Japanese Warship Construction

[JWE]

Found some nifty stuff about IJN warship construction and the utter incompetence (pre-war complaisance and arrogance, then sheer panic after Midway) that obtained throughout the entire Bureau of Naval Affairs (Gunmu Kyoku). Seems it’s an open question whether R.Adm. Suzuki – 2nd Div, Naval General Staff (Armament Replenishment) and R.Adm. Ezaki – 4th Sect, Navy Technical Dept (Shipbuilding) were asleep, on a continuous saki binge, or just low grade morons. Anyhoo, here’s the data (relevant warships only, but the auxiliaries look even worse).

Maru Go(5) – 05/41
1 x Yamato Battleship (# 797) - cancelled
1 x Unryu Aircraft Carrier (# 800) - cancelled
2 x Kai-Taiho (G-14) Aircraft Carriers (# 801, 802) - cancelled
5 x Kai-Agano (C-44) Type B Cruisers (# 810 to 814) - cancelled
16 x Kai-Shimakaze Destroyers (# 733 to 748) - cancelled
16 x Kai-Akitsuki Destroyers (# 770 to 785) - cancelled
4 x Shimushu Escorts (Type A) (# 790 to 793) – cancelled
9 x CH-13 Subchasers (# 870 to 878) – cancelled
9 x CH-60 (700 ton) Subchasers (# 879 to 887) - cancelled

Maru Kyu – 09/21/41
1 x Unryu Aircraft Carrier (# 302) – 1 built
2 x Ibuki Heavy Cruisers (# 300, 301) – 1 built as CVL, 1 cancelled
30 x Etorofu Escorts (Type Mod-A) (# 310 to 339) – 13 built as Etorofu, 17 as Mikura/Ukuru Type B)
16 x Yugumo Destroyers (Type A) (# 340 to 355) – 8 built, 8 cancelled
10 x Akizuki Destroyers (Type B) (# 360 to 369) – 6 built, 1 unfinished, 3 cancelled
20 x CH-13 Subchasers (# 440 to 459) – 4 built as CH-13, 16 as CH-28
100 x CHa-1 Auxiliary Subchasers (# 500 to 599) – all 100 built
28 x W-19 Minesweepers (# 410 to 437) – 17 built, 11 cancelled

Then all get combined (along with Maru-roku) and renamed to the 1942 Warship Construction Replenishment Program on 09/21/41. Maru-Kyo had the fast track. Only small craft Maru-Go components able to be built. Maru-Roku components postponed indefinitely on 11/06/41. Thus the state of things on opening day.

Then Midway … and everything went to poop. Maru-Kyu still operative. Maru-Roku definitively cancelled. Maru-Go cancelled and replaced with Kai-Maru Go 09/21/42.

15 x Unryu Aircraft Carriers (# 5001 to 5015) – 2 built, 3 unfinished, 10 cancelled
5 x Kai-Taiho (G-15) Aircraft Carriers (# 5021 to 5025) - cancelled
2 x Kai-Agano (C-44) Type B Cruisers (# 5037, 5038) - cancelled
23 x Kai-Akitsuki Destroyers (# 5061 to 5083) – cancelled
8 x Kai-Yugumo Destroyers (# 5041 to 5048) – cancelled
42 x Matsu Destroyers (Type D) (# 5481 to 5522) – 18 built as Matsu, 14 as Tachibana, 10 unfinished
34 x Ukuru Escorts (Type B) (# 5251 to 5284) – 21 built, 13 cancelled
30 x CH-60 Subchasers (# 5341 to 5370) - cancelled

Then everything was getting whacked by subs … so planning went further to poop. On top of everything else, the IJN added the Maru-Sen Supplement ’43-‘44.

20 x Tachibana Destroyers (Type D) (# 4801 to 4820) - cancelled
132 x Type C Escorts (# 2401 to 2532) – 53 built, 79 cancelled
143 x Type D Escorts (# 2701 to 2843) – 63 built, 80 cancelled
21 x Ukuru Escorts (Type B) (# 4701 to 4721) - cancelled
20 x CH-28 Subchasers (# 2901 to 2921) – 18 built, 2 unfinished
100 x CHa-1 Auxiliary Subchaser (# 2001 to 2100) - all built as Cha-151 Mod
60 x CDa-101 Auxiliary Patrol/Escort (# 1701 to 1760) – 22 built, 38 cancelled

And the ever popular Maru-Sen Supplement ’44-‘45. These were so far out of reality that they couldn’t be laid down till 1947 and therefore didn’t even get hull numbers before all were cancelled.

79 x Ukuru Escorts (Type B) Escorts
168 x Type C Escorts
120 x Type D Escorts
20 x CHa-151 Subchasers
40 x CDa-101 Auxiliary Patrol/Escort

It makes for a very interesting study. ¾ of all tonnage defined in the 1941 plans were cancelled. Out of all the Replenishment plans defined on or after September 1941, the IJN could only implement 3 Unryus, 18 Matsus, 14 Tachibanas, 137 Escorts (200 feet), 22 aux Patrol/Escorts (90 feet), 18 Subchasers (150 feet), 200 aux Subchasers (75 feet). This was only possible by developing several small/marginal merchant yards into facilities for building small naval craft. All the Navy Yards, and the big merchant yards like Mitsubishi, Kawasaki, Uraga, et al, were so impossibly overburdened with pre-war contracts, arbitrary conversion orders, and damage repairs, that they were still finishing 1939 and 1941 plan vessels in 1944. 2 of the Unryus were cancelled because Yokosuka NSY had no space because of the Shinano conversion. Even so, the IJN could only manage 32 out of 52 Matsu destroyers; 137 out of 330 escort ships; 22 out of 60 auxiliary escort ships; and 18 out of 20 subchasers (ignoring the ’44-’45 Maru-Sen). There simply wasn’t enough material (steel) or enough yard space to build sufficient numbers of even these piddly 100 to 200 foot long boats. Woof!

[herwin]

Something similar happened in the UK and in France (WWI).

Look at steel production by the major combatants, count the tons in the major end items (warships, merchies, tanks and trucks) and ammo, and you discover you've accounted for almost all of it. It was a major constraint on expansion. What you couldn't produce, you had to buy on the open market, and guess what happened to that on 7 December 1941. Toluene production was a similar constraint on the tempo of land/air operations since it went into motor fuel, aircraft fuel, and ammo (explosives). For mobile divisions, one day's movement used about the same amount of toluene as one day's heavy combat.

[Shark7]

ORIGINAL: JWE

Found some nifty stuff about IJN warship construction and the utter incompetence (pre-war complaisance and arrogance, then sheer panic after Midway) that obtained throughout the entire Bureau of Naval Affairs (Gunmu Kyoku). Seems it’s an open question whether R.Adm. Suzuki – 2nd Div, Naval General Staff (Armament Replenishment) and R.Adm. Ezaki – 4th Sect, Navy Technical Dept (Shipbuilding) were asleep, on a continuous saki binge, or just low grade morons. Anyhoo, here’s the data (relevant warships only, but the auxiliaries look even worse).

Maru Go(5) – 05/41
1 x Yamato Battleship (# 797) - cancelled
1 x Unryu Aircraft Carrier (# 800) - cancelled
2 x Kai-Taiho (G-14) Aircraft Carriers (# 801, 802) - cancelled
5 x Kai-Agano (C-44) Type B Cruisers (# 810 to 814) - cancelled
16 x Kai-Shimakaze Destroyers (# 733 to 748) - cancelled
16 x Kai-Akitsuki Destroyers (# 770 to 785) - cancelled
4 x Shimushu Escorts (Type A) (# 790 to 793) – cancelled
9 x CH-13 Subchasers (# 870 to 878) – cancelled
9 x CH-60 (700 ton) Subchasers (# 879 to 887) - cancelled

Maru Kyu – 09/21/41
1 x Unryu Aircraft Carrier (# 302) – 1 built
2 x Ibuki Heavy Cruisers (# 300, 301) – 1 built as CVL, 1 cancelled
30 x Etorofu Escorts (Type Mod-A) (# 310 to 339) – 13 built as Etorofu, 17 as Mikura/Ukuru Type B)
16 x Yugumo Destroyers (Type A) (# 340 to 355) – 8 built, 8 cancelled
10 x Akizuki Destroyers (Type B) (# 360 to 369) – 6 built, 1 unfinished, 3 cancelled
20 x CH-13 Subchasers (# 440 to 459) – 4 built as CH-13, 16 as CH-28
100 x CHa-1 Auxiliary Subchasers (# 500 to 599) – all 100 built
28 x W-19 Minesweepers (# 410 to 437) – 17 built, 11 cancelled

Then all get combined (along with Maru-roku) and renamed to the 1942 Warship Construction Replenishment Program on 09/21/41. Maru-Kyo had the fast track. Only small craft Maru-Go components able to be built. Maru-Roku components postponed indefinitely on 11/06/41. Thus the state of things on opening day.

Then Midway … and everything went to poop. Maru-Kyu still operative. Maru-Roku definitively cancelled. Maru-Go cancelled and replaced with Kai-Maru Go 09/21/42.

15 x Unryu Aircraft Carriers (# 5001 to 5015) – 2 built, 3 unfinished, 10 cancelled
5 x Kai-Taiho (G-15) Aircraft Carriers (# 5021 to 5025) - cancelled
2 x Kai-Agano (C-44) Type B Cruisers (# 5037, 5038) - cancelled
23 x Kai-Akitsuki Destroyers (# 5061 to 5083) – cancelled
8 x Kai-Yugumo Destroyers (# 5041 to 5048) – cancelled
42 x Matsu Destroyers (Type D) (# 5481 to 5522) – 18 built as Matsu, 14 as Tachibana, 10 unfinished
34 x Ukuru Escorts (Type B) (# 5251 to 5284) – 21 built, 13 cancelled
30 x CH-60 Subchasers (# 5341 to 5370) - cancelled

Then everything was getting whacked by subs … so planning went further to poop. On top of everything else, the IJN added the Maru-Sen Supplement ’43-‘44.

20 x Tachibana Destroyers (Type D) (# 4801 to 4820) - cancelled
132 x Type C Escorts (# 2401 to 2532) – 53 built, 79 cancelled
143 x Type D Escorts (# 2701 to 2843) – 63 built, 80 cancelled
21 x Ukuru Escorts (Type B) (# 4701 to 4721) - cancelled
20 x CH-28 Subchasers (# 2901 to 2921) – 18 built, 2 unfinished
100 x CHa-1 Auxiliary Subchaser (# 2001 to 2100) - all built as Cha-151 Mod
60 x CDa-101 Auxiliary Patrol/Escort (# 1701 to 1760) – 22 built, 38 cancelled

And the ever popular Maru-Sen Supplement ’44-‘45. These were so far out of reality that they couldn’t be laid down till 1947 and therefore didn’t even get hull numbers before all were cancelled.

79 x Ukuru Escorts (Type B) Escorts
168 x Type C Escorts
120 x Type D Escorts
20 x CHa-151 Subchasers
40 x CDa-101 Auxiliary Patrol/Escort

It makes for a very interesting study. ¾ of all tonnage defined in the 1941 plans were cancelled. Out of all the Replenishment plans defined on or after September 1941, the IJN could only implement 3 Unryus, 18 Matsus, 14 Tachibanas, 137 Escorts (200 feet), 22 aux Patrol/Escorts (90 feet), 18 Subchasers (150 feet), 200 aux Subchasers (75 feet). This was only possible by developing several small/marginal merchant yards into facilities for building small naval craft. All the Navy Yards, and the big merchant yards like Mitsubishi, Kawasaki, Uraga, et al, were so impossibly overburdened with pre-war contracts, arbitrary conversion orders, and damage repairs, that they were still finishing 1939 and 1941 plan vessels in 1944. 2 of the Unryus were cancelled because Yokosuka NSY had no space because of the Shinano conversion. Even so, the IJN could only manage 32 out of 52 Matsu destroyers; 137 out of 330 escort ships; 22 out of 60 auxiliary escort ships; and 18 out of 20 subchasers (ignoring the ’44-’45 Maru-Sen). There simply wasn’t enough material (steel) or enough yard space to build sufficient numbers of even these piddly 100 to 200 foot long boats. Woof!

Oh it gets worse...

You missed the utterly ridiculous Super Yamatos: 3 Canceled or not ordered, No 797, No 798, No 799
Type 815 CLAA: 4 Cancelled or not ordered, these would have actually been useful 8x2 10cm/65 and numerous 25mm mounts
Type B65 CB: 2 Cacelled or not Ordered, not useful in any event

The conversions: Ise and Hyuga were simply a waste of time and effort. Would have been better off to keep those slips free for two real carriers or even taking two of the partially completed canceled hulls and designing a quick conversion for them (similar to Shinano, just with a more appropriate hull).

I think we can all agree that the plans pre-war ate up too much slip space for very little return, and after things went south, it just got worse. What makes it even worse is that they canceled ships in the slips that might have been somewhat useful if just finished or finished to another design to start new construction of ships that had no chance of being finished in time to make a difference.

And the fact that no planning was made at all to actually ensure supply ships made it to port with resources didn't help matters.

I think your option 2 (saki binge) or 3 (just plain morons) is the accurate description.

[topeverest]

It also speaks to the utter confusion and conflict in the Empire high command.

I've always believed that Leadership, while important in all places, is paramountly needed the top.  A single high command error can erase all the efforts of brilliant subordinates...as we can see in this example.

[JWE]

Yeah. I've often wondered at the Shinano decision, and/or what the thought processes would have been without the Midway panic.

Using the Yamato/Musashi time frames, Shinano would launch in 12/42 as a BB and deliver in 04/44 (as opposed to launching in 10/44 as a overweight trash hauler CV). That frees up the Yokosuka #1 slipway for almost 2 years, during which one of the cancelled Unryus could be laid down, launched by 02/44, and deliver by 10/44. One would get a real CV (although small) and another Yamato in exactly the same time it took them to convert/launch/deliver that useless monstrosity. There just ain't no accounting for the antics of senior military officers trying to run an economic enterprise. King Canute would have had better luck.

[JWE]

ORIGINAL: Shark7
I think we can all agree that the plans pre-war ate up too much slip space for very little return, and after things went south, it just got worse. What makes it even worse is that they canceled ships in the slips that might have been somewhat useful if just finished or finished to another design to start new construction of ships that had no chance of being finished in time to make a difference.

Well, I wouldn’t go quite that far. 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.

Just for fun, here’s the actual construction scheds (keel-to-launch) for the only four yards capable of building a capital ship. A BB or large CV (Taiho/’Kaku) required a 300m slipway (only 3 in existence). A CA or Unryu type CV required a 225-250m slipway (only 3 in existence by end of war). They were actually utilized pretty well … hull # 111 and Shinano seem to be the only major abortions.

I didn’t worry about hulls 795 to 799, since they weren’t scheduled to start till 1944, and weren’t scheduled for completion/delivery till 1948, ‘49, and ’50.

[Shark7]

ORIGINAL: JWE

ORIGINAL: Shark7
I think we can all agree that the plans pre-war ate up too much slip space for very little return, and after things went south, it just got worse. What makes it even worse is that they canceled ships in the slips that might have been somewhat useful if just finished or finished to another design to start new construction of ships that had no chance of being finished in time to make a difference.

Well, I wouldn’t go quite that far. 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.

Just for fun, here’s the actual construction scheds (keel-to-launch) for the only four yards capable of building a capital ship. A BB or large CV (Taiho/’Kaku) required a 300m slipway (only 3 in existence). A CA or Unryu type CV required a 225-250m slipway (only 3 in existence by end of war). They were actually utilized pretty well … hull # 111 and Shinano seem to be the only major abortions.

I didn’t worry about hulls 795 to 799, since they weren’t scheduled to start till 1944, and weren’t scheduled for completion/delivery till 1948, ‘49, and ’50.

Still seems to me that with hull #111 in the slip and partially complete, a better decision for it would be to finish it to a modified design, rather than starting over. And granted you did build the hull in 1 slip, then move it, but any bottleneck along the system causes major problems when you are in 'hurry up' mode...which was the state of Japanese shipbuilding from July 42 forward. And the conversions did tie up those docks, for minimal return IMO.

Not sure what I would have done, but finishing out Shinana in 4/44 as a BB does seem the better choice. For #111, instead of Shinano, how about a real carrier with 100 plane capacity...as a possibility. I'd definately leave Ise and Hyuga out of the dockyards and find something better to refit or be able to utilize those docks for newly built hulls.

But I have hindsight on my side.

[Local Yokel]

That's a very interesting graphic portrayal of slip usage. Am I right in thinking that, of the Yamato class, only Musashi occupied a conventional slip at Nagasaki, and that Yamato and Shinano were constructed within drydocks? IIRC, the dock at Kure had to be deepened by several feet for this purpose.

I don't appear as counsel for the defence of Admirals Suzuki and Ezaki - I know little enough about whether they were effective occupants or otherwise of their posts within N2 and N4 of the NGS. Possibly one yardstick by which to judge Ezaki is the part he played (if any) in rationalisation of the programme for building standard merchant types.

I assume that JWE's initial post has reference to the post-Midway conference that took place aboard Yamato on 20-21 June 1942, at which both Suzuki and Ezaki were present. I have no details of this conference, but I have seen an article which states that the real impetus behind Shinano's conversion to a carrier came from Vice Admirals Fukuda Keiji, as a designer of the Yamato class, and Iwamura Seiichi, as head of the Naval Technical Bureau. The article attributed to these officers the genesis of the 'fortress carrier' idea, involving the use of both Shinano and Taiho as armoured fuelling and arming stations through which the airgroups of other, more vulnerable carriers would stage their attacks, with the intention of keeping the parent carriers of those airgroups outside the range of enemy retaliation. The article suggested that Fukuda and Iwamura prevailed over significant opposition within the NGS to carry this concept into effect, but with the compromise that Shinano would act not only as an arming platform but with an organic airgroup of her own embarked.

It's easy enough to scoff at the the 'fortress carrier' concept with hindsight, but it is one that appears to me no more unrealistic than the premise of British designers that a carrier could be constructed with a flight deck that was proof against bombs. And if it was truly the brainchild of Vice Admirals Fukuda and Iwamura then JWE's excoriation of Rear Admirals Suzuki and Ezaki seems a trifle harsh.

<edit> speling lets me down again </edit>

[JWE]

ORIGINAL: Local Yokel
That's a very interesting graphic portrayal of slip usage. Am I right in thinking that, of the Yamato class, only Musashi occupied a conventional slip at Nagasaki, and that Yamato and Shinano were constructed within drydocks? IIRC, the dock at Kure had to be deepened by several feet for this purpose.

I don’t have the floorplans for Yokosuka, just the “slipway” designations and sizes. There was a hiatus after Shokaku before Shinano’s keel was laid, so presumably it, too, started life and evolved like Kure #1. Kure began as a (relatively) shallow construction/graving slip. Length was sorta ok (272m), but had to be lengthened to 300m and deepened to account for a 25% increase in launch draft. Presume Yokosuka was similar, but a skoosh easier, since the construction way was suitable for a ‘kaku, itself requiring a 300m facility.

I don't appear as counsel for the defence of Admirals Suzuki and Ezaki - I know little enough about whether they were effective occupants or otherwise of their posts within N2 and N4 of the NGS. Possibly one yardstick by which to judge Ezaki is the part he played (if any) in rationalisation of the programme for building standard merchant types.
-----
And if it was truly the brainchild of Vice Admirals Fukuda and Iwamura then JWE's excoriation of Rear Admirals Suzuki and Ezaki seems a trifle harsh.

Ok, I grant you that, but somebody was chewing peyote and Suzuki/Ezaki were convenient targets. After all, they bought in and then convinced Onishi and Kusaka, and then got Shimada and Nagano to buy off on it in turn.

Now I’m sure you know how much I dislike ‘what ifs’, but I believe that short-term speculation on the effect of a specific event result can have some validity, given that nothing else changes.

Here’s a look at a qua-Midway process result, where Suzuki and Ezaki (ok, and Fukuda and Iwamura) weren’t frightened out of their underpants, or decided to give up substance abuse, and Shinano is completed as a BB according to the nominal schedule. As you can see, she was 80-85% complete-to-launch in June ’42; only 5 1/2 more months (out of 32/33). Then she goes to fitting (red). Unryu #5004, which was cancelled because of Shinano, then starts construction in the empty slip. 5004 can stay in the slipway and begin fitting for 1 month till Unryu moves out and 5004 can take her place at the fit slip. That would bump the other cancelled hull 5008 back 1 month, but would still allow 5008 to start more than 9 months before it possibly could have given the Shinano conversion.

The red parts are just fitting out times from launch to delivery to show availability to the fleet.

So, in mid/late 1944, the IJN would have a nifty little BatRon of 3 Yamatos, 4 Unryus, and whatever they could conserve from the original CVs. Heck, even with Midway, they would have a couple of neat, even scary, CVTFs; Taiho, couple ‘Kakus, four ‘Ryus, couple Chitose CVLs, along with a really capable SurfCom main body.

[Ed] Whoops, that would be hulls 5002 and 5005, not 5004 and 5008. sorry 'bout that.

[anarchyintheuk]

Any idea what was wrong w/ the Mitsubishi #2 guys?

[JWE]

ORIGINAL: anarchyintheuk
Any idea what was wrong w/ the Mitsubishi #2 guys?

Don't think there was anything wrong, per se. Don't forget Mitsubishi was a commercial yard and had to make other stuff. Junyo was laid down on the commercial side as Kashawara Maru, a passenger ship.

[JWE]

ORIGINAL: Shark7
Still seems to me that with hull #111 in the slip and partially complete, a better decision for it would be to finish it to a modified design, rather than starting over. And granted you did build the hull in 1 slip, then move it, but any bottleneck along the system causes major problems when you are in 'hurry up' mode...which was the state of Japanese shipbuilding from July 42 forward. And the conversions did tie up those docks, for minimal return IMO.

Not sure what I would have done, but finishing out Shinana in 4/44 as a BB does seem the better choice. For #111, instead of Shinano, how about a real carrier with 100 plane capacity...as a possibility. I'd definately leave Ise and Hyuga out of the dockyards and find something better to refit or be able to utilize those docks for newly built hulls.

But I have hindsight on my side.

Sorry, but I don't play 'what if'. Hull 111 is irrelevant to a Midway event analysis because it was laid down long before the war started and cancelled long before Midway. Shinano is based on an actual construction plan that was in hand and under way, so alternative speculation on a single hull, as the result of a single determinable event, given the alternative path as an actual historical nominal, is valid. Otherwise, it's just pretend play.

Lot of people like to play pretend, and that's ok, but it's just not for me. Not when dealing with historical scenarios.

[vettim89]

Seeing it graphically like that does add a level of amusment to the standard Japanese player move of canceling Shinano on turn 1. She was 20 months into her construction. How long would it have taken to cut all that steel apart and pull it out of the slip?

[stuman]

......were asleep, on a continuous saki binge, or just low grade morons ......

I think I used to work for them.

[PaxMondo]

ORIGINAL: vettim89

Seeing it graphically like that does add a level of amusment to the standard Japanese player move of canceling Shinano on turn 1. She was 20 months into her construction. How long would it have taken to cut all that steel apart and pull it out of the slip?

Just pull her out of the slipway and cut her like they still do in India today. [:D]

[Local Yokel]

ORIGINAL: PaxMondo

ORIGINAL: vettim89

Seeing it graphically like that does add a level of amusment to the standard Japanese player move of canceling Shinano on turn 1. She was 20 months into her construction. How long would it have taken to cut all that steel apart and pull it out of the slip?

Just pull her out of the slipway and cut her like they still do in India today. [:D]

Shinano is a difficult ship to fit into the game's shipbuilding structure.

The Japanese player cannot 'cancel' her construction, but merely suspend it indefinitely. Suspending Shinano's construction yields a healthy saving of HI that can be redirected into accelerated construction of other ships - or not, at the player's option. If you treat the HI saving that results from such suspension as largely reflecting saved steel production, the game handles such a decision quite gracefully. Shinano simply rots in Yokosuka #1 Dock, half built. The Japanese player doesn't gain any other advantage that I can see.

However, the game does have Shinano arriving as a carrier on 20 November 1944, thereby imposing upon the player who decides to continue her construction a building cost that reflects a decision taken in June 1942, seven months into the war. In turn, that decision reflects the catastrophic loss of carriers at Midway that may well not have occurred in the game. Perhaps there's a case for having her arrive in March 1944 as a battleship, but with the option to convert to carrier - not perfect, but avoids imposing upon the Japanese player the assumption that Midway took place.

On a completely different tack, can anyone explain exactly what differentiates a graving dock from any other form of drydock? One source I've seen suggests that 'graving' derives from the French word 'grève' - a sandy beach on which a 'tidal' dock might be constructed for careening a ship. Evidently 'grève' became the French word for a strike because La Grève was a strand on the banks of the River Seine where disgruntled workers assembled. The etymology may be interesting, but it doesn't explain whether a graving dock is functionally different from other drydocks, and if so, how.

[JWE]

ORIGINAL: Local Yokel
On a completely different tack, can anyone explain exactly what differentiates a graving dock from any other form of drydock? One source I've seen suggests that 'graving' derives from the French word 'grève' - a sandy beach on which a 'tidal' dock might be constructed for careening a ship. Evidently 'grève' became the French word for a strike because La Grève was a strand on the banks of the River Seine where disgruntled workers assembled. The etymology may be interesting, but it doesn't explain whether a graving dock is functionally different from other drydocks, and if so, how.

It differs only in use/function (if indeed even that), from other drydocks. I sometimes think trades and professions invent their own vocabularies only to confuse and irritate the uninitiated. [;)]

Technically, a 'graving' dock is a drydock used for periodic hull cleaning (thus the derivation from careening); relatively low sides (freeboard), not much superstructure, just a quickie in-and-out, grease the shaft bearings, polish the props, and scrape the barnacles off kind of thing. But raise the sides a bit, add a tooterville railway along the edges, put a couple cranes alongside, and poof ... a full boogie drydock. A 'fitting' dock is the same thing, it can be a drydock, or it can be an in-water slip (and a shallow or deep water slip), with piers on both sides, railways and cranes. A shallow fitting slip can easily have the end enclosed and voila ... a fitting drydock (need to have the bottom finished off, however, at some point).

So basically, they are all generally fungible and the terminology says more about utilization (at any particular time) than form.

[Local Yokel]

John, thank you for that comprehensive and instructive explanation!

[JWE]

Just for fun, looked at another aspect of Japanese construction of critical ship types (this time DDs) and found yet more fewmets deposited by those paragons of Replenishment and Shipbuilding planning (to avoid pointing fingers, let’s call them Giblet son of Groin and Legolam the Dork). Just looking at the two types built throughout the war (1940 to 1945) Yugumo (36 planned, 20 built) and Akizuki (39 planned, 12 built). The two types were built in 5 different yards, each having very short production runs. Here’s the premise data.

Yugumo fits well in a 125m slipway. Akizuki fits well in a 150m slipway.
Maizuru NSY had 1 @ 150m and 4 @ 125m slipways.
Sasebo NSY had 3 @ 150m.
Mitsu-Naga had 2 @ 150m and 4 @ 125m.
Uraga Dock had 1 @ 150m and 2 @ 125m.
Fujinagata had 3 @ 125m.

Mitsubishi, Nagasaki built 5 Akizukis on two construction ways. The lead ship for each c-way took 12 months to launch (plus 9 months to fit out), but the follow-on ship got it down to 9+8. The third ship from c-way B got down to 8+8. But no Yugumos laid down after 03/43 and no Akizukis after 07/42.

Uraga Dock built 6 Yugumos (and 1 stinking Akizuki) on three c-ways. No lead ship issues, they built everything at about 10+5. Notably, Uraga built one of the Yugumos on #1 which was Akizuki capable; The rest were 2 on #2, 3 on #3. The one Akizuki it did build was a typical one-off run and came in at 12+8. Laid nothing down after 03/43, except for the Akizuki on 08/43.

Fujinagata SB built 7 Yugumos on two c-ways. Times started at 10+5, but both ways got it down to 9+4 on the second ship, then 8+4 on the third. Laid nothing down after 05/43.

Maizuru NSY built 6 Yugumos and 4 Akizukis on three ways. The 150m way #1 did a fair job with Akizukis, starting at 11+10 for the lead ship, dropping to 9+8, 9+4, and 8+4. Yugumos were a bit more spotty; #2 went from 9+8 down to 9+4 (the 4th ship). #3 only had one ship to build, so no surprise that this one was 11+6. For some strange reason, #1 got a Yugumo stuffed in between the Akizukis. This one too was a one-off for that way and timed out at 12+5. No Yugumos laid down after 01/43, but Akizukis continued laying down till 02/44

Sasebo NSY is a wonderful case in point. Had 3 Akizuki scale slipways, so wha’hoppen? She only gets three stinking ships to build, at oddball timeframes (1 in 12/43, 1 in 05/44, and 1 in 12/45 which was cancelled – duh). Built the two on two ways. They came in at 7+5 and 7+4. Woof!!

All this begs the question (begs two questions). Scale efficiency (production run experience) and sheer yard efficiency seem to have had no part in the contract award process. Sasebo must have annoyed someone because they were very fast, had Akizuki space up the wazoo, and weren’t much of anything with it. So, of course they don’t get squat.

The Navy Yards, alone, could build all the Akizukis that were built, and darn faster too, using slipways that were actually used or sitting idle, if it were done efficiently. Economy of scale, economy of experience. Additionally Uraga could dedicate their #1 slipway and Mitsu-Naga could consolidate on their #1, and I’ll be dipped if you couldn’t finish off the Maru-Kyu Akizukis and make a dent in the Yamazuki group of Kai-Maru Go, without effecting ANYTHING else. Not one single solitary ship of any other type would have to be bumped.

Yugumos were similar. Why spread the Ks around so much? Maizuru and Fujinagata, alone, had 7 Yugumo ways, and they were the most efficient (getting down to 8+4). So, one ends up with the best 3 yards being fully utilized for one type in 2 classes (Maizuru, Sasebo, Fujinagata). Economy of scale, economy of experience. It ain’t rocket science. Heck even I could figure this out with a pencil and a piece of paper over my morning coffee.

[Alfred]

JWE,

All info is very interesting and informative. Two variables which probably impacted upon the decision making process are:

1. steel (already mentioned by Herwin). When available, quality issues, cost from suppliers.

2. tender costs. Variability between different shipyard firms, ability to be met within allocated military budget within a specific fiscal year.

Alfred