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Latest version - v11/b - 25th January 2010

Scenario 42 - BB Variant
RAR - http://www.mediafire.com/download/d5zhx ... Scen42.rar
ZIP - http://www.mediafire.com/download/gry21 ... Scen42.zip

Scenario 43 - Enhanced BB Variant
RAR - http://www.mediafire.com/download/hvotc ... Scen43.rar
ZIP - http://www.mediafire.com/download/9c0ob ... Scen43.zip

Scenario 44 - Ultimate Battleships (New version 11c!)
RAR - http://www.mediafire.com/download/5563k ... Scen44.rar
ZIP - http://www.mediafire.com/download/rpgmg ... Scen44.zip

Scenario 46 - Enhanced CV Variant (Version 12b)
RAR - http://www.mediafire.com/download/fjn3l ... Scen46.rar
ZIP - http://www.mediafire.com/download/89l00 ... Scen46.zip

Artwork
RAR - http://www.mediafire.com/download/u9226 ... %20Art.rar
ZIP - http://www.mediafire.com/download/qchy4 ... %20Art.zip

Complete Pack (All Scenarios + Artwork)
RAR - http://www.mediafire.com/download/7brgh ... mplete.rar
ZIP - http://www.mediafire.com/download/7ykr3 ... mplete.zip

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A couple of months ago I started a thread talking about an Alternate History scenario I was planning on doing for AE.

The background for the AH is in the thread linked above, but essentially I am looking at producing 4, maybe 5 scenarios;

UPDATED!
40) 'Lite' Adapted Stock AE (naval mod only) Discontinued
41) Full Adapted Stock AE (all changes) Discontinued
42) Alternate WNT - BB Variant
43) Alternate WNT - Enhanced BB Variant
44) Ultimate BB Scenario In collaboration with csatahajos
45) Alternate WNT - CV Variant
46) Alternate WNT - Enhanced CV Variant

48) Full Adapted Coral Sea Discontinued
49) Full Adapted Guadalcanal Discontinued

Firstly, the two variants;
-The BB Variant follows a timeline where the IJN continues, as historically, thinking in terms of the decisive battle, and ship development in the treaty and post-treaty era reflects this. This also means the responses by the allies in the game are initially geared that way also.
-The CV Variant is an alternative where in the early 30s, the IJN thinking shifts to regarding attrition by carrier warfare and fast forces as an important part of their strategic planning. This means a much stronger carrier force and also a much better regard for the danger of air attacks to themselves in the early war. As above, the allied response is obviously adapted to this threat.

-The Enhanced versions are something like the Scen 2) in Stock AE - a couple more units, a little better industry, more pilots, and some more shiny toys latewar.

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Overview
The scenario is based around 3 points of departure from the original time line (OTL), which are as follows;

1) A different outcome to the Washington Naval Treaty (WNT). I can detail the exact changes if you want, but in short the limits for both BBs and CVs are slightly higher than historical, and that each country is allowed to keep (or in the UKs case build) a pair of ships in excess of the 35,000ton limit, up to 43,000tons - these are the two Lexington CCs for the USN, the two Tosa BBs for the IJN, and a pair of J3 BCs for the RN. In addition to this, the Japanese get a 3.5 to 5 ratio in capital ships rather than the historical 3 to 5.

1b) As a result of the changes in the WNT, the London Naval Treaty (LNT) is also slightly different, mainly in the form of higher limits of cruiser and destroyer tonnages, and the modification of the 'building holiday' inlcuded in the OTL treaty to allow for a pair of replacement ships in the early 30s.

2) A much less severe Great Kanto Earthquake, meaning that Amagi is not damaged and subsequently scrapped as in OTL, and the damage to in industry in that area is significantly smaller.

3) More foresight by the Japanese in planning for the war. While the aim is still to 'crush the allies decisively in 6 months', there are voice amongst the leadership (particularly in the CV Variants) that consider this an impossibility, and expect the war to take for years.

The BB and CV variants differ in that in the first the Japanese continue their thinking that victory will come from a decisive surface action, and their construction plans in the 1930s reflect that, culminating in a powerful 27knot battleline. The CV variat diverges from this in that there is a significant doctrinal shift in the IJN in the early 1930s, with the strategy shifting to attrition by night surface action by fast ships and daytime air strikes by carrier aviation. Thus this variant sees less surface combatants (and those that are built are fast, 30knt+ ships), and more carriers and supporting ships.

The Enhanced scenarios are a modification to each of the above where the Japanese through even further foresight and a few strokes of luck and quick thinking have put themselves in an even better position than before. This includes niceties like a version of the 40mm Bofors, earlier and better Radars, and a sizeable synthetic oil project in both Japan proper and in Manchuria.

In all of these situations of course, the allies react differently. Particularly the US forces vary greatly from scenario to scenario, reflecting the somewhat 'reactive' nature of the allied construction program.

Hi Juan,

count me in, I'm here and willing to help you as indicated earlier . Let's continue off the forum if you're interested.

Akos

Juan,
I working on the very same type os scenario ideas as I write this.  Strictly for my own use.  Once I'm done I'll send the scenario files to you if you like.  Do with them as you will.  I'm sure that some of my ideas could be improved upon.  The scenarios just reflect my own warped thinking of Alt History.

I've finished work on most of the database changes and bugfixes, so heres a preliminary version of Scenario 40, the modified Scenario 1.

Changes include;
-Completely redone Naval gun devices, and most DP devices too (I didnt want to mess with the land based ones too much)
-Several fixes to incorrect entries in the ship class database (old or wrong devices assigned)
-Several fixes to incorrect or missing devices in aircraft database
-Increased mine production
-Some changes to ship data

Download;
http://www.fileden.com/files/2009/8/1/2529503/Scen40v1.rar

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The next on the list is the BB Variant, Scenario 41, where Japan follows a roughly historic approach to naval construction, though accounting for the changes due to the altered treaty.

Do remember that because the 1923 Kanto eartquake was far less severe, Japans is in a better position in terms of her shipbuilding industry. Likewise, because of the limited construction in the early 30s, the US and UK are much faster to get into the swing of things in the late 30s.

The following is a list of the BB/CV in this scenario;

Japan

2 x BC Kongo - 32400t - 30kts - (8 x 36cm/45) + (8 x 14cm/50) + (12 x 12.7cm/40)
-Kongo was coverted to a target ship in 1930, Hiei to a training ship in 1929.
-Both received extensive rebuilds from 1936 onwards
-Remaining 15cm/50 mounts changed to 14cm/50 to standardize casemate and CL caliber

2 x BC Kirishima - 31800t - 30kts - (8 x 36cm/45) + (14 x 14cm/50) + (8 x 12.7cm/40)
-Kirishima and Haruna, whose development is roughly as historically
-Remaining 15cm/50 mounts changed to 14cm/50 to standardize casemate and CL caliber

2 x BB Fuso - 34800t - 24kts - (12 x 36cm/45) + (14 x 14cm/50) + (8 x 12.7cm/40)
-As historical
-There are two coversion options for these. As a fast BB loosing one of the central turrets for 27kts, available from the start, and as a BBCV conversion from 43 onwards.

2 x BB Ise - 35700t - 24kts - (12 x 36cm/45) + (16 x 14cm/50) + (8 x 12.7cm/40)
-As historical
-There are two coversion options for these. As a fast BB loosing one of the central turrets for 27kts, available from the start, and as a BBCV conversion from 43 onwards.

2 x BB Nagato - 39000t - 27kts - (8 x 41cm/45) + (18 x 14cm/50) + (8 x 12.7cm/40)
-Because of other units in the fleet standardizing on 27kts, her reconstruction also includes engines to keep her at this speed

2 x BB Tosa - 42600t - 27kts - (10 x 41cm/45) + (16 x 14cm/50) + (12 x 12.7cm/40)
-The two ships allowed for the IJN under the new treaty which allowed for two up to 43,000t ships per nation

1 x BB Harima - 41200t - 27kts - (8 x 41cm/45) + (12 x 14cm/50) + (12 x 12.7cm/40) - In Service 1927
-Post-Treaty BB built by the IJN using the spare tonnage from the new treaty. An improved version of the Nagato class

2 x BB Sagami - 42500t - 27kts - (9 x 41cm/50) + (12 x 14cm/60) + (12 x 12.7cm/40) - In Service 1934
-A pair of modern BBs built in the early 30s, under the limited replacement schedule agreed upon in the 1st London Treaty
-Officially 35,000tons

2 x BB Echizen - 56500t - 27kts - (12 x 41cm/50) + (14 x 14cm/60) + (16 x 12.7cm/40) - In Service 1939
-The first pair of large BBs built by the IJN immediately after the failure of the 2nd London Treaty

2 x BB Yamato - 58000t - 27kts - (8 x 46cm/50) + (14 x 14cm/60) + (16 x 12.7cm/40) - In Service 1941
-The second pair of large BBs built by the IJN


1 x CVE Hosho - 7500t - 25kts - (4 x 12cm/45) + 18 aircraft
-The IJNs first CV

2 x CV Amagi - 36000t - 31kts - (16 x 12.7cm/40) + 81 aircraft
-Both Amagi and Akagi are converted to CVs as originally planned. The 1923 eartquake is much less severe, and further from the industrial areas - so Amagi survives unharmed.

1 x CVL Shokaku - 13000t - 31kts - (8 x 12.7cm/40) + 36 aircraft - In Service 1924
-An enlarged version of the Hosho, it was a marginal success at best

2 x CV Taiho - 17000t - 33kts - (12 x 12.7cm/40) + 63 aircraft - In Service 1932
-A larger CV design after the limitations in a carrier the size of the Shokaku became apparent
-Roughly comparable to the histoical Soryu/Hiryu

2 x CV Soryu - 26000t - 33kts - (16 x 12.7cm/40) + 78 aircraft - In Service 1940
-Much larger CV design begun in paralell with the super BB program
-Similar to historic Shokaku

2 x CV Hiryu - 26500t - 33kts - (16 x 12.7cm/40) + 78 aircraft - In Service 1942
-Repeat build of Soryu class
-Hiryu due early 42
-Unryu due mid 42

2 x CVB Omi - 55000t - 32kts - (24 x 10cm/65) + 130 aircraft - In Service 1943/44
-Large CV design
-Omi due late 43
-Kii due early 44

6 x CV Katsuragi - 22000t - 33kts - (16 x 10cm/65) + 72 aircraft - In Service 1943-45
-New midsized CV design
-Katsuragi/Aso due mid 43
-Kasagi/Ikoma due mid 44
-Owari/Osumi due mid 45

There are also some scattered shadow program ships and tanker/liner conversions, but nothing organized. For that wait for the CV variant.

The IJN Naval Yards will be worked out so that the player can complete either the Katsuragi or Omi class CVs on schedule, or both with some delays - or choose to expand the Naval Yards.

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Please note that for the US and UK I list the entire fleets - not all of these will be in the Pacific throughout the game

United States

2 x BB Nevada - 28000t - 21kts - (10 x 14in/45) + (12 x 5in/51) + (8 x 5in/25)
-As historical
-All standards have both 'limited' and 'full' rebuild conversions available. They are available from 01/42. Both upgrades and unupgraded versions have a full upgrade line

2 x BB Pennsylvania - 32000t - 21kts - (12 x 14in/45) + (12 x 5in/51) + (8 x 5in/25)
-As historical
-All standards have both 'limited' and 'full' rebuild conversions available. They are available from 01/42. Both upgrades and unupgraded versions have a full upgrade line

3 x BB New Mexico - 33400t - 22kts - (12 x 14in/50) + (10 x 5in/51) + (8 x 5in/25)
-As historical
-All standards have both 'limited' and 'full' rebuild conversions available. They are available from 01/42. Both upgrades and unupgraded versions have a full upgrade line

2 x BB Tennessee - 33600t - 21kts - (12 x 14in/50) + (12 x 5in/51) + (8 x 5in/25)
-Receive a limited reconstruction along the lines of the New Mexicos in 1930
-All standards have both 'limited' and 'full' rebuild conversions available. They are available from 01/42. Both upgrades and unupgraded versions have a full upgrade line

4 x BB Colorado - 33000t - 21kts - (8 x 16in/45) + (12 x 5in/51) + (8 x 5in/25)
-As historical, none of this class have receive a proper reconstruction
-All standards have both 'limited' and 'full' rebuild conversions available. They are available from 01/42. Both upgrades and unupgraded versions have a full upgrade line

2 x BC/CC Lexington - 44000t - 33kts - (8 x 16in/50) + (16 x 6in/53) + (10 x 5in/25) - In Service 1927
-The two ships allowed for the USN under the new treaty which allowed for two up to 43,000t ships per nation
-The USN selected the two less complete ships, Constellation and Constitution, for this purpose. With their double allowance of refit tonnage, these ships turned out not nearly as flawed as the original designs
-Received limited rebuilds in 1935

2 x BB North Carolina - 35500t - 27kts - (8 x 16in/50) + (20 x 5in/38) - In Service 1935
-A pair of new style BBs built in the early 30s for the limited replacement program, their construction was delayed severely and they were almost scrapped due to the Depression
-With most other nations having battleline speeds in excess of 25knots, the USN decide to begin increasing their own

4 x BB South Dakota - 37500t - 27kts - (9 x 16in/50) + (20 x 5in/38) - In Service 1941/42
-The first of the USNs post-treaty designs, following the collapse of the 2nd London Treaty
-South Dakota and Indiana are in service
-Alabama and Massachusetts due in early 42
-Use a new model of 16in/50 and a 2700lbs shell

4 x BB Iowa - 48000t - 33kts - (9 x 16in/50) + (20 x 5in/38) - In Service 1942/43
-USN fast battleship design
-Iowa/New Jersey due late 42
-Missouri/Wisconsin due late 43

4 x BB Montana - 61000t - 27kts - (12 x 16in/50) + (20 x 5in/54) - In Service 1943-44
-USN heavy BB design
-Montana due in mid 43
-Maine due in late 43
-Ohio/Louisiana due in mid 44

2 x BB Illinois - 74000t - 33kts - (12 x 16in/50) + (24 x 5in/54) - In Service 1945
-USN fast heavy BB design
-Illinois due in early 45
-Kentucky due in late 45


2 x CV Lexington - 38000t - 34kts - (12 x 5in/38) + 92 aircraft
-Lexington and Saratoga converted to CVs as historically

2 x CV Wasp - 16500t - 32kts - (8 x 5in/38) + 72 aircraft - In Service 1931
-Slightly larger equivalent to Ranger
-Successful design results in a second design being ordered

3 x CV Yorktown - 20500t - 32kts - (8 x 5in/38) + 86 aircraft - In Service 1937-39
-Larger sucessor to Wasp class

4 x CV Essex - 28000t - 32kts - (14 x 5in/38) + 90 aircraft - In Service 1941-42
-New design based on Yorktown
-Essex in service mid 1941
-Interpid/Franklin due mid 42
-Randolph due late 42

14 x CV Ticonderoga - 29000t - 32kts - (16 x 5in/38) + 90 aircraft - In Service 1943-45
-'Long Hull' Essex class, ordered during wartime
-Ticonderoga/Bunker Hill due mid 43
-Hancock/Bennington due late 43
-Boxer/Kearsarge due early 44
-Oriskany/Antietam due mid 44
-Princeton/Leyte due late 44
-Shangi-La/Reprisal due early 45
-Tarawa/Lake Champlain due late 45

5 x CVB Midway - 46000t - 33kts - (18 x 5in/54) + 130 aircraft - In Service 1944-45
-Large CV class
-Midway due early 44
-Coral Sea due late 44
-Philippine Sea due early 45
-Iwo Jima due mid 45
-Franklin D. Roosevelt due late 45

The CVE/CVL programs are of course extensive as historically.

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United Kingdom

3 x BB Royal Sovereign - 30000t - 21kts - (8 x 15in/42) + (12 x 6in/45) + (8 x 4in/45)
-Royal Sovereign and Revenge decomissioned in early 30s
-Remaining ships assigned to reserve duty or as convoy escorts

5 x BB Queen Elizabeth - 33000t - 24kts - (8 x 15in/42) + (20 x 4in/45)
-Received limited reconstructions in 1935

2 x BC Renown - 33000t - 30kts - (8 x 15in/42) + (20 x 4.5in/45)
-Received complete reconstructions in 1938

1 x BC Hood - 43000t - 30kts - (8 x 15in/42) + (16 x 5.25in/50)
-Received complete reconstruction in 1940

2 x BC Invincible (J3) - 43000t - 31kts - (9 x 15in/50) + (12 x 6in/50) + (12 x 4.5in/45) - In Service 1925
-The two ships allowed for the RN under the new treaty which allowed for two up to 43,000t ships per nation
-Received limited reconstruction in 1937

2 x BC Anson (F3) - 36000t - 30kts - (9 x 15in/50) + (16 x 5.25in/50) - In Service 1927
-Pair of BCs built with leftover tonnage from treaty
-Received complete reconstruction in 1939

2 x BB King George V - 35000t - 28kts - (9 x 15in/50) + (20 x 4.5in/45) - In Service 1934
-A pair of new BBs built in the early 30s for the limited replacement program

2 x BB Jellicoe - 36000t - 30kts - (8 x 15in/42) + (16 x 5.25in/50) - In Service 1939
-A pair of fast BBs built using the guns of BB Revenge and Royal Sovereign

2 x BB Lion - 36000t - 28kts - (9 x 15in/50) + (16 x 5.25in/50) - In Service 1940
-A pair of repeat BBs based on King George V class

2 x BB St. Andrew - 48000t - 28kts - (12 x 15in/50) + (24 x 5.25in/50) - In Service 1942
-A pair of heavy BBs
-St. Andrew due mid 42
-St. George due late 42


1 x CVL Hermes - 16000t - 25kts - (6 x 5.5in/50) + (3 x 4.5in/45) + 20 aircraft
-RNs first CV

1 x CV Eagle - 24500t - 22kts - (9 x 6in/50) + ????? + 21 aircraft
-Experimental CV

1 x CV Furious - 22500t - 30kts - (12 x 4in/45) + 36 aircraft
-CV Conversion

2 x CV Courageous - 23000t - 30kts - (16 x 4.7in/40) + 48 aircraft
-CV Conversions

1 x CV Ark Royal - 22000t - 31kts - (16 x 4.5in/40) + 60 aircraft - In Service 1937
-First real RN CV
-Built 1 year earlier than historically

4 x CV Illustrious - 23000t - 30kts - (16 x 4.5in/40) + 36-54 aircraft - In Service 1939/40
-Armoured RN CV Design

2 x CV Implacable - 26500t - 31kts - (16 x 4.5in/40) + 60-80 aircraft - In Service 1942/43
-Armoured RN CV Design, improvement on Illustrious class
-Implacable due late 42
-Indefatigable due early 43

2 x CV Audacious - 41000t - 31kts - (16 x 4.5in/40) + 85 aircraft - In Service 1945
-Armoured RN CV Design, improvement on Illustrious class
-Audacious due early 45
-Irresistible due mid 45

And various assorted CVL/CVE.

Of course, some of these will be lost in other theatres, so we wont be seeing everything in the pacific. HMS Hood may pay a visit however...

Thanks, Juan. I was trying to fix up bugs in the database as well, but was falling behind on the bug reports. I think I'll just give your version a try.

I'm always glad to see some well-reasoned alternate history scenarios as well. I will be looking forward to your scenarios.

ORIGINAL: ChickenOfTheSea

Thanks, Juan. I was trying to fix up bugs in the database as well, but was falling behind on the bug reports. I think I'll just give your version a try.

I'm always glad to see some well-reasoned alternate history scenarios as well. I will be looking forward to your scenarios.

There are a couple of fixes I've come across since then that arent in that version, as well as a couple of fixes I havent included because I dont know how to fix (like the extra support on those 101st PA units).

I wish I'd had the foresight to do a 'non-modified' version alongside this, for convenience.

Ill see if I can do something by comparing the databases, but it may be a few days.


Im working on a v2, including the changes noted above, as well as chaging the numbers for the AA guns slightly.

For comparison, heres the stock, current and planned values for some key weapons - the value is what I call effective firepower, and is (accuracy/10 * effect)

40mm Bofors - 320 - 288 - 360
20mm Oerlikon - 135 - 90 - 112.5
2pdr Mk VIII - 129.2 - 175 - 210
1.1in Mk 1 - 150 - 102 - 127.5
.50cal M2 - 50 - 43.8 - 54.75

25mm T96 - 59.4 - 55 - 68.75
13.2mm T93 - 54 - 34.2 - 42.75

For the 'Enhanced' Scenarios there are two weapons I'm adding to the Japanese;
25mm T1 - 175 - A redesign of the 25mm, using a new feed system (similar to the bofors), normally mounted in pairs. Appears early '42.
37mm T99 - 250 - Based on the german 3.7cm/83 SK C/30 which Japan brought in the mid 30s, this is an automatic gun based on that design. Mounted in pairs, but very rare throughout the war.

This isnt the whole picture of course, as some weapons (particularly 40mm) benifit from a range advantage compared to the others.

So in the BB variant, Japan will have fewer CVs than the USN from the start?

ORIGINAL: Historiker

So in the BB variant, Japan will have fewer CVs than the USN from the start?

Yes, the USN begins with 8 CVs, 2 Lexingtons, 2 Wasps, 3 Yorktowns and 1 Essex. Of these 1 Wasp and 2 Yorktown are in the Atlantic. Both Yorktowns arrive early 42. By the end of 42 the USN has 3 more Essexes.

Japan has 6 CVs, 2 Amagis, 2 Taihos, 2 Soryus (and Shokaku, I guess). The two Hiryus are due before mid 42, but after that Japan very quickly looses ground on the CV ratios.

This isnt figuring the RNs CVs into the balance, but thankfully they're mostly tied up in the atlantic.

Japans advantage lies in her slightly superior aircraft, and better pilots. But both sides thought this was going to be a 'heavy metal' kind of show, and thats visible from the fleet compositions.


The CV variant is a whole different story .[;)]

I may do a 'balanced' one too, because the two are pretty starkly different.


Personally I'm very torn on the issue of the last two USN BBs. I like the idea of 18in Montanas, but cant help but wonder if they would be more plausible as 12 x 16in/50 fast super BBs at 33 knots. Japanese beware. Would kick their displacement up to 70,000+ tons though.

Will you change something concerning planes and pilots? Otherwise, the USN might go right into the offensive. You may think about telling something like "the two Lexingtons were under refit until late february" and the pacific Wasp was grounded on december 1st and need extensive repairs in San Francisco, now. This would leave the Jap player at least a window of two and a half months until the USN CVs are superior.

Good point Historiker...having them in refit/unvailable would force the USN player to be more cautious and as you say allow the IJN player some freedom of action before the tide turns..[:)]

A fair point.

One thing I am doing is pushing back aircraft availability a little, so the USN CVs are mostly using F2As and SBD-2s at the start. The F4F will start getting phased in early 42. Same with the SBD-3.

Maybe having one of the Lexingtons finishing a refit would also help things here.

Or, I could switch the Hiryu class construction schedule with the Yamato classes one. This way the IJN has 8 CVs in service, with the two 18in BBs due early/mid 42.

In the first refit, they may already recieve radars as a payoff for haveing to wait for them.
Moreover, you might give the Japs an additional 100 or 200 G3N and G4N in the Pacific. Japan would've put more effort in the "unsinkable aircraft carriers" if they aren't able to match the US carrier strength. Consequently, the airfields in the Marshalls are big enough from the start to fly them.


The tests in the CAP thread seem to show that the Buffalo is good enough to match the Zero in carrier battles, so this won't change a lot.

Thats definately one solution.

Any thoughts on the option of switching Hiryu class and Yamato class schedules?


Or, cruel as it is, having one of the CVs in PH on the 7th Dec?

Haveing so much CVs, itsreally not unlikely that one or even two of them are in Pearl.
A strengthend Japan will also make the Force Z stronger and its not unlikely that their carrier - wasn't it the Illustrious that should've joined it anyway but was grounded - is with the Force Z in either SIngpoore harbour or steaming northwards toward Kota Bharu.

You may let the two CVs undergoing refits recieving them both in Pearl. Its not unlikely that both will survive as well as both may sink. Anyway, they should be out of war until April/Mai (haven't played long enough to say how fast repairs work). Japan should have a timetable of naval superiority until April/Mai as there's a lot necessary to conquer...

Just imagine all the US CVs steaming into the DEI in January 42... I transfered both US CVs in the Pacific in CHS there and they were a shock to my PBEM opponent. Now haveing the whole US Carrier force there might well end Japan's ambitions.


Your scenario is good, but IMO you have to implement some tricks to allow Japans conquering of some Pacific posessions, the Rabaul area and the DEI.

Refits, two carriers in Pearl, one at 50sys and 60engine damage as well as the only or one of the two RN carriers exposing itself to the Torpedobombers off Malaya will be a good way to do this.

Any thoughts on the option of switching Hiryu class and Yamato class schedules?

You mean prodcing the Hiryu class carriers before the Yamato class BBs?

IMO, Japan with already more BBs than 8-8 might be willed to build smaller BBs but more of them as there's no need for a officially 45.000ts BB that is in fact able to match two 45.000ts in theory.

So why not change your Yamato BBs into smaller 35-40.000ts fast battleships that are designed from the start to accompany the CVs. Consequently enormous range (bunkers aren't accounted into the displacement, so that's rather easy) 33kn or even more and just 3 turrets. Either 3x16in and weaker armour as they aren't expected to fight BBs due to their high speed, just CAs or 2x16 and good BB armour?

Edit:
So around 20.000t of steel spared for each of the two BBs would either allow a drastically speedup for other ships or allow other ships with the combined tonnage of 40.000t to be completed till the war begins if there are enough slips. So maybe two B-61 (IIRC) 20.000ts CBs also for CV protection or maybe two additional Carriers that are (almoust) complete? Anyway, Japan would benefit from cheaper Yamatos!

ORIGINAL: Historiker

Any thoughts on the option of switching Hiryu class and Yamato class schedules?

You mean prodcing the Hiryu class carriers before the Yamato class BBs?

IMO, Japan with already more BBs than 8-8 might be willed to build smaller BBs but more of them as there's no need for a officially 45.000ts BB that is in fact able to match two 45.000ts in theory.

So why not change your Yamato BBs into smaller 35-40.000ts fast battleships that are designed from the start to accompany the CVs. Consequently enormous range (bunkers aren't accounted into the displacement, so that's rather easy) 33kn or even more and just 3 turrets. Either 3x16in and weaker armour as they aren't expected to fight BBs due to their high speed, just CAs or 2x16 and good BB armour?

Edit:
So around 20.000t of steel spared for each of the two BBs would either allow a drastically speedup for other ships or allow other ships with the combined tonnage of 40.000t to be completed till the war begins if there are enough slips. So maybe two B-61 (IIRC) 20.000ts CBs also for CV protection or maybe two additional Carriers that are (almoust) complete? Anyway, Japan would benefit from cheaper Yamatos!

Ah, but the battleship megalomania remains in this scenario. Remeber that its not only Japan that has larger surface fleets.

The direction you describe is exactly what happens in the CV variant. The early 1930s designs are 8x16 BCs capable of 30 knots, and the late 30s ships are 9x16 fast BBs capable of 32 knots. There is also a 'large' cruiser project similar to the B-65 due during wartime, able to make 33 knots.

But thats for later. [;)]

Ah, it was B-65... [:)]

OK, but Japan needs some BBs to keep pace with the CVs, no? So maybe even bigger Yamatos but with 33kn instead of 27? Consequently completed late 41, early 42. One maybe already complete, the other one arriving in february or march 42? I doubt Japan hasn't reacted to the faster RN and USN ships as it was always a IJN advantege to have the faster ships and thus be able to descide where and when to fight.
RN has 13 ships faster than the IJN 27kn battleline, USN has two.

I'd propose Echizen, Sagami and Yamatos at 33kn standard to do something against the RN fast ships. Done by rebuilt (Sagami) and from the start (Echizen and Yamatos) by either bigger deplacement or reduced armour/armement.

ORIGINAL: Historiker

Ah, it was B-65... [:)]

OK, but Japan needs some BBs to keep pace with the CVs, no? So maybe even bigger Yamatos but with 33kn instead of 27? Consequently completed late 41, early 42. One maybe already complete, the other one arriving in february or march 42? I doubt Japan hasn't reacted to the faster RN and USN ships as it was always a IJN advantege to have the faster ships and thus be able to descide where and when to fight.
RN has 13 ships faster than the IJN 27kn battleline, USN has two.

I'd propose Echizen, Sagami and Yamatos at 33kn standard to do something against the RN fast ships. Done by rebuilt (Sagami) and from the start (Echizen and Yamatos) by either bigger deplacement or reduced armour/armement.

To be honest my initial designs for the Echizen and Yamato classes was at 30knots, same as the Kongos. But this makes them the size of the historical Yamatos and really pushes the plausibility to Japan managing to build them, even with her superior industrial position in this scenario. So I settled for 27kts, and enough combat capability to shread anything else afloat until the latewar allied BBs come in.

For CV escorts, there are the 4 Kongos, along with many more CA than historically. Japan was allowed 14 CA under the 1st London Treaty in this AU, and then built 2 more before the start of the war (repeat of the 'Tone' equivalents in this scenario). In addition to that she had a program similar to the historical Mogami that produced another 4 CA.

Theres also a program for two 15,000ton 12x8 CBs due during 43.


Also, the Japanese know about the speed difference, and while they envy the Lexingtons which are superior to their Kongos in every way, they reason that the 6 knot (except for Fuso/Ise classes) advantage over the main USN battleline is enough to ensure they will be in control of the Decisive Battle.

The reasoning regarding the RN is that, yes, they do have a faster battleline, but the IJN expects the RN to deploy mainly the older QE and R classes to the far east, along with one or two of the old battlecruisers.

The reasoning regarding the RN is that, yes, they do have a faster battleline, but the IJN expects the RN to deploy mainly the older QE and R classes to the far east, along with one or two of the old battlecruisers.

I doubt that the IJN would do such a gamble and consider one of their potential main enemys will just send its old ships. IMO, Japan would never accept a smaller battleline that doesn't even have the initiative!

How long will it delay the 6 ships if they are faster? half a year each? Is that realistic? You already expect the Echizens and the Yamatos to be built parallel, right? So the Sagamis mid 1940 and the Yamatos early 1942?

You might use a trick with the Echizens: Since Hiraga shortly after WW1, the belt armour of the Ships was used as hull itself and "just welded" onto the basic structure. In theory, one may design the belt very weak to save weight and prepare ths ship from the beginning to recieve additional armour as soon as the Treatys allow it. For stability, it might recieve huge concrete pieces under the keel and the "real" armour may already lay ready in the navy yards. This was never done but must be theoretically possible and would consequently allow a much bigger ship to be built without violating the treaty as the fitting with the intended armour would just take as much time as it takes to replace the armour.

I doubt there won't show up someone who says this is stupid, but understand it as animation. I came to that idea reading Wilhelm Treue's "Die Deutsche Marinerüstung" where he described that Germany built subs despite the Versailles treaty. They were dismantled in the navy facitlitys and prepared for a fast assembly in case of war.

If Japan is willed to do such a thing, it can find a way to do it for sure. Whether this is too far away from reality or not is your choice! [:)] I'm no naval engineer, but from my understanding, with additional weight under the ship, this should be really possible to do!

Just to clearify: I don't want to disencourage you. You are actually makeing a kind of mod I had in mind myself, so my ideas are now trying to find their way into your mod [;)]
It's most likely I will play your mod unchanged or just with small further changes!