Calling all Yamato (大和) and Musashi (武蔵) fans

[chuck]

Chuck - I assume that Shinano's turrets were then cut up and melted down. *SIGH*

Parts of the turret armor were taken to the us for testing, and are still in existence.

[SailorJack]

I know this is a model forum (in more ways than one ) but would anyone care to please take a guess what the combined total weight of both bow anchors and chains might be?

Edit- Found it; 15 tons for each main anchor. Not sure of the chain or 'cable' though.

[Atma]

Maybe 20 tons ?

[SailorJack]

Thank you.

[Atma]

Im not sure it was 20 tons it was a guess.

[SailorJack]

Various sources give IJN Yamato's 46cm barrel life as 200 to 250 service rounds.
What would happen if they tried to run the same barrels to 400 or 500 rounds?

[Atma]

They will suffer the same fate that all barrels that pass the usefull point. But/terrible dispersion.

[SailorJack]

I'm sorry but I don't know what you mean.
Is there an increasing danger that the overused barrels will suddenly rupture?
Or do they start to get increasing propellent blow-by but still fire?
Do they start to become increasingly less accurate?
Do the projectiles begin losing their 28-to-1 spin (or whatever the ratio is) and wobble more in flight?
I'm not that familiar with gun barrels and what happens when they start to become worn out or exceed useful life span.

If I had to compare to aircraft TBO (time before overhaul), in which the engines use hour meters, the analogy doesn't carry over because TBO is merely a recommended figure and not an actual legal requirement, and many engines with modern materials and synthetic lubricants can go well beyond their recommended TBOs.


I"m curious if IJN Yamato had not been sunk and had ended up engaging American forces for a prolonged period of time, I can see the IJN wanting to do that with her guns; just to keep firing regardless of their service life of 200 to 250 service round RBO (rounds before overhaul).
But I really don't have the slightest idea what would happen if a 46cm barrel was fired for 400, 500, or 600 service rounds. Or 1,000.

[Atma]

According to this book:
http://www.1999.co.jp/eng/10171751
IJN Yamato (and IJN Musashi) had their guns replaced for the last time in May 1944, and IJN Yamato had 4 new guns in February 1945 for the last time.

I'm sorry but I don't know what you mean.

Do they start to become increasingly less accurate?

Thats the first sign that your guns need to be replaced by "fresh" new ones.

[Atma]

Forgot to add, Japanese designers NEVER really loved the idea of triple guns, cause after heavy use the projectiles tend to interfere between them after long/heavy use.

[SailorJack]

Yes, I've seen references that there was a built-in firing mechanism delay of adjacent 46cm barrels.
One online reference says the middle barrel was given a built-in .08 second delay that could not be overruled.

[Atma]

And dont forget that the IJN Yamato class was the only triple turret battleship in Japanese Navy, even in the 1920's noone of the 8-8 fleet program battleships had tripple(they where designs with triple and quadruple, but they always favoured the double mode). Even in heavy cruisers the Japanese designers favor the double barrel turret instead of triple or more. Royal British Navy also favored the double barrel turret. In Norman Friedman book "USN Battleships an Illustrated History" there a line were British officials are very harsh for the new tripple turrets of USS New Mexico class and criticism them for cramped space and dangerous interference at long ranges after heavy use.

[SailorJack]

It sounds like they wanted 'fresh' barrels for precision targeting.
But that heavily worn barrels might still be serviceable, just a little less accurate, with very slight increase in propellent gas blow-by from the barrels as more service rounds are fired beyond the official 250 round limit.
It sounds as if they would still be fairly useful for shore bombardment of inexact targets.

[Atma]

In a perfect world yes, or in a non wartime period those guns might be used for training or shore bombardment.
But in the decaying Japan of mid 1940's steel is almost equal as gold.

[SailorJack]

I just discovered a reference on page 60 of 'The Battleship Yamato' by Janusz Skulski, to a 'radar jammer';
"Radar jammer -- 7 antennas fitted on both sides and aft yard of air defence combat post, fore wall of tower, decks IX-X, and both sides of signal platform, deck V (1945)."
Could this have prevented American shore, surface ship, or aircraft radar from detecting IJN Yamato accurately, or at least interfered with it somehow?
Or what's the deal with the 'radar jammer'?

[Senkan]

I read somewhere that Yamato never had any jamming devices.

[redoctober27]

Hello dose anyone know what the triple AA shields on yamatos decks would have been like? 1 is just a plain shield no bottom like seen in lionraors PE kits and have been resently seen on some kits. ....or.. 2. Is the same as one only with a anti-skid plate on the bottom and 3 is a plain gun tub base like the ones that we find in the tamiya 1/700 kits. Sorry for lack of picture still more resizing issues
Thank you

[Atma]

The shielded AA 25 mm guns of IJN Yamato were of two types. And that means a small variation on the cover.

[Atma]

And here is a picture of the two kind of shielded triple 25mm AA guns:

[Atma]

Number 2 is the standar shielded triple 25mm AA gun mount used on aircraft carriers and in IJN Yamato and IJN Musashi, the number 1 was used only in IJN Yamato in 1945, the arrows points at the differences between them: