Unlike the smooth operation of industry and agriculture, the trade industry, on which high hopes were placed, did not meet expectations. The trade routes to be developed will not be effective at all in the short term, and the top brass of the Thunderbolt army are mentally prepared, but the three immature routes are not going well, which is unexpected. In the commercial and trade activities of Meizhou and Jiading, because the Mongolian army occupied Pengshan City, every time a caravan passed through this section of water, it needed to be escorted by the Xinjin City naval army. Since the formation of the naval army trained by Liu Heima in Chengdu, the pressure of escort has become more and more intense, and Yu Xing's father and son have levied extremely heavy taxes on business travel, which is similar to robbery, so although doing business in the two places is highly profitable, they actually do not make much money.

Although the direction from Yazhou to the arrow furnace is extremely profitable, and there are resources such as fire, salt, horses, copper, and mercury urgently needed by the Thunderbolt army, this road is really far and dangerous. What's even worse is that during this time, a new group of bandits emerged between Yazhou and Lizhou, burning and looting everywhere. The original bandits were either hurt by the armed caravans of the Thunderbolts, or they were attracted by economic interests and chose to cooperate with the Thunderbolts, and did not come to seek trouble. But this gang of bandits seemed to have a grudge against the Thunderbolts, and never missed the opportunity to attack the Thunderbolt caravans. A few days ago, Li Gongzi led a team to escort Huoyan back to Qiongzhou, but was suddenly attacked by this gang of bandits, and more than 10 people were killed and wounded. The gang of bandits even attacked the Thunderbolt Army's fire mine cave in Lizhou, only to be repelled by Qian Bao.

The northern route of tea and horse trade from Guankouzhai to Wei and Mao went smoothly, and the trading volume was also large and the profits were extremely considerable, but it was not able to purchase the horses, copper, nitrate and other resources urgently needed by the Perak army. On the one hand, there is no suitable local agent, and these controlled materials cannot be purchased at all. The Ministry of Commerce and Trade also sent people to contact Uncle Xie Fang's clan in Taoping, trying to find an agent in the Xie clan, but there was no result for the time being; On the other hand, after the Mongol army was surrendered to these two states, the Mongols sent officials to be stationed here, although the number was small, but the locals only dared to trade with the Thunderbolt army on the sly.

There was no significant military information during this period. It's just that the Mongolian army rangers have not stopped sneaking into the territory to reconnoitre. Although the Thunderbolt army controlled the river, because the military strength was too small, it was impossible to closely monitor the river, so the Mongolian cavalry often secretly crossed the river to harass, which was already a common thing in the eyes of Cao Ergou and other brigade leaders. The question they are now concerned about is when the equipment will be in place. Cao Ergou first complained that the number of muskets in the cavalry battalion was too small, and then said that the two infantry battalions lacked artillery, carts to transport baggage, and supporting mules and horses—in short, good equipment should be prioritized for field brigades. Yu Zhu had a very strong view of the overall situation, and although he did not complain, he euphemistically raised the problem of the lack of density of fortresses. Moreover, except for the training battalion, the firearms armament rate of other companies in the garrison brigade is too low, and some companies only have two light guns. In some militia companies and even in the backbone companies, the soldiers had not yet touched firearms.

Ouyang Xuan interrupted and complained, he knew all these situations. He is not an arbitrary person, but a problem raised by Cao Ergou and others will take time to solve. Of course, it is important to increase the production capacity of the military industry, but this matter must not be urgent. In his opinion, the most important thing at the moment is to tighten the fence of defense. During his trip to Diaoyu City, he encountered water bandits and the Mongolian army, and learned that Liu Heima's water army almost broke the Meizhou water army, which made him aware of the flaws in the defensive strategy. Originally, it was thought that the Mongols could be firmly controlled by artillery warships, and the Mongols could be helpless with the help of fortress artillery, but the premise of this assumption was that the Mongol army did not have a naval army, or was very weak. If the Mongolian navy and the Thunderbolt navy are equal or even stronger, how will the battle situation develop? The thought of the consequences made him shudder. Now it seems that the Thunderbolt navy is not as strong as imagined, but the Mongol navy is making rapid progress.

Ensuring the security of the current jurisdiction is the premise of all development, and Ouyang Xuan proposed three measures to strengthen the defense and explained the reasons, which everyone has no objection to. The first measure is the dredging of the river. On the way back to Diaoyu City, due to the dry water in early winter, many places exposed a lot of riverbeds, and some sections of the river even rely on manual fiber pulling to sail. Seeing this, Ouyang Xuan asked about the hydrological situation of the river under the rule of Huang Dagen's Thunderbolt Army. Although the Chengdu Plain is not too cold in winter, the river will not freeze, but the water volume will drop a lot, and the water volume in the upper reaches and tributaries of the river is even smaller, and large boats cannot pass. For example, Guan Kou Village and Pujiang City cannot run gunboats when the water volume is at its lowest. The Nanhe, Xiejiang River, Wenjing River, Jinma River and other rivers also have shallow water and shallows to varying degrees in winter, and can even wade across the river. Only by widening and deepening these sections of the river to at least allow heavy artillery ships to pass through it could the Mongol army be prevented from crossing the river easily and reinforcing the cities and forts along the river in time.

The second measure is shipbuilding, building a large number of small light and fast ships. Previously, Ouyang Xuan was obsessed with "giant ship cannons" and focused the construction of the naval army on artillery warships. Although the results were obvious, when Xuzhou was attacked by water bandits, the shortcomings of the gunboats were exposed to the heavy and slow shortcomings, and they were easily approached by light warships. "Ants bite elephants to death", once they are close to the enemy ship with superior numbers, the gunboat may be destroyed or even taken away. These gunboats were expensive, and the price of a single gun was worth the price of a small warship. Ouyang Xuan's idea was to build a large number of small light warships for reconnaissance, patrol and escort purposes, these small warships can be controlled by more than ten people, and can be controlled by two or three people, and can even be used for fishing in peacetime.

After Ouyang Xuan talked about this measure, Huang Dagen proposed to equip some light express boats with small cannons to increase their combat capability, which also won the support of everyone. The increase in ships will inevitably increase the number of sailors, but if the number of standing troops is increased, it will inevitably squeeze the economy. Ouyang Xuan's method was to change the basic company and militia company near the river from an infantry army to a naval army. These part-time sailors fish and farm on weekdays and undertake auxiliary tasks in wartime, which not only solves the problem of the reserve source of the navy, but also enhances the combat strength of the garrison brigade.

The third measure is to build a fence. The so-called fence consisted of several parts, the foremost of which was the addition of watchtowers where the enemy might cross the river. In addition to the pebble river sand excavated from the dredging of the river, Ouyang Xuan also ordered the supply of cement as a priority, so that these fortifications could be poured entirely of concrete. Behind the watchtower, there is a lag zone of woods, thorn bushes, ditches and artificial swamps. Even if the enemy broke through the naval line and the fortress on the shore, it would have to be difficult to walk through this artificial labyrinth several miles wide and deep.

Behind the hysteresis zone is a military dock fort surrounded by several artificial ditches and ponds. These dock forts were more fortified, with towers, moats, drawbridges, and turrets equipped with fortress cannons. Ouyang Xuan even wanted these dock forts to be equipped with newly developed mines. The technical content of the research and development of this mine is not higher than that of the new musket, and when the problem of raw materials for mine mercury is solved, it is not too difficult to manufacture it after a large number of tests. In Ouyang Xuan's vision, these military dock forts would become the Ten Thousand Forts and Yokohara Forts in the plains, and the enemies who tried to swallow them would have their teeth shattered and their mouths full of blood.