After knowing the reason why the outstanding cruisers in history were strong, Xu Jie had to set the technical standards for heavy cruisers according to the current needs of the Chinese Navy. Then it involves the trade-off between speed, protection and firepower.

Judging from the current tasks, as long as the cruisers of the Huaxia Navy can outrun the battleships, the speed can completely refer to the speed of about 32 knots in France and Italy. The cruiser of this speed could only run away in the face of two classes of battleships, the first was the American Iowa-class fast battleship, the most powerful battleship in history, and the other was the second most powerful Richelieu-class battleship, which could run at a speed of 32 knots, and the rest of the battleships could not run at a speed of more than 32 knots. Considering the current situation, the original and prepared battleships of various countries are not so high-speed, then 32 knots is also acceptable.

So how much output is needed to achieve this horsepower, the French Algiers ran at a speed of 31.71 knots with a displacement of 12,000 tons, with a output of 85,190 horsepower, and a sharp speed of 33.2 knots with a output of 93,230 horsepower, while the average maximum speed in one hour was 32.93 knots. The Italian Zara-class cruisers could run at 98,000 horsepower at 33.87 knots. The output of some ships of the same class has reached more than 100,000 horsepower, and the speed will fluctuate up and down on this standard, so according to this number, Xu Jie believes that the capital ship of the 15,000-ton standard row, with a displacement of 19,000 tons, the maximum output of 120,000 horsepower is enough to run at a speed of more than 32 knots. After all, the German-American German-American cruiser with a displacement of 20,000 tons can run at a speed of 32.66 knots with an output of 125,000 horsepower.

So the maximum output of the new ship was set at 120,000 horsepower, and based on experience. Generally speaking, the maximum output power will be higher than the rated power, which means that the rated power is set at 110,000 horsepower, which is basically enough. Now China does not need to reach a high speed of more than 35 knots like the Japanese Navy to go up with destroyers and launch torpedoes, as long as they can throw off the battleships, then the goal will be achieved. The increase in cost due to the increase in power is a problem, but at the same time, it is more important to put pressure on the design, and it is easy to say that putting too much boiler will stretch the armor belt. But what exactly is it? Xu Jie, as a person who used to use a ruler in front of the computer desk, still has some understanding of this.

The same cruisers, the Japanese Kaohsiung-class cruisers and Tone-class cruisers had hull lengths of up to 200 meters! And the Italians' Zara-class cruisers are only 182 meters! And if you look at the length of the main armor belt coverage. Then the gap will be even more obvious, the Kaohsiung class is a typical Japanese heavy patrol model, and its armor belt length is 123 meters! (This is from Conway's analysis of the battleship, not the author's own comparison.) And the length of the armor belt of the Italian Zara-class heavy cruisers was about half the length of the hull. That's 90 meters! (This is the author's comparison of looking at the picture-!) That is. The length of the armor belt of the Zara class is nearly 30 meters shorter than that of the Kaohsiung class! Of course, there is one less turret in the Zara class. However, it can also be seen from this that the length of the armor box is guided by the power gap. THIS IS WHY THE ZARA CLASS CAN ACHIEVE FULL 150MM ARMOR COVERAGE, WHILE THE JAPANESE CRUISERS CAN ONLY COVER THE AMMUNITION DEPOT WITH 140MM INCLINED ARMOR.

Then there is the issue of defense standards, historically the Japanese chose defense standards for ammunition depots to defend against 8-inch guns, and power compartments to defend against 6-inch guns. This choice is still relatively rational. IN THIS PLANE, THE LIGHT CRUISER HAS A FIRE CAP OF 175MM GUNS, WHILE THE HEAVY CRUISER HAS A FIRE CAP OF 10-INCH GUNS, ALTHOUGH THE TONNAGE HAS INCREASED. But the defense is even more difficult, and God knows how strong the 10-inch cannon of this plane will be! Therefore, Xu Jie thinks that if you want to defend against a 10-inch cannon at a normal combat distance. At least 9 inches of inclined armor are required. This basis of defense was inferred from the defense standards of historical Dunkirk-type battlecruisers.

In history, when the German pocket battleship Deutschland appeared, it once attracted the attention of the world, and this kind of guy with a long range and a battleship that could beat a battleship and a cruiser became the sharpest weapon of the German Navy for a time. Its 11-inch guns were fully capable of penetrating the armor of all cruisers. According to the assumption of the German Navy, as long as the pocket battleships could avoid the three battle cruisers of the British at sea, then there was no need to be afraid of other opponents. As a feud with Germany, the French dealt with this kind of fast attack ship, specially designed a small fast battleship, which is the famous Dunkirk-class battleship in later generations, of which the Dunkirk in order to deal with Germany's 11-inch guns, specially arranged 250MM inclined armor, so according to Xu Jie's estimate, on the basis of the gun is one inch smaller, the armor belt is also appropriately shrunk and reduced by about an inch, it should be able to prevent 10-inch L50 level firepower. IF YOU USE A QUILT CAP DESIGN, YOU CAN MAKE THE 230MM ARMOR PLATE INTO TWO LAYERS OF 40MM AND 190MM, AND EVEN REDUCE THE THICKNESS OF THE ARMOR EVEN FURTHER.

ACCORDING TO XU JIE'S PLAN, IF HE CAN, THEN THE THICKNESS OF THE ENTIRE ARMOR BELT SHOULD BE WEAKENED TO 210MM AS MUCH AS POSSIBLE, OF WHICH THE THICKNESS OF THE OUTER ARMOR PLATE USED FOR REMOVING THE QUILT IS 30MM, AND THE THICKNESS OF THE MAIN ARMOR IS 180MM. Strive to cover the entire armor belt, as for whether it can be specific or not, it depends on the design. Xu Jie decided to use a single layer of large-thickness armor to resist the horizontal attack of 10-inch shells, but also to resist the dive attack of 1000-pound armor-piercing shells at a certain angle. SO THE HORIZONTAL ARMOR THICKNESS SHOULD BE AT LEAST ABOUT 110MM. THE MAIN TURRET DEFENSE DEPENDS ON THE SITUATION, AND IT IS BEST TO HAVE A FRONTAL AREA OF 250MM. As for underwater protection? Its lightning protection depth should not be less than 3.5 meters. AND THE THICKNESS OF THE ANTI-MINE ARMOR CANNOT BE LESS THAN 50MM.

Overall, this defense standard is somewhat difficult to achieve for a standard 15,000-ton warship, but considering that everyone may slightly exceed some tonnage in practice, then it is understandable that Huaxia is surpassed. IF IT REALLY DOESN'T WORK, MAKE SOME FUSS ABOUT THE SECONDARY ARTILLERY NOW, INSTALL TWO LESS SECONDARY GUNS IN PEACETIME, AND THEN INSTALL THEM WHEN THE TREATY ENDS OR WHEN THE WAR IS FOUGHT, ACCORDING TO XU JIE'S LAYOUT, THE SECONDARY ARTILLERY MUST HAVE AT LEAST 12 100MM GUNS, DIVIDED INTO 6 TURRETS. AS FOR THE 20MM GUNS AND 40MM GUNS? It depends. Anyway, based on historical experience, it is relatively easy to add these weapons.

Then there is the layout of fire, and how the artillery is arranged is directly related to the length of the armor belt. Like the 5-turret layout and 4-turret layout of historical cruisers (which are divided into two types, one is 4 twin main guns, and the other is 2 3-gun and 2 twin. Xu Jie doesn't like it, Xu Jie still prefers 3 3 guns with 3 units. And there is another bold idea to go directly to two 4-pack 10-inch gun turrets! If you look at it from the point of view of saving the length of the armor belt, the latter is undoubtedly the most advantageous in the case of guaranteeing the distance between the two turrets.

But let's not talk about the technical difficulty of the 4-pack turret, even if the turret can be built, the stability will be passed. The hull width itself is also a challenge, with cruisers historically mostly between 18 and 21 meters wide. Even if the tonnage on this plane is enlarged, the increase in width will not be too large, after all, this is limited by the size of the cruiser. And even if it can be installed, the depth of the underwater defense system in the lower part of the turret will be relatively weak, because the bloated ammunition depot will be relatively large, the solution of the French is to increase the thickness of the underwater anti-mine armor, if Huaxia wants to design it this way, it can only be solved in the same way, but this has another advantage, that is, two twin 100MM level anti-aircraft guns can be arranged along the central axis at the stern and bow, so that the unilateral anti-aircraft fire of the battleship becomes 8.

In short, the choice of firepower layout of the heavy cruisers of the Huaxia Navy will ultimately choose one of these two ways. And light cruisers generally choose a 3-seat 3-group layout. After finalizing the defense, speed and artillery, there were two remaining issues to be solved, one was whether torpedoes were still needed, and the other was the question of carrier-based aircraft. For torpedoes? Xu Jie meant that the light cruiser could consider loading a few rounds. After all, the 175MM gun is worse than the 8-inch gun in terms of effective range and power, and the oxygen torpedo that the Japanese Navy once had in history is known for its ultra-high speed, ultra-long range and super attack power, although the effective range cannot reach the theoretical number, but it is still good within 8KM, and if you are lucky, you can hit a target 10KM away. So as a supplement to the artillery, a few rounds can be appropriately arranged.

Of course, the arrangement of carrier-based aircraft is as much as possible, Xu Jie has not thought about the plan of the aviation cruiser, but considering that once the treaty period is over, if there is a war, Huaxia will definitely put the construction of aircraft carriers in the first place, and there will be no shortage of aviation power at that time. And the construction of gunboats will definitely be postponed, and perhaps even the importance is still after the destroyers, after all, destroyers are still the main force of air defense and anti-submarine and are in great demand. In addition, the construction period of heavy cruisers is relatively long, so in order to ensure the number of artillery in the fleet, Xu Jie does not plan to build aviation cruisers. It was also not intended to use conventional aircraft on heavy cruisers.

However, Xu Jie still has to deploy some seaplanes on the cruiser, according to historical experience, if all the turret front-facing methods, even the historical treaty cruisers can be equipped with 8 seaplanes, if the Huaxia heavy cruiser adopts the method of 2 4-mounted main guns in front or 3-seat 3-mounted main guns in front, then the carrier capacity will definitely be no problem to reach 10. As for more, it depends. The main role of these seaplanes is to conduct reconnaissance, reconnaissance, and anti-submarine operations. According to Xu Jie's plan, Huaxia will first start construction of 2 heavy cruisers to test the water, and if successful, start construction of another 4 ships. These cruisers were to be commissioned by 1928, which would have taken up one-half of China's heavy cruiser tonnage under the treaty. How the remaining 6 heavy cruisers will be built will depend on the situation. And work on the light cruiser will also begin.

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