Part 2 - Enter the 5th Turret
Design A-119
[URL unfurl="true"]https://www.deviantart.com/tzoli/art/IJN-Battleship-Design-A-119-857069640[/URL]
A-119 was a unique design in the post Nagato series. The official drawing I've linked shows the 14 underwater torpedo tubes an extremely strong torpedo armament for a capital ship but as you can see the design number 119 was looks like erased or ruled over. The next drawing A-120 depicts the same drawing with same dimensions just 1.000tons heavier and 4.000shp more engine power but without the underwater torpedo tubes. The A-120 drawing clearly shows the erased parts of A-119. Also the data tables in the Hiraga archive all states 4 above water 53cm torpedo tubes and different dimensions! So I've created two versions, this original A-119 which is exactly same above water as A-120 (minus the torpedo tubes) and the modified smaller version with above water torpedo tubes.
The design had the following characteristics:
Dimensions: 243,84 (pp) x 260 (oa) x 29,57 x 9,14 meters
Displacement: 39.400tons (standard)
Armour: 229mm Belt inclined at 25 degrees, 76mm Deck, 51mm at Machinery 76mm at Magazine Slopes
Engines: 120.000shp Gihon Steam Turbines, 4 shafts
Range: 10.200km at 30km/h (5.500nm at 16knots)
Speed: 56km/h (30knots)
Armaments:
5x2 410mm/45 Type 3 / 3rd Year Type Cannons,
20x1 140mm/50 Type 3 / 3rd Year Type Guns,
4x1 76mm/40 Type 3 / 3rd Year Type AA Guns,
14x1 53cm Underwater Torpedo Tubes
Original drawing:
[URL unfurl="true"]https://iiif.dl.itc.u-tokyo.ac.jp/repo/s/hiraga/document/b092ab84-b704-4db5-bbf7-83bad620fa10#?c=0&m=0&s=0&cv=1&xywh=-659%2C0%2C8261%2C4927[/URL]
Data table:
[URL unfurl="true"]https://iiif.dl.itc.u-tokyo.ac.jp/repo/s/hiraga/document/62342cb9-e432-49c6-b8da-767bbf081fed#?c=0&m=0&s=0&cv=5&xywh=969%2C481%2C3551%2C2118[/URL]
[URL unfurl="true"]https://iiif.dl.itc.u-tokyo.ac.jp/repo/s/hiraga/document/d059f655-21b8-4530-8979-ce9ac0733c10#?c=0&m=0&s=0&cv=23&xywh=1268%2C337%2C2118%2C3551&r=270[/URL]
Design A-119 Modified
[URL unfurl="true"]https://www.deviantart.com/tzoli/art/IJN-Battleship-Design-A-119-Modified-857302513[/URL]
This is the alternative modifed version of the A-119 design:
[URL unfurl="true"]https://www.deviantart.com/tzoli/art/IJN-Battleship-Design-A-119-857069640[/URL]
As the data in the Hiraga Archive not entirely clear about this proposal (Having a drawing with different data then the data tables)
I've made both versions. While the drawing version shows 14 underwater torpedo tubes, this modified version was smaller (some 3meters shorter) and displaced 1.000tons less, 38.400 rather 39.400 but the engine power and speed remained the same. It is possible that the 14 torpedo version was Yuzuru Hiraga's private own proposal or maybe a mis interpretation for a requirement set on one of the meetings of the Admiralty. As a sidenote the A-119 proposal seems to be the very first design to incorporate 5 twin turrets of the 41cm cannons introduced on the Nagato class and what essentially became the standard for all subsequent designs:
good speed, long sleek hull, 3 turrets aft 2 forward, 41cm main armament, 4 AA guns. until the later No.13 designs and their 46cm weaponry.
The design had the following characteristics:
Dimensions: 240,79 (pp) x 256,95 (oa) x 29,57 x 8,76 meters
Displacement: 38.400tons (standard)
Armour: 229mm Belt inclined at 25 degrees, 76mm Deck, 51mm at Machinery 76mm at Magazine Slopes
Engines: 120.000shp Gihon Steam Turbines, 4 shafts
Range: 10.200km at 30km/h (5.500nm at 16knots)
Speed: 56km/h (30knots)
Armaments:
5x2 410mm/45 Type 3 / 3rd Year Type Cannons,
20x1 140mm/50 Type 3 / 3rd Year Type Guns,
4x1 76mm/40 Type 3 / 3rd Year Type AA Guns,
4x1 53cm Above Water Torpedo Tubes
Data table:
[URL unfurl="true"]https://iiif.dl.itc.u-tokyo.ac.jp/repo/s/hiraga/document/62342cb9-e432-49c6-b8da-767bbf081fed#?c=0&m=0&s=0&cv=5&xywh=969%2C481%2C3551%2C2118[/URL]
[URL unfurl="true"]https://iiif.dl.itc.u-tokyo.ac.jp/repo/s/hiraga/document/d059f655-21b8-4530-8979-ce9ac0733c10#?c=0&m=0&s=0&cv=23&xywh=1268%2C337%2C2118%2C3551&r=270[/URL]
[URL unfurl="true"]https://iiif.dl.itc.u-tokyo.ac.jp/repo/s/hiraga/document/62342cb9-e432-49c6-b8da-767bbf081fed#?c=0&m=0&s=0&cv=0&xywh=-1118%2C-274%2C9179%2C5475[/URL]
Design A-120
[URL unfurl="true"]https://www.deviantart.com/tzoli/art/IJN-Battleship-Design-A-120-856886466[/URL]
Design A-120 was strongly connected to the previous A-119 proposal. This design probably the modified version of 14 torpedo launcher armed A-119 variant as the drawings show exactly the same hull and layout having only difference in the number and layout of torpedo tubes! Weirdly this design was heaver by 2.000tons despite only mounting 4 53cm torpedo tubes which could be the result of restoring the underwater torpedo bulkheads in the previously spaces allocated for the torpedo launchers
The design had the following characteristics:
Dimensions: 243,84 (pp) x 260 (oa) x 29,57 x 9,14 meters
Displacement: 40.400tons (standard)
Armour: 229mm Belt inclined at 25 degrees, 76mm Deck, 51mm at Machinery 76mm at Magazine Slopes
Engines: 124.000shp Gihon Steam Turbines, 4 shafts
Range: 10.200km at 30km/h (5.500nm at 16knots)
Speed: 56km/h (30knots)
Armaments:
5x2 410mm/45 Type 3 / 3rd Year Type Cannons,
20x1 140mm/50 Type 3 / 3rd Year Type Guns,
4x1 76mm/40 Type 3 / 3rd Year Type AA Guns,
4x1 53cm Above Water Torpedo Tubes
Original drawing:
[URL unfurl="true"]https://iiif.dl.itc.u-tokyo.ac.jp/repo/s/hiraga/document/b826131a-236c-46d3-b265-04fa73999c4c#?c=0&m=0&s=0&cv=0&xywh=-1988%2C0%2C10918%2C4927[/URL]
Data table:
[URL unfurl="true"]https://iiif.dl.itc.u-tokyo.ac.jp/repo/s/hiraga/document/62342cb9-e432-49c6-b8da-767bbf081fed#?c=0&m=0&s=0&cv=5&xywh=969%2C481%2C3551%2C2118[/URL]
[URL unfurl="true"]https://iiif.dl.itc.u-tokyo.ac.jp/repo/s/hiraga/document/d059f655-21b8-4530-8979-ce9ac0733c10#?c=0&m=0&s=0&cv=23&xywh=1268%2C337%2C2118%2C3551&r=270[/URL]
Design A-121
[URL unfurl="true"]https://www.deviantart.com/tzoli/art/IJN-Battleship-Design-A-121-853248424[/URL]
Design A-121 was most likely a modified fast version of A-119 with extra length and engine power added to reach the desired speed of 59km/h or 32knots. The next variant A-122 is very similar just longer by 14 meters. As I did not found any drawing for this particular proposal I've used a modified main armament layout of A-122 where I've changed the position and angle of the 3rd turret as well as the aft mast.
The design had the following characteristics:
Dimensions: 252,98 (pp) x 266,7 (wl) x 269,14 (oa) x 29,57 x 9,14 meters
Displacement: 40.600tons (standard)
Armour: 229mm Belt inclined at 25 degrees, 76mm Deck, 51mm at Machinery 76mm at Magazine Slopes
Engines: 150.000shp Gihon Steam Turbines, 4 shafts
Range: 10.200km at 30km/h (5.500nm at 16knots)
Speed: 59km/h (32knots)
Armaments:
5x2 410mm/45 Type 3 / 3rd Year Type Cannons,
20x1 140mm/50 Type 3 / 3rd Year Type Guns,
4x1 76mm/40 Type 3 / 3rd Year Type AA Guns,
4x1 53cm Above Water Torpedo Tubes
Data table:
[URL unfurl="true"]https://iiif.dl.itc.u-tokyo.ac.jp/repo/s/hiraga/document/62342cb9-e432-49c6-b8da-767bbf081fed#?c=0&m=0&s=0&cv=5&xywh=1362%2C716%2C2766%2C1650[/URL]
[URL unfurl="true"]https://iiif.dl.itc.u-tokyo.ac.jp/repo/s/hiraga/document/d059f655-21b8-4530-8979-ce9ac0733c10#?c=0&m=0&s=0&cv=23&xywh=1503%2C730%2C1650%2C2766&r=270[/URL]
Design A-122
[URL unfurl="true"]https://www.deviantart.com/tzoli/art/IJN-Battleship-Design-A-122-853143096[/URL]
Design A-122 was the largest and heaviest among the fast series of 32knots preliminary variants of the Tosa/Kaga havign reaching more then 280m in length and 43.000+tons of displacement! Armour wise it continues the same layout begun with the first post-Nagato design of A-115. Based on the stats and available info this proposal might be the fast version of A-120 showing how much engine power (extra 33.000shp) and waterline length (extra 23meters) required to propel a ship from 56 to 59km/h!
With armament remains unchanged the extra length allows wide placement of the secondary casemated guns in the 1st deck.
The sheer size of the design clearly illustrates the requirements for high speed: Long sleek hull with large engine power
The design had the following characteristics:
Dimensions: 266,7 (pp) x 281 (wl) x 282,85 (oa) x 29,57 x 9,14 meters
Displacement: 43.500tons (standard)
Armour: 229mm Belt inclined at 25 degrees, 76mm Deck, 51mm at Machinery 76mm at Magazine Slopes
Engines: 157.000shp Gihon Steam Turbines, 4 shafts
Range: 10.200km at 30km/h (5.500nm at 16knots)
Speed: 59km/h (32knots)
Armaments:
5x2 410mm/45 Type 3 / 3rd Year Type Cannons,
20x1 140mm/50 Type 3 / 3rd Year Type Guns,
4x1 76mm/40 Type 3 / 3rd Year Type AA Guns,
4x1 53cm Above Water Torpedo Tubes
Official drawing:
[URL unfurl="true"]https://iiif.dl.itc.u-tokyo.ac.jp/repo/s/hiraga/document/982cefd9-3342-484c-958e-f81fefcd9d19#?c=0&m=0&s=0&cv=0&xywh=-1988%2C0%2C10918%2C4927[/URL]
Data table:
[URL unfurl="true"]https://iiif.dl.itc.u-tokyo.ac.jp/repo/s/hiraga/document/62342cb9-e432-49c6-b8da-767bbf081fed#?c=0&m=0&s=0&cv=5&xywh=1362%2C716%2C2766%2C1650[/URL]
[URL unfurl="true"]https://iiif.dl.itc.u-tokyo.ac.jp/repo/s/hiraga/document/d059f655-21b8-4530-8979-ce9ac0733c10#?c=0&m=0&s=0&cv=23&xywh=1503%2C730%2C1650%2C2766&r=270[/URL]
Design A-123
[URL unfurl="true"]https://www.deviantart.com/tzoli/art/IJN-Battleship-Design-A-123-853009611[/URL]
While A-121 and 122 were the fast versions of the Tosa preliminaries or more like fully armoured battlecruisers (like how the RN described HMS Vanguard! ) A-123 was a return to the acceptable size of the IJN shipyards and normal fleet speed of 50km/h or 27knots. Essentially A-123 was the slow version of the previous two proposals with a very similar casemated deck layout and turret arrangement.
The design had the following characteristics:
Dimensions: 213,36 (pp) x 227,08 (wl) x 229,51 (oa) x 30,48 x 9,14 meters
Displacement: 36.600tons (standard)
Armour: 229mm Belt inclined at 25 degrees, 76mm Deck, 51mm at Machinery 76mm at Magazine Slopes
Engines: 90.000shp Gihon Steam Turbines, 4 shafts
Range: 10.200km at 30km/h (5.500nm at 16knots)
Speed: 50km/h (27knots)
Armaments:
5x2 410mm/45 Type 3 / 3rd Year Type Cannons,
20x1 140mm/50 Type 3 / 3rd Year Type Guns,
4x1 76mm/40 Type 3 / 3rd Year Type AA Guns,
4x1 53cm Above Water Torpedo Tubes
Official drawing:
[URL unfurl="true"]https://iiif.dl.itc.u-tokyo.ac.jp/repo/s/hiraga/document/9c7f56e6-a80a-45bf-903c-55d5bbfaefe0#?c=0&m=0&s=0&cv=0&xywh=-1988%2C0%2C10918%2C4927[/URL]
Data table:
[URL unfurl="true"]https://iiif.dl.itc.u-tokyo.ac.jp/repo/s/hiraga/document/a8333836-8b1f-4cc3-8ef8-d7e4af4da6e0#?c=0&m=0&s=0&cv=1&xywh=-196%2C675%2C4781%2C2851[/URL]
Design A-124
[URL unfurl="true"]https://www.deviantart.com/tzoli/art/IJN-Battleship-Design-A-124-852901703[/URL]
Design A-124 uses the same hull dimensions and main armament layout as A-123 but a on a different hull shape especially aft where it is more fuller and different casemated layout for the secondary 14cm guns moving most of them one deck up to provide better firearcs and less effect from the ocean. Integrally the armour layout copies that of the Nagato with 305mm belt armour which weren't inclined contrary to A-123's 229mm and 25 degrees.
The design had the following characteristics:
Dimensions: 213,36 (pp) x 227,08 (wl) x 229,51 (oa) x 30,48 x 9,14 meters
Displacement: 37.200tons (standard)
Armour: 305mm Belt, 70mm Deck, 76mm Slopes
Engines: 91.000shp Gihon Steam Turbines, 4 shafts
Range: 10.200km at 30km/h (5.500nm at 16knots)
Speed: 50km/h (27knots)
Armaments:
5x2 410mm/45 Type 3 / 3rd Year Type Cannons,
20x1 140mm/50 Type 3 / 3rd Year Type Guns,
4x1 76mm/40 Type 3 / 3rd Year Type AA Guns,
4x1 53cm Above Water Torpedo Tubes
Official drawing:
[URL unfurl="true"]https://iiif.dl.itc.u-tokyo.ac.jp/repo/s/hiraga/document/bfa4aa40-66f4-48dd-9f4d-7f77cb41edcd#?c=0&m=0&s=0&cv=0&xywh=3543%2C954%2C1224%2C552[/URL]
Data table:
[URL unfurl="true"]https://iiif.dl.itc.u-tokyo.ac.jp/repo/s/hiraga/document/a8333836-8b1f-4cc3-8ef8-d7e4af4da6e0#?c=0&m=0&s=0&cv=3&xywh=2821%2C180%2C4261%2C2541[/URL]
Comparison table between A-124, B-61, Fuso and Hiei:
[URL unfurl="true"]https://iiif.dl.itc.u-tokyo.ac.jp/repo/s/hiraga/document/92cdfb52-21f7-4942-98e3-643167773975#?c=0&m=0&s=0&cv=0&xywh=-1118%2C-274%2C9179%2C5475[/URL]
Armour layout comparison:
[URL unfurl="true"]https://iiif.dl.itc.u-tokyo.ac.jp/repo/s/hiraga/document/7e13a22b-a72e-41c3-9a0e-77d93e1c209a#?c=0&m=0&s=0&cv=0&xywh=-1089%2C307%2C9179%2C5475[/URL]
Design A-124'
[URL unfurl="true"]https://www.deviantart.com/tzoli/art/IJN-Battleship-Design-A-124-852802391[/URL]
A-124' was a simple alteration of the previous A-124 design with the only change of 4 extra underwater torpedo tubes but consequently a 9m extra length 600tons more displacement and a mere 1.000shp more engine power to maintain the desired speed. Armour scheme remained the same, a half-all or nothing style where the belt only covers the machinery and magazine spaces but the deck armour goes all the way to the ship ends. The closely spaced twin funnel arrangement remained the same as on A-124 and no other visible serious changes made.
The design had the following characteristics:
Dimensions: 222,5 (pp) x 236,2 (wl) x 238,66 (oa) x 30,48 x 9,14 meters
Displacement: 38.800tons (standard)
Armour: 305mm Belt, 70mm Deck, 76mm Slopes
Engines: 94.000shp Gihon Steam Turbines, 4 shafts
Range: 10.200km at 30km/h (5.500nm at 16knots)
Speed: 50km/h (27knots)
Armaments:
5x2 410mm/45 Type 3 / 3rd Year Type Cannons,
20x1 140mm/50 Type 3 / 3rd Year Type Guns,
4x1 76mm/40 Type 3 / 3rd Year Type AA Guns,
4x1 53cm Underwater and 4x Above Water Torpedo Tubes
Official drawing:
[URL unfurl="true"]https://iiif.dl.itc.u-tokyo.ac.jp/repo/s/hiraga/document/c7e5c782-0647-4785-bc74-0e74ead04e43#?c=0&m=0&s=0&cv=0&xywh=2639%2C422%2C1469%2C663[/URL]
Comparison table between A-124', B-61, Fuso and Hiei:
[URL unfurl="true"]https://iiif.dl.itc.u-tokyo.ac.jp/repo/s/hiraga/document/92cdfb52-21f7-4942-98e3-643167773975#?c=0&m=0&s=0&cv=0&xywh=-1118%2C-274%2C9179%2C5475[/URL]
Armour layout comparison:
[URL unfurl="true"]https://iiif.dl.itc.u-tokyo.ac.jp/repo/s/hiraga/document/7e13a22b-a72e-41c3-9a0e-77d93e1c209a#?c=0&m=0&s=0&cv=0&xywh=-1089%2C307%2C9179%2C5475[/URL]
