After the signing of the Washington Treaty, appeared so uncomfortable and unwelcome for all parties involved, except that of the United States, the Japanese decided to close the infringement in the linear ships, number and tonnage of which was strictly determined by a ratio of 5:5:3 in favor of the United States and England, at the expense of cruisers. “Minimum” fleet’s new policy, developed in 1923, included no less than forty cruisers of the maximum allowed size — 10 thousand tons! They had to form 10 divisions of four ships and become, essentially, the backbone of a fleet. It is clear that such a full swing in its implementation would cost a huge amount, hardly inferior to the cost of those superliners, the construction of which had to be abandoned in accordance with the agreement.
However, to work on the project began almost immediately after signing the “Washington bondage” at the beginning of 1922. As in the case of shestidesiatniki “half Ling”, the subsequent characters of the epic was the same Uzura Hiraga and his assistant, and later successor Kikuo Fujimoto. I must say that in your case Hiraga manifested in the guise of a samurai, honing your sword to unimaginable sharpness. The chief designer of the fleet steadily and purposefully sought to improve the fighting quality. Although the initial requirements of the Naval staff included new cruisers, eight 203-mm guns in two-gun towers (three of which were grouped the already familiar “pyramid” in the nose and one was located in the rear), the designer suggested to add one more, the fifth tower. One and a half times increased and artillery units instead of four 120-mm guns was supposed to have six. Hiraga really wanted to have his “product” was the strongest among the “contract workers”. He wanted to provide his “iron warrior” is not only a long sword and a reliable shield. So on the heavy cruisers were a real underwater defense, with a solid armored torpedo bulkhead that for 1920-ies, no doubt, was the most advanced innovation. Of course, for all these truly pioneering solution had something to pay. Hiraga stopped at a somewhat reduced cruising range, that has not caused special objections, as in a truncated version of the cruiser could accompany the fleet. Much more controversy was another, quite conscious step: a complete rejection of torpedo. The chief designer of the Japanese Navy believed that many torpedoes on the big ship are a great danger to themselves than to the enemy, which they still have at least to release (not saying to get). But here again intervened Fujimoto, who succeeded his boss. Being human is more flexible, he listened to the urgent requirements of Naval staff, which believed that a future war will be largely “torpedo” and that this type of weapon in every way necessary to cultivate it on heavy cruisers, now laid claim to the role of the backbone combined fleet. So in Japanese “Washingtonians” came back torpedo tubes, and quite a number of four three-pipe installation.
In the end, of course, “extreme sacrifice” was the displacement. Numerous advantages does not fit in required 10 000 t. Not helped by all the ingenious measures for reducing the weight of the body, constructed according to the same principles of the “Japanese wave”, and “Kako”. For a lot very long and rather narrow body accounted for only 30% of the displacement, but in absolute terms this corresponded to four thousand tons. Big savings made a brave step to enable the side and deck armor as a power subassembly. To this plate was just attached with bolts to the hull, not really increasing the strength of the case; now they are tightly welded with stringers and frames, seeing 100% load at compression and 70-0% of tensile. And yet the waves of the whole structure to “breathe”, the body is severely twisted, but… stand up, and we wanted to prove.
The Japanese are often accused of “Eastern intrigue”, believing that all the violations of the treaties they went deliberately. Actually it is not so. Of course, some the release of “beyond” was planned, but not so significant. Overload”, MLEKO” and its cousins, the displacement of which in tests made up of 13 300 t, was an unpleasant surprise for the designers. Decreased the freeboard and intact stability, less space remained for later upgrades, but the heroic efforts of the all the problems were resolved in a satisfactory manner.
Another consequence of overload is unwanted immersion of the armor belt that had a “notched” shape: wide in the middle part to close the high engine and boiler compartments, and narrower in the area of the cellar, towards the extremities. In the end, at normal load, the cellars above the waves rose only 30 cm of armor, and with full fuel belt in these areas completely disappeared under the water. However, this did not reduce the protective properties of the shells was kept even lower, and armor box created a kind of air cushion that holds the ship afloat even in case of partial destruction of the Board above it.