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  1. ...wow Your ship weighs around the same as Bismarck, but is 17 (!!!) knots faster, has a belt 50% thicker, has decks literally three or four times stronger, and has four extra 15in guns to boot. Poor barbettes and torp belt and so on, but... yikes.
  2. It is hard to say for sure. Rebuilding Hiei and the twelve original Japanese heavy cruisers, Furutaka through Takao, cost 184,825,248 yen. For the same price, the IJN could buy five new Tone heavy cruisers (31,265,000 each) and an Agano light cruiser (26,400,000), with a little extra to spare. By the time funds were appropriated, the London Treaty had been abrogated, so in theory the money could be used for just about anything. I am not sure why reconstruction was so aggressively pursued, rather than construction of new ships. I think there may have been a few reasons. The rebuilds were faster than building new ships: for the heavy cruisers, a year or two versus three or four years to build from scratch. If the old ships were not replaced and discarded, this would mean more crew, more facilities, and increased total maintenance costs. In terms of quality, it was wise to either rebuild or completely replace, but not to supplement without rebuilds. The twelve heavy cruisers originally all had important defects (especially overweight) which it was prudent to fix. It may have been politically advantageous not to make new ships, perhaps to avoid provocation at home or abroad. Hiei's rebuild provided a prototype for Yamato's bridge.
  3. Japan' first battleship was the old Chinese ironclad Zhenyuan, which was renamed Chin Yen. It was built in Germany for China 1882-1884 and taken by Japan in 1895. By German standards it probably qualified as an "armoured frigate," although that distinction is a little pedantic. After that, Japan's next battleship was the Fuji, built for them in the UK 1894-1897. This was a pre-Dreadnought of classic design.
  4. There's no reason a battleship or carrier can't equip chemical smoke generators, but my impression is that they were disfavored. The smoke from a chemical generator comes from the stern of the ship. If the first battleship in a division lays smoke, it fails to cover itself, and it completely blinds those behind it in a corrosive cloud. A smoke-screening destroyer or cruiser off to one side makes much more sense. I imagine the concentration of caustic substances was also not wanted on battleships. I do not recall ever seeing smoke generators on US battleships; I think virtually all US cruisers had them. Two can be seen on CL USS Cleveland's stern, on either side of the crane. They are the small bundles of four cylindrical tubes on the rearmost deck. For the game, I don't know. The idea behind smoke was that it would limit vision, like a solid curtain at first, or as a fog as it dissipates. If you had a spotter plane or radar, you could shoot through the curtain; otherwise, it would ostensibly break contact until it started to clear up. Right now it just acts as an accuracy modifier zone, as near I can tell (does it reduce detection range?). The AI has no clue what it's good for. I think more iteration is needed.
  5. The Iron Duke, Queen Elizabeth, and Revenge battleship classes had secondary battery directors at Jutland, so at least they were not shooting under local control. I think, but do not know, that the secondary battery was connected with a Turret Control Table, a fairly simple computer. Secondary battery accuracy may have improved fairly substantially later in WWI with new synthetic computers (eg the "Baby Ford"). Small gun accuracy may also have been relatively bettered with radar, such that the difference was lessened between them and big guns, but that is my own speculation. Either way, secondary guns were virtually destined to survive past WWI, for anti-aircraft use.
  6. I think that the odd dispersion pattern is a product of the modified shell trajectories. The computer has (probably) decided whether each shot will hit or miss from the moment of firing, so the visual shell is literally turned midair to hit or miss the target. This is why radical maneuvers are pretty ineffective even at long range. Possibly the strange pattern of overs and unders is an unintended consequence of this system.
  7. The majority of casemates did not exceed 20 degrees in elevation. The range at that elevation would vastly depend on the gun's power. A 6in gun might reach between 10000 to 21000 yards, depending, so it is hard to say what "should" be without looking at the specific gun and shell. The elevation restriction was not a hard and fast rule, mind. It is somewhat harder to increase the elevation of a central pivot gun, but this can be worked around. Japan upgraded its casemate guns to 30 to 35 degrees after WWI. Lower range is also acceptable for fighting off destroyers, which may be expected to make point-blank night attacks. However, the threat of longer range DD day attacks grew over time. Casemates ultimately died out for a few reasons. They are harder to give high elevations; they have poor firing arcs; unless they are set significantly back from the hull, they suffer from spray and green seas; they may require relatively more armor than a battery concentrated in turrets.
  8. The demise of the battleship is rooted in the Washington Naval Treaty. The battleship holiday stunted dreadnought development, and efforts were forced into other avenues, most notably aircraft. The US realized very quickly that the number one priority of carriers was to neutralize enemy carriers. In the 1920s, it was even envisioned that US battleships would carry both fighters and torpedo planes. That this did not occur is probably not from a lack of interest, but rather the advent of carriers. The long-range battleship gunnery duel envisioned in the 1920s was predicated on the idea of air superiority. From a 40 meter tall battleship mast (eg Yamato), the horizon is at 22600 meters (24700 yards). Beyond 22000 yards, the US believed that artillery air spotters would double accuracy. At 34000 yards, a battleship could not be reasonably expected to make any hits without an air spotter -- or, as it eventually developed, radar.
  9. The actual advantages of superheavy shells are complicated. Superheavy shells can have reduced range. The US 16in/45 gun lost 3300 yards of range (8%) with the superheavy shell, from 40200 yards to 36900 yards, with a minimal decrease in charge weight (545lb to 535lb, less than 2% decrease). The US 8in/55 also lost some range, although to some degree this was related to the proportional reduction in charge weight. Unlike the 16in shell, the 8in super-heavy had identical external dimensions to the normal shell, so ballistically it had few differences. Shell travel time increases with lower muzzle velocity, but at longer range this is partially mitigated by greater retained velocity for a heavier shell. Still, the lighter US 16in shell had a shorter travel time at all ranges when fired from the 16in/45. Heavier shells are harder to handle, especially in a seaway, and they require stronger hoists. The US stuck with parbuckling, interestingly enough, but this did not end up biting them. Superheavy shells are usually longer (the 8in superheavy was not), so that must be dealt with, too: this is partially why older US ships didn't get the superheavy shell. Of course the shells themselves add more weight, too. Although it is often said that barrel life is improved, the increased shell weight basically nullifies the reduced muzzle velocity. Thus the 16in/45 Mk6 (with 2700lb shells) and Mk8 (with 2240lb shells) had the same 395 round life. The actual penetration change is a subject unto itself. Although the US formulas generally predicted that the heavy shells would have increased deck penetration with no reduction in belt penetration (or even a modest increase in belt pen), Nathan Okun's work argues that this is wrong: Though deck pen really was improved, belt pen got worse. Thus the US Navy was partially mistaken. I am not sure how gun precision was changed with heavier shells.
  10. Oh yeah, sorry. My mistake. Poor labeling is the bane of many things, yes? Anyway, there must have been a good reason for this armor layout....
  11. Yes, I did. This is the amount of armor required to cover the same vertical space as the sloped deck, at the same 100mm thickness and same 20 degree slope, meeting our new flat deck at its outboard extremity. So I think there must have been another reason for the cambered deck. Possibly it was desired to strengthen the outermost deck strake. To get the same weight, the conventional layout could have an outermost strake of ~39.7mm. It may also have been more difficult to penetrate at the expected engagement distance of the ship; possibly there are structural reasons, as I have alluded. I'll have to check if Ducol steel, CNC, and NVNC differed in densities, but I don't think they did by very much.
  12. Let us not quibble about the definition of "turtleback." It is a curved deck, I suppose we can agree. I guess I was thinking of the curved decks on the original destroyers, which are usually termed "turtlebacks" in references. The best technical description would be a deck with heavily cambered outboard strakes. This the approach I used in comparing weights. Unfortunately it seems I did the math wrong on Tone. Here it is, corrected: For Tone, with a slope of 2.9m at 15 degrees, a slope thickness of 65mm, a flat deck of 31mm, and a 100mm belt at 20 degrees, and assuming a steel density of 8g/cm^3, the following calculations can be made: The weight of the angled deck section is about (290cm*6.5cm*8g/cm^3) = 15.08kg/cm (of length) per side. Additionally, there is 18mm structural plating extending 0.751m up to the level of the flat deck, adding (75.1cm*1.8cm*8g/cm^3) = 1.08144kg/cm. The total weight is thus 16.16144kg/cm per side. If the ship had a more conventional design, with the flat deck extending outward more (without camber), and the belt extending up to the level of the flat deck: The flat deck would extend (2.801m+0.273m) = 3.074m further out. It would weigh (307.4cm*3.1cm*8g/cm^3) = 7.62352kg/cm more. The armor deck (edit: belt) would extend 0.751m farther up, replacing the structural plating; along its own axis (as it has a 20 degree slope), it would extend 0.799m. It would weigh (79.9cm*10cm*8g/cm^3) = 6.392kg/cm more. The total weight would thus be 14.01552kg/cm per side. So on Tone, the curved deck adds 2.14592kg/cm per side. Given that Tone's machinery deck extended about 76.8m, the angled deck (vs a conventional design without camber) with the same 20 degree 100mm homogeneous belt cost approximately (2*7680cm*2.14592kg/cm) = 33 tonnes. Why was this preferable? Can structural weight savings explain this away...?
  13. Yamato, Tone, and Mogami all had "turtlebacks," in the sense that their armored decks curved down at the sides. This was not comparable to the turtleback on, say, Bismarck, in that the curve connected to the top of the heavy belt armor. Here is the layout on Tone, per Japanese Cruisers of the Pacific War. There was no curved deck over the magazines (the right-hand image). Mogami's layout was essentially the same, though with a thinner deck slope (60mm) and thicker flat deck (35mm). Yamato's deck had less slope angle. I am unsure why this layout was adopted. References do not say the reason. Some simplistic calculations show this layout saved some weight on Mogami and probably Yamato, but it was likely about weight neutral on Tone. It likely reduced topweight, although I haven't done the math. It may have also made the connection with the sloped belt simpler. The effects on overall armor protection are complicated.
  14. The "armored brick" approach works well. For ship construction: Pick the guns and fire control upgrade. Pick the armoured cruiser IV hull. Maximum bulkheads, minimum range, 15 knots speed, induced boilers. Max out the "protection" options. Pick heavy shells and semi-auto reload. Do whatever for ammo amount and turret traverse. Guncotton, Ballistite, or White Powder for propellant. ~12in belt, turrets, and conning tower. You may want more armor on the turrets and conning tower; they can't be angled like the belt. ~6in for extended belt. 1-2 inches for turret tops and decks. Whatever for secondary armor. Two twin 10in (or 11in) turrets. Best towers available. Two "standard" funnels (ie the smallest; you could probably do ok with just one). No secondary guns or torpedoes necessary. Change displacement and specific armor amounts until the weight and cost % approach 100 (I ended up with 16700 tons). For the battle: It is only necessary to sink the battleship. Screen out their cruisers with your light cruisers. If they are heavily targeted, use smoke. If you lose your own light cruisers, no big deal. Direct your armoured cruiser to approach the battleship at an angle. Dodge torpedoes as needed. Until the penetration chance exceeds 50%, use HE. This will have limited effect. Continue closing at an angle. If it is steep enough, the enemy will be unable to penetrate your armor even close in. Once you have reached close range, and the penetration chance becomes high, switch to AP. The AI often will present a flat broadside. The Semi-Dreadnought is very fragile. It will usually take just a few penetrating hits to sink it. You win.
  15. I think it is most unwise to discount the potential use of observation planes as spotters the day after they were used for that role at Java Sea, without a source saying so. That said, I have no information on their precise use, so I cannot say for certainty they were. I will have to consult more sources. I am pretty sure Dull deals with the subject. I suspect this because they did not seem to be tracking the destroyers very well. USS Pope escaped in a squall. Either way, we have four major daylight surface battles in the Pacific War: Java Sea (Sea Battle off Surabaya), Komandorski Islands, Samar, and Cape Engaño. We know for sure that spotters were used at Java Sea; that an attempt was made at Komandorski, regardless of its results (Commander Miura commented that it was planned to launch spotters from the start); that reports were made of Japanese seaplane use at Samar. Rear Admiral Koyanagi reported that two or three spotters remained with First Battleship Squadron, so I wonder if these were the planes involved. Of the four, the only one I have any surety that spotters weren't used is Cape Engaño. Were artillery spotters used at Cape Matapan? Friedman indicates they were, but I don't know anything about that battle. Spotters are more-or-less essential to long range fire without radar. The Royal Navy estimated that air spots doubled accuracy outside 22000 yards (20.1km). Of course radar changed this calculus.
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