Kii

Design and Construction

Upon the eve of the First World War, the Imperial Japanese government had approved the latest 1918 Naval Construction program; dubbed the “six-eight” fleet, calling for six new battleships and eight new battlecruisers. Despite the fact that this was already taxing the national budget by a third, the Navy proposed to extend the plan to “eight-eight” in order to maintain closer parity with the United States, whom declared in 1919 they would resume their 1916 Naval construction plan of 10 battleships and 6 battlecruisers. The task fell to Captain Yuzuru Hiraga, to design what would be the 4 ships of the Kii-class.

To speed up the design process, the work on the Amagi-class battlecruisers was re-purposed into this design. Conceptually, Kii-class battleships were Amagi-class battlecruisers that traded speed for more protection. This philosophy was borne out of the lessons that Japan learned from observing the Battle of Jutland. Although speed has always been a decisive factor in combat, the eponymous battle made it clear that sacrificing protection is not an intelligent decision. As such, the Kii-class was a step in amalgamating speed and armor; the conception of the fast battleship.

Therefore, the most significant aspect of Kii’s design was the choice to mount a main belt with a thickness of 293mm belt. Furthermore, it was angled out 15˚ from vertical. Not only did this allow an increase in effective thickness for lateral hits, but it also created an “immunity zone” between 12,000-20,000 meters against 16” shells. The Japanese understood 16” were quickly becoming the standard, and thought best to mitigate damage from hits received at standard engagement distances.

Regardless of the increase in protection, the designers sought not to make the new class of ships sluggish, and as such ensured that the Kii-class could attain speeds close to 30 knots. To do so, they would install no less than 19 oil-fired boilers that fed to 4-geared turbines. In total, this generated over 130,000 shaft horsepower.

The armament for the Kii-class was never fully standardized in the designs, but the most common proposal was to mount ten 410 mm/45 Type 3 guns in 5 turrets: two forward, two aft, and one amidships. Such an arrangement allowed for a broadside weight of about 10,000 kg flying at sub-800m/s. Standardized on the Nagato-class battleships, the Japanese found no error in carrying the same armament over for their latest projects. On the other hand, in a nod to the era of dreadnoughts, the Kii-class still carried its sixteen 140mm/30 Type 3 secondary armaments in casemates, which had limited traverse and manual operation. A unique addition to round out the offensive complement of the new battleships, designers opted to install eight torpedo-tube launchers on traverseable above-water mounts.

By 1921, all four ships were ordered to be constructed in pairs. The projected completion date would be late 1923, but the year 1922 would change all that. All major naval powers convened in Washington and in a few days ratified the eponymous naval treaty that would curb this foreseeable resurgence in naval competition. It stated all battleships above the displacement of 35,000 tonnes would be scrapped forthwith, and as the Kii-class was above 42,000 tonnes, the treaty spelled their termination. Progress on 'Kii and her sisters was halted prior to their keels ever being laid down, and they were officially cancelled in 1924.

Historical Inaccuracies

• Light and dark green camouflage was only applied to aircraft carriers in 1944. Even though Kii is fictionally modernized, Japanese battleships during World War II were painted in overall dark gray.
• Actual planned anti-aircraft complement was four single 120 mm guns.
• Kii’s anti-aircraft configuration is fictitious; Kii is sporting World War II era AA guns even though she was a 1920s design that was ultimately cancelled and never constructed.
• Japan only acquired 40mm Bofors guns from captured stocks in December 1941, during the Malayan Campaign.
• The Japanese version of the 40mm Bofors had a defective fuse design which limited its effective range to ~3.0 km.
• The triple mount version of the 25mm gun did not enter service until 1941.

• 

  Yuzuru Hiraga, famed Japanese naval architect and lead designer of Kii.