IJN Armed Merchant Cruisers

[fontessa]

In 戦前船舶資料集 Prewar Ship Materials No.147 which is the newsletter of the Prewar Ship Study Group 戦前船舶研究会, I found below drawings created IJN Naval Yards.
(1) Auxiliary Seaplane Tender (聖川丸 Kiyokawa Maru) Gunnery Armament Drawing created Yokosuka Naval Yard Ordnance Manufacture
(2) Auxiliary Seaplane Tender Air Tubes for Barrel Exhaust Laying Drawing created Yokosuka Naval Yard Ordnance Manufacture
A system that exhausted the combustion gas with compressed air after the firing of 15cm gun.
All drawings for Kiyokawa Maru seems to have been created at Yokosuka Naval Yard.
(3) Auxiliary Seaplane Tender actually Maine Layer “Tatsumiya Maru” Electric Ordnance Drawing created Kure Naval Yard Electric Department
It was classified 軍機密 Gunki - Hi. But 軍機密 didn’t exist. It may be the error of 秘.
軍機 was the best secret. When BB Musashi was constructed at Mitsubishi Heavy Industrial Nagasaki Shipyard, all drawings lent by Kure Naval Yard were designated as 軍機 and strict security measures were required. When a part of the drawings was lost, Army Military Police investigated Nagasaki Shipyard and Nagasaki City. It became a big problem.

The size of the newsletter is B5. This is too big as data size, so I uploaded the file downsized in half.

The Tech Officers and 技師 Engineers assigned to naval yards designed such details at their naval yards.

fontessa
P.S. The below is clarified in Prewar Ship Materials No.147.
Copyrit Free if you indicade the original, when you reprint the article in the book.

[fontessa]

Additional Info:
Auxiliary Seaplane Tender Kiyokawa Maru Outfit Drawing, maybe made based on the outfit drawing created by Yokosuka Naval Yard Shipbuilding Department. She cidn't have a hanger deck, so the seaplanes seemed to be open-air anchored on the upper deck.

fontessa

[Eugen Pinak]

Yes, me and my co-author covered them too. As well as all other seaplane carriers, both converted and purpose-built.
Unfortunately the book is in Russian.
You can see cover and some pages here at my Dream: https://eugen-pinak.dreamwidth.org/39918.html

Unfortunately, the images of the book itself aren't working on my end (maybe pc settings-I need to figure out). But the auto-translations of adjoining info is VERY interesting! I have much reading ahead me! Love your work! -I didn't see much on the midget subs, maybe I just haven't found the right link within the link, yet. Is your book drawing/illustration/picture heavy?? The other images in that thread link show up just fine, pics/drawings I haven't seen before. GREAT STUFF! Thank you!! I NEED TO GET YOUR BOOK.

It's a pity. Here are couple links I've found with photos of some pages from my book. Drawings are not shown, unfortunately.

https://violity.com/109335794-v-sidoren ... oj-mirovoj

https://meshok.net/uk/item/58040308_102 ... 1%82%D0%B0

I'm very curious about the "speedboats Ko & Otsu" any further info?

You mean a cover name for midget submarines?
There is an appendix in our book about them.

P.S.-It looks like the Japanese were far beyond everyone else in regards to amphibious assault ships, definitely the inspiration for modern ships.

Indeed.

BTW, some posts from my co-author of this book about IJA landing ships. In Russian but I hope Google-translate will help here.
"Shinshi Maru" - https://sidorenko-vl.livejournal.com/51640.html
"Akitsu Maru" - https://sidorenko-vl.livejournal.com/51846.html
"Kumano Maru" - https://sidorenko-vl.livejournal.com/52047.html

[Eugen Pinak]

In 戦前船舶資料集 Prewar Ship Materials No.147 which is the newsletter of the Prewar Ship Study Group 戦前船舶研究会, I found below drawings created IJN Naval Yards.
...

Thank you for the interesting drawings, Fontessa.
"Senzen Senpaku" is a treasure trove of a unique information. Unfortunately those issues are really hard to find.

[Eugen Pinak]

And another source on "Kawa-gata" ships - and article about salvage of "Kiyokawa Maru" from the Journal of the Kansai society of naval architects.
BTW, "Kiyokawa Maru" was the last survivor of IJN seaplane carriers, serving as merchant ship till 1969.

Still no hull shapes, but some general drawings and drawing of hull plaitings.

[fontessa]

Hello Eugen,

Thanks very much for interesting info.

"Kumano Maru" - https://sidorenko-vl.livejournal.com/52047.html

About the picture of this book, it seems to say about the movement of 45th Air Regiment to New Guinea. Does AB「Tyūё̄」in the caption mean Chuyo? According to the record of 45th Air Regiment, Ryuho and Chuyo carried them to New Guinea, departed Yokosuka in December 1942.
Will you translate the Russian at the top of this figure into English?

飛行第45戦隊.jpg (32.21 KiB) Viewed 845 times

fontessa

[ShindenKai]

Thanks Fontessa, now I need hull plans for any of the midget-sub carriers. So many great drawings!

As for the speedboats, they're mentioned as being one of the many options of load-outs for the Shinshu Maru: "The figure shows one of the "intermediate" loading options: 2 armored boats, 2 speedboats "Kō", 2 speedboats "Otsu", 12 "toku daihatsu", 14 "daihatsu", 14 (16) "sho'hatsu"."

-The armored gunboats are shown on upper rear deck and the two types of speedboats appear to be shown on the forward upper deck of the upper drawing.

-This info is listed in the links provided by Eugen Pinak, Thank you very much Eugen!

[fontessa]

Thanks Fontessa, now I need hull plans for any of the midget-sub carriers. So many great drawings!

As for the speedboats, they're mentioned as being one of the many options of load-outs for the Shinshu Maru: "The figure shows one of the "intermediate" loading options: 2 armored boats, 2 speedboats "Kō", 2 speedboats "Otsu", 12 "toku daihatsu", 14 "daihatsu", 14 (16) "sho'hatsu"."

-The armored gunboats are shown on upper rear deck and the two types of speedboats appear to be shown on the forward upper deck of the upper drawing.

-This info is listed in the links provided by Eugen Pinak, Thank you very much Eugen!

I thought that the landing operation ships with a slope or slopes on the stern shows the foresight IJA / IJN had, so I created the following thread. This thread started with 神州丸 Shinshu Maru you mentioned. Although there was a considerable amount of counterargument, I think this thread have led to meaningful discussions.
Please refer to:
viewtopic.php?f=65&t=262386&p=2390455

fontessa

[Eugen Pinak]

Hello Eugen,

Thanks very much for interesting info.

You are always welcome!

"Kumano Maru" - https://sidorenko-vl.livejournal.com/52047.html

About the picture of this book, it seems to say about the movement of 45th Air Regiment to New Guinea. Does AB「Tyūё̄」in the caption mean Chuyo? According to the record of 45th Air Regiment, Ryuho and Chuyo carried them to New Guinea, departed Yokosuka in December 1942.

Yes, that's "Chuyo" carrying Type 99 bombers in 1942.

Will you translate the Russian at the top of this figure into English?

Above this photo of "Chuyo"? Of course. Here is the translation:

"Above the upper deck, the structures and equipment of the ships remained practically unchanged, with the exception of the installation of artillery and radio-technical weapons. The ships initially had advanced cargo handling equipment, with numerous derricks, including heavy ones. This made it possible to take on the upper deck additional landing craft and other watercraft (armored boats, submarine chasers, etc.) (or other cargo - in this respect, "special" ships did not differ much from other cargo-passenger ships).
All these transports were actively used to deliver reinforcements to the southern front of the Empire, and their ability to take on board a large number of various combat and landing craft and quickly unload them in poorly equipped ports, if not without them, was very valuable. A feature of the war on the islands is the need not only for manpower, military equipment and various supplies, but also for small combat and transport watercraft, which were used extremely widely (not only between these islands, but along the islands, because many islands did not have any roads, except for the paths of the natives, so that one can deliver people and goods from one point of the coast to another only by water), which means that they also had to be brought to the front to build up efforts and compensate for losses.
But for modern warfare aircraft were also required, and Akitsu-maru was especially convenient for their transportation. Of course, the sailors rescued their brothers in arms by providing their aircraft carriers for the transportation of army aircraft, but there were few aircraft carriers, so the Navy effort itself was not enough."

[Eugen Pinak]

-This info is listed in the links provided by Eugen Pinak, Thank you very much Eugen!

Glad to be of help. If Vladimir will make more posts about Japanese landing ships - I'll post them here.

[fontessa]

Hello Eugen,

Thanks for the translation. Deeply grateful.

fontessa

[Eugen Pinak]

You are always welcome, Fontessa.

[fontessa]

Nisshin
At the first, Nisshin was designed as a pure Seaplane Tender (Condition 1), and re-designed as a Ko-target Tender (Condition 2) later.

Condition 1
Note that slopes on the stern were already prepared.
Open-air anchored on the upper deck
Type12 Trial Two-seater Reconnaissance Seaplane x 12
Special Reconnaissance Seaplane x 2
Folded in the hanger deck
Type12 Trial Two-seater Reconnaissance Seaplane x 5
Special Reconnaissance Seaplane x 6
Condition 2
Open-air anchored on the upper deck
Jake, Pete x 12 total
In the hanger deck
Ko - Target x 12

Click below for enlarged figures.

fontessa

[fontessa]

Nisshin (Condition II) Scale Model (1 / 700, Length~25cm)

fontessa

[ijnfleetadmiral]

Seeing incredible model ships like that make me wish for ship versions of Hot Wheels / Matchbox cars.