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ORIGINAL: Gary Childress

ORIGINAL: Shark7

http://astilleros1939.blogspot.com/sear ... Reparacion

Site is in Spanish, but running it through Yahoo Babelfish or Bing Translate will put it in English fairly accurately. It has quite a bit of info on the slips, drydocks, and facilities for all the Major and most of the Minor countries for 1939.

Many thanks Shark7. I ran it through Babelfish but I don't see where it gives any detail of how long a ship was under construction or how many slips a particular construction yard had nor what lengths the slips are. It just seems to give a list of yards and then a list of ships that were constructed by the yard and then a few minor details on each ship produced there. Am I missing something? [&:]

ORIGINAL: Gary Childress

ORIGINAL: Shark7

Didn't the Alt_Naval assume the enlargement of the major launching slips and fitting docks though? At least I seem to remember that from browsing the site before it went down.

Not sure, I'll have to go back over his site.

Meanwhile I've set up my own building queue for the major IJN shipyards which I think should be able to produce the Alt_Naval fleet in ample time. Basically, using JWEs chart of shipbuilding capacity, I've come up with the following building plan:

Up until the Japanese withdraw from all the naval treaties, we have most of the major shipyards pumping out "shadow carriers". These are large tenders and auxiliaries (AVs, ARs, and ASs) designed optimally to be easily converted into CVLs. They basically side step treaty limitations of the early 30s so that the slips are still being utilized. Then around 1936 the dam breaks loose and the big boys start to get cranked, CVs and BBs. The larger shipyards are producing CVs and BBs by 1936 while the smaller ship yards continue with the shadow carriers and CAs. I'm going to assume that Kairyu class CVs and Harima class BBs are not going to be able to be built in the #2 slips.

I've taken the liberty of forgoing the building of APDs for the IJN which are part of the Alt_Naval building plan. I don't think they really need them so most of the later auxiliaries in the building queue are going to be build form the keel up as CVLs from the get go.

Pretty much any ship which hasn't been completed by the later stages of 1940 can be considered as not being available on December 7, 1941. So, I'm drawing the line at CV Koryu. Any ship completed after her is going to miss Pearl Harbor. Also ships being laid down in 1943 probably won't make it into the fleet before the war ends. So effectively the last two ships to be deployed will probably be CV Tairyu and AR Shijiki. Both are completed in the first month of 1944. But if Japan does linger, there will be a couple more ships in the making for deployment in 1946 or beyond.

Grand total the building queues of the major yards from 1932 forward hold the following new builds:

22 "Shadow" CVLs
17 CVs
2 BBs
8 CAs

Also one more note. Yokosuka NSY #2, according to JWEs research, was expanded from 175m to 275m between 1936 and May 1942. During this time no ships appear to have been laid down historically. In my alternative universe conversion of the slip will take place in 1932 and extend only 3 and 1/2 years, in which time the slip will be increased from 175m to a more modest 210m. The yard begins construction again in 1935. This will make the slip large enough to accomodate my shadow carriers and a Kurama class CA in late 1938. Since 175m is not much bigger than a light cruiser slip I'll assume that it won't hurt production much to remove the slip from operation for a few years, especially since the majority of those years will be during the freeze on new warships brough about by the London treaty.

Below is a chart depicting the Japanese building program of Admiral Gary.

ORIGINAL: Terminus

ORIGINAL: Gary Childress

ORIGINAL: Shark7

Didn't the Alt_Naval assume the enlargement of the major launching slips and fitting docks though? At least I seem to remember that from browsing the site before it went down.

Not sure, I'll have to go back over his site.

Meanwhile I've set up my own building queue for the major IJN shipyards which I think should be able to produce the Alt_Naval fleet in ample time. Basically, using JWEs chart of shipbuilding capacity, I've come up with the following building plan:

Up until the Japanese withdraw from all the naval treaties, we have most of the major shipyards pumping out "shadow carriers". These are large tenders and auxiliaries (AVs, ARs, and ASs) designed optimally to be easily converted into CVLs. They basically side step treaty limitations of the early 30s so that the slips are still being utilized. Then around 1936 the dam breaks loose and the big boys start to get cranked, CVs and BBs. The larger shipyards are producing CVs and BBs by 1936 while the smaller ship yards continue with the shadow carriers and CAs. I'm going to assume that Kairyu class CVs and Harima class BBs are not going to be able to be built in the #2 slips.

I've taken the liberty of forgoing the building of APDs for the IJN which are part of the Alt_Naval building plan. I don't think they really need them so most of the later auxiliaries in the building queue are going to be build form the keel up as CVLs from the get go.

Pretty much any ship which hasn't been completed by the later stages of 1940 can be considered as not being available on December 7, 1941. So, I'm drawing the line at CV Koryu. Any ship completed after her is going to miss Pearl Harbor. Also ships being laid down in 1943 probably won't make it into the fleet before the war ends. So effectively the last two ships to be deployed will probably be CV Tairyu and AR Shijiki. Both are completed in the first month of 1944. But if Japan does linger, there will be a couple more ships in the making for deployment in 1946 or beyond.

Grand total the building queues of the major yards from 1932 forward hold the following new builds:

22 "Shadow" CVLs
17 CVs
2 BBs
8 CAs

Also one more note. Yokosuka NSY #2, according to JWEs research, was expanded from 175m to 275m between 1936 and May 1942. During this time no ships appear to have been laid down historically. In my alternative universe conversion of the slip will take place in 1932 and extend only 3 and 1/2 years, in which time the slip will be increased from 175m to a more modest 210m. The yard begins construction again in 1935. This will make the slip large enough to accomodate my shadow carriers and a Kurama class CA in late 1938. Since 175m is not much bigger than a light cruiser slip I'll assume that it won't hurt production much to remove the slip from operation for a few years, especially since the majority of those years will be during the freeze on new warships brough about by the London treaty.

Below is a chart depicting the Japanese building program of Admiral Gary.

Only two years to build a battleship or an aircraft carrier, and the same for a heavy cruiser? I know the Harima and Inaba get their gun turrets "for free", but still?

ORIGINAL: Terminus

As to the auxiliaries, Japan needs them very much. It sets out to adopt a forward defence strategy, along its national perimeter, the outer edges of which are hundreds and hundreds of miles away from any developed bases. Where is the fuel, ammunition and repair services for all those warships going to come from?

The "shadow carrier" program is a very bad idea.

ORIGINAL: Terminus

Speaking of which, where is the yard time for the reconstruction of the Ise, Hyuga, Fuso and Yamashiro? They all lose gun turrets and gain better machinery; not work you do tied up at a pier.

Back then, there was a difference between a construction slipway, drydock and graving or fitting dock. You built capital ships on a slipway (the keel-to-launch part) then moved them to a fitting facility (sometimes graving dock, sometimes fitting slip, sometimes g-dock then f-slip, depending). Conversions were done first in a drydock (or g-dock) then in a fitting slip, since most of the work was topsides/interior. Wet dock work was for stuff like hull mods (bulges, armor work, engine/prop mods, etc..).

Conversions didn’t impact construction slipways, except … some ships took longer to fit than they did to launch. If you had a limited number of fitting facilities of the proper size (like Japanese yards) you could build another ship to launch in the empty slipway, but the launched hull would just have to sit there until the first guy finished fitting and moved out to give the second guy room at the bar. So it’s not really just construction space, it’s number and availability of facilities at each step of the process. If fitting space is choked with conversions, it don’t matter how many empty construction slips there are … ya can’t build nothing ‘cause there ain’t nowhere to put them to finish them off.

ORIGINAL: Gary Childress
I was operating on the assumption that the ships could be reconstructed using other facilities than the construction slips.

ORIGINAL: JWE

ORIGINAL: Gary Childress
I was operating on the assumption that the ships could be reconstructed using other facilities than the construction slips.

Ok, don’t want to get too deep into this, but here’s a quickie on ship construction/conversion.

Ships can be built in a dry slipway or a wet slip or a wet dock. In a dry slip, can be oriented two ways, lateral launch or longitudinal launch, depends on shipyard terrain. If a dry slip (pics 1, 2, and 5), it is built, primarily to main deck level (see Missouri, pic 5), with darn little superstructure, no guns, no fittings, i.e., as little weight as possible to avoid damage during launch (or to avoid it being so heavy it doesn’t move at all).

Pic 3 is Mount Vernon in what I call a graving dock (shallow with little in the way of heavy equipment – good for hull work). Ships can be constructed in wet slips like this. One may complete more of a ship constructed in this manner, prior to launch, but as one can see, they might be draft limited so, again, launch weight becomes a factor, depending on the depth of the slip.

Pic 4 is Texas in a full-boogie drydock (deep, wide, stuff for heavy lifting). A modern one, yes, but one gets the idea. Ships can be constructed in wet slips like this (a construction drydock) in which case they can complete through topsides prior to launch. The Yamato-type construction ways looked like a cross between pics 3 and 4, with construction girders like pic 5 (good also for hanging tarps to hide the things).

If built in a dry slip, a ship “may” be moved to a graving-type fitting dock, and/or a fitting drydock (maybe one, maybe the other, maybe both, maybe neither – depends). Then ship goes to a fitting pier like in pic 6. Fitting pier (or fitting dock) has heavy lifting gear alongside, and might be one sided (port side to, in pic 6) or two sided. So one must have a sufficient sized (and facilitated) construction slip, and a sufficient sized (and facilitated) graving and/or drydock, and a sufficient sized (and facilitated) fitting dock/pier/slip/whatever.

Conversions don’t require construction dry slips, but do require some time in a graving/dry dock. If the drydock is also a construction dock one is borked. If the drydock is also a fitting drydock (almost always the case), one is equally borked. Conversions next require substantial time at the fitting dock/pier/slip. Depending on how many (or few) of these there are, and of what size and facility scale, one may well be equally borked.

As one may imagine, full-boogie capital-ship construction drydocks were a horridly inefficient use of resources in the ‘30s and ‘40s. They were populated for years by each ship, during which time they were unavailable for fitting or hull upgrades (bulges, armor/girder mod, reboilering/reproping) and wartime damage repair, to other ships of consequent size. One must have yet another large drydock with yet more duplicate facilities, and yet another fitting pier with yet more duplicate facilities.

It’s not rocket science, but ship construction planning is a professional endeavor because of things like this. Every ship class is different, every yard is different, every constructor (the one who makes it happen) is different. But that’s construction/conversion in a nutshell; the actuality (in the 30s and 40s) was much more complex, particularly for Japan.

ORIGINAL: Shark7
Given the types of docks here, and given that you need a suitable site for such a dock (it seems a natural harbor would be a natural location for a ship-building endeavour)....Did Japan have any expansion room to help boost their ship-building programme (barring any logistical considerations)?

What I'm asking is did Japan have any additional suitable locations to allow for construction of large ship-building slips and docks? And if so, how involved would the building of a new slip/dock be?

ORIGINAL: JWE

ORIGINAL: Shark7
Given the types of docks here, and given that you need a suitable site for such a dock (it seems a natural harbor would be a natural location for a ship-building endeavour)....Did Japan have any expansion room to help boost their ship-building programme (barring any logistical considerations)?

What I'm asking is did Japan have any additional suitable locations to allow for construction of large ship-building slips and docks? And if so, how involved would the building of a new slip/dock be?

That’s a good question and a really hard one. The best answer is no, not in any practical sense. To have a capital yard, you need three things: a suitable terrain footprint, a population (and desirably an industrial) center right next door, and a transportation infrastructure to move materials (steel, and systems, and bears, oh my) to the yard.

Look at the Yamato pic. That’s the majority of Japan’s coastline; mountains down to the beach. Good in one sense because there’s deep water up to the beach (one requirement), but bad in that there’s very little flat land in contact with the shore (another requirement, and one reason why some places built and launched laterally). Where there was some flat land (Tokyo, Osaka, etc …) it was already built up and one would have to purchase and demo city parts to expand. Many of the city parts were already industrialized so one might have to demo a factory to expand a yard. Big bucks.

It was done during the war, and in more than one location, but total floorplan increases, for the few that did, were on the order of 20% - not much. One could expand outward by dredging, but then an advantage (deep water) becomes a liability and bites you in the tush. Also big bucks. So not a lot of room for expansion, for lots of different reasons.

New yards were even harder. There may well have been places with suitable terrain footprints, but nothing in the vicinity of a population center, and no place to put a population center (otherwise there would already be one). Yokosuka NSY employed 40,000 people. Transportation infrastructure was nonexistent to out-of-the-way places; recall the stories of moving prototype airplanes from the factory to the test field by ox-cart over dirt roads. Japan built several small new yards in places like that, but they were real dinky and set up on an emergency basis; barracks for a few hundred (maybe up to 1,000) workers, and supplied by sea. They did trawler type auxiliaries, woodies, and some std-D & E merchies – 30 to 50m stuff.

Not just my opinion, Mark Parillo describes all these things, as do Evans & Peattie. They might be even more categorical.

ORIGINAL: Shark7
So the answer is no...other than expanding the existing facilities to the strained limit...which in itself caused additional problems.

The only thing I see as feasibly possible by your description is a very small new yard or two, complete with rail/industrial expansion required, to build Kaibokan type vessels...and even that would be an expensive endeavor or a pure logistical nightmare. Not worth the expense pre-war unless you were certain you would need the capacity, which the powers that be did not plan for.

ORIGINAL: JWE

ORIGINAL: Gary Childress
I was operating on the assumption that the ships could be reconstructed using other facilities than the construction slips.

Ok, don’t want to get too deep into this, but here’s a quickie on ship construction/conversion.

Ships can be built in a dry slipway or a wet slip or a wet dock. In a dry slip, can be oriented two ways, lateral launch or longitudinal launch, depends on shipyard terrain. If a dry slip (pics 1, 2, and 5), it is built, primarily to main deck level (see Missouri, pic 5), with darn little superstructure, no guns, no fittings, i.e., as little weight as possible to avoid damage during launch (or to avoid it being so heavy it doesn’t move at all).

Pic 3 is Mount Vernon in what I call a graving dock (shallow with little in the way of heavy equipment – good for hull work). Ships can be constructed in wet slips like this. One may complete more of a ship constructed in this manner, prior to launch, but as one can see, they might be draft limited so, again, launch weight becomes a factor, depending on the depth of the slip.

Pic 4 is Texas in a full-boogie drydock (deep, wide, stuff for heavy lifting). A modern one, yes, but one gets the idea. Ships can be constructed in wet slips like this (a construction drydock) in which case they can complete through topsides prior to launch. The Yamato-type construction ways looked like a cross between pics 3 and 4, with construction girders like pic 5 (good also for hanging tarps to hide the things).

If built in a dry slip, a ship “may” be moved to a graving-type fitting dock, and/or a fitting drydock (maybe one, maybe the other, maybe both, maybe neither – depends). Then ship goes to a fitting pier like in pic 6. Fitting pier (or fitting dock) has heavy lifting gear alongside, and might be one sided (port side to, in pic 6) or two sided. So one must have a sufficient sized (and facilitated) construction slip, and a sufficient sized (and facilitated) graving and/or drydock, and a sufficient sized (and facilitated) fitting dock/pier/slip/whatever.

Conversions don’t require construction dry slips, but do require some time in a graving/dry dock. If the drydock is also a construction dock one is borked. If the drydock is also a fitting drydock (almost always the case), one is equally borked. Conversions next require substantial time at the fitting dock/pier/slip. Depending on how many (or few) of these there are, and of what size and facility scale, one may well be equally borked.

As one may imagine, full-boogie capital-ship construction drydocks were a horridly inefficient use of resources in the ‘30s and ‘40s. They were populated for years by each ship, during which time they were unavailable for fitting or hull upgrades (bulges, armor/girder mod, reboilering/reproping) and wartime damage repair, to other ships of consequent size. One must have yet another large drydock with yet more duplicate facilities, and yet another fitting pier with yet more duplicate facilities.

It’s not rocket science, but ship construction planning is a professional endeavor because of things like this. Every ship class is different, every yard is different, every constructor (the one who makes it happen) is different. But that’s construction/conversion in a nutshell; the actuality (in the 30s and 40s) was much more complex, particularly for Japan.

ORIGINAL: JWE

Thought you might like a list of construction yards that provided ships to the IJN during the war period. No warranty about the pre-war period. Only the NSYs and civilian yards in bold built warships from DDs on up (assumes Matsu was a DD). The rest built the little things (Es, SCs, auxPBs, etc ..). Civilian yards also had to build large numbers of replacement cargo and tanker vessels.

Naval Shipyards
Kure Naval Yard: Kure: Ways - 1 @ 300m, 1 @ 225m, [1 @ 175m, 2 @ 150m]; alt 5 @ 125m, longitudinal construction.
Yokosuka Naval Yard: Yokosuka : Ways – 1 @ 300m, 1 @ 200m, 2 @ 175m, 2 @ 150m.
Sasebo Naval Yard: Sasebo: Ways – 1 @ 200m, 1 @ 175m, 3 @ 150m.
Maizuru Naval Yard: Maizuru: Ways – 1 @ 150m, 4 @ 125m.

Civilian Shipyards
Mitsubishi Heavy Industries: Nagasaki: Ways - 1 @ 275*m, 1 @ 225m, 2 @ 150m, 4 @ 125m.
Mitsubishi Heavy Industries: Kobe: Ways - 1 @ 150m, 2 @ 125m, 3 @ 100m.
Mitsubishi Heavy Industries: Yokohama: Ways - 1 @ 200m, 1 @ 150m, 2 @ 100m.
Mitsubishi Heavy Industries: Shimonoseki: Ways - 1 @ 150m, 2 @ 100m

Kawasaki Shipbuilding: Kobe: Ways - 1 @ 250m, 2 @ 150m, 3 @ 100m.
Kawasaki Shipbuilding: Tanagawa: Ways - 3 @ 100m
Kawasaki Shipbuilding: Senshu: Ways - 3 @ 125m

Hitachi Shipbuilding: Sakurajima: Ways – 2 @ 125m
Hitachi Shipbuilding: Mukojima: Ways – 2 @ 100m.
Hitachi Shipbuilding: Innoshima: Ways – 1 @ 100m, 2 @ 75m.
Hitachi Shipbuilding: Hikoshima: Ways – 1 @ 100m, 2 @ 75m.

Kawaminami HI: Koyagi: Ways – 1 @ 125m. 1 @ 100m, 2 @ 75m
Kawaminami HI: Urasaki: Ways – 1 @ 125m. 1 @ 100m.

Uraga Dockyards: Uraga/Tokyo: Ways - 1 @ 150m, 2 @ 125m, 2 @ 100m.
Fujinagata Shipbuilding: Sakai/Osaka: Ways – 3 @ 125m.

Tokyo Shipbuilding: Ishikawa: Ways - 3 @ 125m.
Mitsui Shipbuilding: Tamano: Ways – 3 @ 125m.
Harima Shipbuilding: Harima: Ways – 1 @ 125m, 1 @ 100m, 1 @ 75m.
Nippon Koukan: Tsurumi: Ways – 1 @ 125m. 2 @ 75m
Osaka Shipbuilding: Osaka: Ways – 1 @ 125m, 1 @ 75m
Niigata Iron Factory: Niigata: Ways – 1 @ 125m, 2 @ 75m
Naniwa Dock: Osaka: Ways – 1 @ 100m, 1 @ 75m
Hakodate Dock: Hakodate: Ways – 1 @ 100m, 1 @ 75m