Radarless Iowa vs Yamato: 1944

[Bgile]

Any ship without a sloped armour deck behind its armour belt becomes more vunerable at shorter ranges - unless like Yamato, you have a whopping great thick armoured belt to begin with.

Did Yamato have a sloped armour deck behind her belt?
I suspect not - she'd hardly need it with her walls of Jericho belt armour

Yamato had an internal Belt design similar to the US Battleships. It had a serious defect in torpedo protection, but should have been very good against shells.

[Karl Heidenreich]

So, we must accept the fact that, considering only the ship (which it´s what matter more to us), not their miscellaneous electronic upgrades, the Yamato was, in all structural, armoured, ballistic and mechanical aspects the superior battleship of WWII. And, in being so, it´s also the superior battleship in all History. Of course it has some weakness because nothing built by man is invulnerable, but it was, clearly, superior to the Iowas... and a more beautiful vessel too.

[Gary]

Hi Karl

I agree.

Iowa "cheated".
A true battleship doesnt use radar

She had monstrous cannons and walls of Jericho armour.
Thats what a true BB should have.

[Bgile]

In BB vs BB combat, I agree.

[Captain Morgan]

Hi Karl

I agree.

Iowa "cheated".
A true battleship doesnt use radar

She had monstrous cannons and walls of Jericho armour.
Thats what a true BB should have.

The US fire control computer does not require the radar to fuction. It was capable of full remote dirctor controlled fire even without the radar just using the stereo-optic rangefinders. Iowa would probably get at least as many hits as Yamato and probably more since Yamato didn't have full remote fire control. The US 2700 lb APC shell was capable of doing pretty severe damage to Yamato and Iowa would be choosing range etc since she had a 6 knot advantage in speed.

Your biggest misconception seems to be the US radar controlled fire. It was great if you were fighting at night (Surigao Strait) or poor visibility in daylight (Samar with the smoke screens and squalls) because the US continued to track and target IJN ships that couldn't see to shoot back. But when you say "forget the radar lets shoot in good visibilty" you assume that the Iowa won't hit anything without radar. That is not a good assumption because the optical systems for daylight use are very good. The IJN had better night optics and training for night combat, but that isn't how you set the stage.

[Karl Heidenreich]

Captain Morgan:

Posted: Tue Aug 22, 2006 2:50 pm Post subject:

--------------------------------------------------------------------------------

Gary wrote:
Hi Karl

I agree.

Iowa "cheated".
A true battleship doesnt use radar

She had monstrous cannons and walls of Jericho armour.
Thats what a true BB should have.


The US fire control computer does not require the radar to fuction. It was capable of full remote dirctor controlled fire even without the radar just using the stereo-optic rangefinders. Iowa would probably get at least as many hits as Yamato and probably more since Yamato didn't have full remote fire control. The US 2700 lb APC shell was capable of doing pretty severe damage to Yamato and Iowa would be choosing range etc since she had a 6 knot advantage in speed.

Your biggest misconception seems to be the US radar controlled fire. It was great if you were fighting at night (Surigao Strait) or poor visibility in daylight (Samar with the smoke screens and squalls) because the US continued to track and target IJN ships that couldn't see to shoot back. But when you say "forget the radar lets shoot in good visibilty" you assume that the Iowa won't hit anything without radar. That is not a good assumption because the optical systems for daylight use are very good. The IJN had better night optics and training for night combat, but that isn't how you set the stage.

I´m sure you misunderstood us. We´re not saying that an Iowa Class will "not hit anything" when using optical systems instead of her "radar controlled fire director". Nope. What we are saying is that, in the hypothetical scenarios, let´s not assume Iowas using the radar for targeting. This is due because anytime someone comes forward with an Iowa vs anything scenario, the Iowa with her Mark VII 16" Shells + the radar always won. So, in order to have a more "fair" combat between battleships then we "eliminate" the radar, that´s all. But in that order of things we´re not saying that the Iowa isn´t gonna hit, they could always win against Bismarck or Hood or KGV, etc. But using only her optical system.

Best regards.

[Bgile]

The use of radar directed FC in US battleships didn’t just help during poor visibility. It was also a major advantage at long ranges during really good visibility. It provided an outstanding picture of the splash location of every shell in the salvo in relation to the target. This is something you can do with optics, but it becomes harder and harder as the range increases.

It seems obvious to me that the Yamato class was an outstanding technical achievement – larger everything compared to an Iowa class ship. For that reason one would think Yamato would have a significant advantage assuming equal crew training.

The much better protected Montana class would have been the equal of a Yamato, I think, but they were never built.

[Tiornu]

Radar always helps, even when the target is clearly visible.
Iowa would likely lose to Yamato, regardless of the radar situation.
Since we're being "fair," I assume Yamato has no radar in this scenario either.
Montana would likely defeat Yamato.

[Karl Heidenreich]

In this scenario: Radarless Iowa vs. Yamato, I do believe the Yamato would win, eventually. I wouldn´t say it will be a piece of cake and it´s certain that Yamato would be damaged also, but the sheer impact of the 18" shells would be devasting to the Iowa.

Tiornu:

Since we're being "fair," I assume Yamato has no radar in this scenario either.
Montana would likely defeat Yamato.

Maybe. In this case Yamato wouldn´t be as superior as with an Iowa, so if it´s not a draw then it could be a Montana victory. This case is very academic since the Montanas were never built and never tested in a Battleship vs. Battleship engagement... well, neither the Iowas nor the Yamato!

Best regards!

[Tiornu]

"During the war, the USN believed that Yamato carried 16" guns."
There's no single figure to describe what the USN thought about Yamato's guns. I believe the official ONI publications continued to indicate 16in guns to war's end, but that did not reflect the beliefs in other departments, or even among all ONI personnel. Many folks thought the guns were 17.7in. A prewar British document shows the theoretical capabilities of a Japanese 17.8in gun (a strange figure--452mm--but that's what it says).

"Japanese AP shells were IMO inferior to US AP shells"
The advantages of the Japanese shell are its 20% greater striking energy and 20% larger burster. The TNA explosive is slightly more powerful than American Explosive D, but it is also subject to premature detonation. The American shell has more demanding proof conditions, but there aren't a lot of plates on Iowa that are caliber-thick to Yamato's shells. There is a range band near 17-20,000 yards where belt hits would exceed the proof angle for Yamato's shells but not those for Iowa's, but Iowa's shells have much thicker armor to deal with.
Japanese shells give better underwater performance, but the fuze delays might be impractically long.

"Did Yamato have a sloped armour deck behind her belt?"
No, Yamato was one of the most radical AoN ships. Probably only Nelson was further in that direction. Iowa has a bit more internal splinter protection.

[Karl Heidenreich]

Tiornu:

"Japanese AP shells were IMO inferior to US AP shells"
The advantages of the Japanese shell are its 20% greater striking energy and 20% larger burster. The TNA explosive is slightly more powerful than American Explosive D, but it is also subject to premature detonation. The American shell has more demanding proof conditions, but there aren't a lot of plates on Iowa that are caliber-thick to Yamato's shells. There is a range band near 17-20,000 yards where belt hits would exceed the proof angle for Yamato's shells but not those for Iowa's, but Iowa's shells have much thicker armor to deal with.
Japanese shells give better underwater performance, but the fuze delays might be impractically long.

Well, more or less we have Yamato with advantage here, against Iowa.
Thanks to Tiornu for the quote.