FLUFF: HECTOR BYWATER PART III: HOW DOES THE AU USN STACK UP VERSUS RTL?
This is a bit of fluff to explore the way technically things look before we get back to the Pacific War. As is the case in technical analysis, one likes to have a benchmark, or set of benchmarks.
In this case, the IJN and the IJA provides good ones.
Aircraft carrier: being typical is the KIJMS Akag
Class and type: Akagi class (In this AU, the Amagi, survives the earthquake and is also constructed to the same profile.)
Type: Aircraft carrier
Displacement: 36,500 long tons (37,100 t) (standard); 41,300 long tons (42,000 t) (deep load)
Length: 260.67 m (855 ft 3 in)
Beam: 31.32 m (102 ft 9 in)
Draught: 8.71 m (28 ft 7 in)
Installed power: 133,000 shp (99,000 kW); 19 Kampon water-tube boilers
Propulsion: 4 shafts; 4 Kampon geared steam turbines
Speed: 31.5 knots (58.3 km/h; 36.2 mph)
Range: 10,000 nmi (19,000 km; 12,000 mi) at 16 knots (30 km/h; 18 mph)
Armament: 6 × single 20 cm (7.9 in) guns, 6 × twin AA 12 cm (4.7 in) AA guns
4 × 8 barrel 4 cm (1.6 inch )”Yokusuka Organ” 2 pounder AAA guns
Armor: Belt: 152 mm (6.0 in)
Deck: 79 mm (3.1 in)
66 (+25 disassembled as reserve in the hanger).
1 In the AU, the Japanese do not have access to the their version of the gas operated Hotchkiss or the French director that comes with it., so they are left with the Vickers 2 pounder Pom Pom as their AAA medium range weapon. This gun in the multiple barrel mounts comes with the Japanese version of the repeater pointer Mark III directors the British use. This limits the Yokusuka Organs to L/A barrage fire.
2. The air group in 1931 is as follows. 22 fighters, 32 torpedo/level bombers and 12 scouts, artillery spotter aircraft.
Types available from Japanese production
Nakajima A1N (Fighter, Gloster Gandet)
Nakajima A2N (Fighter, Boeing P-100)
Mitsubishi B2M (Torpedo/level bomber, indigenous design.)
Mitsubishi 1MR (Scout plane of indigenous design).
It should be noted that except for the Boeing P-69 and P-100, bought from a third party (Argentina) and Nakajima reverse engineered with a British engine (the P-100 is the F4B in USN service), many of these aircraft are derived from the work of British expatriate; Herbert Smith; who comes from the Sopwith Aircraft Company of Sopwith Camel fame. Mitsubishi, when they need an aircraft expert to compete with Nakajima , hire HIM. If the US had known what he is doing from 1920-1924 with Mitsubishi and what Smith’s Japanese students will do with what he teaches them, the Americans would have killed him before he ever set sail for Japan.
The AU Lexingtons which are typical:
General characteristics (as built)
Type: Aircraft carrier
Displacement: 36,000 long tons (37,000 t) (standard); 43,055 long tons (43,746 t) (deep load)
Length: 885 10 inches ft (270. m)
Beam: 108 ft 4 inches (33 m)
Draft: 30 ft 5 in (9.3 m) (deep load)
Installed power: 180,000 shp (130,000 kW), 12 diesel electric complexes, 15,000 hp (10,833 kW) each
Propulsion: 4 shafts, 4 sets of electric transmission final drives
Speed: 33.25 knots (61.58 km/h; 38.26 mph)
Range: 10,000 nmi (19,000 km; 12,000 mi) at 10 knots (19 km/h; 12 mph)
2,000 (including aviation personnel) in 1931
Armament: 4 × 2 twin 3.9-inch (10 cm) DP guns AAA/ASh
16 × 4 barrel (3 cm) anti-aircraft guns
Armor: Belt: 5–7 in (127–178 mm)
Deck: 2 in (5 cm)
Gun turrets: 0.75 in (2 cm)
Bulkheads: 5–7 in (12.5–18 cm)
Aircraft carried: 64-78 in air-group with 32 spares in hanger^1 and ^2
Aviation facilities: 2 catapults, (drum cable accelerators, limited to 4,000 kgs at 45 m/s)^3
^1 Going into the Great Pacific War, the USN opens up with this lineup.
Boeing F2B biplane fighter
Boeing F3B biplane fighter
Boeing F4B biplane fighter, best of the American fighters available.
Curtiss F6C obsolescent biplane fighter
Curtiss F7C obsolescent biplane scout/fighter
Curtiss F8C current biplane scout/fighter
Martin BM scout/dive bomber
Consolidated BY-1 level bomber
Great Lakes GF, reconnaissance/utility seaplane
Vought O2U scout/fighter, famous for “killing” King Kong.
^2 The Japanese will find that they are handicapped by the Armstrong Siddley Jaguar engine. In a rare mistake for the Japanese, this piece of absolutely dreadful engineering is licensed and built by Mitsubishi to power some of their aircraft. On the American side of the ledger, the Boeing F4B in their fighter line historically and in this AU is outclassed by the Nakajima A1N in both climb and turn. As goes the Boeing F4B, so goes the lineup type for type. As in the RTL 1941 Japanese torpedo planes are better than American ones, while dive bombers are the American advantage in this AU. Oddly enough; the Americans have an edge in shipborn reconnaissance in aircraft as well as doctrine.
Comparing the aircraft carriers to each other, in the AU, the Japanese are slower, have better turning circles, better flight deck armor, worse torpedo protection, and smaller hangers, more fly-off decks and generally better attack and fighter aircraft. In 1931 however, the Americans have working bow catapults (2 of them on Lexington to Akagi’s 0. ) which allow for a strike package of 40 + aircraft off in 30 minutes. The Americans also have better scout planes and more of them. Neither navy has entirely abandoned the British battle model of tacking the aircraft carrier to the battle line as a tail-end Charlie, though both navies have concluded that the aircraft carrier needs to detach and flee to the rear while the battleships slug it out. As a general evaluation in 1931, either RTL or AU, these carriers are too close to each other to say, it will be up to technology. The better ships purely depend on the better trained crews. Edge in the beginning goes to Japan in that regard. More time at sea + more intensive and brutal mission oriented peace-time training makes the “war” trained surface ship Japanese sailor about 20% more efficient than his peacetime American counterpart. Now after the shooting starts and the Japanese navy loses many signalmen strikers, mechanics, engine room gangs, and carpenters of all types and their petty officer corps is wiped out, they are done. 120 day replacement wonders will lead to AU disasters typical of the RTL HIJMS Shinano. The IJN will never recover what damage control discipline they have once their specialists are gone. In that one critical area which is training, the USN with its huge training establishments and Atlantic fleet cadre reserves will enjoy superiority.
IN THE AIR:
Objective research shows that in the RTL 1930s, the Russians and the Chinese engage the IJA and IJN in the air and usually come out the loser in the exchange. The Russians never seem to learn, but the ROCAF pilots stuck in those Polikarpov and Ilyushin deathtraps that Stalin’s Russia supplies, became very good at the dogfight game until killed off by flying too many missions. Long before Boyd teaches the USAF about energy management, the ROCAF pilots know about ZOOM and BOOM as applied against nimble Japanese aircraft that can out-360 circle them in a turning fight. This is exactly what USN pilots are not taught, though the Boeings and the Curtisses are inadvertently set up for this kind of aerial combat approach. What the USN does have on the Japanese is WW I combat experience, it never gives up. In 1931 or 1941, the Americans fly like the French or Germans do, not the British who have dreamed up new and terribly wrong fighter formation tactics that will cost them dearly until they get back to their own Royal Flying Corps roots. The Japanese have learned the wrong British methods of 1931 and they will use them against the USN. The Americans will simply cut them to ribbons, even though the Japanese aircraft line is nimbler, faster and at this date, has more reliable aircraft. The Three Vick is a disaster.
But enough about aircraft carriers; this 1931 AU or RTL era is still arguably dominated by the battleship and surface warfare.*1 When it comes to battleships the USN will show the IJN what is what. Right?
Let us look at the 1931 Japanese standard: HIJMS Hyuga:
General characteristics of Ise class battleship
Class and type:Ise-class battleship
Displacement:38,872 long tons (39,496 t)
Length: 219.62 m (720 ft 6 in)
Beam: 33.8 m (110 ft 11 in)
Draft: 9.14 m (30 ft 0 in)
Installed power: 33,556.5 kW (45,000 shp)
Propulsion: 4 × Parsons turbines, 24 × Kansei boilers (as built), 24 × Kampon boilers (after 1935 refit),
4 × shafts
Speed: As built: 23 kn (43 km/h; 26 mph); 25 kn (46 km/h; 29 mph) when re-engined
As built: Coal: 1,000 tons (normal), 4,000 tons (maximum);Fuel Oil: 4,500 tons of fuel oil when re-engined
As built: 12 × 356 mm (14 in)/45 cal guns (twin turrets, 2 fore, 2 mid, 2 aft), 20 × 140 mm (5.5 in)/50 cal guns, 16 × 12-pounder (76 mm (3 in)) guns, 4 × 12-pounder (76 mm (3 in)) AA guns, 6 × submerged 533 mm (21 in) torpedo tubes
After refit: 12 × 356 mm (14 in)/45 cal guns; 16 × 140 mm (5.5 in)/50 cal guns; 8 × 127 mm (5.0 in)/50 cal DP guns; 4 × 8 barrel Type 96 4 cm (1.6 in Pom Pom) AAA guns
4 × 533 mm (21 in) torpedo tubes
Belt: 228.6 to 305 mm (9 to 12 in) (amidships); 76 to 127 mm (3 to 5 in) (ends)
Deck: 31.75 to 63.5 mm (1.25 to 2.50 in)
Turrets: 203 to 305 mm (8 to 12 in)
Conning Tower: 152 to 305 mm (6 to 12 in)
Aircraft carried: 3 × floatplanes
Aviation facilities: 1 × catapult, compressed air type.
It should be of note that the Japanese 14 inch (35 cm)/45 caliber gun is a British design.
Specifications: Vickers: 14 inch/L45 BLNR (Wellin interrupted screw block)
Weight: 86,000 kilograms (86 t)
Barrel length: Bore 52 ft 6 in (16.002 m) (45 calibres)
Shell:673.5 kg (1,485 lb)
Calibre: 14-inch (355.6 mm)
Elevation: -3° to +43°
Rate of fire: 2 rpm (optimistic. It was more like 45 seconds.)
Muzzle velocity: 775 m/s (2,540 ft/s)
Effective firing range: 28.7 degrees; 32,810 yards (30,000 m)
Maximum firing range: 38,770 yd (35,450 m)
The Japanese gun in 16.1 inch/L45
102,000 kilograms (224,872 lb)
Length: 18.84 meters (61 ft 10 in)
Barrel length: 18.294 meters (60 ft 0.2 in) (bore length)
Shell: Separate-loading, bagged charge
Shell weight:1,020 kilograms (2,250 lb)
Caliber:41 centimeters (16.1 in)
Breech: Welin breech block
Elevation: –2° to +35° (later after 1935 –3° to +43°)
Rate of fire: 24 seconds (More like 45 seconds)
Muzzle velocity: 780–790 meters per second (2,600–2,600 ft/s)
Effective firing range: 30,200 meters (33,000 yd)
Maximum firing range: 38,400 meters (42,000 yd)
To contrast with the Ise, let us look at an AU “Stamdard battleship”
Class and type: Maryland-class battleship
Displacement: 32,600 long tons (33,100 t)
Length: 656 ft 2 in (200 m)
Beam: 97.3 ft (29.7 m) (original), 114 ft (35 m) (rebuilt with torpedo defense added.)
Draft: 30 ft 6 in (9.30 m)
Installed power: 90,000 shp (65,000 kW), 6 diesel electric complexes, 15,000 hp (10,833 kW) each
Propulsion: 4 shafts, 4 sets of electric transmission final drives
Speed: 25 knots (46.3 km/h; 28.77 mph)
Range: 10,000 nmi (19,000 km; 12,000 mi) at 10 knots (19 km/h; 12 mph)
Complement: 1,080 officers and enlisted
Armament: 8 × 15.75 in (40 cm)/L45 guns (4 x 2)^1
12 × 7.9 in (20 cm)/L45 guns (6 x2)
16 × 3.9 in (10 cm)/L50 guns DP AAA/ASh
4 x 4 barrel Remington 3 cm/L50 AAA guns.
Belt: 8–13.5 in (20–34 cm)
Barbettes: 13 in (33 cm)
Turret face: 18 in (46 cm)
Turret sides: 9–10 in (23–25 cm)
Turret top: 5 in (13 cm)
Turret rear 9 in (23 cm)
Conning tower: 11.5 in (29 cm)
Decks: 3.5 in (8.9 cm)
Aircraft carried: 1 × floatplanes (peacetime); 4 x floatplanes (wartime)
Aviation facilities: 1 × aircraft catapults (after refit; 2 x catapults)
The notional US 15.75 inch/L45 gun…
Weight: 230,948 lb (104,756 kg) (without breech), 235,796 lb (106,955 kg) (with breech)
736 in (18.7 m)
Barrel length: 720 in (18 m) bore (35 calibers)
Shell AP Mark 3: 2,222 lb (1000 kg) armor-piercing (AP) (Mark 1 gun)
AP Mark 5: 2,240 lb (1,020 kg) AP (Mark 5 and 8 guns)
HC Marks 13 and 14: 1,900 lb (860 kg) High explosive (HC) (Mark 5 and 8 guns)
Caliber: 15.76 inches inches (~ 40 cm)
Elevation: -4° to +45°
Traverse: 300° max/280° min
Rate of fire: 1.5-2 rounds per minute
AP Mark 3: 2,700 ft/s (790 m/s)
AP Mark 5: 2,520 ft/s (770 m/s) Full Charge
HC Marks 13 and 14: 2,635 ft/s (803 m/s) Full Charge
AP Mark 5: 1,935 ft/s (590 m/s) Reduced Charge
HC Marks 13 and 14: 2,075 ft/s (632 m/s) Reduced Charge
Effective firing range before turret refit.
AP Mark 3: 22,900-yard (20,940 m) at 15° elevation
AP Mark 5: 23,000-yard (21,031 m) at 15° elevation
Effective firing range after refit
AP Mark 3: 34,300-yard (31,364 m) at 30° elevation
AP Mark 5: 35,000-yard (32,004 m) at 30° elevation
Maximum firing range
AP Mark 3: 40,600-yard (36,700 m) at 45° elevation
As can be seen, the AU US Standard Battleships are smaller, almost as fast or faster, more heavily armored and have roughly equivalent overall gun armaments to their Japanese counterparts. Their shorter and beamier hulls roll considerably in a seaway, which necessitates firing on the clock to time the salvo to coincide with the zero of a period (about 15 seconds for a roll or 7.5 seconds via roll inclinometer). The same comparisons can be drawn for most AU US cruiser classes except that the Japanese cruisers have a marked advantage in tonnage, size, and numbers of gun barrels. When it comes to torpedo armament, it is a wash. In this AU, the Japanese do not have a crushing superiority as they do in the RTL, but all that means is that with torpedo parity, both sides will suffer catastrophically in melee combats such as Savo Island. So once again it comes down to the ship’s crews, the leadership and the training. If the RTL is any guide, the US surface fleet will have a rough time of it. The IJN will have it worse, though. US ship captains seem to have fought their ships better.
Let us look at submarines:
Class and type: Kaidai-class submarine (KD5 Type)
Displacement: 1,732 tonnes (1,705 long tons) surfaced
2,367 tonnes (2,330 long tons) submerged
Length: 97.7 m (320 ft 6 in)
Beam: 8.2 m (26 ft 11 in)
Draft: 4.7 m (15 ft 5 in)
Installed power: 6,000 bhp (4,500 kW) (diesels), 1,800 hp (1,300 kW) (electric motors)
Propulsion: Diesel-electric, 2 × diesel engines, 2 × electric motors, 2 screws
Speed: 20 knots (37 km/h; 23 mph) surfaced, 8.25 knots (15.28 km/h; 9.49 mph) submerged
Range: 10,800 nmi (20,000 km; 12,400 mi) at 10 knots (19 km/h; 12 mph) surfaced, 60 nmi (110 km; 69 mi) at 3 knots (5.6 km/h; 3.5 mph) submerged
Test depth: 70 m (230 ft)
Armament: 6 × 533 mm (21 in) torpedo tubes (4 bow, 2 stern) up to 16 each 21 inch torpedoes carried
1 × 120 mm (4.7 in) deck gun, 1 × 13.2 mm (0.52 in) anti-aircraft machinegun
This would be the typical Japanese AU patrol submarine, based on the German WW I U-cruiser.
The AU US equivalent is a far different beast.
General characteristics (GUPPY fleet boat)
Class and type: Type 171-class submarine
Displacement: 1,870 tons (1,900 t) surfaced
2,440 tons (2,480 t) submerged
Length: 243 ft (74 m)
Beam: 32 ft 8 in (10.33 m)
Draft: 17 ft (5.2 m)
Propulsion: 1 × diesel engine with a snorkel, driving an electrical generator
SARGO type batteries, 504 cells (4 × 126 cell batteries)
1 × low-speed direct drive electric motor driving one ducted propeller
Speed: Surfaced: 18 knots (33 km/h) maximum; 13.5 knots (25.0 km/h) cruising
Submerged; 16 knots (30 km/h) for 4 hours on the battery, 9 knots (17 km/h) while snorting, 3.5 knots (6.5 km/h) cruising on battery typical
Range: 15,000 nautical miles (28,000 km) surfaced at 11 knots (20 km/h)
Test depth: 150 m (460 ft)
Endurance: 96 hours at 4 knots (7.4 km/h) submerged on battery
Complement: 9–10 officers, 5-10 petty officers 60-70 enlisted men
Sensors and processing systems:
Fessenden oscillator, the US version of ASDIC (called SONAR) and hydrophones
Mk 6 torpedo fire control system
4 × 21.67 inch (55 cm) torpedo tubes all forward. 20-24 torpedoes carried.
1 x 3.9 in (10 cm)/L40 Model 1910 retractable deck gun with 60 rounds
This “fleet boat” is faster, deeper diving and better equipped for infiltration and ambush attacks inside an enemy coast than its Japanese counterpart. Japan’s coastline is tailor-made for this kind of boat. And that is something to keep in mind when we turn our attention to the Philippine Islands in a bit.