After the opening of the Military Academy, Li Zhi felt that the effect was very good. Pen × fun × Pavilion www. ｂｉｑｕｇｅ。 infoIn particular, the teaching of naval tactics benefited the officers a lot, and it can be said that it was an emergency charge before the decisive battle with Zheng Zhilong.

The distance between the combat ships at sea is very large, and sometimes the battleships are more than ten miles away from the flagship, and the flag on the flagship is not visible at all. In such a situation, how to fight often depends on the personal command ability of the captains.

Li Zhi's navy was established only a few years ago and did not fight a major battle. The captains had no idea at all about how to set up a formation, how to exert firepower, how to make a detour and how to break through. Even Lu Hu, the captain of the naval fleet, only commanded by feeling, and did not know the experience and lessons of his predecessors.

But the Spanish and Portuguese instructors were familiar with the naval battles of the last decade or so. Although there were no major naval battles in the Armageddon style in this decade, there was constant naval friction between European countries. In particular, the Dutch, who were in full swing, constantly attacked and plundered the merchant ships of other countries at sea.

This information on naval warfare is a valuable experience and lesson, and the navies of various European countries have vigorously collected and organized officers to study it. Therefore, several foreign instructors are well acquainted with naval warfare in this era. Whether it was English pirates in the Caribbean plundering French merchant ships, or Dutch warships at the Cape of Good Hope challenging Spain's Galen fleet, these officers were all at home.

Why did the English always have the upper hand, and why did the Portuguese like to use breech guns? If you don't listen to these instructors, it's hard to figure it out on your own.

The officers of the navy, especially the dozens of captains promoted by Li Zhi's line of fire, were very fascinated by what they heard, and they even pulled a few foreign instructors to ask questions every time after class.

Li Zhi felt that these foreign instructors were equivalent to an encyclopedia of European war history, and they were worth the money. The war in Europe has entered the era of thermal weapons with one foot, and although it is inferior to Li Zhi's troops in terms of equipment, it has a great inspiration for the officers under Li Zhi's command to command operations. Li Zhi gave bonuses to the instructors, and sometimes communicated with these instructors to discuss the advantages and disadvantages of skirmisher tactics and line tactics, and the key to gaining the initiative on the T-shaped front.

However, Li Zhi often knew more tactics than the Western generations at this time, and often stunned several officers as soon as he said it.

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On March 28, the sixteenth year of Chongzhen, Li Zhi's ten ironclad ships were all built and anchored in Dagu Port.

Because it was made by different shipbuilders in Tianjin, Shandong, Nanzhili and other places, the craftsmanship of each shipbuilding site is somewhat different, and the appearance of these ten ironclad ships is not the same. The eight ironclad ships built in Tianjin and Shandong were all pointed, while the two built by the Nanzhili shipwrights were flat-headed, with higher stern towers.

Of course, this difference does not affect the use. The ten ships were twelve zhang long and two zhang and one foot wide. Each ship was loaded with thirty-two eighteen-pounder guns, and it was a great ship in the age of wooden sailing ships.

Li Zhi estimated it and felt that the full load displacement of these ironclad ships was about 500 tons. In fact, after these ten ironclad ships were loaded with iron armor and cannons, and then loaded with hundreds of sailors, fresh water, and supplies, they were basically fully loaded. These ironclads could only be used as pure warships, and could not be used as merchant ships even in peacetime.

The hulls of the ten ships were covered with an inch-thick iron plate, which was almost brand new at this time, and the outside was painted with gray tree paint according to Li Zhi's request, which looked completely like a nineteenth-century warship.

The ironclad ship was equipped with two large steam engines, and could sail at a speed of nine knots at full power, which was faster than the sail warships of this era, and even faster than the sailing ships of the tailwind.

The appearance of such a strange warship at the end of the Ming Dynasty certainly aroused great interest among the people. Every day, the wharf of Dagu Port is full of people, and everyone comes to see the dense cannons on the ironclad ship, and the ironclad ship does not need to paddle to enter the port. Fortunately, Li Zhi insisted on practicing firing ten miles offshore, otherwise there would be more people who came to see the excitement.

Ironclad ships have the problem of rust prevention, and the iron plate will rust when exposed to water for a long time. If he wants to completely solve this problem, Li Zhi will probably need to engage in research for several years. It is unrealistic to solve it completely, but Li Zhi has a way to alleviate the problem:

The first thing Li Zhi did was to paint a layer of tree paint on the iron armor. China is the origin of tree lacquer, and Li Zhi can buy this cheap commodity in large quantities in Tianjin. In fact, tree paint has a considerable anti-rust ability, and if it is applied once every six months, although it cannot completely eliminate the rust of iron armor, it can also greatly slow down the speed of rust.

Li Zhi also used zinc rods to alleviate the rate of rusting of iron armor. Li Zhi fixed a large number of zinc rods to the lower edge of the armor, so that zinc, iron, and seawater constituted the galvanic battery. Since zinc is more reactive than iron, it preferentially loses electrons as the negative electrode of the power supply to be corroded. The continuous corrosion of zinc protects the iron, which is the cathodic protection method of sacrificial anode.

Until modern times, there were quite a few boats that used zinc rods to protect their steel hulls.

The craftsmen of the Ming Dynasty have produced a large amount of metal zinc, which is recorded in the "Tiangong Kaiwu": the craftsmen put zinc oxide ore and pulverized coal into a specific reaction tank to form gaseous zinc at high temperatures. The zinc vapor rises to the condensation zone through the air permeability of the condensation nest, cools and condenses into liquid zinc, and drops into the groove of the condensation nest. After cooling, people break the reaction tank and remove the zinc block. After that, the craftsmen will put it on the stove for purification, and the purity of the zinc block can reach 90%.

Tianjin is a place where merchants gather, and Li Zhi and the merchants ordered and easily bought a large number of zinc rods. There is no armor below the waterline of the ironclad ship, Li Zhi only needs to wrap a row of zinc rods on the ironclad near the waterline, and the cost is acceptable.

Of course, both of these methods can only alleviate the corrosion of iron armor. Li Zhi saw the paper data in later generations and knew that the average annual corrosion rate of steel in seawater was about one millimeter. With the help of Li Zhi's various means, the rate of corrosion can be greatly reduced, perhaps only half a millimeter.

After the corrosion rate is reduced, the armor corrosion of the ironclad ship is not a big problem, because Li Zhi's ironclad ship itself does not need perfect anti-corrosion means. Li Zhi's 5,000-material ship was made of practical wood, not perfect wood, and the ship actually only had a lifespan of seven or eight years. After being treated by anti-corrosion means, the 33 mm thick iron armor corrodes half a millimeter or less every year without much of a problem, and the rust can be removed during half a year of maintenance.

In the 19th century, the French were troubled by the lack of anti-rust paint, and even wrapped the iron hulls of ironclad ships with wood and copper skin, because their ships wanted to be used for decades. If they were like Li Zhi and a ship that lasts seven or eight years and can endure annual attrition, they don't need to use such a complicated solution.

In February, Zheng Zhilong sent another letter.

Zheng Zhilong did not take Li Zhi, who only had a few dozen boats, in his eyes, and the words in the letter were even more naked, asking Li Zhi to give him eighty percent of the land rent income in Hsinchu. And what the Zheng family can repay is the "protection" given to Li Zhi's caravan in the East China Sea.