AH IJN carrier conversion question

[stevep]

I wouldn't be surprised if there was a clause that allowed the RN to build two more battleships as replacements for some of the R's or QE's a little earlier than the other powers. My question is this: assuming that the RN has the following warships

4 G3s
Hood
5 QE's
3 R's
2 Refit and Repair

which two ships will be replaced with new construction when it rolls around c. 1932?

Douglas

Good question. Presuming they have the resources for reconstructions as historical I would still go for replacing two R's. Possibly even all 3 as David suggests. Their a little newer than the Queen's but the latter have the extra speed and capacity for reconstruction.

Actually probably go for that regardless. With 4 G3s, Hood and 2 newer ships the fleet is markedly more modern that OTL. So are the Japanese and American but the European powers are probably not greatly changed due to economic restrictions and Germany will be restricted by the Versailles Treaty. That is probably more important to Britain as since conflict with the US is highly unlikely so the relative advantage compared to OTL is huge for Britain.

Steve

 

[stevep]

Probably given HMS Australia and New Zealand, but those probably get scrapped due to finances/renegotiation of Anglo-Japanese Treaty in the early 20's.

Douglas

I think that Australia wanted to keep its name ship, partly out of national prestige, partly to give a significant increase to its strength. It was very old but have seen discussion on the naval board that's been mentioned, that for half the price of one of the 10k cruisers you could have dramatically refitted it and would have resulting in a pretty effective unit. Not much good against even the weakest capital ship but a good cruiser killer for trade protection and say against ships such as the pocket battleships

I doubt that the ship would be cancelled as a result of a revival of the Anglo-Japanese Treaty. It would be too politically sensitive as it would imply that Japan and Australia didn't trust each other - true but not something they would admit. Also there's no point in seeking to weaken a power your allied to. What would be probably fatal would be when the 1927 Treaty was signed. Although things might be more relaxed I suspect that the US would still insist on Australia count towards the imperial total. Also, with the alliance with Japan being broken I presume, it would have no interest in disagreeing with the US on the issue.

Steve

 

[David S Poepoe]

Probably given HMS Australia and New Zealand, but those probably get scrapped due to finances/renegotiation of Anglo-Japanese Treaty in the early 20's.

There wasn't anyway the Anglo-Japanese Alliance was going to be renewed in OTL. The main hurdle to pretty much any Anglo-American agreement is the AJA. The British also recognized this. The Admiralty and the Foreign Office recognized that the Japanese were in the same position as the pre-war Germans was it Britain in wanting to expand their fleet and dominate Asia. The Admiralty was also very worried about the Japanese having access to their technical developments while they remained very secretive with their own.

HMS New Zealand is a part of the Royal Navy, pretty much in the same sense as HMS Malaya. They were both gifts. HMAS Australia could be returned to her owners. It would be nice to release an R class or two battleship to Australia.

I've always wondered about India. It had a small colonial fleet, but couldn't it have afforded more? Two Rs to Australia, two to India and one to Canada?

 

[Grey Wolf]

More than one to Canada would be useful and perhaps convoy experience of WW1 might lead people to remember BBs on convoy escort etc

Best Regards
Grey Wolf

 

[bard32]

Scenario: It's 1927, and the US, UK, and Japan are finally getting around to signing a naval disarmament treaty.

The United States has three carriers: two Lexington conversions and Langley, as in OTL, for a total tonnage of 83,500 tons.

Japan currently has two carriers: OTL Hosho and a never-realized carrier planned in OTL for a total of 21,000 tons.

Japan is required to scrap the following under the terms of the treaty:

OTL planned battleship Kii, 40-60% complete, original design 42,600 tons, 820 x 101 feet, 29.75 knots.

OTL Fuso class, Fuso and Yamashiro. 30,600 tons, 665 x 94 feet, 22.5 knots.

OTL Kongo class, Kongo, Hiei, Kirishima, Haruna. 27,500 tons, 704 x 92 feet, 27.5 knots.

All figures include speed and tonnage in battleship/battlecruiser form, not reduced to reflect the weight of a carrier modification.

As you may guess, here is the question. If Japan is allowed to build up to 60,000 tons of carriers total, what is the least expensive and most effective way to take these hulls and convert them into carriers to maximize tonnage?

The first Japanese aircraft carrier was a converted troop transport. I think,
it was the Hiei,

 

[bard32]

Scenario: It's 1927, and the US, UK, and Japan are finally getting around to signing a naval disarmament treaty.

The United States has three carriers: two Lexington conversions and Langley, as in OTL, for a total tonnage of 83,500 tons.

Japan currently has two carriers: OTL Hosho and a never-realized carrier planned in OTL for a total of 21,000 tons.

Japan is required to scrap the following under the terms of the treaty:

OTL planned battleship Kii, 40-60% complete, original design 42,600 tons, 820 x 101 feet, 29.75 knots.

OTL Fuso class, Fuso and Yamashiro. 30,600 tons, 665 x 94 feet, 22.5 knots.

OTL Kongo class, Kongo, Hiei, Kirishima, Haruna. 27,500 tons, 704 x 92 feet, 27.5 knots.

All figures include speed and tonnage in battleship/battlecruiser form, not reduced to reflect the weight of a carrier modification.

As you may guess, here is the question. If Japan is allowed to build up to 60,000 tons of carriers total, what is the least expensive and most effective way to take these hulls and convert them into carriers to maximize tonnage?

The first Japanese aircraft carrier was a converted troop transport. I think,
it was the Hiei, and the battlecruisers Akagi and Amagi,
were originally chosen to be converted to carriers, and the battlecruiser
Kaga, be scrapped. However, after the 1923 Tokyo earthquake, Kaga/I] was chosen for carrier conversion

 

[MrP]

The first Japanese aircraft carrier was a converted troop transport. I think,
it was the Hiei,

Nope. You can either opt for -

1) Wakamiya, a prize of the R-J War, "In 1914 she became the first Japanese air-capable ship, flying her Farman biplanes from September to November in support of the assault on Tsingtao. Her aircraft reportedly sank one German minelayer and damaged shore installations; they arguably therefore made the first successful carrier air raid in history." Conway's All the World's Fighting Ships 1906-1921, 1986

or, since I'm feeling generous today -

2) Hosho, "Originally laid down 16 December, 1919 as an auxiliary, intended to be a tanker, to be named Hiryu. Re-named Hosho in 1920, redesignated 13 October, 1921 as Aircraft Depot Ship (Kobubokan). A sister ship, Shokaku, was planned, but construction never began, because of the limitations of the Washington Treaty." p.41, Jentschura, Jung, Mickel, Warships of the Imperial Japanese Navy 1869-1945, 1977 translation of 1970 German original Die Japanischen Kriegsschiffe 1869-1945

Hiei was one of Kongo's sisters. Twice, in fact, since not only was the second Hiei sister to the battlecruiser Kongo, but the first Hiei had been sister to the first Kongo in the last quarter of the nineteenth century.

 

[MrP]

The first Japanese aircraft carrier was a converted troop transport. I think,
it was the Hiei, and the battlecruisers Akagi and Amagi,
were originally chosen to be converted to carriers, and the battlecruiser
Kaga, be scrapped. However, after the 1923 Tokyo earthquake, Kaga/I] was chosen for carrier conversion

Bard, Douglas is trying to consider the make-up of the IJN in a different timeline. I'm sure he's fully aware of the make-up of the IJN in our own history.

 

[Douglas]

Douglas

I think that Australia wanted to keep its name ship, partly out of national prestige, partly to give a significant increase to its strength. It was very old but have seen discussion on the naval board that's been mentioned, that for half the price of one of the 10k cruisers you could have dramatically refitted it and would have resulting in a pretty effective unit. Not much good against even the weakest capital ship but a good cruiser killer for trade protection and say against ships such as the pocket battleships

I doubt that the ship would be cancelled as a result of a revival of the Anglo-Japanese Treaty. It would be too politically sensitive as it would imply that Japan and Australia didn't trust each other - true but not something they would admit. Also there's no point in seeking to weaken a power your allied to. What would be probably fatal would be when the 1927 Treaty was signed. Although things might be more relaxed I suspect that the US would still insist on Australia count towards the imperial total. Also, with the alliance with Japan being broken I presume, it would have no interest in disagreeing with the US on the issue.

Steve

You make a lot of good points. I suppose I was looking at the end result, as seen from 1927: Australia is not going to survive a disarmament treaty.

 

[Douglas]

More than one to Canada would be useful and perhaps convoy experience of WW1 might lead people to remember BBs on convoy escort etc

Best Regards
Grey Wolf

In a perfect world, I suppose so. Unfortunately, Canada never seemed particularly willing to provide for one BB, much less more than that, and people are unlikely to think of the battleship as being good for convoy escort, especially with the 1927 situation of a practically non-existent Kriegsmarine.

 

[Douglas]

There wasn't anyway the Anglo-Japanese Alliance was going to be renewed in OTL. The main hurdle to pretty much any Anglo-American agreement is the AJA. The British also recognized this. The Admiralty and the Foreign Office recognized that the Japanese were in the same position as the pre-war Germans was it Britain in wanting to expand their fleet and dominate Asia. The Admiralty was also very worried about the Japanese having access to their technical developments while they remained very secretive with their own.

The AJA alliance will probably be renewed for a short period of time after the failure of the Washington Treaty ITTL, but it will finally come to an end after the tentatively-named London Treaty of 1927.

HMS New Zealand is a part of the Royal Navy, pretty much in the same sense as HMS Malaya. They were both gifts. HMAS Australia could be returned to her owners. It would be nice to release an R class or two battleship to Australia.

True, but funds for the G3s aren't coming from nowhere, and the US and Japan aren't going to simply allow Britain to pawn off battleships to its dominions so it can be allowed to keep more. New Zealand will get scrapped in 1927, if not in 1922.

I've always wondered about India. It had a small colonial fleet, but couldn't it have afforded more? Two Rs to Australia, two to India and one to Canada?

As I said, I don't think the Americans or the Japanese are going to believe that these units are independent of the RN for a second, and thus any RN attempt to "spread ships around" is going to be met with a firm no.

 

[Douglas]

Bard, Douglas is trying to consider the make-up of the IJN in a different timeline. I'm sure he's fully aware of the make-up of the IJN in our own history.

Not to mention the fact that Kaga was a battleship, not a battlecruiser...

 

[MrP]

Not to mention the fact that Kaga was a battleship, not a battlecruiser...

Is bard from an ATL with slight differences in ship names? I think we should be told.

 

[Douglas]

Is bard from an ATL with slight differences in ship names? I think we should be told.

Maybe...as well as from one where the IJN aviators flew at wave height to avoid American radar and attack Pearl Harbor, where Nagumo's fleet was nuclear-powered (to stay on station for ten days!), and where the USN had ships that could steam across the Pacific at 45 knots continuously without breaking a sweat before obliterating the Japanese carrier fleet in its home waters.

 

[MrP]

Maybe...as well as from one where the IJN aviators flew at wave height to avoid American radar and attack Pearl Harbor, where Nagumo's fleet was nuclear-powered (to stay on station for ten days!), and where the USN had ships that could steam across the Pacific at 45 knots continuously without breaking a sweat before obliterating the Japanese carrier fleet in its home waters.

 

[David S Poepoe]

True, but funds for the G3s aren't coming from nowhere, and the US and Japan aren't going to simply allow Britain to pawn off battleships to its dominions so it can be allowed to keep more. New Zealand will get scrapped in 1927, if not in 1922.

Don't think New Zealand would last on the records till 1927. She'll be gone by 1922 with all the other 12in gunned dreadnoughts. They are worn out.

 

[stevep]

Don't think New Zealand would last on the records till 1927. She'll be gone by 1922 with all the other 12in gunned dreadnoughts. They are worn out.

David

She's actually about a year older than Wyoming and Arkansas, the latter of which lasted in service until 45 and the former being demilitarised in 1930 under the London Treaty.

As such agree that she will go, because very likely no one will want to maintain her and also the 27 Treaty TTL would force her scrapping. However with decent maintenance, let alone the massive reconstruction that occurred in some ships OTL she could have found a use. The basic hulls could and did last for decades.

Steve

 

[Douglas]

Next question: post treaty, the UK gets to build two battleships in 1932. What do these battleships look like, if they are limited to 35,000 tons and 16" guns?

 

[stevep]

Next question: post treaty, the UK gets to build two battleships in 1932. What do these battleships look like, if they are limited to 35,000 tons and 16" guns?

Douglas

If those are the limits then quite I suspect possibly very similar to OTL Nelson and Rodney. A bit more concern for protection against air attack perhaps. More advanced power plants and the like as they will have progressed in the mean time. It gives useful if slightly slow units, well protected, with powerful guns. Big question might be if Britain changes parts of the gun structures from brass to steel to try and save weight. This was a big cause of problems with the OTL 16" guns, along with the decision to go for a max elevation of 45 degrees. If you avoid those steps and with a tried and tested triple 16" developed then they should avoid the problems with the guns that the two ships had OTL. Might be largely completed by the time the depression hits, provided the work is not spread out too much between the various companies. [Also depends on what part of 27 the treaty occurs in of course].

Reason I asked about those limits was that in OTL 1921, other than the Hood, all ships built/to be completed were up to about 33k. As such and given the difficulty of cutting the G3 design down to treaty limits and the fact Britain was only getting two ships 35k was a suitable minimal limit. However in TTL there are numerous ships of ~40+k [5 RN, 4 USN, 6IJN] so the limit may seem more arbitary. Especially since, depending when new construction is allowed, designers, needing to consider the big ships other powers have and a lot of new equipment to go in as AA and electrionics increase in importance, may consider they can not build viable ships on that tonnage].

On the other hand that could be a good reason for the big 3 to try and impose such a limit. Its in their interests, at least in the short term, that their big ships can't be matched by other powers. Such as France and Italy who may be looking at each other nervously by now, and any newly emerging contentor.

One possible spanner that might have been thrown into the work? OTL 1921 amongst other things prevented construction of capital ships for other powers. Without a treaty its a possibility that someone may have been asked to build something for a 3rd power. [Most likely from the southern Latin trio or possibly China]. Can't see any of the other European powers building any new capital ships as France and Italy are too exhausted in the early 20's and no one else is in a position to. [Unless you have the Netherlands or Spain say but that is unlikely I suspect]. Presume TTL 1927 treaty will also ban such construction?

Steve

 

[bard32]

Nope. You can either opt for -

1) Wakamiya, a prize of the R-J War, "In 1914 she became the first Japanese air-capable ship, flying her Farman biplanes from September to November in support of the assault on Tsingtao. Her aircraft reportedly sank one German minelayer and damaged shore installations; they arguably therefore made the first successful carrier air raid in history." Conway's All the World's Fighting Ships 1906-1921, 1986

or, since I'm feeling generous today -

2) Hosho, "Originally laid down 16 December, 1919 as an auxiliary, intended to be a tanker, to be named Hiryu. Re-named Hosho in 1920, redesignated 13 October, 1921 as Aircraft Depot Ship (Kobubokan). A sister ship, Shokaku, was planned, but construction never began, because of the limitations of the Washington Treaty." p.41, Jentschura, Jung, Mickel, Warships of the Imperial Japanese Navy 1869-1945, 1977 translation of 1970 German original Die Japanischen Kriegsschiffe 1869-1945

Hiei was one of Kongo's sisters. Twice, in fact, since not only was the second Hiei sister to the battlecruiser Kongo, but the first Hiei had been sister to the first Kongo in the last quarter of the nineteenth century.

I don't have to. I believe you. Trust me. According to what I read, the Akagi and Amagi were both scheduled for conversion to carriers after the signing of the Washington Naval Treaty. The battlecruiser Kaga, was scheduled to be
scrapped. By a twist of fate, that being the Tokyo earthquake of 1923, Amagi was destroyed on the ways and ended up being scrapped. So Kaga,
which was on her way to the breakers, was converted into an aircraft carrier
instead.