Japanese Warship Construction

[John 3rd]

The slipways are the key to any Japanese 'what if.' Ignoring this simply creates TOTAL fantasy.

In the RA Mod I account for increased ship-building starting in late-38/39 (4th Circle) by the addition of two CA+-sized slipways and several much smaller DD-sized slipways. It isn't much but allows for a few more hulls to be built. The cost, in terms of supply and fuel, are also taken into account.

One can see a few more ships being built by better usage of the slipways as well as specialization in building (ie larger orders of ONE Class to a single facility) in terms of months spent empty but that doesn't help a bunch. Kaigun addresses this quite a bit.

[RyanCrierie]

I have something similar to this on my site at LINK
 
Japanese Cruisers of the Pacific War by Eric Lacroix and Linton Wells
Kaigun: Strategy, Tactics, and Technology in the Imperial Japanese Navy, 1887-1941 by David Evans
The Imperial Japanese Navy by A.J. Watts and B.G. Gordon

Are very good sources to look at concerning the "Circle" Plans.

[John 3rd]

I don't have the first book on your list but have now ordered it. Thanks!

[JWE]

There's a website, http://www.alternatewars.com/WW2/IJN_Programs.htm that condenses a lot of that information and references those three books as sources. Realize the 'alternate' in the name would tend to lead one astray, but the info on that page seems to follow reality quite closely.

[JeffroK]

ORIGINAL: JWE

Really have to be careful with internet dates. One site makes a typo and everybody just copy-pastes and then you get bad info becoming gospel because "everybody" says so. [;)]

And this gem of wisdom is posted on the Internet [8|]

[RyanCrierie]

ORIGINAL: JWE
There's a website, http://www.alternatewars.com/WW2/IJN_Programs.htm that condenses a lot of that information and references those three books as sources.

Um, that's my website. [:D]

Realize the 'alternate' in the name would tend to lead one astray, but the info on that page seems to follow reality quite closely.

Some of it I got from trawling Japanese websites, some from the above three books.

Is there anything that's grossly off? Thinking about it; it might be the later war programs, due to how confusing they were -- like you said, the IJN mixed and matched elements of various plans, cancelled stuff wholesale, etc once the Pacific War started.

As for the "alternatewars" website name; it came from when I was brainstorming to create a site similar to Luft46, etc to showcase the kind of stuff the allies would have had if WW2 had continued. I then realized that if I shifted it to "alternate wars"; I could cover more than just WWII; I could also cover the cuban missile crisis for example, or the Cold War going hot in 1973 over the Yom Kippur War; a US invasion of Iran in 1979 for example, etc.

The general idea is instead of offering a whole bunch of poorly written timelines and "What if" theses, to focus on the primary source material for creating such timelines; like for example, various memorandums on DOWNFALL detailing how it was to be executed, and to create second source materials for easy reference.

That page is one of those secondary sources -- I started it when I was looking at IJN ship production for a scenario idea I had a whiel back for WITP:AE; to help me nail down a general idea of what the IJN would be like in 1945 if no war. [:'(]

[JWE]

Howdy Ryan. Didn't know that was your site. Cool.

Stumbled across that page once or twice during my travels. Must admit I was confused at first by the alternatewars thing, but did some checking and everything looks very nice. It's very convenient to have all that stuff organized on a single page for easy reference. It's also kind of fun to see some of the DDs and Escorts called-out by their different series lead-ship names. Very good job.

[John 3rd]

Ryan--Does your site have the slipway times for the Japanese CLs (Agano, Oyodo, etc...)?

Probably could simply look...
[8|]

[JWE]

ORIGINAL: John 3rd
Ryan--Does your site have the slipway times for the Japanese CLs (Agano, Oyodo, etc...)?

Probably could simply look...
[8|]

I don't know if Ryan has these or not, but there is an excellent internet source for this info. Hiroshi Nishida has done a magnificent job at http://homepage2.nifty.com/nishidah/e/index.htm and lists darn near everything you ever wanted to know about the IJN construction programs: The FY authorized (Maru Keikaku), what Yard built it, when Laid-down, when Launched, when Delivered (commissioned).

He has reproduced the original Japanese source material as precisely as I have ever seen it collected in one place. Recommend Hiroshi's site highly.

For purposes of your main question, the 'slipway' time would be from Laid-down to Launch. There were some exceptions - certain warships built in 'graving' slips that also fitted out there, and would have an 'administrative' launch date, without leaving the 'slipway', but these are far and few between, and common sense evaluation of the data will bring that out. For the most part, 95+% of the Keel to Launch dates are right what you are looking for.

[stuman]

You know, reading this thread reinforces the idea that entering into a Big-Ass, Society-Ending World War without having your ducks together is generally going to end badly

[RyanCrierie]

ORIGINAL: John 3rd

Ryan--Does your site have the slipway times for the Japanese CLs (Agano, Oyodo, etc...)?

Try THIS PAGE.

Not exactly the best, as it does admittedly need more work to clean off some rough edges.

But it does show how messed up the IJN was -- starting a war on the world's biggest ocean without even bothering to increase it's cruiser force materially? *headbang*

[Zorch]

Fascinating stuff. [&o]

My impression is that this kind of production chaos was not limited to shipbuilding, but pervaded the wartime Japanese economy.
This goes a ways towards explaining their postwar obsession with planning, efficiency, and quality control. And why they loved W. Edwards Deming.

[John 3rd]

Had forgotten about this thread until Admiral Dadman brought up the subject. Great discussion and sources here!

[decourcy2]

I know the original poster did not want alt history, but much of this came down to the cost of infrastructure for the
Yamato's; the new docks and floating docks were horrifically expensive and I did work on the cost of this back in 'historical' mod days.
It came to 2 medium size BBs and 2 BC 65s for the infrastructure cost alone! Mind boggling.

On steel, Japan should have been fine; there was plenty of nickel in Indonesia, but seemingly none of this ever made it home. I would love to see papers on specific cargoes lost to see if this is the case but I have never seen anything.

[John 3rd]

ORIGINAL: JWE

There's a website, http://www.alternatewars.com/WW2/IJN_Programs.htm that condenses a lot of that information and references those three books as sources. Realize the 'alternate' in the name would tend to lead one astray, but the info on that page seems to follow reality quite closely.

Do we have a source like this that goes back into the 20s? This page begins with Circle 1. I'd like to go back to the construction of Kako and the CAs that came after along with their building programs.

[RyanCrierie]

Since this thread has reappeared; what about the MONTANA Class.

They required the construction of extensive super large drydocks.

The Montanas simply CANNOT be laid down before the following dates:

Norfolk Naval Shipyard Drydock No. 8 (1942)
Philadelphia Naval Shipyard Drydock No. 4 (Finished May 1942)
Philadelphia Naval Shipyard Drydock No. 5 (Finished February 1943)
New York Naval Shipyard Drydock No. 5
New York Naval Shipyard Drydock No. 6
Naval Supply Depot Bayonne, NJ Drydock

---------

NORFOLK NAVAL SHIPYARD DRY DOCK NO 8

It's known that the Norfolk Naval Shipyard Dry Dock No 8 was used for the following ships due to inspecting construction photos that clearly show them being built in dry docks and the knowledge that they were built at Norfolk Naval Shipyard and the fact that Norfolk had only one super dry dock built:

CV-39 LAKE CHAMPLAIN 15 MAR 1943 to 2 NOV 1944
BB-66 KENTUCKY 6 DEC 1944 to HALTED

PHILADELPHIA NAVAL SHIPYARD DRY DOCK NO 4

UNKNOWN AT TIME

PHILADELPHIA NAVAL SHIPYARD DRY DOCK NO 5

It's pretty obvious because we know that No. 5 was finished February 1943 and a ship was laid down in March 1943 with photographic proof of it in a dry dock, plus some inference from construction dates:

CV-36 ANTIETAM - 15 MAR 1943 to 20 AUG 1944
CV 45 VALLEY FORGE - 7 SEP 1944 to 18 NOV 1945 (http://www.navsource.org/archives/02/45.htm)
BB-65 ILLINOIS - 15 JAN 1945 to HALTED

NEW YORK NAVAL SHIPYARD BROOKLYN DRY DOCK NO 5
CVB-42 FRANKLIN D ROOSEVELT - 1 DEC 1943 to 29 APR 1945
CV 51 or CV 52 (FY1945 program, never laid down, cancelled, but assigned to NYNY)

NEW YORK NAVAL SHIPYARD BROOKLYN DRY DOCK NO 6
CV-20 BENNINGTON - 15 DEC 1942 to 26 FEB 1944 (https://www.reddit.com/r/drydockporn/co ... launching/)
CV-35 REPRISAL - 1 JULY 1944 to HALTED
CV 51 or CV 52 (FY1945 program, never laid down, cancelled, but assigned to NYNY)