Calling all IJN Kuma-class (球磨), Nagara-class (長良) & Sendai-class (川内) fans

[maxim]

The armarment of Tenryu and its changes is described very detailed in the new Hasegawa kit. When she was sunk her AA armament was 1x 3 in and 4x 25 mm twins.

[Dan K]

Were there any distinct differences in Compass Bridge Windows, or in the portholes in the bridge superstructure?

There are no clear photos of all three but I think it ok to assume they are the same. Smaller in the front and as they wrap around the sides, then enlarged for the rest of the side. You can use the 1/350 versions as a guide.

[MatthewB]

Were there any distinct differences in Compass Bridge Windows, or in the portholes in the bridge superstructure?

There are no clear photos of all three but I think it ok to assume they are the same. Smaller in the front and as they wrap around the sides, then enlarged for the rest of the side. You can use the 1/350 versions as a guide.

Some of the plans I have found online shows some of the Nagara-class with a shorter bridge. And a different roof structure.

I am guessing that the shortening (looking at the dates) came during the '43/'44 "Modernization" of these ships, when they had radar installed (and their Director replaced with said radar).

So I am pretty sure that an early War Nagara would have the taller, rectangular bridge.

And there are a few photos in the Galley here of models that show some differences in the front windows. It seems that the center five panes were slightly larger (deeper) than the outer windows.

I will get some links when I wake up (I keep meaning to go to sleep).

MB

[Dan K]

You are most likely seeing some sort of optical illusion in terms of shortening the height of the bridge, as no such modifications took place. That's confirmed in LaCroix & Wells "Japanese Cruisers of the Pacific War" (aka - the IJN cruiser bible).

[MatthewB]

You are most likely seeing some sort of optical illusion in terms of shortening the height of the bridge, as no such modifications took place. That's confirmed in LaCroix & Wells "Japanese Cruisers of the Pacific War" (aka - the IJN cruiser bible).

Either that or the drawers of the plans messed up.

LaCroix & Wells, huh??? The IJN Cruiser Bible... Googles....

ZOMG! THAT is one expensive book:

http://www.amazon.com/LaCroix-Japanese- ... acific+war

http://www.amazon.com/Japanese-Cruisers ... acific+war

And here I was thinking I would just pop over to Amazon and pick up a copy.

All I can afford are the Vanguard Books on the subject, and the few books on Scribd (which are semi-"Free").

Is it really worth $300 - $2,000?

MB

[maxim]

For the 5500 t cruiser try to find this one:
Model Art No. 29 Waterline Special 2008 Autumn

http://www.hlj.com/product/MDAKS-29

Unfortunately also - as LaCroix-Wells - not longer in print. Check e.g. also abebooks.com

There is not indication that the bridge of Nagara was shortened in height. Some of the class had the bridge shortened in length above the level of the former starting deck, but these were mostly late war modifications.

Isuzu had a the start of the war only 2 twin 25 mm next to the forward funnel and one quadruple 13 mm mount in front of the bridge.

Apparently her AA armament was modified only after she was damaged on 14th November 1942 in the Battle of Guadalcanal by Marine Corps Dauntless dive-bombers.

Nagara's armament was the same at the start of war. According to LaCroix-Wells her quad 13 mm was replaced in April 1942 by two 13 mm twins. The next modernisation was in December 1942.

[MatthewB]

The Model Art book on Light Cruisers is on Scribd. So I can peruse it (and maybe pick out a few things, since I can read some Japanese - although I have probably a Japanese Third Grade education in Kanji, which causes many problems).

But I think I have got the bridge for the Nagara down (I completed a 3D model of it this morning - images of the nearly complete bridge are posted in my WIP thread on the Nagara.

I was just confused by some of the drawings I have found online of the Nagara-class ships that show a shortened bridge structure.

From examining these drawings, it looks like they may have copied flawed Fujimi Models of the ships, rather than basing the drawings off of photos, or actual Japanese plans of the ships.

I am now trying to get the Conning Tower structures and differences sorted out.

The Isuzu and Kinu seem to have a different Conning Tower structure than the Nagara.

And, I would like to know what the six-pointed "platform" or "antennae" (or whoever it is), underneath the upper Conning Tower structures on the Forward Mast are. The kit does not contain this part, yet I notice in some of the 1/350 builds of the Nagara for 1942 that the ship retains this part:



I am on my iPad, or I would annotate the image to point out the structure to which I am referring.

You can see the two long points of this "star-shaped" part underneath the upper, cylindrical part of the Conning Tower on the mast.

MB

[maxim]

I guess you are talking about the starfish. These structure is needed for the stays (?) to stabilise the upper spar of the mast.

The "conning tower" on the foremast is a target-survey platform.

A "conning tower" is an armoured tower, which is part of the bridge structure. The Tenryu class and Kuma class still had one, but the Nagara class had no armoured conning tower.

According to LaCroix-Wells the bridge and foremast was identical on Natori, Isuzu and Nagara after the conversion in 1933 - perhaps also still in 1942.

[MatthewB]

I guess you are talking about the starfish. These structure is needed for the stays (?) to stabilise the upper spar of the mast.

The "conning tower" on the foremast is a target-survey platform.

A "conning tower" is an armoured tower, which is part of the bridge structure. The Tenryu class and Kuma class still had one, but the Nagara class had no armoured conning tower.

According to LaCroix-Wells the bridge and foremast was identical on Natori, Isuzu and Nagara after the conversion in 1933 - perhaps also still in 1942.

Ok... Then I need to make some adjustments to my 3D model of the Nagara Bridge Structure, as I have very clear images and plans for the Isuzu, but the plans I have for the Nagara remain a bit "fuzzy."

I can see at least three areas where the Nagara plans depart from the Isuzu plans, and images, where I will need to make corrections. I trust the Isuzu plans, as they match both models of the ship, and the photos I can find, yet the Nagara plans do not match the images as well.

And, I need to make a "Starfish" (I wonder if I can keep it symmetric with just styrene, or if I should just add it as a separate part in the 3D model).

MB

[Dan K]

This illustration is for Tama's. Nagara's is similar, but not exact.

[MatthewB]

The Osprey New Vanguard book I have, IJN Light Cruisers, '41 - '45by Mark Stille, states that the Nagara Cruisers, when they underwent modifications in '39 - '41 all came out with different looking bridges.

. Imperial Japanese Navy Light Cruisers 1941-45 (New Vanguard) (Kindle Locations 674-675). Osprey Publishing. Kindle Edition. ]"This led to a bridge-modification program, which was carried out 1929� 34. Each ship emerged with a different bridge arrangement,. . .

So... Is this authoritative enough to suggest that maybe the bridges were a bit different?

After all, the book includes a photograph (which I cannot currently extract from the Kindle - damned copyright protections) of the Natori in 1935 (IJN Light Cruisers, '41 - '45. Stille, Mark) which shows the beveling on the bridge leading in to the forward structure that used to support the hangar mounted in front of the bridge. So I did not image that I saw this bevel, only the image on which I saw it was incorrectly labeled.

And, the images it has of the Isuzu show that the bridge was shortened when it had the radar mounted during its conversion to an AA cruiser. These are drawings, so they are not as objective as photographic evidence would be. But they do suggest that the artist had reason to depict it as such.

All this does though, in the absence of harder evidence, is to suggest that either interpretation of the bridge structure at the front corners over the front extension could be correct. The rear platforms look to be similar enough, with only a few minor differences (what looks like a notch in the upper platform between where the forward shielding ends, and the railing begins, and the lowest platform being absent on at least one ship - not the Nagara. I cannot find the picture, but I want to say it was the Isuzu after AA modifications, or the Kinu).

Oh! And thank you for the image of the Fire Control Tower. That helps considerably. I also found a set of plans/blueprints of the Nagara in '42, which I think I mentioned, which show the starfish in enough detail to be able to simply make one from styrene after importing the image into CAD, and scaling it to 1/700 scale - then do a tracing of the part, print out the tracing, paste it on a sheet of styrene, and cut.

Alternately, I can take the tracing to a company I know that does custom laser cut parts, and have it cut out of sheet brass, which seems to be a better option (I need to look for a company that does custom PE, and learn how to make PE stencils in CAD).

But back to the bridge.

There is a small house abaft the middle platform between the aft uprights of the forward mast tripod. What is this housing?

Also, where are the ladders located that lead to the Fire Control platforms on that mast?

MB

[maxim]

The bridge of Isuzu after her 1944 conversion was not shortened in height, only in length. Anyway, you asked about the 1942 fit

For sure, there could be differences in the bridge in 1942 (in contrast to the LaCroix-Wells statement), but as you recognised many plans are wrong and you need photographic evidence - or trust in some drawings. And there are many wrong drawings of Japanese cruisers...

[Dan K]

Yes, all the bridges were reconstructed to some extent in the early 1930s (though not in deck height, just arrangements and appearances) but had minimal changes in the years before the war, mostly changes in terms of navigation stations, mast, searchlights, director, addition of steel roofs to the compass bridge deck, but not the actual structure. I repeat, nothing to do with the overall height.

[MatthewB]

I finally found photographic evidence of the front of the Bridge for the Nagara, as well as something else.

I found a photo of the ship from after its last refit before the war (and before its first refit during the war), which shows that it did not have the bevel in the front of the bridge (but another photo of the Abukuma shows that it did have this bevel.

And it shows that the Nagara Bridge had a flat roof, and not the peaked roof that it was built with (When it was given a permanent roof to the compass bridge, the roof was raised and flattened).

This was in the mark still book I have been reading about the IJN Light Cruisers.

The book draws the conclusion about the IJN Cruisers that they were all failures, due to the Japanese's inability to let go of their Victory over the Russians at Tsushima in thinking that a Decisive Surface Action was the only way to go (and thus neglecting Submarines, Aircraft, and Light Cruisers - and Destroyers to an extent, which they saw primarily as a continuation of the Motor Torpedo Boat Destroyer of the same period of their victory over the Russians).

This is not surprising given the extreme conservatism of the Japanese over issues of "Tradition."

It is a pity that they did not scrap their insistence upon using Light Cruisers as Destroyer Squadron and Submarine Squadron Flagships, as the later CL class (Agano and Oyodo) would both have been fit as regular CL duty CLs with a few minor modifications.

The fate of these ships is heartbreaking considering their misuse and abuse.

MB

[maxim]

What do you mean with "level in front of the bridge"?

Abukuma had in 1941 a very different bridge. She was modernised as destroyer leader. I think that the Tamiya kit is correct:


http://www.modellmarine.de/index.php?op ... &catid=112

For me this is a very likely representation of Nagara (also) in 1942:


It is from the already recommended Model Art No. 29 Waterline Special 2008 Autumn.

P.S. Mark Stille's statement about the Japanese cruisers, as you state it, ignores the success of Japanese cruisers early in the war, when Japanese cruisers won nearly all cruiser battles. Even the at that time already very old light cruisers were employed very successful. For sure the were optimised for surface warfare, in which they were very good - but non of the cruisers of other navies were optimised for something else (and for sure all of them had no capabilities against submarines and very weak ones against aircraft). But that is a topic for thread in "History & Technology"! There were also no "Motor Torpedo Boat Destroyer" in the Russian-Japanese war, but only torpedo boats and (torpedo boat) destroyers with steam engines. I understand that is about the use of torpedoes as destroyers main weapon - but again Japanese destroyers were very successful up to 1943 causing heavy losses for the USN, especially in night battles. They lacked escorts - and the yard capacity to built them in sufficient numbers during the war. But that is also a topic for a thread in "History & Technology"!

[MatthewB]

Bevel in front of the bridge, not "Level."

On some images, it looks as if there is a bevel or chamfer to the upright edges of the bridge structure, which blends with the projection that supports the platform with the AA guns on it.

Here, you can see this on the Natori:



See how the upper bridge is not perfectly rectangular, but has a bevel that leads into the platform on the front of the bridge.

And the Natori has the temporary, peaked compass bridge roof (The Image is from 1935).

I cannot find pictures of it online, but the book shows images that the Abukuma, Natori, and Isuzu all had this bevel to their front, and that the other ships in the class has rectangular upper bridge structures, lacking this bevel/chamfer.

Here is the Isuzu after her conversion to an AA Cruiser showing the same thing:



And, it looks like the Nagara, which had a peaked compass bridge roof when the roof was a temporary shelter, had that roof leveled off in the '39 refit, when a permanent roof was constructed.

Here is the Nagara before her '38/'39 refit, with the temporary Compass Bridge Roof:



I cannot find the image of the Nagara from 1940 that is in the book (which says the source is the Yamato Museum in Japan), but the image is labeled with "Nagara, 1940, after her '39 refit," and it shows the Nagara with a rectangular upper bridge structure (without that bevel - as the above image shows prior to that refit), and with a flat roof, rather than the peaked roof.



MB

[Dan K]

First, a word about references. While I consider the Squadron Books on IJN subjects by Mark Stille as good introductory volumes for basic information on various IJN classes and ships, keep in mind that they are drawn from secondary sources and must be considered, for lack of a better word, simplistic. They often have incorrect information.

For instance, the example you cite of Nagara 1940 was actually taken in Shanghai in late 1936, and she does show the peaked rook. (The colorized photo is misleading.) In fact, at minimum, Nagara, Natori, Yura and Isuzi carried the peaked bridge roof. They also carried those bevels to either side of the bridge face. Of the second grouping, only Kinu's may have been completely square.

All of the 5500 tonners were reconstructed in the mid 1930s, with additional, though minor improvements.

As a designated destroyer squadron leader, Abukuma's bridge was further improved in the late 1930s, as were the three Sendais.

Natori in 1943 shown with the peaked roof and quad 13mm mounting up front. Isuzu would have looked like this as well until she was reconstructed in 1944 as an AA CL, following extensive bomb damage.

[MatthewB]

I looked again at the 1938 image of the Nagara from the IJN Light Cruiser book by Stille, and it does show that bevel.

It is very difficult to make out.

But it also shows a flat roof.

So the 3D model of the bridge I have is almost correct (It needs a new roof, and the slant under the windows that has the roof extend slightly out in front of the face of the bridge).

Good... I don't need to kill myself re-creating the bridge.

I wonder, though, the image you have above of the Nagara looks like that slanting face under the windows extends all the way around the three front sides of the bridge structure.

Also, what are those little houses on the sides of the bridge?

MB

[maxim]

Also, what are those little houses on the sides of the bridge?

See the legend on the plan Lookout posts...

[MatthewB]

Also, what are those little houses on the sides of the bridge?

See the legend on the plan Lookout posts...

I discovered that after going back to look.

Why does it look like on one of the other ships (Abukuma I think) it looks like there are Rangefinders mounted there?

Well, the plan says there are rangefinders there. I suppose the question is:

Why are they on Abukuma, and not the other ships?

MB