Slitherine

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Original: Tiornu
Iowa cannot defeat Yamato's belt at 25,000 yards, and while an improved shell entered service c1945, I doubt either one can effectively defeat the other's belt at that range. The belts are steeply inclined in both ships. Iowa cannot defeat Yamato's faceplates at any range.

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ORIGINAL: SamRo

Case point HMS HOOD......

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The official assessment of the USN at this time was that radar remained inferior to top spot.

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Several folks have noted a 6-knot speed advantage for Iowa. Apart from the fact that the real-world advantage was 4-5 knots at most

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I'd suggest we consider factors such as firing arcs and trunnion tilt before we decide Iowa can keep Yamato at a certain distance.

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While 25,000 yards has been suggested as a good range for Iowa, this is actually a terrible choice. Yamato is in the heart of her immune zone, and she's near the best range for her shells' diving performance. She can defeat Iowa's main battery armor, but Iowa cannot return the favor.

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I agree that Iowa is superior. However, in a gun battle, Yamato would likely defeat Iowa.

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ORIGINAL: mdiehl
Also, since these games exist, for ME anyhow, there is no interest in purchasing a game that is mechanically somewhat different but based on the same old flawed assumptions used in several other games.

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This does not mean that Iowa would beat the Yamato in every imaginable occurrence.

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ORIGINAL: Tiornu

"The MK 38 GFCS radar (Mk 12) could track targets out to 80,000 yds." Plus, Iowa had nuclear shells! But more seriously, on the one occasion where Iowa and Yamato almost came to blows (Leyte), another battleship carrying the same Mk 8 radar as Iowa managed to put together its firing solution at a range of 37,500 yards. While US radar-directed fire control was scary-good, it wasn't magic, and we shouldn't get euphoric about the stuff. The official assessment of the USN at this time was that radar remained inferior to top spot.
Several folks have noted a 6-knot speed advantage for Iowa. Apart from the fact that the real-world advantage was 4-5 knots at most, I'd suggest we consider factors such as firing arcs and trunnion tilt before we decide Iowa can keep Yamato at a certain distance.
While 25,000 yards has been suggested as a good range for Iowa, this is actually a terrible choice. Yamato is in the heart of her immune zone, and she's near the best range for her shells' diving performance. She can defeat Iowa's main battery armor, but Iowa cannot return the favor.
On Hood, I don't think her armor was theoretically capable of defeating Bismarck's shells at a range of 16,000 yards.

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ORIGINAL: barbarrossa

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ORIGINAL: Tiornu
Not hearsay, not out of a book. I done it myself.

What year was that?

(in reply to barbarrossa)

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ORIGINAL: barbarrossa

1987-1989.

Plankowner.

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ORIGINAL: Damien Thorn

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ORIGINAL: barbarrossa

1987-1989.

Plankowner.

Well, I think we understood a little better how radar worked in 1987 than we did in 1945.

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Whoh! That doesn't seem to mesh with your eariler claim that Yamato would always be at 100% sys damage before Iowa even gets hit. I told you earlier in this thread you would be backtracking from that hyperbole and I see it has begun.

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ORIGINAL: mdiehl

Here is more about the penetration resistence of different ships. This article from Nate Okun's guns n armor page. It presumes Km Bismarck firing its 380mm main armament (15") at its BB contemporaries. It is to be noted that the US 16" had substantially greater penetration than the German 380mm. It is also to be noted that this comparison examines SoDak, not Iowa class vessels. The SoDaks were in general protected by the same armor as the Iowas, but the placement on the Iowas was superior. HL is the maximum range (in thousands of yards/meters) in which the armor could be holed, although the shell may be destroyed in the proccess. NL the "navy ballistic limit" (shell penetrates the armor plate but may be decapped) and EL (effective limit, the shell penetrates, retains its cap, and detonates to its maximum theoretical capability). The target is belt armor. Again, all the credit goes to Nate Ogun.

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HL NL EL
SHIP Yards (Meters) Yards (Meters) Yards (Meters)

KM BISMARCK 35 (32) 29 (26.5) 27.9 (25.5)
HMS KING GEORGE V
-Amidships 28.4 (26) 23.8 (21.6) 22.9 (20.9)
-Magazines 27 (24.7) 21.5 (19.7) 20.8 (19)

RICHELIEU 24.5 (22.4) 20.8 (19) 18.6 (17)
VITTORIO VENETO 22.6 (20.7) 17.5 (16) NEVER (Shatter)
IJN YAMATO 21 (19.2) 17.7 (16.2) 15.5 (14.2)
USS SOUTH DAKOTA 20.3 (18.5) 16.4 (15) NEVER (Shatter)

Notice who's got the "never" listings in that?

Also there's this comment based on post war ballistics tests (IIRC at Dahlgren) also on Nate's page:

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Japanese WWII projectiles remained at the British 1921 quality level, which was about the best for that time period, but very poor by WWII, especially at impact obliquities over 20o even against thin plates. U.S. post-WWII testing confirmed this. The YAMATO's 18.1" (460 mm) projectiles were better and could penetrate thin VH armor at 30o obliquity, but the improvement was rather slight. Their fixation on the diving shell design seems to have made improving their armor-penetration (and the armor itself) a low priority feature. In addition, the super-long fuze delays used for long underwater trajectories resulted in their WWII projectiles acting like solid shot unless they hit enough armor to drastically slow them down.

and this

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The best all-round WWII armor-piercing projectiles were the U.S. designs. They were less able to remain in effective bursting condition after penetration than British projectiles, but they remained rigid under very difficult impact conditions and could penetrate armor of much greater thickness at much higher obliquities than anyone else's. For example, at least one WWII U.S. 14" Mark 16 MOD 8 capped armor piercing projectile (APC in British and U.S. Army nomenclature, but AP in U.S. Navy nomenclature, since the U.S. Navy assumed an AP cap was always used on a "true" AP projectile) penetrated intact through a WWII U.S. 13.5" (343 mm) Class 'A' plate at 49o obliquity at barely above the NL, which far exceeded any foreign design capability that I know of.

And this, a comment that encapsulates another length discussion about internal design. It is to be noted that Yamato was far more likely to suffer a "critical hit" than either a SoDak or an Iowa.

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The BISMARCK and most of its contemporaries, with the major exception of the USS SOUTH DAKOTA, had very little armor between the magazines and the other spaces inside the Citadel

So much WitP and so little time to play.... :-(

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ORIGINAL: mdiehl

http://www.combinedfleet.com/gunarmor.htm

So much WitP and so little time to play.... :-(

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"By the way, I haven't seen anyone argue about the supposed 'indirect hit' gunfire by the Japanese."

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By the way, I haven't seen anyone argue about the supposed 'indirect hit' gunfire by the Japanese. According to 'Japanese Cruisers of the Pacific War', the Japanese found they could drop a shot into the sea at a certain distance before a target and the shell would curve up into the bottom of the target. Any takers for this one?

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Yamato has more powerful weaponry and superior armor. It should be no surprise that she'd likely win a duel with Iowa.

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Yamato's system suffered from ineffective joins between the lower and upper armor belt. Her belt was penetrated by American air-dropped torpedoes which had warheads below her minimum designed explosive loadings. Not a very effective design for the weight.

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Extremely good design, though not as wide as some. The carrying of the armor belt down to the hull bottom added strength, but the rigidity of the armor plate could possibly have caused sheer of the plate away from the hull bottom. Still, a very good design.

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Suffice it to say that I am surprised as you that Iowa has the most effective belt armor of the lot; I would have bet on Yamato any day. But Iowa's combination of an inclined belt, and a highly effective STS-steel shell plate outboard of the belt (which has just enough resistance to strip the AP cap off of an incoming shell) tips the score in her favor. Richelieu also had this same design, and very good protection as a result. Bismarck, despite the reputation of her side armor, fares very poorly in this category. From a deck armor perspective, Yamato comes out on top, followed closely again by Richelieu and Iowa.

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The bottom line is that, after 1943 or so, having the world's best optical fire-control systems was largely irrelevant. The night battle between Washington and Kirishima near Savo pretty much settled the point; good radar usually beats good optics in a stand-up fight. And the radar used by Washington off of Guadalcanal was not as good as the sets fitted aboard Iowa.

Then there's the fact that all radar fire-control is not created equal. Radar operating at meter or decimeter wavelengths is useful for ranging, but lacks the angular accuracy necessary for training. In practical terms, this means that a decimetric set can develop a range solution via radar, but must rely on an optical director to supply training information for the battery. This hybrid fire-control solution is, of course, limited by the quality of the optics available, and also by the visual horizon (which is closer than the radar horizon), and weather conditions. Only with the advent of 10cm and (later) 3cm wavelength sets was true 'blindfire' radar fire-control achievable, wherein the firing ship need never come into visual range of the opposing vessel. The Germans, Japanese, and Italians never developed sets of this capability (both the Japanese (despite its 10cm wavelength) and German sets were usable for fire control against a battleship-sized target only out to a range of about 27,000 yards.) The bottom line is, then, that the Allied vessels, and particularly Iowa and South Dakota, would enjoy an enormous advantage in gunfire control over their adversaries. She would have the ability to lob shells over the visual horizon, and would also perform better in complete darkness or adverse weather conditions

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In 1945 test, an American battleship (the North Carolina) was able to maintain a constant solution even when performing back to back high-speed 450-degree turns, followed by back-to-back 100-degree turns.7 This was a much better performance than other contemporary systems, and gave U.S. battleships a major tactical advantage, in that they could both shoot and maneuver, whereas their opponents could only do one or the other.

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Yamato does not have more powerful weaponry.

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She also has inferior armor quality and it is poorly placed.

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Repulse, which displaced less than half of Yamato, took about the same amount of time to kill from start of attack to final plunge.