Steve Backer - Shipcraft 5 - Japanese Heavy Cruisers, Myoko and Takao classes

The Nachi was the first of the class to complete and the only one to appear as shown in this photograph taken in December 1928. The 4.7in (120mm) guns to the right are hand-operated without gun shields and there is no extension of the shelter deck from the superstructure to deck edge. Nachi received power-operated secondary guns with gun shields and shelter deck extension within months of this photograph. The other three class members were completed with these modifications. Also note the significant overhang of the bridge platform at the rear of the superstructure tower.

At the end of the First World War there were basically two types of cruisers, the old armoured cruiser and the scout/fleet cruiser. The armoured cruiser was an obsolete design, effectively superseded by the battlecruiser. The scout/fleet cruiser design was a much smaller and lighter gunned vessel designed to act in conjunction with the battle fleet to scout for the presence of the enemy. However, the Royal Navy also had a desperate need for a cruiser designed to protect her worldwide trade routes, since fleet cruisers built during the war were designed specifically to operate with the Grand Fleet in the North Sea, so their range was far too short for effective cruising on the very long British trade routes. Neither the United States nor Japan faced the need for a trade protection cruiser. In 1920 most of the newer cruiser construction among the navies of the world was generally similar. Each navy had small to mid-size cruisers with little or no armour. Main armament calibres had evolved from 4in to 6in but most designs still had a significant percentage of their guns placed in wing positions and had broadsides far less than the total number of guns would suggest.

One exception to this standard was a late-war British design. The Hawkins class or the Elizabethans were a class of cruisers significantly stronger than the typical fleet cruiser. Armed with 7.5in guns and close to 10,000 tons displacement, the existence of ships of this design was a major reason Great Britain agreed to the 8in gun and 10,000-ton limitation on new cruiser construction. The USN had also looked into the possibility of producing cruisers of similar design but armed with 8in guns and so was also in favour of these arbitrary design constraints. Japan had no fleet cruisers remotely approaching this limit and so she too agreed to these individual ship limitations. All new cruiser designs were initially typed as light cruisers, as opposed to the obsolete armoured cruisers, regardless of whether they mounted 4in, 6in or 8in guns. Cruisers armed with 8in guns were not classified as heavy cruisers until the London Treaty of 1930 subdivided the cruiser category into light and heavy categories based not on displacement but on gun size. All cruisers of 6.1in and smaller armament were called light cruisers and those armed with 8in to 6.1in guns were classified as heavy cruisers.

The bow of Myoko in 1933 clearly shows her sheer and flare. The ship is as completed with 7.9in (200mm) main guns, which were not replaced by 8in (203mm) guns until the Second Modernisation in 1939.