirements, or are they going to design a raider, or a panzerschiff killer? This will affect the balance of speed firepower, protection, and range that is required. Does Freedonia have bases worldwide? Does Freedonia want to be a regional naval power or a worldwide naval power? What about resources, especially fuels and fuel type?

The overall balance of battleship design such as the tradeoffs between speed, protection, and firepower, has been altered by advances in naval propulsion technology. It is now possible to build a battleship with an IZ from 20k to 30k against new 14” guns or older larger guns, with 14” guns itself, and a speed of 30 knots, while honoring treaty limitations. However, the Italians have complicated matters with their new Littorio class design mounting a new 15” gun that changes the whole ball game. More, and more technical stuff, later.
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: Battleship for Freedonia

Post by Dave Saxton » Fri Jun 22, 2018 1:53 pm

The Italian 15” gun represented a dramatic increase in penetrative power. All new large caliber naval guns could potentially bring such capability. No longer could a belt of face hardened armour that was approximately the thickness of the caliber of shell it was designed to defeat provide protection at likely battle ranges. It was not just a matter of increasing the thickness of the belt in compensation. About 13” thickness is the point of diminishing returns in terms of providing a full measure of protection. 15” does not provide 15” worth of protection. Moreover, the aircraft delivered bomb was now becoming a serious threat requiring that massive armour weight be committed to the horizontal protection at the expense of the vertical protection.

Here are presented options for dealing with these problems:

The first option could be to use a traditional belt but place tactical restrictions on how the ship must be fought, such as rescheduling the IZ to long ranges such as 25,000 yards to 35,000 yards and requiring the ship always fight presenting an oblique target angle. The disadvantage of this option is that real world tactical circumstances may not fit such restrictions.

Another option could be to install steeply sloped belts either externally or internally. (It is highly recommended that the belt be external to better protect the water plane). A disadvantage of steeply sloped belts is that they protect less area of the ship’s side. They have to be made taller and deeper in compensation, which is weight inefficient. Additionally, they greatly increase the vulnerability to diving shell and underwater hits. A lower belt can be added but it further increases the weight out lay and makes a mess of the torpedo defense system. Other disadvantages are that they a more difficult and more expensive to construct, and very difficult to repair by dock yards, especially if the belt is internal.

Another option is the German scarp triangle design. In this design an external belt is backed up by heavy scarps that present a very unfavorable striking angle to any shell that penetrates the belt. Done correctly, a shell must have such a high striking velocity to penetrate the system that it will shatter upon impact. Thus, the system cannot be defeated by any battleship caliber shell at any range. Moreover, since the scarps are extensions of the main armoured deck, the massive weight committed to the main armoured deck provides both horizontal and vertical protection. Hits that strike higher up, passing over the scarps are dealt with by the flat sections of main armoured deck, striking at an unfavorable angle or not striking the deck at all. Additionally, it provides protection to plugs, cartwheels and splinters caused by nonpenetrating hits to face hardened armour. The low position of the main armoured deck improves the metacentric height specification, improving the stability of the ship and increasing the amount of flooding that can be tolerated before stability is lost. Another advantage of the design are that the scarps buttress the main belts structurally. The disadvantages are that the system requires an effective spaced array for the horizontal protection system, and a longer citadel length (which is probably desirable anyway,) and an upper citadel. The longer protected length and the upper citadel are weight inefficient.

Another option is to use a de-capping array for the vertical protection. The Italians are using such a system. This design is based on destroying incoming shells rather than stopping incoming shells. In such a system a de-capping plate is placed in front of a sloped main belt of face hardened armour. A de-capped shell with shatter against the face hardened main belt if its velocity is high enough to penetrate it. The de-capping plate needs to be at least 70mm thick to be effective against battleship caliber projectiles, and the inter-space should ideally be several calibers in distance between the two plates. Such a system also requires effective splinter and plug barriers behind the main belt. This system is space and weight inefficient and potentially presents a flooding liability with the inter-space between the de-capping plate and the main belt.
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: Battleship for Freedonia

Post by Dave Saxton » Sat Jun 23, 2018 6:06 pm

There are options concerning construction materials and methods circa 1936.

Type of steels available are:
Mild Steel. Mild Steel has a carbon content of .18% by weight. The ultimate tensile strength is about 60,000 psi. One advantage of mild steel is that it is very weldable. Elongation in 8-inches is 25% at typical levels of hardness.

High Tensile Steel. HTS has greater carbon content than mild steel- up to .30% in weldable versions. This is the maximum carbon content that can be tolerated and still have acceptable weldability. Pulling the carbon content down to around .22% greatly improves weldability. Riveted high tensile steel may have carbon content as high as .45%. The UTS of HTS is from 70,000 psi to 80,000 psi. Elongation is more than 20%. Weldability is good as long the carbon content is less than .30%

The most common type of construction steel for warship construction in 1936 is British Ducol or D Steel. Not only do the British use D steel but so do the Japanese, the French, and the Italians. D steel is a manganese/carbon alloy steel with a tensile strength of up to 90,000 psi. However, the ductility at that level of strength is only 17% elongation. Carbon content is only .30% if over 20 lbs thickness but D Steel is noted for very poor weldability. The nickel equivalency apparently is high because of the manganese/carbon relationship causing the poor weldability. The use of D Steel limits the construction method to riveted construction for the most part.

In 1936 the Americans and the Germans are pursuing welded warship construction, with greater than 90% of new construction being welded. Welding is the way to go as most of the technical barriers to successful welded warships have been or are being over come by American and German ship building industries. Nonetheless, the Kriegesmarine still do not allow welding directly to armoured bulkheads despite assurances by Blohm und Voss engineers in 1936. This restriction will be dropped by 1939. Of course, face hardened armour cannot be welded.

The Germans are using a new weldable construction steel called Stahl 52. The chemical composition of Stahl 52 is:
.14% C, .36% Si, 1.49% Mn, and .37% Cu. (Copper is commonly used in marine steels to inhibit corrosion.) The impurity levels are extremely low with only trace amounts of P and S thanks to the world leading electric arc smelting technology already used in Germany. For the highest quality steels, it is recommended that Freedonia copy the German technology or purchase steels from German firms. ST 52 has a tensile strength of 70,000 psi and is not brittle at all. Elongation is 31%. Moreover, it has excellent weldability, and can use the new revolutionary low hydrogen welding technology. There is a special low hydrogen welding electrode to use known as the E52K.

The Americans are unique in using an armour grade steel, STS, for much of the construction steel on new battleship construction. For welding STS to STS, they use a stainless-steel welding rod with 25% chrome and 25% nickel also known as E310. For welding STS to mild steel, the E309 SS welding rod that pulls the chrome content back to 20% is used.
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: Battleship for Freedonia

Post by ede144 » Sun Jun 24, 2018 6:37 pm

Mostlyharmless wrote:
Wed Jun 20, 2018 5:14 pm
It is around 1936 and I have been appointed as Navy Minister by Freedonia. We are planning to build a battleship or class of battleships. As Freedonia has reasonably good relations with all the World's major naval powers, we are able to use technology from any country. We even have a few engineers who can test, modify or develop technologies although they don't have too many original ideas. I need your advice on what sort of ships we should build. Unfortunately, for reasons of security, I have to be vague about our strategic plans, the extent of our budget, the size of our dry docks and even the maximum draft of ships that can use our naval bases.
During 1936, with all of the new Battle ship building, there are very few machinery or tools available. May be you should start your Freedonia building plan some years earlier.

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Re: Battleship for Freedonia

Post by OpanaPointer » Sun Jun 24, 2018 8:08 pm

ede144 wrote:
Sun Jun 24, 2018 6:37 pm
Mostlyharmless wrote:
Wed Jun 20, 2018 5:14 pm
It is around 1936 and I have been appointed as Navy Minister by Freedonia. We are planning to build a battleship or class of battleships. As Freedonia has reasonably good relations with all the World's major naval powers, we are able to use technology from any country. We even have a few engineers who can test, modify or develop technologies although they don't have too many original ideas. I need your advice on what sort of ships we should build. Unfortunately, for reasons of security, I have to be vague about our strategic plans, the extent of our budget, the size of our dry docks and even the maximum draft of ships that can use our naval bases.
During 1936, with all of the new Battle ship building, there are very few machinery or tools available. May be you should start your Freedonia building plan some years earlier.
How about buying salvage from the Washington Treaty? Surplus battlecruiser hulls in various states of completion were available at one point.

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Re: Battleship for Freedonia

Post by Thorsten Wahl » Mon Jun 25, 2018 8:27 am

Where is Freedonia situated.

Atlantic - Pacific.

Does Freedonia require limited rawmaterials (Iron, Steel alloys, oil) or is it a exporter. Are there antagonistic interests to anyone?
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Re: Battleship for Freedonia

Post by Mostlyharmless » Sun Jul 08, 2018 12:36 am

I feel that I must pause on watching football to give a few more details of Freedonia's position. As most of you know, Freedonia is positioned in the Indian Ocean and is descended from the kingdom of Queen Ranavalona https://en.wikipedia.org/wiki/Ranavalona_I, who was instrumental in creating a navy with British assistance. Freedonian warships probably require similar range to British or Japanese ships but are not expected to carry out trans-Pacific operations.

One of Freedonia's possible strengths are its amazing fortune tellers, one of whom, an elderly lady with no military experience, nonetheless appears to know some details of the future via a crystal ball. In fact, she denies knowing what actually happened to battleships in the future but claims that her ball gives her glimpses of a weird thing from the future called the internet where all sorts of claims and unreliable information about battleships can found. On the basis of this unreliable data, she tells me that Freedonia will side with the Allies in something called WW2.

Apparently, Freedonia will enter the war in 1942 after receiving a huge American bribe and may send one or more of Freedonia's battleships to help defend the Netherlands East Indies, where they may be attacked by something called the Kido Butai, possibly at Darwin. At the end of 1942, another ship may engage an enemy called Tirpitz in the Battle of the Barents Sea (oddly it seems that Freedonia's existence will speed up Tirpitz's refit). Either the same ship or another of its class will be hit by something called a Fritz-X off Italy in 1943. Finally, she believes that our battleships, if any survive, will take part in a British led invasion of Sumatra in early October 1944 https://en.wikipedia.org/wiki/Operation_Culverin and will be opposed by Japanese battleships under Kurita sailing from Singapore which are equipped with something called the Type 91 shell.

I should mention that we hope to invest about 160 million Dollars in building battleships, which my fortune teller says will buy three or four King George V or Lion class or two Bismarcks, North Carolinas, South Dakotas or Yamatos. However, apparently Iowas cost about 100 million and Montanas may cost even more. Unfortunately, I do not know why the costs are so different. The fortune teller speculates that King George V and Yamato, which cost about the same per ton, are mostly riveted and have much less redundancy in things as diverse as electric generators, pumps or fire control. It is also clear that Ducol is much cheaper than STS but that does not account for Bismarck's cost although the slightly artificial $/RM ratio may have an impact.

The last generation of battleships all represent highly optimized designs. However, it seems legitimate to ask whether use of the best "available" technology could improve one of these designs. Thus, Freedonia has obtained a sketch of the design of Yamato and I would be interested to know what the cost would be if we built the hull out of welded ST 52 to try to save some weight, fitted American machinery to try to save space (unfortunately Montana's 172,000 shp plant isn't obviously much smaller than Yamato's older machinery but clearly generates more electricity as well as giving more power) and fitted a British main armour belt.

One point of using narrower machinery is that it would give us room to improve the obvious weakness of Yamato, which was its protection against torpedoes http://www.spacecruiseryamato.com/ijn/a ... /heel.html. Given more space, the simplest way to avoid the weakness at the joint of main and lower belt would be to have the lower belt continuing the upper belt's slope, so that amidships both are at 20 degrees rather than the lower belt being at 8 degrees. The connection can then imitate that in South Dakota or Iowa. The requirement is that the width of the machinery is approximately 3 metres less. Unfortunately, the lower belt is still nearer to a torpedo explosion than Iowa's lower belt because Iowa's whole belt is internal and Iowa's system did not perform perfectly in tests.

Alternatively, one could separate the main and lower belt as in the Montana Class. This gives better protection against torpedoes (in fact Montana could have almost certainly survived significantly more hits than the similarly sized Yamato or Musashi) and armour could ride on the torpedo bulkhead to stop shells passing below the main belt. The main cost is extra weight. The upper belt is no longer supported by the lower belt but needs to be supported to resist either shell hits or explosions and the torpedo bulkhead or lower belt has to connect strongly to something above. Yamato did not have a structurally significant lower deck below the main armour deck with only 8 mm or 9 mm decks at varying heights. Thus, either a strong lower deck must be added or the torpedo bulkhead must extend to the main armour deck. If the new bulkhead were the same 45 mm thickness as those of Bismarck and had to go up 6 metres, it would add around 600 tons for just that upward extension. Then we would have to decide how much armour to fix to the bulkhead, assuming that we add face hardened armour rather than making a complicated tapered homogeneous plate. The Vickers Cemented armour of Yamato's lower belt was fixed to a 14 mm Ducol plate. If we use 3 cm thinner armour fixed to 45 mm of homogeneous armour, we will have less resistance to Type 91 shells. Thus, again we must chose between reduced protection and increased weight. Finally, note that the magazines must also be narrower and thus either longer or deeper, so that again we are scrabbling to save compensating weight.

At this point, we might ask if the Japanese Navy was justified in fitting such strong armour to stop underwater hits. Clearly they knew more about the Type 91 shell than anyone else and the speed after passing some distance underwater would not be too hard to measure. Thus the estimate that a shell lost half its initial velocity after travelling 100 calibres was probably not too bad if using suspiciously round numbers. However, possibly the shell would be yawed by the water and estimates of its penetration from firing shells at reduced velocity through air at plates might be optimistic.

Nonetheless, there is no doubt that a Type 91 shell could have penetrated into the citadel of any non-Japanese battleship. For example, the initially 8.5" lower belt of Montana quickly reduces to 3.75" and then stops leaving about half the target above the triple bottom defended only by 25 lb and 30 lb bulkheads. A shell from Yamato at 20,000 yards entering the water at 15 degrees and landing 20 to 40 metres short would probably defeat the bulkheads and longer range would move the window closer without narrowing it too much. The reason that the USN was unconcerned about that danger was that a shell with a USN 0.035 second fuse would have exploded before striking a ship at that depth. The 0.4 second Japanese fuse would allow a shell that did not hit thick armour to pass through a ship before exploding but would also allow hits below 5 metres (as would a defective shell from Bismarck).

I realise that Dave would have preferred Freedonia to take the H39 design as a starting point and I can see the case. However, Germany seems to have concluded that the Bismarck or H39 armour scheme, whilst an efficient use of weight against shells by using yaw, was not effective against bombs and thus the H41 project had a much thicker main armour deck http://www.kbismarck.org/forum/viewtopi ... =13&t=8281.

Thus, we are currently exploring modifications of the basic Yamato design with its thick main deck, especially as our fortune teller suggests that bulbous bows and transom sterns may become standard practice on large fast warships.

Yamato has a very high freeboard amidship (see https://www.flickr.com/photos/27417638@N07/4181515847 which seems to be a copy of the illustration from page 52 of Skulski's Anatomy of a Ship - The Battleship Yamato). I am hoping that Freedonia may be able to follow German ideas with a continuous 50 mm or 80 mm weather deck and a fairly thick outer shell to allow us to use much thinner main barbettes, which are 560 mm in Yamato, and perhaps use a slightly thinner main deck especially for the angled sections, which may be 230 mm on 14 mm, with the additional thickness only needed to resist shells. If this does not cost significant weight nor lower the GM too much, we will have greatly strengthened our protection against bombs dropped by dive bombers as armour piercing bombs will not kill the anti aircraft gunners whilst general purpose bombs will not penetrate the weather deck.

Of course, we will still have maintain an angle to an enemy to prevent the 41 cm belt of hopefully British face hardened armour being penetrated and we may need to maintain a similar angle at long range to protect the angled sections of main deck, which will be wider but less slopped as the torpedo protection becomes wider.

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Re: Battleship for Freedonia

Post by Dave Saxton » Mon Jul 09, 2018 2:10 pm

Bombs represent an intractable problem because they can strike at or near the normal. Perhaps Freedonia's fortune tellers will discover that even the Musashi's horizontal protection will fail against bombs. The bomb damages inflicted on Tirpitz showed that it was not particularly vulnerable to bombs compared to contemporary designs.

The use of a upper armoured deck as a bomb deck or a yaw deck as in the American designs and the German designs could help reduce the vulnerability to bombs, but not eliminate it. The Luftwaffe Technical Academy studied the problem independently with live tests and determined that an upper armoured deck of Wh type armour above an primary armoured deck was better than a single thick armoured deck of comparable sum thickness at dealing with bombs. This was because because Wh reduced the velocity significantly enough to reduce the bomb's remaining penetration ability by the time it reached the primary armour. The reduction of velocity also induces yaw. In the case of the American design the potential effective thickness enhancement of the upper deck against both bombs and shells is more limited by the short distance between the upper armoured deck and the main armoured deck. This last point is because yaw takes time-distance to become more fully manifest.
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: Battleship for Freedonia

Post by Dave Saxton » Mon Jul 09, 2018 2:49 pm

Mostlyharmless wrote:
Sun Jul 08, 2018 12:36 am


Yamato has a very high freeboard amidship (see https://www.flickr.com/photos/27417638@N07/4181515847 which seems to be a copy of the illustration from page 52 of Skulski's Anatomy of a Ship - The Battleship Yamato). I am hoping that Freedonia may be able to follow German ideas with a continuous 50 mm or 80 mm weather deck and a fairly thick outer shell to allow us to use much thinner main barbettes,
The principle here is that a de-capped shell will shatter against a face hardened barbet even if the barbet thickness is less than required to stop the shell in question at the striking velocity. This will be proven by the 14" AP shell striking the South Dakota's Number Three barbet at Guadalcanal, after striking and passing through the upper armoured deck at an angle acute enough to cause de-capping.
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: Battleship for Freedonia

Post by Dave Saxton » Mon Jul 09, 2018 6:54 pm

If Freedonia's fortune tellers can see forward well enough to know that from 1942 on that 90% of surface combat will be at night, it will require a complete re-think of IZ ranges. An inner IZ well below 20,000 yards will be required. The outer IZ will likely be more than adequate if the horizontal protection is designed to provide improved protection from bombs.

Shorter range night combat will also affect the choices of main and secondary batteries. Larger caliber, heavier shell weight, combinations are more useful for greater than 30,000 yards battle range. At night combat battle ranges, the main battery will be better served by higher muzzle velocity guns with a reasonable rate of fire. Slow shooting 18" guns are likely to be liability. Also striking velocity is the more important factor against vertical armour and it gives the greater danger space against smaller targets.

In night battle situations the dual purpose (and a DP is the only way to go) battery becomes important because there are likely to be multiple cruiser and destroyer threats to deal with a closer range. It must be handy with a high rate fire, but powerful enough to have knock out firepower against such threats. More powerful than 5"/38 will be required. Perhaps a 5"/60 or a 5.25"
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: Battleship for Freedonia

Post by Thorsten Wahl » Tue Jul 10, 2018 12:29 pm

Weapon how about a 38 cm SK C/34 with 865 m/s and elevation 35 dgrees from a early design study.

Range about 42,5 km Flightime 85 sek impact velocity ~500 m/s
at 20 km the shell should be about 25 m/s faster then the Vo 820m/s Version.
and somwhat mm more penetration versus vertical armor plate (~445 mm)
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Re: Battleship for Freedonia

Post by Mostlyharmless » Tue Jul 10, 2018 6:55 pm

Dave Saxton wrote:
Mon Jul 09, 2018 2:10 pm
Bombs represent an intractable problem because they can strike at or near the normal. Perhaps Freedonia's fortune tellers will discover that even the Musashi's horizontal protection will fail against bombs. The bomb damages inflicted on Tirpitz showed that it was not particularly vulnerable to bombs compared to contemporary designs....snip...
I agree that something very undesirable happened when one of the 1,000 lb bombs hit Musashi over the machinery. Unfortunately, I don't know what. I am, however, fairly sure that a well designed 190 mm main deck of good quality armour should be able to resist a 1,000 lb bomb from a dive bomber. We know, for example, that Prince of Wales' 160 lb on 40 lb deck stopped a Japanese 500 kg bomb from 2,500 metres.

It is quite hard to chose between the German armour scheme and the various American and Japanese schemes. However, once the Germans started taking bombs seriously, there is a convergence towards 200 mm armour decks for H41, the Montana 1942 proposal and Yamato.

Freedonia's General Staff are currently attracted to Yamato because the citadel is only 140 metres long compared to 170 metres for Bismarck. They are looking at using German ideas in a more limited way by using a single 175 mm thickness of Wotan hart under a 50 mm or 80 mm weather deck and hoping that this can be a weight and stability neutral substitution for Yamato's Ducol weather deck and 190 mm (Dickson) or 200 mm (Skulski) of armour on 10 mm of Ducol. There is an estimate on the ever reliable internet that the penetration possible with a Fritz-X from 6,000 metres was a 170 to 180mm single plate of Wotan hart quality https://www.tapatalk.com/groups/warship ... 5-s80.html. Thus they hope to defeat either shells from a 16"/45 to 31,000 yards, which was Montana's specification, or a Fritz-X from 6,000 metres.

The actual area of upper belt armour is just over twice the area of the main barbettes. Thus having a 145 mm face hardened upper belt will be roughly neutral if we reduce the barbette thickness from Yamato's 560 mm to H39's 240 mm and any reduction in the slopped section of the main deck from 230 mm on 14 mm of Ducol will be pure profit.
Dave Saxton wrote:
Mon Jul 09, 2018 2:49 pm
The principle here is that a de-capped shell will shatter against a face hardened barbet even if the barbet thickness is less than required to stop the shell in question at the striking velocity. This will be proven by the 14" AP shell striking the South Dakota's Number Three barbet at Guadalcanal, after striking and passing through the upper armoured deck at an angle acute enough to cause de-capping.
Unfortunately, my fortune teller cannot see things not published and they do not know if Bismarck's 220 mm barbettes survived hits without internal damage. As the wreck is upright, it would be nice to have a robot crawl down one or two to check.

Given the short range of night encounters, our Staff are worried that even 41 cm of British, German or Italian face hardened armour at 20 degrees may be vulnerable, so that they do see the logic of the German alternative. Also a long citadel gives more space for anti-aircraft guns and may reduce the threat from torpedoes.

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Re: Battleship for Freedonia

Post by Mostlyharmless » Wed Jul 11, 2018 1:20 am

Let us try to choose the best armament for our battleship. I am going to agree with Dave on the secondary armament. The only available alternatives are USN's 5"/38 or the RN's 5.25". We will select the 5.25" as it will be better for dealing with destroyers or aircraft dropping Fritz-X bombs. However, even Vanguard's improved turrets will put up fewer shells against dive and torpedo bombers. Thus we need to carry as many Bofor 40 mm guns as we can (the German M43 37 mm was too late, their 55 mm even later and the USN's automatic 3"/50 was first tested on 1st September 1945).

The best main gun is much less obvious. Popular culture chiefly remembers the Japanese 46 cm gun and Iowa's 16"/50 https://thefiringline.com/forums/archiv ... 03067.html. Unfortunately, whilst Iowa's 16"/50 is almost as powerful, lighter and requires smaller turrets and barbettes, it is only available from 1943 and the 46 cm has better belt penetration. We could use the older 16"/50 which was originally going to be mounted on Iowa and which presumably could fire the 2,700 lb shells but that gun required larger and heavier turrets and barbettes. The 16" guns for H39 should give impressive penetration of belts but were rather over engineered, almost as heavy as the Type 94, and it was proposed to bore them out to 42 cm for the H41 design. However, no 42 cm gun was ever tested. Naturally, we could also consider the USN's 16"/45 Mark 6 of North Carolina or the RN's 16"/45 Mark 2 for Lion. Dave has meanwhile drawn our attention to the impressive belt penetration possible with Littorio's 38 cm, which would be attractive if one could understand and prevent the wide dispersion sometimes observed.

Things get more complicated as we prepare to mount our guns in three or four turrets. One problem is that we may need very special equipment to transport and install very heavy turrets. Another problem is that it is not clear if using the strongest armour on turrets is justified. The survivors of Bismarck's turret Caesar reported that the turret was disabled by a non-penetrating hit (see Garzke and Dulin's article "Bismarck's Final Battle" http://www.navweaps.com/index_inro/INRO_Bismarck.php) and there were other similar cases from Jutland as well as the slightly different cases of Jean Bart and South Dakota. Thus, there may be a case for many turrets or for turret designs which attempt to deflect rather than stop shells. However, to complicate this, a partially flat roof may be desirable to mount something like a sextuple Bofor on turrets 2 and 3.

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