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

[nimitz4145]

Here is the never finsihed Yamato of my son. He was 12 years old when he began but due to not enough time, he let the model as shown

[Serhan Oflas]

Hello All,

In Gakken No:11, there is an article about green painted waterline hull instead of red for this sisters. Does anybody have ideas what is it about?

Thanks,

Regards
Serhan OFLAS

[Mperor]

Hey there, all fellow Yamato & Musashi fans!

I'm new to the forum, so still peeking around, and I'm glad to see this thread has so many pages.


I actually had a technical question for the more knowledgeable Yamato/Musashi experts out there (as I'm still learning, heh)...

It is about the 12 X 127mm AA guns on either sides of the superstructure, both the ones with the blast pocket and those without.

Historically speaking... were those AA guns rotatable? In movies, I've only seem them facing directly ahead in a perpendicular fashion, and never saw them turn, though I've seen them play with the elevation. I ask because I was planning on trying not to glue them, but instead, add small pieces of magnets in order to keep them stuck onto the ship, but still manage to rotate them. I've had a dilemma of how to arrange those guns...

All pointing to the side, of mspread them out like sun rays around the super structure...

I'd assume the triple 25mm AA guns inside the gun pockets were not rotatable...?

Thanks!

[chuck]

They were rotatable. That's why there are elevation and train limiting rails around them to keep them from firing into own ship. Turning the whole ship to aim those guns at airplanes would seem somewhat futile, don't you think?

[Mperor]

Turning the whole ship...? Well, why not... they were...

LOL Just kidding.

Thanks for the information!

It's too bad though, because the 127mm guns without the pockets will be very tough to be made rotatable. =\ But I guess having some being rotatable is still better not none at all...

I'd assume the triple 25mm ones inside the blast pockets were NOT rotatable?

[chuck]

The triple 25mm guns in those little domed blast pockets are also rotatable.

[Mperor]

Really? I really had no idea they could rorate...!

I figured the not pocketed guns obviously could rorate, I'd be curious to know through which mechanism they can make the whole dome rorate with the gun inside...!

Thanks for the information!

[chuck]

Really? I really had no idea they could rorate...!

I figured the not pocketed guns obviously could rorate, I'd be curious to know through which mechanism they can make the whole dome rorate with the gun inside...!

Thanks for the information!

The domed triple 25mm mounts can be remotely controlled from AA directors on the superstructure. So that suggests they are turned by electric motors with control leads going up to the directors.

[Mperor]

Were they not manned then?

Or did the AA controller simply control the traverse & elevation?

[J. Soca]

Talking about Yamato does any1 in here owns the 1/250 scale Yamato from Woody-Joe?

i found this while doing a more thorough research on the 1/250 scale kits, the price is high although with all the p.e set, metal barrels, wooden deck and rest of goodies might be uhh reasonable.

http://www.zootoyz.net/en-us/p_851.html



Jose

[chuck]

Were they not manned then?

Or did the AA controller simply control the traverse & elevation?

They were manned because the 25mm guns are magazine fed, and each barrel requires 3 loaders to keep supplied with fresh magazines. Also the mount has local control for backup, which requires 2 more men to operate. So when in action, each of these little domed turrets houses an amazing 11 men. The primary AA computation function was done by mechanical computers in the AA director (controller), so the AA controller controlled both traverse and elevation of the 25mm gun mount. There is a set of backup aiming equipment in the mount itself, but that was much less sophisticated and consisted of basically a glorified ring sight.

[chuck]

Talking about Yamato does any1 in here owns the 1/250 scale Yamato from Woody-Joe?

i found this while doing a more thorough research on the 1/250 scale kits, the price is high although with all the p.e set, metal barrels, wooden deck and rest of goodies might be uhh reasonable.

http://www.zootoyz.net/en-us/p_851.html



Jose

Unfortunately, the photo on the web site shows that Woody Joe shares many of the same inaccuracies as found in Tamiya

[J. Soca]

Unfortunately, the photo on the web site shows that Woody Joe shares many of the same inaccuracies as found in Tamiya

sooo true, the first thing i noticed was the size of the bridge's aft ready room it looks to me the same size from Tamiya's and other inaccuracies on the bridge structure, a missing searchlight i believe. it needs some work too just like all the others.



Jose

[Mperor]

You may be able to get a 1/200 Nichimo kit for less than what they're charging... =\

http://www.freetimehobbies.com/index.as ... odID=21768

Though I've never had the experience with the Nichimo kit because it is outside of my current student budget, heh. Anyone else on here may know better.



And chuck! Thanks for clarifying the things... I did realize the 25mm AA guns on the Yamato were pretty... bad. Having seen them in action in the Yamato movie, I did feel sorry for the crew who had to wrestle with such a nasty gun.

I have yet to understand, actually, how do those AA controllers calculate/figure out what elevation and traverse to call for at all. I've seen them peek through some kind of... fixed scope device, but I never understood how they figured out for instance, which airplane to stick to (and how to lock on target), and then figure out what elevation and angle to call, because they do have to fire 'slightly ahead' of the airplane so that the speed of the bullet compensates that extra distance...

But yeah, complex stuff! >_<

[chuck]

The ring sight on the AA mount is just that, a collection of rings. The gunnery tries to estimate the range and speed of the aircraft by eye and experience, and then use the concentric rings to estimate how much he should lead his aim by. It's extremely crude, and give little chance of hitting an aircraft.

The director is more sophisticated. Here several men are responsible for aiming a sight directly at the aircraft, and a range finder is used to find the range to the aircraft. A mechanical sensor keeps track of where the sight is pointed and how fast the sight is moving in X and Y direction, and also receives input from the range finder. A mechanical computer than integrates these data, and use sets of cams and gears to compute the direction the gun should aim at, accounting for target speed, target range, shell trajectory, and own ship motion. In the original 25mm dome turrets on the Yamato, the aiming direction is then used to directly remote control the turret. So the gun mount automatically follows the aiming instructions from the director. This in theory gives better odds of hitting aircraft, and it probably does in practice as well.

In the open 25mm mounts, the director is still used, but no direct remote control is provided. Instead elevation and traverse instructions from the director is transmitted via electric cable to dials on the mount, where they are displayed by a set of needles which tells the gun crew what the proper traverse or elevation is. Another set of needles of another color show what the actual traverse and direction of the mount currently is. The crew operating hand wheels to crank the mount around in traverse and elevation to try to bring the two sets of needles together. When the needles overlap, then the gun is pointed in the direction computed by the director. This method of controlling AA guns is called "follow the pointer". So long as the gun crew can crank the mount around fast enough to follow the moving dial showing the continuously changing fire control solution, the open AA mounts ought in theory be as effective as the remote controlled ones. But in practice the Japanese open 25mm mounts have too low of a gear ratio in its manual traverse and elevation gears, so when the aircraft became faster, the mounts could not be manually cranked around fast enough to follow the instruction sent from the director via the dial. So they seldomly hit anything.

All in all, Japanese light shipboard AA was quite poor. It's guns were too light, except for the round domed turrets incapable of tracking fast, late war aircraft, inferior to every other major naval power's in one important way or another. Except in number of mounts, Japanese light AA never significantly improved during the whole war. So by 1945 when Yamato shipped so many AA guns that her midship looked like a beehive, she still shot down very few American planes.

[Mperor]

That's some awesome explanation you have given there, Chuck. I'll read them a few ore times to fully understand the extent of the complexity of AA firing...

But watching the movie, I think they did a pretty good job at... conveying how inneffective the guns were. It's almost sad to see so many guns and none of them being effective.

I guess the only effect it had really was to not give the American bombers free rein to fly slow and aim their bombs more slowly. It seemed more like scaring them into missing, or flying away, as opposed to actually shooting them down.

I'd imagine the single barrel portable 25mm wasn't any better? But I figured it'd at least be somewhat more manoeuvrable than the triple barrel ones, but the reloading was such a hassle... except it was thrice the trouble in the triple barrel guns. =\ Such a shame they did not develop a more effective AA system to counter the airforce. They had such a powerful battleship, yet even if battleships were made obsolete, it shouldn't have gone down in such a pathetic way, heh.



I've actually heard from a while ago that the Yamato deck was designed in a such a way that it had a (albeit slight) chance of bouncing off bombs that were dropped on top of it. Can anyone confirm this 'rumor'? Or is it just fabricated... myth? Heh.

[chuck]

Yamato's upper deck is made from 1.5 inch armor. It might bounce a very light bomb off, but it won't stop a heavier bomb. What it is intended to do is to trigger the fuse of any bomb that doesn't have a time-delay fuse so it might explode outside instead of inside the ship. 2 decks down from the upper deck is another 8 inch thick armored deck. That deck is the main protective deck for the engine, magazine, and main fire control computers. That deck is strong enough to stop vast majority of bombs used against ships in WWII. The lower deck is the strongest armored deck of any battleship, and never penetrated even though the Yamato and her sister ship together absorbed almost 40 armored piecing bombs.

The Japanese single portable 25mm guns are swung by hand and aimed by eye, and the single gunner must also at the same time remove a spent magazine and replace it with a full one every 15 rounds (That is every 4 seconds). Their chance of hitting anything before the enemy is close enough to drop a bomb or torpedo is almost zero. But it is said that seeing these single guns fire improves the crew's morale. So they are basically morale boosting noise makers. Japanese ability to seriously jeopardize fast, late war aircraft making dive bombing or torpedo attacks is quite weak.

But before we completely trash all aspect of Japanese shipboard AA defense, I like to point out that Japanese heavy AA guns were pretty good, at least by 1941 standard. Prior to 1939 the Japanese thought high level horizontal bombers like the B-17 were the most serious threats to the Japanese fleet, and they did manage to develop a shipboard AA system that was as effective as any in the world against this type of threat. In their defense it should be said that the US army airforce also believed prior to 1942 that bombers like B-17 could do great damage to warships at sea. Yamato's 5"/40 AA guns were as good as American 5"/37, and probably more effective and more versatile than typical British, German and Italian heavy naval AA guns of the era. Yamato's type 94 heavy AA director was also technically comparable ( it had a few flaws, but it was technically very advanced) to American Mk37 director and more advanced than anything the Germans, Italians and British have at the time. In fact the British won't have any heavy AA fire control computers quite so advanced until well after the war. But the Japanese failed to keep up with radar and fuse development. So by 1945, their advanced computer not withstanding, the overall effectiveness of their heavy AA systems were also quite behind the times. And lacking radar to pierce clouds, Yamato's heavy AA, its advanced computer not withstanding, was effectively inactive during her final voyage thanks to low cloud cover and intermittent showers.

[Dan K]

I agree with your assessment, Chuck

[Mperor]

Ooof, that's terrible, must have been painful, being a AA crewman on the Yamato.

It's surprising, for an advanced nation such as Japan to have such a weakness while maintaining a relatively powerful surface fleet.

Were they actively aware of that weakness? I'd assume so!

Or did the ressources get so strained eventually that they just gave up altogether on the idea of researching better AA?



I'm just thinking of this fictional gun setup (because I'm bored), where the 'beehive' like guns on the Superstructure would have even multiplied by a great few times, and it'd be non-discriminatory firing, that is, all guns would fire to blindly fill the skies with bullets, lol. Like a porcupine, if you will. And because of the crazy numbers of guns that would be there, it'd almost be impoosible to 'miss' something if all direction and all height had a gun firing at. Or it could serve as a good repeller, playing on the fear of pilots to charge into a storm of bullets. Obviously, it's a fictional set up that'd work in films, not in battle, lol, but never hurts to dream! I can imagine it'd be a ammunition nightmare, but hell, the Yamato was huge, it could have stored more bullets, heh - for better guns, perhaps! 15 rounds is pathetic, really.

Or, considering the main batteries of the ship produced such a massive shockwave when it fired, what if they placed some of those guns on the superstructure in order to fire those clouds of fire and force into the air to repel incoming aircrafts? I mean, those aircrafts eventually have to dive in closer to launch their bombs, hah. And most guns (except the highest ones) were domed... That could have protected the crew from the blast, perhaps...

I can imagine the Yamato turning into a sphere of flying bullets and clouds of fire, hah.

Don't mind me, haha, just thinking of... 'what if' scenarios that would have saved the Yamato...! We certainly would need these 'fantasy' situations and equipment setting, considering battleships were already obsolete as a surface combattant anyways...

[chuck]

Overall Japan was not an advanced country prior to WWII. Japan sustained a herculean effort to keep her peacetime arms industry up to date, at the expense of the rest of civilian economy. Much of the specialized industrial equipment used to make Yamato's armor and guns had to be purchased from abroad because the Japanese domestic industry was not up to making these equipment. When war came, there was just not much slack remaining in the civilian economy to further boost her arms industry to meet the needs of the war.