The conspiracy went from brewing to launching. It always takes a certain amount of time. Although Zhao Xing is very powerful, he also does not have the ability to pinch and calculate, so he does not know that Yuan Shao, Cao Cao, Yuan Shu, Sima Yi and Liu Bei and others have joined forces to calculate themselves.

Because he couldn't be an unpredictable prophet, Zhao Xing could only resist the risk according to his own ideas, and the Qingxu army, who had been staying in the territory of the Jin Kingdom for two years, was finally going to return home.

When besieging and annexing the state that year, Qingzhou Kong Rong and Xuzhou Tao Qian were worried that the imperial court would anger them, so they each sent 10,000 county soldiers, and they were commanded by the fierce general Tai Shici in one place, and went to Jizhou to join the East Road coalition army, which was known as the "Qingxu Army" in history.

A series of dazzling events that took place later have now been spread all over the world by the big mouth of the storyteller. Although many of them were conjectured by the people, there was one thing that was agreed upon and there was no objection. In the entire battle to defend the state, the unit with the lowest casualty rate was the Qingxu Army. Whether it is a real surrender or a fake rebellion, anyway, the soldiers of the Qingxu Army are alive and well so far, and more than 13,000 of them are fortunate to go north to make a cameo appearance in the defending troops, and have experienced a real war against foreign peoples.

According to Zhao Xing's original plan, Qing Xujun was supposed to return to his hometown in May last year, but for some reasons, it was delayed for another year.

There are two main reasons that hindered the return of the Qingxu army. One reason is that Yuan Shao and Cao Cao, who had suffered losses, happened to be separated between Jin and Qingzhou, and if the 20,000-strong troops wanted to pass harmlessly from the boundary between Jizhou and Yanzhou, then Zhao Xing would not get so many benefits at the "round table". The reason is very simple, Yuan Shao and Cao Cao are not stupid, if they want Qingxu Jun to return to their hometown, then Zhao Xing has to come up with the bargaining chips exchanged.

Another reason is that Zhao Xing's ambition to develop sailors was restricted by the restrictions of the Jin state's own shipbuilding industry, and there was no large-scale fleet that could sail in the Yellow River, so although the plan to let the Qingxu army go down the river was set early, it was not until the arrival of 500 shipwrights in Yangzhou and Wuzhou in the south that this plan really worked.

When the Quanzhou shipyard was established in the first month, Zhao Xing only asked Xu Shu to take 400 shipwrights to Yuyang County in Youzhou, and there were still 100 shipwrights left in the Jin Kingdom. According to Zhao Xing's plan, the 100 shipwrights were sent to the eastern part of Yang'a City, on the bank of Qinshui, a tributary of the Yellow River, where a smaller shipyard was set up called "Yang'a Shipyard".

"Yang'a Shipyard" is located in the southwest of Shangdang County, between Yang'e County and Gaodu County, and is now garrisoned by a division of the Crouching Tiger Army.

According to the overall plan of Zhao Xing's development of the water division, combined with the actual characteristics of the Yellow River, the task of the "Yang'a Shipyard" is mainly to provide transportation ships for the Jin naval division, and the large warships and ships that can be used for sea navigation will be undertaken by the Quanzhou Shipyard.

In Zhao Xing's eyes, compared with the Yangtze River and the sea, the Yellow River is really difficult to give full play to the characteristics of naval warfare, and at best it can only be used as a trade route, and it can only be used in summer and autumn. In winter, the Yellow River freezes everywhere, and the movement of the sailors is restricted. Rather than focusing on the meaningless construction of the Yellow River Naval Division, it is better to build a real naval division that can fight across the sea at the Quanzhou shipyard in the northern Yellow Sea from the very beginning.

Zhao Xing was born in the army and knew little about the modern shipbuilding industry, but he at least knew the difference between iron ships and wooden ships, knew that Zheng He's treasure ships when he went to the West and sailing ships in the Age of Discovery, and also had a clear understanding of the key role played by the power part in the development of ships.

If you want to run a boat on the Yellow River, power has undoubtedly become the biggest problem. Going down from the upstream is as simple as using the current. Although the speed will be slower, it will have stable power, and if you add the help provided by the sails, the speed will be faster. The difficulty lies in the counter-current process from the downstream to the upstream, and the Jin State happens to be in the middle and upper reaches of the Yellow River.

Sailing against the current, if you don't advance, you will retreat. Relying on the impetus provided by the wind to the boat, regardless of whether the wind is actually stronger than the current, the mere fact that the wind direction changes from time to time makes it impossible to rely on the power of the boat to sail against the current.

The easiest way to do this is to tie long ropes to the boat, hire a large number of skilled laborers as slender men, and drag the boat step by step against the current. But the problem came again, the lower reaches of the Yellow River were in the hands of the four forces of Jizhou, Qingzhou, Yanzhou and Sili, except for Qingzhou, which was the most downstream, which would not stumble on the Jin State, the other three parties were all on guard against Zhao Xing, how could they let the fleet of the Jin State hire slender men on both sides of the river section under their jurisdiction?

The final solution of the problem started with an idea from Zhao Xing.

Since it is not possible to use external forces, it has to find a way to load the power of the ship itself. Zhao Xing was not crazy enough to build a steam engine in the late Eastern Han Dynasty, but he had a guy named Ma Jun, who was very good at making shafts and conveyor belts, and the keel waterwheel that relied on pedals to generate power to draw water was invented by Ma Jun in history.

In this life, Zhao Xing snatched the patent of Ma Jun, and made a wind-powered pedal keel waterwheel driven by wind and manpower in advance, which has made contributions to the agricultural production of the Jin Kingdom for 12 years. However, this will not prevent Ma Jun from seriously studying the principles of physical machinery such as rotating shafts and fixed and movable pulley sets, especially the gradual improvement and enhancement of the steel-making process of Shangdang Iron and Steel Plant, which can provide strong material and technical support for Ma Jun to study this field. So when Zhao Xing told Ma Jun about his idea, he immediately got the understanding and affirmation of the great inventor.

The power system of the medium-sized transport vessel produced by the Yanga shipyard is the paddle wheel device. The system uses dozens of strong men to step on a device similar to the pedals of a bicycle bridge in later generations, forming a powerful joint force, and the power conveyor belt drives a device similar to the wheel of a water wheel, which allows the boat to maintain a speed not lower than that of an adult walking when sailing against the current. If the paddle steamer were to sail down the river and sail on it, it would be as fast as a horse-drawn carriage at high speed.

Paddle steamers are not ships, this is a fundamental difference. Paddle steamers convert manpower into power for the navigation of wooden boats by means of transmissions, while steamships convert thermal energy into kinetic energy by pushing propellers through steam engines.

Although the difference is very large, Zhao Xing feels that as long as the big ship can run, it is a good design, and this device can also be used on sea ships in the future, leading the Han sailors to expedition to the world.

There is no doubt that the birth of the paddle wheel has made the shipbuilding industry of the Han Empire ahead of all human civilizations of that era, and has also made Zhao Xing's dream of blue navigation in the future within reach. It was a world-changing invention, even though it was still lying quietly in a warehouse at the Yanga shipyard.