Tianjin Water Master School, Xu Jie's residence. After nearly two weeks of initial contact, Xu Jie had a general understanding of his students, as the most modern education received in the Qing Dynasty at that time. Xu Jie is still quite satisfied with their Su zhì. Although these students are more or less conservative and flawed due to the limitations of the times, Xu Jie still has high expectations for them. And these intellectuals, as China's most recent modernization, are also full of respect for this expert who returned from abroad, with Xu Jie's accumulation of technical and historical knowledge. It is also the best in the entire Tianjin Water Master School. Plus Xu Jie is approachable. Therefore, the students are also willing to interact with this newcomer after class. No, on the first month off after Xu Jie's arrival, Zhang Yun and his party of 4 people came to visit. And the issue they came to discuss was, naturally, a topic between the Beiyang Naval Division and a potential enemy.

"Teacher, I have benefited a lot from reading your "Japanese Navy Overview" today, and if I continue like this, I will lose to the Japanese fleet in Beiyang in a few years. In addition to purchasing new ships, can Beiyang improve its existing warships to increase its combat effectiveness? After everyone sat down, Zhang Yun said first.

"Tell me about it." Xu Jie encouraged.

"Teacher, please see, my Beiyang Jiyuan, Zhiyuan, and Jingyuan 3 ships actually have the foundation of a new type of fast dome cruiser, fast, emphasizing side-chord firepower, and can install rapid-fire guns. (In the design of Zhiyuan in history, it was planned to place 2 earrings on each side of the side chord to place the artillery, but the funds were not enough, so only a 6-inch gun could be placed on the left and right) For example, the ship can be equipped with 6 6-inch guns on the side chord, or replace all the side chords with 4.7-inch Armstrong rapid-fire guns, and then match the 3 8.2-inch guns at the beginning and end, the side chord firepower is quite considerable.

"And our three armored cruisers in the Beiyang can also carry out similar transformations if they go far and come far away. A total of 6 earrings were placed on the side chords to place 6-inch rapid-fire guns. And because the tonnage of Longwei is too small, you can consider adding an additional rapid-fire gun on each side of the side chord. In this way, the artillery power of our Beiyang 6 Yuan has increased by more than 1 times compared with the original after adding artillery and replacing rapid-fire guns in Tongguò. A Fujian student named Ye Ming continued.

"What are the improvement plans for the Dingzhen No. 2 ship, which is the core of my Beiyang combat power?" Xu Jie does not comment on the students' opinions, but only listens.

"These two ships are the foundation of my Beiyang. The difficulty of improvement is the greatest. Because the construction time was too early, the Dingzhen 2 ships are the products of the standard bow against the enemy, and the 4 powerful 12-inch guns are its main attack power, if you refer to the sidestring of the other 6 capital ships, then the firepower of the 2 main guns will be lost anyway. Therefore, the rash use of the side-chord against the enemy's thinking is somewhat worth the loss. A tall and thin official student named Li Xuan whispered.

"Your ideas are good, although there are still some unsound. But the general idea is still correct. "Now let me ask you a few questions." Xu Jie looked at the four people and said.

"First, can the Zhiyuan ship accommodate a total of 6 6-inch guns on the lower side chord?" Xu Jie asked. Xu Jie clearly remembers that Zhiyuan's parent type, the Chilean Navy's Esmeralda protective cruiser (later renamed Izumi after Japan purchased it), has a standard displacement of 2,900 tons and a length of 82 meters. Its main firepower is one 10-inch naval gun at the bow and one at the end. The side chord is a total of 6 6-inch guns, and the power system is similar to that of Zhiyuan. But the armor protection was much inferior to Zhiyuan, the armor slope was 1 inch and the horizontal plane was 0.5 inches. The inclined plane of Zhiyuan's dome armor is 4 inches. In other words, compared with Zhiyuan, the Hequan left the weight of the armor protection as much as possible for the weapon. In this case, the tonnage of Hequan also reached 2,900 tons, more than 600 tons of Zhiyuan. Although there are certainly reasons for the low tonnage utilization rate due to the early construction, from the comparison of the two, it is still quite difficult for Zhiyuan to equip 3 6-inch fast guns on each side of the side chord if it wants to keep other performance basically unchanged (such as speed, stability).

"Second, if the three armored cruisers in the Beiyang are to be equipped with so many rapid-fire guns, it is a question whether they can be installed, and how to balance the impact of the stability and speed of the battleship after installation? Xu Jie continued to ask. The performance of a battleship is more than just a superposition of numbers on a straight face. The stability of the battleship and some seemingly unimportant numbers directly affect the combat power of the battleship. For example, the Agile class 2 battleship built by the British for Chile (later Chile did not ask for it, the British asked for it themselves), at a tonnage of less than 12,000, the British installed 4 10-inch guns, 14 7.5-inch guns, the main armor belt is 7-inch Harvey armor, and the speed is as high as 19 knots. But for a naval expert, the combat power of this warship simply cannot be used on paper. First of all, because the battleship is equipped with too many weapons, in order to maintain the stability of the battleship, the gun position is too low, and in the case of high-speed navigation or slightly worse sea conditions, the gun is likely to be unusable due to water ingress from the gun. (The German battleship Scharnhorst during World War 2 had this problem, because it was overweight, so the guns were sometimes unusable due to water ingress.) Of course, this has something to do with high sea conditions) Secondly, the seemingly beautiful 7-inch armor belt actually does not play its due role, because the height of its armor belt is not enough, and the height of the 7-inch main suit is only 8 feet (it is also recorded as 7 feet, what does this mean?). This means that the protection range of the main equipment is not enough, and it is even possible to put the entire main equipment into the water in the case of high sea conditions. (The battleships and battle cruisers of the British 1 wartime 343 guns also had this problem, and the height of the main armament was too low, which made the whole defense useless.) This is even more true of the 3 so-called armored cruisers of the North Ocean. The height of the main outfit seems to be only 5 feet. It doesn't work at all. …,

Looking at the silent students, Xu Jie softened his tone and said, "War is not child's play, it needs to be carefully calculated and designed. It's not something that can be decided by patting your head at all. Even if you can't get an accurate number jù due to horizontal limitations, then you need to do a good job of horizontal comparison. Conclusions can only be drawn after comparing them with ships of the same type, or ships of the same period. ”

"Teacher, since it is impossible to achieve the desired effect by increasing armament alone, why don't we improve the battleship in terms of power, armament and protection?" Sheng Huaixuan, a student from Zhili who had not spoken, asked.

"There are a few questions to be asked about. First, the problem of adding more water to the surface and adding more water to the surface. You want to increase the firepower and protection, in order to maintain the speed, you definitely have to increase the power, and increasing the power will definitely increase the weight. And after adding weight, you have to increase power in order to maintain speed, so you fall into an endless loop. Second, there is the issue of cost. If a warship rebuilds its equipment and compartment structure, the cost is often no less than that of a new warship. But the combat effectiveness is not as good as the newly built battleship, which loses the meaning of improvement. Xu Jie explained carefully. There are many examples in history, such as the Italians' improved Gavre, don't look at the Italians who expanded and bored the guns and increased the power, but its combat power was still inferior to the newly built Strasbourg-class battlecruisers of the French. The same is true of Kongo in Japan. After changing it, it is still inferior to Strasbourg, and Nagato has increased the weight of tens of thousands of tons in the process of improvement, but it is still inferior to the new European 3 Musketeers (who are the Three Musketeers?). Richelieu, Veneto and Bismarck)

"What is your opinion, teacher? If this town is to be improved, how will the teacher plan? Sheng Huaixuan asked respectfully.

"This fixed town is as you say, and the design concept of its bow against the enemy makes it impossible for these two warships to be improved into flank-fighting warships with direct cannon like the other six warships." Xu Jie said with a slight flush. There is nothing good to do about these two baby bumps in Beiyang, Xu Jie. ACCORDING TO HISTORICAL RECORDS, BEFORE THE WAR, BEIYANG PLANNED TO INSTALL 6 120MM RAPID-FIRE GUNS FOR EACH DINGZHEN. However, it was abandoned because of the silver problem, that is, in terms of tonnage, it was no problem for Dingzhen to be equipped with 6 rapid-fire guns. But after the artillery is installed, the battleship still has to bow to the enemy, why? The 12-inch gun can't be ignored. Moreover, its powerful combat power was also fully demonstrated in the naval battle of the Yellow Sea. IF YOU WANT TO CONTINUE TO INCREASE THE BOW FIREPOWER, IT IS ALMOST IMPOSSIBLE, AND THE FRONTAL 4 12-INCH GUNS AND 150MM KRUPP GUNS HAVE ALREADY FILLED UP THE FRONTAL SPACE, AND BASICALLY CANNOT BE ADDED. Therefore, Xu Jie's improvement idea for Dingzhen is to appropriately strengthen the side-chord firepower and replace and renovate the power system.

"First of all, we can make good use of the space originally used for torpedo boats in Dingzhen, redesign the cabins, and place one single 6-inch gun and one twin 6-inch gun in the direction of the ship's central axis, and of course, the 150 Krupp guns in the bow and stern will also need to be replaced with rapid-fire guns. This firepower aspect is enough. Secondly, the repair of the boilers and pipes of the battleship. This town has been in service for 5 years, if another 5 years, the aging of the power system will be very obvious, in order not to drag down the entire fleet because of the low speed, the repair of the power system will be a very important work. Xu Jie said. In addition, in addition to the addition of 4.7-inch and 6-inch rapid-fire guns, we can also place 3-pounder guns, or 6-pounder guns. Even a 9-pounder gun. Most of the Japanese warships were dome-armored cruisers, and the protection was not good, and the blow to the Japanese warships by strafing the deck with small-caliber rapid-fire guns was also very huge. Finally, Xu Jie added.

(Here, the author doesn't understand very well, there are a lot of conclusions drawn after comparing the number of warships of various types, there may be various problems, everyone bear with me)