Shinano Aircraft Carrier Conversion

[Tzoli]

Thanks.
And actually based on the 57+2 storage layout in one of the sources it is possible to put 25+1 Reppus, 25+1 Ryuseis and all 7 Saiuns in the Hanger!
Here:
A bit cramped but this was normal in WW2 to my knowledge. Of course if you store the Saiuns on the deck you have more space for other aircraft or store them less dense.
I don't know why the C6N Siaun was not designed with folded wings though....

 

[eltf177]

Well if everything had gone to plan for the Japanese re aircraft development
Fighter - A7M Reppu
Dive/torpedo bomber - B7A Ryusei
Recce - a handful of C6N

The B7A Ryusei was meant to replace both the D4Y Suisei in the dive bomber role and the B6N Tenzan in the torpedo bomber role. But relatively few were produced (c100).

So in reality, more likely to be A6M-5/D4Y-2/B6N-2 with a handful of C6N for recce.

I've seen drawings of the C6N carrying a torpedo, but not too sure just how accurate that is...

 

[EwenS]

Well if everything had gone to plan for the Japanese re aircraft development
Fighter - A7M Reppu
Dive/torpedo bomber - B7A Ryusei
Recce - a handful of C6N

The B7A Ryusei was meant to replace both the D4Y Suisei in the dive bomber role and the B6N Tenzan in the torpedo bomber role. But relatively few were produced (c100).

So in reality, more likely to be A6M-5/D4Y-2/B6N-2 with a handful of C6N for recce.

I've seen drawings of the C6N carrying a torpedo, but not too sure just how accurate that is...

Never got beyond the project stage AFAIK.

 

[Tzoli]

And here is my imagination of the Shinano's original project as designed with 10cm Type 98 Guns and how it would looked like fully commissioned with all the equipment on board:

IJN Shinano Carrier as Designed by Tzoli on DeviantArt

www.deviantart.com

My aircraft complement as follows:
25+1 Mitsubishi A7M Reppu / Sam Fighters
10 Yokosuka D4Y Suisei / Judy Dive Bombers (6 of them on the deck)
10+1 Aichi B7A Ryusei / Grace Torpedo-Dive Bombers
or 17+1 Aichi B7A Ryusei / Grace Torpedo-Dive Bombers
6+1 Nakajima C6N Saiun / Myrt reconnaisance planes

The design had the following characteristics:
Dimensions: 244 (pp) x 256 (wl) x 266 (oa) x 36,3 x 10,3 meters
Displacement: 62.000tons (standard)
Armour: 400mm Belt at Magazines, 160mm at Machinery inclined at 20 degrees, 190mm Deck over Magazines and 100mm over Machinery, 230mm Slopes, 76mm Flight deck
Engines: 150.000shp Kanpon Steam Turbines, 4 shafts
Range: 18.500km at 33km/h (10.000nm at 18knots)
Speed: 50km/h (27knots)
Armaments:
8x2 10cm/60 Type 98 DP-AA Guns,
35x3,5x2,13x1 25mm Type 96 AA Guns,
12x21 12cm Type 5 AA Rockets
Aircraft Capacity: Hanger: maximum 60 aircraft plus around 10 on deck.

Sensors:
Type 13 Air search radars (two sets on the mainmast)
Type 21 Air search radars (on top of the bridge and on the aft part of the island superstructure)
Type 22 Surface search radars (two sets, one on each side aft part of the funnel)

 

[lancer21]

The Japanese wiki article about Shinano is much more extended that of the English sources and have way more source material as expected.
The aircraft storage was quite how can I say shows many variants from full hanger storage to hanger and deck storage (on flight deck via anchors)
According sources:

No.1: ( Showa Shipbuilding History 1 )
18 fighters + 2 spares
24 bombers + 3 spares
Total: 42+5

No.2: ( Navy Shipbuilding Technology Overview )
18 A7M Reppu fighters + 2 spares
18 B7A Ryusei Torpedo Bombers + 2 spares
6 C6N Saiun reconnaissance planes + 1 spares
Total: 42+5

No.3: ( Aviation Headquarters )
25 A7M Reppu Fighters + 1 spares (1 flightdeck stored)
25 B7A Ryusei Torpedo Bombers + 1 spares (7 flightdeck stored)
7 C6N Saiun reconnaissance planes (7 flightdeck stored)
Total: 57+2

No.4 ( Aircraft Carrier and Ship-Related Report Material )
24 A7M Reppu Fighters + 1 spares
17 B7A Ryusei Torpedo Bombers + 1 spares
7 C6N Saiun reconnaissance planes
Total: 48+2
This last source state that due to the slow development of the A7M, the fighter complement would be the N1K Shiden land based fighters

Just thought to add that according to the same japanese wiki article on Shinano, there is also mention of 72 aircraft in the hangar and 13 as deck-park, so total 85 (no mention of types)? At least that what the translator seems to suggest!

Could that refer to how many older (and smaller) generation planes they could fit on Shinano, like A6M, D4Y etc? Would the A6M and D4Y take less space than the A7M, B7A and C6N?

 

[Tzoli]

Likely, The A6M zero, D4Y Judy and B5N Kate was quite smaller than the A7M Reppu, B7A Ryusei and C6N Saiun

 

[Preußen Blue]

Does anyone tried to calculate how much aircraft could Shinano carry in a full fleet carrier configuration?
I have a drawing of her hanger shape and using C8N Suisei, A7M Reppu and B7A Ryusei planes I determined around 50 aircraft could be easily stored in her hanger (8 Suisei the rest are Reppu and Ryusei) with another 40-50 on the flight deck giving her an Akagi-Kaga like large capacity but with modern planes. But I wish to ask your opinions on this matter.

I don't know much about the construction of warships. I don't even know what I'm saying is possible.

But what's interesting is that USS Lexington was built way before WW2 and shortly after WW1 when aircraft carriers came under question about their purpose. Now USS Midway was built in 1945 as the future of aircraft carriers and as the war came to a close in 1945.

Now the reason Shinano has a high tonnage is that she was to be built as a battleship. Yamato was 69,000 tons. Rewinding it back, say the Japanese decided to covert Shinano earlier and were able to convert it into a proper carrier. Even in deciding earlier to covert her. Her design would be vastly different because her outline in the dockyard would be 265.8 meters and she would be at least 50% complete. Maybe more. Therefore if you're going to construct an aircraft carrier to her true tonnage of 67,000 tons, her dimensions would have to be readjusted to fit in accordance with an aircraft carrier of 67,000 tons because she's half-built. The major difference in dimension is that she would have been lengthed to fit in accordance with 67,000 tons. Now, this bit I don't know. How much extra tonnage would equate between 265.8 meters and 305 meters to meet 67,000 tons? Despite this, her overall length could be even longer, anything from 305 to 340 meters.

The reason I say this is because Midway was 305 meters and 45,000 tons. Shinano is 23,000 tons more than Midway. Finally, if anything is to go by, if Lexington can carry 78 aircraft and Midway could carry 137 then Shinano would theoretically carry something in the region of 150+

The Japanese most definitely would not have redesigned and constructed to her true potential because it is a logistical and construction nightmare. It would require the bow to be dismantled to lengthen her for a start. They would have just converted her according to her length of 267 meters but she still would have been massively overweight of 67,000 tons. In this configuration, her full potential would still not have been met because she'd carry fewer aircraft according to her true weight.

(See table for details)

Year built	Ship	Tonnage	Overall Length (Meters)	Aircraft
1944	Shinano	67,000	265.8	47
1945	Midway	45,000	305	137 theoretically, 100 reality
1927	Lexington	36,000	270.7	78

I suppose this explanation emphasises how complicated it would have been to covert her to an aircraft carrier. Ideally, she should have been built like a battleship otherwise she should have been scrapped but it was wartime so they couldn't.

 

[Tzoli]

According to navypedia:
Lexington: Flight Deck: 268.2 x 27.4m - 7,349m² Hanger: 129.2 x 22.6 x 6.4m - 2,920m² / 18,687m³
Midway: Flight Deck: 281.6 x 34.4m - 9,687m² Hanger: 210.9 x 28.9 x 5.33m - 6,095m² / 32,486m
Shinano: Flight Deck: 256.0 x 40.0m -10,240m² Hanger: 167.0 x ? x 5.0m - 4,175m² / ~20,900m³

So theoretically based on the numbers it should had the hanger capacity halfway between Lexington and Midway and as large flight deck capacity as Midway.

 

[ceccherini]

Does anyone tried to calculate how much aircraft could Shinano carry in a full fleet carrier configuration?
I have a drawing of her hanger shape and using C8N Suisei, A7M Reppu and B7A Ryusei planes I determined around 50 aircraft could be easily stored in her hanger (8 Suisei the rest are Reppu and Ryusei) with another 40-50 on the flight deck giving her an Akagi-Kaga like large capacity but with modern planes. But I wish to ask your opinions on this matter.

I don't know much about the construction of warships. I don't even know what I'm saying is possible.

But what's interesting is that USS Lexington was built way before WW2 and shortly after WW1 when aircraft carriers came under question about their purpose. Now USS Midway was built in 1945 as the future of aircraft carriers and as the war came to a close in 1945.

Now the reason Shinano has a high tonnage is that she was to be built as a battleship. Yamato was 69,000 tons. Rewinding it back, say the Japanese decided to covert Shinano earlier and were able to convert it into a proper carrier. Even in deciding earlier to covert her. Her design would be vastly different because her outline in the dockyard would be 265.8 meters and she would be at least 50% complete. Maybe more. Therefore if you're going to construct an aircraft carrier to her true tonnage of 67,000 tons, her dimensions would have to be readjusted to fit in accordance with an aircraft carrier of 67,000 tons because she's half-built. The major difference in dimension is that she would have been lengthed to fit in accordance with 67,000 tons. Now, this bit I don't know. How much extra tonnage would equate between 265.8 meters and 305 meters to meet 67,000 tons? Despite this, her overall length could be even longer, anything from 305 to 340 meters.

The reason I say this is because Midway was 305 meters and 45,000 tons. Shinano is 23,000 tons more than Midway. Finally, if anything is to go by, if Lexington can carry 78 aircraft and Midway could carry 137 then Shinano would theoretically carry something in the region of 150+

The Japanese most definitely would not have redesigned and constructed to her true potential because it is a logistical and construction nightmare. It would require the bow to be dismantled to lengthen her for a start. They would have just converted her according to her length of 267 meters but she still would have been massively overweight of 67,000 tons. In this configuration, her full potential would still not have been met because she'd carry fewer aircraft according to her true weight.

(See table for details)

Year built	Ship	Tonnage	Overall Length (Meters)	Aircraft
1944	Shinano	67,000	265.8	47
1945	Midway	45,000	305	137 theoretically, 100 reality
1927	Lexington	36,000	270.7	78

I suppose this explanation emphasises how complicated it would have been to covert her to an aircraft carrier. Ideally, she should have been built like a battleship otherwise she should have been scrapped but it was wartime so they couldn't.

There Is no linear correlation between between a ship dimensions and its displacement, that Is its Mass. The Key factor you left out to correlate the dimensions and the displacement Is the block coefficient, that Is how much boxy a ship hull is calculated as its mass as a fraction of the mass of a water parallelepiped with the same dimensions. Shinano had actually a very High block coefficient of nearly 0,7 against around 0,6 of most battleships and carriers of the time. So you can have very simply a carrier with the same width, immersion and displacement as Shinano but longer just with a slender hull and so a lower block coefficient. As an example if you scale the Tahio hullform to a 67000 ton standard displacement you get a waterline lenght of about 330 meters with about One meter more in immersion and One meter less in beam compared to Shinano.

 

[Silencer1]

Sorry, but the topic's name is confusing.
Is it possible to correct the typos?

 

[Hood]

Sorry, but the topic's name is confusing.
Is it possible to correct the typos?

Edited the title.

 

[Preußen Blue]

Does anyone tried to calculate how much aircraft could Shinano carry in a full fleet carrier configuration?
I have a drawing of her hanger shape and using C8N Suisei, A7M Reppu and B7A Ryusei planes I determined around 50 aircraft could be easily stored in her hanger (8 Suisei the rest are Reppu and Ryusei) with another 40-50 on the flight deck giving her an Akagi-Kaga like large capacity but with modern planes. But I wish to ask your opinions on this matter.

I don't know much about the construction of warships. I don't even know what I'm saying is possible.

But what's interesting is that USS Lexington was built way before WW2 and shortly after WW1 when aircraft carriers came under question about their purpose. Now USS Midway was built in 1945 as the future of aircraft carriers and as the war came to a close in 1945.

Now the reason Shinano has a high tonnage is that she was to be built as a battleship. Yamato was 69,000 tons. Rewinding it back, say the Japanese decided to covert Shinano earlier and were able to convert it into a proper carrier. Even in deciding earlier to covert her. Her design would be vastly different because her outline in the dockyard would be 265.8 meters and she would be at least 50% complete. Maybe more. Therefore if you're going to construct an aircraft carrier to her true tonnage of 67,000 tons, her dimensions would have to be readjusted to fit in accordance with an aircraft carrier of 67,000 tons because she's half-built. The major difference in dimension is that she would have been lengthed to fit in accordance with 67,000 tons. Now, this bit I don't know. How much extra tonnage would equate between 265.8 meters and 305 meters to meet 67,000 tons? Despite this, her overall length could be even longer, anything from 305 to 340 meters.

The reason I say this is because Midway was 305 meters and 45,000 tons. Shinano is 23,000 tons more than Midway. Finally, if anything is to go by, if Lexington can carry 78 aircraft and Midway could carry 137 then Shinano would theoretically carry something in the region of 150+

The Japanese most definitely would not have redesigned and constructed to her true potential because it is a logistical and construction nightmare. It would require the bow to be dismantled to lengthen her for a start. They would have just converted her according to her length of 267 meters but she still would have been massively overweight of 67,000 tons. In this configuration, her full potential would still not have been met because she'd carry fewer aircraft according to her true weight.

(See table for details)

Year built	Ship	Tonnage	Overall Length (Meters)	Aircraft
1944	Shinano	67,000	265.8	47
1945	Midway	45,000	305	137 theoretically, 100 reality
1927	Lexington	36,000	270.7	78

I suppose this explanation emphasises how complicated it would have been to covert her to an aircraft carrier. Ideally, she should have been built like a battleship otherwise she should have been scrapped but it was wartime so they couldn't.

There Is no linear correlation between between a ship dimensions and its displacement, that Is its Mass. The Key factor you left out to correlate the dimensions and the displacement Is the block coefficient, that Is now much boxy a ship hull calculated as its mass as a fraction of the mass of a water parallelepiped with the dame dimensions. Shinano had actually a very High block coefficient of nearly 0,7 against around 0,6 of most battleships and carriers of the time. So you can have very Simply a carrier with the same width,immersion and displacement as Shinano just with a slender hull and so a lower block coefficient. As an example if you scale the Tahio hullform to a 67000 ton standard displacement you get a waterline lenght of a out 330 meters with about One meter more in immersion and One meter less in beam compared to Shinano.

I apologise, I don’t anything about engineering.

Ok... higher block coefficient, bulky hull... Lover block coefficient slender hull... Ok... so how does the block coefficient relate to how many aircraft she could hold? If the hull is bulky then the higher block coefficient means something which I don’t know.

I don’t know if I’m getting ahead of myself again but Shinano was not just an aircraft carrier. She was also a maintenance ship.

The forward area of the hanger was dedicated to maintenance and storage facilities. There were also two lifts, one at each end, one measuring 15 by 14 meters. She could also carry 720,000 litres of aviation gasoline.

 

[Tzoli]

It does not. It is required for calculations on ship speed, natural speed and thus optimal hull form and propulsion efficiency.
Deck space is required for aircraft handling.

 

[ceccherini]

I apologise, I don’t anything about engineering.

Ok... higher block coefficient, bulky hull... Lover block coefficient slender hull... Ok... so how does the block coefficient relate to how many aircraft she could hold? If the hull is bulky then the higher block coefficient means something which I don’t know.

I don’t know if I’m getting ahead of myself again but Shinano was not just an aircraft carrier. She was also a maintenance ship.

The forward area of the hanger was dedicated to maintenance and storage facilities. There were also two lifts, one at each end, one measuring 15 by 14 meters. She could also carry 720,000 litres of aviation gasoline.

There isn't a direct relation. Aircraft carriers are different from the other warships because the key platform requirement to support their weapon system is related to the volume, not to displacement. In that regard they are quite similar to passenger ships. Obviously given the same architecture, the larger the carrier the larger the airwing but different hullform can well result in a carrier of larger displacement but less volume and so less aircraft carriers than a fisically larger ship with a smaller mass.

 

[Preußen Blue]

Does anyone tried to calculate how much aircraft could Shinano carry in a full fleet carrier configuration?
I have a drawing of her hanger shape and using C8N Suisei, A7M Reppu and B7A Ryusei planes I determined around 50 aircraft could be easily stored in her hanger (8 Suisei the rest are Reppu and Ryusei) with another 40-50 on the flight deck giving her an Akagi-Kaga like large capacity but with modern planes. But I wish to ask your opinions on this matter.

I don't know much about the construction of warships. I don't even know what I'm saying is possible.

But what's interesting is that USS Lexington was built way before WW2 and shortly after WW1 when aircraft carriers came under question about their purpose. Now USS Midway was built in 1945 as the future of aircraft carriers and as the war came to a close in 1945.

Now the reason Shinano has a high tonnage is that she was to be built as a battleship. Yamato was 69,000 tons. Rewinding it back, say the Japanese decided to covert Shinano earlier and were able to convert it into a proper carrier. Even in deciding earlier to covert her. Her design would be vastly different because her outline in the dockyard would be 265.8 meters and she would be at least 50% complete. Maybe more. Therefore if you're going to construct an aircraft carrier to her true tonnage of 67,000 tons, her dimensions would have to be readjusted to fit in accordance with an aircraft carrier of 67,000 tons because she's half-built. The major difference in dimension is that she would have been lengthed to fit in accordance with 67,000 tons. Now, this bit I don't know. How much extra tonnage would equate between 265.8 meters and 305 meters to meet 67,000 tons? Despite this, her overall length could be even longer, anything from 305 to 340 meters.

The reason I say this is because Midway was 305 meters and 45,000 tons. Shinano is 23,000 tons more than Midway. Finally, if anything is to go by, if Lexington can carry 78 aircraft and Midway could carry 137 then Shinano would theoretically carry something in the region of 150+

The Japanese most definitely would not have redesigned and constructed to her true potential because it is a logistical and construction nightmare. It would require the bow to be dismantled to lengthen her for a start. They would have just converted her according to her length of 267 meters but she still would have been massively overweight of 67,000 tons. In this configuration, her full potential would still not have been met because she'd carry fewer aircraft according to her true weight.

(See table for details)

Year built	Ship	Tonnage	Overall Length (Meters)	Aircraft
1944	Shinano	67,000	265.8	47
1945	Midway	45,000	305	137 theoretically, 100 reality
1927	Lexington	36,000	270.7	78

I suppose this explanation emphasises how complicated it would have been to covert her to an aircraft carrier. Ideally, she should have been built like a battleship otherwise she should have been scrapped but it was wartime so they couldn't.

There Is no linear correlation between between a ship dimensions and its displacement, that Is its Mass. The Key factor you left out to correlate the dimensions and the displacement Is the block coefficient, that Is now much boxy a ship hull calculated as its mass as a fraction of the mass of a water parallelepiped with the dame dimensions. Shinano had actually a very High block coefficient of nearly 0,7 against around 0,6 of most battleships and carriers of the time. So you can have very Simply a carrier with the same width,immersion and displacement as Shinano just with a slender hull and so a lower block coefficient. As an example if you scale the Tahio hullform to a 67000 ton standard displacement you get a waterline lenght of a out 330 meters with about One meter more in immersion and One meter less in beam compared to Shinano.

Does anyone tried to calculate how much aircraft could Shinano carry in a full fleet carrier configuration?
I have a drawing of her hanger shape and using C8N Suisei, A7M Reppu and B7A Ryusei planes I determined around 50 aircraft could be easily stored in her hanger (8 Suisei the rest are Reppu and Ryusei) with another 40-50 on the flight deck giving her an Akagi-Kaga like large capacity but with modern planes. But I wish to ask your opinions on this matter.

I don't know much about the construction of warships. I don't even know what I'm saying is possible.

But what's interesting is that USS Lexington was built way before WW2 and shortly after WW1 when aircraft carriers came under question about their purpose. Now USS Midway was built in 1945 as the future of aircraft carriers and as the war came to a close in 1945.

Now the reason Shinano has a high tonnage is that she was to be built as a battleship. Yamato was 69,000 tons. Rewinding it back, say the Japanese decided to covert Shinano earlier and were able to convert it into a proper carrier. Even in deciding earlier to covert her. Her design would be vastly different because her outline in the dockyard would be 265.8 meters and she would be at least 50% complete. Maybe more. Therefore if you're going to construct an aircraft carrier to her true tonnage of 67,000 tons, her dimensions would have to be readjusted to fit in accordance with an aircraft carrier of 67,000 tons because she's half-built. The major difference in dimension is that she would have been lengthed to fit in accordance with 67,000 tons. Now, this bit I don't know. How much extra tonnage would equate between 265.8 meters and 305 meters to meet 67,000 tons? Despite this, her overall length could be even longer, anything from 305 to 340 meters.

The reason I say this is because Midway was 305 meters and 45,000 tons. Shinano is 23,000 tons more than Midway. Finally, if anything is to go by, if Lexington can carry 78 aircraft and Midway could carry 137 then Shinano would theoretically carry something in the region of 150+

The Japanese most definitely would not have redesigned and constructed to her true potential because it is a logistical and construction nightmare. It would require the bow to be dismantled to lengthen her for a start. They would have just converted her according to her length of 267 meters but she still would have been massively overweight of 67,000 tons. In this configuration, her full potential would still not have been met because she'd carry fewer aircraft according to her true weight.

(See table for details)

Year built	Ship	Tonnage	Overall Length (Meters)	Aircraft
1944	Shinano	67,000	265.8	47
1945	Midway	45,000	305	137 theoretically, 100 reality
1927	Lexington	36,000	270.7	78

I suppose this explanation emphasises how complicated it would have been to covert her to an aircraft carrier. Ideally, she should have been built like a battleship otherwise she should have been scrapped but it was wartime so they couldn't.

There Is no linear correlation between between a ship dimensions and its displacement, that Is its Mass. The Key factor you left out to correlate the dimensions and the displacement Is the block coefficient, that Is now much boxy a ship hull calculated as its mass as a fraction of the mass of a water parallelepiped with the dame dimensions. Shinano had actually a very High block coefficient of nearly 0,7 against around 0,6 of most battleships and carriers of the time. So you can have very Simply a carrier with the same width,immersion and displacement as Shinano just with a slender hull and so a lower block coefficient. As an example if you scale the Tahio hullform to a 67000 ton standard displacement you get a waterline lenght of a out 330 meters with about One meter more in immersion and One meter less in beam compared to Shinano.

I apologise, I don’t anything about engineering.

Ok... higher block coefficient, bulky hull... Lover block coefficient slender hull... Ok... so how does the block coefficient relate to how many aircraft she could hold? If the hull is bulky then the higher block coefficient means something which I don’t know.

I don’t know if I’m getting ahead of myself again but Shinano was not just an aircraft carrier. She was also a maintenance ship.

The forward area of the hanger was dedicated to maintenance and storage facilities. There were also two lifts, one at each end, one measuring 15 by 14 meters. She could also carry 720,000 litres of aviation gasoline.

There isn't a direct relation. Aircraft carriers are different from other warship because the key platform requirement to support its weapon system is related to the volume, not the displacement. In that regard they are quite similar to passenger ships. Obviously given the same architetture, the larger the carrier the larger the airwing but different hullform can sell result in a carrier of larger displacement but less volume and so less aircraft carriers than a fisically larger ship with a smaller mass.

Right. So Shinano was big ship of 67,000 tons. But her hull form of large displacement resulted in less volume because she was initially designed as a battleship, not as an aircraft carrier which resulted in her having fewer aircraft.

Right. Therefore because hull form determines the volume. Even being 50% complete she was useless because the hull would have been constructed by then to be that of a battleship, not as an aircraft carrier.

Ok. Shinano was laid down on 4th May 1940 at the Yokosuka Naval Arsenal. Had the Japanese altered the blueprints to represent an aircraft carrier of 67,000 tons. Thus emphasising expanding the volume within the aircraft carrier to the full extent. How much aircraft could she hold? Is 150 a minimum or a maximum?

 

[Arjen]

@Preußen Blue , while I appreciate your discussion - could you please limit your comments to new content? Your use of the REPLY button makes this thread near unreadable.

 

[Preußen Blue]

Having posted these three posts I have just found the most revealing information. Had I found the information first I would not have written the posts but that's how it works. I only pieced it together through deductive and inductive thinking/logic which was the enjoyment.

However more importantly I learned a lot; about block coefficient and how internal volume equates to the sizes of ships etc. That's invaluable because I know nothing about warship engineering.

Anyway, I just found this piece of information:

"Shinano was intended to be the most powerful aircraft carrier in the world. Her flight deck would be 870 feet long and armored against the largest of air-dropped armor-piercing bombs, while a belt of armor at the waterline and a network of internal watertight doors would protect against torpedoes. Her immense hangar would have room for almost 150 combat aircraft. She even had enough room to carry and launch two-engined medium bombers. With 16 5-inch anti-aircraft guns and almost 150 25mm cannon, she bristled with AA. Shinano would also have the best electronic radar technology that Japan could provide, and, utilizing the same engines found in Yamato and Musashi, her speed of 27 knots and range of 10,000 nautical miles meant that she could reach any American base in the Pacific. She would, it was hoped, turn the Imperial Navy into an effective fighting force again." (https://www.dailykos.com/stories/20...History-The-Carrier-Shinano-Japan-s-Last-Hope)

Now, what's interesting!!!!! Is how this relates to other hulls, battleships and aircraft carrier designs!!!! That's where the real juicy stuff is.

Regards

 

[Tzoli]

Not sure the accuracy of that article. The 4th and 5th Yamato was never named, IJN Kii pops up sometimes but no concrete info on the source where it was first found. Shinano as a Battleship would had been armed with 6x2 10cm AA guns with likely change to 12x similarly arranged like on Yamato. As a Carrier she too was designed with 8x2 10cm guns but due to production shortages the older 12,7cm guns were chosen. The 150x aircraft and twin engine bombers I found very dubious!
Even the Japanese Midway design G-14, was described having less aircraft, around 84 and that was a carrier to begin with! Shinano was heavy partly because of her size but mostly because of the thick armour belt of 16cm at machinery, 40cm at magazines, 23cm slopes and 10/19cm deck!
Did the author of that articles confused by the hypothetical Muteki Nippon drawing?

 

[Tzoli]

Though that twin engine bomber might be the abortive Aichi D3A replacement, eventually evolving into the Yokosuka D4Y:

https://www.secretprojects.co.uk/threads/ijn-post-taiho-fleet-carrier-plans.32387/

 

[Tzoli]

You can see the hanger space available for aircraft here:

https://www.secretprojects.co.uk/threads/shinano-aircraft-carrier-conversion.33281/page-2#post-418201

I will post later the original drawing I've based mine of.

 

[Preußen Blue]

Your more than likely won’t find blue print designs on Shinano as being converted to an aircraft carrier of said proposal. She was converted ad-hoc during a war. In the end she became half carrier and half maintenance ship. The Japanese designer/s and construction managers would have amended her onsite/verbally. “You need to change this, change that, reduce this etc.” If they did draw blue prints they are either lost or destroyed.

It does fit logic to have an aircraft carrier of that size in their own delusional thinking because of the situation they were in. They had no other options at all on the table. They were unknowingly facing nuclear proliferation and knowingly facing direct invasion. (Operation Downfall)

What I’m surprised about is why the Yamato class was not originally designed in mind as an aircraft carrier. It’s just absolute madness, because an aircraft carrier of that class would possibly change the war because of her capabilities. With 2 aircraft carriers of that size you could invade Hawaii along with everything else you’ve got. Plus I’m not surprised if her design conversion between 1940-44 was rushed.

This all just reminds me of the Germans and their backward thinking. Everything is the wrong way round.

 

[Tzoli]

There were serious design work was done for even conversions during the war! It's just the size of the conversion was reduced to reduce the time needed both to design and to actually do the work. It's not like you have a cruiser hull half done to to the main deck and they decide to put a large box on it as a hanger and then here you go a cheap light carrier finished!
That cruiser hull was designed with set margins as a cruiser and topweight calculated accordingly taking into account some growth of tonnage during the ship's lifetime! They had to recalculate the entire hull stress calculations design a hanger, supports bridge, their weight, new armament etc. The centre of gravity the trim of the hull changes, these are not just simply thrown out when they make a change to the design!

As for why the Yamatos never considered as carriers.
Read after the IJN Naval battle doctrine of the time:
The Peace Goddess Doctrine:
"These battleships were well protected exceptionally armed large vessels, the jewels and prides of the Imperial Japanese Navy, designed for the doctrine of Peace Goddesses where these large ships though numerically inferior but firepower and armour wise superior to anything the allies especially the USN could build, and their own existence would prevent an eruption of a naval war!"
Here:

The Japanese Super battleship Strategy

Visit this link to preview document

files.fm

As for plans:
IJN Shinano:

https://imgur.com/fV7ZvGW

View: https://i.imgur.com/fV7ZvGW.jpg

https://imgur.com/wC76Fb7

View: https://i.imgur.com/wC76Fb7.jpg

 

[Tzoli]

And more high resolution plans of IJN Shinano from the book:
Plans of Ships of the Imperial Japanese Navy by Hans Lengerer, ISBN13 (EAN): 9781608880836

 

[Preußen Blue]

I meant said proposal of a carrier that can hold 150 aircraft. You won't find the design of it anywhere because why has no one ever heard of it. Why is it, like you said yourself "dubious" which is perfectly understandable. You know, it's like "really!!!?" The Japanese were simply delusional and part of that delusion was converting Shinano in a war they knew they couldn't now win but were still fighting the war.

The Japanese may have put an exceptional amount of resources into converting her into a carrier but the war was over after Midway. Like Yamamoto said, "In the first six to twelve months of a war with the United States and Great Britain, I will run wild and win victory upon victory. But then after that, I have no expectation of success".

As for the battleship policy, it was a critical failure of government not to recognise, compare/contrast and conceptualise how a Super-battleship doctrine and how Super-carrier doctrine would operate in battle fleet operations. You definitely need battleships in a war, no doubt about it but you always need an unlimited amount of aircraft carriers because they are more versatile. They could have used the internal volume as a giant troopship.

 

[Tzoli]

Don't believe everything you read on the net until you know the source is creditable. In this case we don't know where the author got that 150+ number. Also this line he wrote might be the culprit:

NOTE: As some of you already know, all of my diaries here are draft chapters for a number of books I am working on. So I welcome any corrections you may have, whether it's typos or places that are unclear or factual errors. I think of y'all as my pre-publication editors and proofreaders.

Also interesting that after one day, comments were closed on this story (first comment on 2021 july 20 last on july 21 )
No sources I've read state Shinano could carry 150 aircrafts. Maybe if were built and designed from start as a carrier to the size of the Forrestal then I can see it could carry 150 WW2 era aircrafts (likely the early war Zeros, Judys and Vals and not the later Reppus, Tenzans and Suiseis)

Actually let's see what navypedia states for the Flight deck and Hanger area for the Forrestals compared to Shinano:
Forrestal: Flight Deck: 310.2 x 73.0m - 18,600m² Hanger: 225.5 x 30.8 x 7.60m - 6,945m² / 52,785m³ - 90 mostly jet fighters, not sure in only hanger or hanger and Deck park

Shinano: Flight Deck: 256.0 x 40.0m -10,240m² Hanger: 167.0 x ? x 5.0m - 4,175m² / ~20,900m³

Now let's compare the very first Super Carrier design, the cancelled USS United States:
United States: Flight Deck: 320.0 x 61.2m -19,584m² Hanger: 261.0 x 34.4 x 8.55m - 8,978 m² / 76,765m³)

Which means Shinano needs around 50% more hanger space and associated flight deck space to carry that mystical 150 aircraft number.
Note it was designed to carry almost 100 jet aircrafts mostly F2H Banshees

 

[Preußen Blue]

I understand what trying to say but I went looking around because there seems to be a lengthy debate on how much he could actually carry. I found Shinano on the website wreck site. It says she has an armament of 139 aircraft. If that's fake then I don't know what is. (https://www.wrecksite.eu/wreck.aspx?57656)

It appears that people know about Shinano's hidden potential and they are talking about it. I found this quote on a forum.

"The 47 Aircraft capacity was what it carried for its own use, but also carried 120 planes to be delivered... So if you intended to use Shinano as full combat CV she would have large airgroup or up to 167 aircraft."

Someone replied to this post and said the following:

"The problem, of course, would be accommodating their aircrew, their maintenance personnel and the necessary extra deck-handling crew (as well as feeding them all). Also fueling, arming and repairing such an oversize group for more than just one or two flights would be an issue.

Shinano's operational support facilities were tailored for a group of 47-ish. Like the British armoured carriers, this could probably be boosted by another 50 per cent or so by severe overcrowding.

A 167 air group could work for a one-way, one-off trip. But not on a campaign level."

(https://forum.worldofwarships.com/topic/52816-ijn-shinano-yamato-hull-cv/)

I know it's World of Warships forum but it's the only other place it's being discussed.

I think the telling statistic is of Midway and how she could carry 137 but only carried 100 and she was 45,000 tons. Shinano is 70,000 tons, 25,000 tons more and extremely bulky. Therefore if Midway can squeeze 137, Shinano must be able to squeeze 150 or more. 167 is mind-blowing. As for operating her in a campaign, the aircraft will be lower. Well, the wreck site says 139.

In conclusion, one strand of argument is a fluid abstraction of how she was going to be used on a day to day basis. If you want to put 90 aircraft on her for this campaign you can, but this is her not running a full capacity. She completes the campaign, now we'll put 125 aircraft in her hanger room. Still not running a full capacity etc, etc.

The other strand of argument is that she couldn't hold more than a certain number of aircraft regardless based on the information you have given. That is true depending on what type of carrier you are thinking of her to be. It's safe to say had she been built as a carrier from the start she'd have 150 aircraft but it becomes murky what with her conversion and the fact she actually became a maintenance ship. I believe the Japanese what her to have 150 aircraft during her conversion but how far they got to achieving this is unknown.

The following quote gives perspective on Shinano's conversion:

"To be used as a fully-fledged fleet CV, she would have to be rebuilt internally for all the accommodation and support services necessary for extra air crew, maintenance crew, handling crew. Then there's the extra maintenance and service equipment. Not to mention mess decks, cooking and cleaning crew...

It could have been possible to build full carrier functionality into Shinano from the outset (with the additional compromises and delays that entailed). But it wasn't."

 

[TomS]

"The 47 Aircraft capacity was what it carried for its own use, but also carried 120 planes to be delivered... So if you intended to use Shinano as full combat CV she would have large airgroup or up to 167 aircraft."

This misunderstands how aircraft were transported. In general, they would be disassembled for carriage as cargo, with the wings only mounted in order to fly them off at the destination. This sort of stowage was much more compact, but not suitable for operational use.

 

[Tzoli]

Those 137 other aircraft was as storage disassembled eg removed wings

"The 47 Aircraft capacity was what it carried for its own use, but also carried 120 planes to be delivered... So if you intended to use Shinano as full combat CV she would have large airgroup or up to 167 aircraft."

This misunderstands how aircraft were transported. In general, they would be disassembled for carriage as cargo, with the wings only mounted in order to fly them off at the destination. This sort of stowage was much more compact, but not suitable for operational use.

Exactly what I wanted to say. that 100+ number could only be achieved by this way.

 

[Preußen Blue]

Those 137 other aircraft was as storage disassembled eg removed wings

"The 47 Aircraft capacity was what it carried for its own use, but also carried 120 planes to be delivered... So if you intended to use Shinano as full combat CV she would have large airgroup or up to 167 aircraft."

This misunderstands how aircraft were transported. In general, they would be disassembled for carriage as cargo, with the wings only mounted in order to fly them off at the destination. This sort of stowage was much more compact, but not suitable for operational use.

Exactly what I wanted to say. that 100+ number could only be achieved by this way.

Remember I have no idea what you are talking about because I'm not a military engineer. @ceccherini was able to explain in more layman's terms. But you were contesting the legitimacy of a 150 carrier as "dubious". I only found information to say otherwise. That's it.

Anyway, I think I've exasperated this discussion enough.

 

[TomS]

But you were contesting the legitimacy of a 150 carrier as "dubious". I only found information to say otherwise. That's it.

And we explained why that information was wrong or misleading.

 

[Tzoli]

What is not understandable about disassembled aircrafts? They stored as fuselage with wings next to them, empty fuel tanks and likely no ammo, some might even lacks engines. To make them fly that requires like 30-60 minutes or even more of preparation time, not ideal for a strike carrier.

 

[EwenS]

The problem with operational carriers is how do you define how many aircraft it can carry? Is it hangar capacity? How big a deck park do you want to operate with? Different navies, different policies that changed over time.

By way of example, in 1940 an HMS Illustrious was rated at a capacity of 33 by virtue of its hangar capacity. The same ship in 1945 was operating c55 aircraft. Same ship but change of policy.

And change the aircraft type or mix of types and you can affect the capacity. Larger aircraft = fewer carried.

As for Midway, she didn’t complete until Sept 1945 when the war was over. So there was no need for her to cram aboard her 1945 planned air group of 135 aircraft. But there were limits. In the Essex class there were complaints in 1945 that a ship designed for 90 was struggling with 100-105 on board.

There are examples in other navies in WW2 of carriers ferrying numbers of aircraft in excess of their designed operational air groups by virtue of their being either fully or partially disassembled or where use was made of the flight deck to ferry them.

Lot of factors in play when looking at any carrier let alone Shinano.

 

[lancer21]

Re-reading about Shinano, it got me thinking, could they have converted it with a double (upper/lower) hangar, if they had more time or they started earlier? Converting Akagi and Kaga are the obvious examples. How early in the construction would they need to start this conversion, during 1941 or so?

But in this case, they couldn't have put an armoured deck on Shinano because of increase height of the double hangar and potential top heaviness?

On the other hand such a double hangar could have really brought Shinano's aircraft capacity to more than 100 of even the large A7M, B7A, C6N, is this realistic?

 

[Tzoli]

Shinano would had carried 3x 2.774ton triple 46cm turrets, 2x triple 190ton 15,5cm turrets and 6 twin 34,5ton 10cm turrets totalling 8.909 say 9.000tons of armament plus ammo and barbette armour, I doubt she would had any issues with stability even with a double hanger deck layout.
The problem is the Japanese wanted carriers as fast as they could get them and creating another hanger deck would cause a later construction date, more materials, and design workhours for calculations.

 

[lancer21]

Fascinating. So you think Shinano could have been built/converted with double hangars, pretty much doubling the aircraft capacity, which even if we take the lowest figures means something like 90 plus (!) of the new generation Reppu, Ryusei, Saiun etc. or even more (120-130?) of the smaller Zero, Suisei, Tenzan etc. AND an armoured flight deck too, and still be ok stability wise?

 

[Tzoli]

After the 4th fleet / Tomozuru incident I'm sure all new construction vessels were built with plenty of stability margins in their designs and also note it took tremendous amount of water and many bomb and torpedo hits to sink both of her sister ships.

Sidenote: The G-14 aircraft carrier design of 50.000tons standard displacement was designed with 84 aircrafts in mind and knowing the usual Japanese carrier aircraft storage all that would be in hangers. No dimensions data was found but I expect it to be as large as the Shinano with hurricane bow and double deck hangers.

 

[lancer21]

Presumably the 84 planes must be of the new generation types? I imagine this japanese supercarrier as a longer and a bit wider Taiho, sort of like the speculative image on the previous page. With the benefit of hindsight they would have been better off building G-14s instead of Shinano and No.111 of course.

 

[Tzoli]

It's an 1942 design so any aircraft that was in use or likely under development were used to calculate the aircraft number.
So far this is the only artist impression on the G-14 design and only top view:

https://www.secretprojects.co.uk/threads/ijn-post-taiho-fleet-carrier-plans.32387/

 

[Scott Kenny]

What is not understandable about disassembled aircrafts? They stored as fuselage with wings next to them, empty fuel tanks and likely no ammo, some might even lacks engines. To make them fly that requires like 30-60 minutes or even more of preparation time, not ideal for a strike carrier.

Longer than that, attaching wings and rigging the control cables (and all the fuel and electrical connections) is a 4-8 hour job for at least 2 people. Per plane.

 

[Yellow Palace]

What is not understandable about disassembled aircrafts? They stored as fuselage with wings next to them, empty fuel tanks and likely no ammo, some might even lacks engines. To make them fly that requires like 30-60 minutes or even more of preparation time, not ideal for a strike carrier.

Longer than that, attaching wings and rigging the control cables (and all the fuel and electrical connections) is a 4-8 hour job for at least 2 people. Per plane.

While I'm no expert, I'd guess you probably want to take it for a spin around the traffic pattern afterwards to make sure it flies right, as well. Probably not the best plan in the middle of combat operations.