On the same day that the promotion order was issued, all the soldiers of the First Garrison Brigade set out from Porto Alegre under Li Mingyuan's order and arrived at Santa Maria, the resettlement place of the first batch of retired soldiers, two days later.

Located in central Rio Grande do Sul, away from rival states such as Brazilian-controlled states of Santa Catarina and Uruguay, Santa Maria is in the heart of areas occupied by the Chinese Independence Army (CIA) and is a planned rear base for Li Mingyuan.

The main force of the sweeping force was stationed in the Santa Maria area, and the first batch of retired troops were also placed in the countryside around Santa Maria, plus the 4,000 soldiers of the 1st Garrison Brigade who were ordered to come, the number of Chinese in the Santa Maria area reached more than 20,000, and in Rio Grande do Sul, there were seven or eight cities of Santa Maria's size, but in terms of the number of people settled, Santa Maria was second only to Porto Alegre.

Porto Alegre is the capital of Rio Grande do Sul and the temporary headquarters of the Chinese Independence Army, a large number of Chinese soldiers and retired soldiers were placed in Porto Alegre, taking advantage of the geographical advantages of the coastal waters of Porto Alegre, while a large number of field forces are also in order to guard against the naval attack of the Brazilian army.

In the Paraguayan War, the Chinese Independent Army captured a total of three ironclad ships, one of which had a damaged main gun and had recovered most of its combat capability after a short repair and removal of a battery, and the other two ironclad ships formed the main battleship, which was taught by the captured Brazilian Navy at the port to conduct operational training for Chinese soldiers, and there was still a long way to go before the formal formation of maritime combat effectiveness.

Naval warfare is different from water warfare, when fighting in Paraguay, you can rely on captured Brazilian naval soldiers to operate artillery to attack the unprepared enemy, but in the vast sea, the Brazilian navy will not have enough room to operate, and will not be attacked by the Chinese independent army like a live target, so it is dangerous to establish its headquarters in Porto Alegre when the sea power is inferior to the Brazilian navy.

Fearing that the Brazilian army would attack Port Alegre Lee by sea, Liu Pu and others persuaded Li Mingyuan to move his headquarters to Santa Maria, but Li Mingyuan rejected their proposal.

Porto Alegre is one of the few excellent ports in Rio Grande do Sul, and is the only way for the Chinese Independence Army to communicate with the outside world, and if the main force moves back, the remaining troops will have difficulty resisting the Brazilian army with ironclad ships.

Brazil has a population of nearly 10 million, is the most populous country in the South American continent, the Paraguayan war of more than 100,000 land losses will make it lose the ability to counterattack on land for a while, but with a population of nearly 10 million Brazil's sea power is still not to be underestimated, two large ironclad ships plus a large number of gunboats, sail warships, if Britain intervenes in it to encourage Brazil to attack from the sea, and then seize the port of Alegre, the Chinese Independence Army will not only lose the best port, but will also be blocked on land by the Brazilian Navy,

The sea passage was blocked, the land was full of hostile countries, there was no import supplement of Chinese immigrants and the exchange of trade materials from overseas countries, and the combat effectiveness honed by the Chinese Independent Army in the battle of thousands of miles was useless.

Liu Pu, Sun Bin and others, as Li Mingyuan's advisers, may have provided useful advice to Li Mingyuan in the traditional wars in peacetime, but as they did not accept the influence of modern sea power theory, they would not have thought of the decisive significance of naval power for a modern war. It was agreed to establish a large amount of supplies for retired soldiers and a production line of rifles and bullets dismantled and transported from Peru in Santa Maria as a production and construction base for the rear.

In order to complete the construction of the military factory and put it into production at an early date, Li Mingyuan transferred 3,000 Brazilian prisoners of war to He Yanliang for use, and the remaining nearly 20,000 Brazilian prisoners were concentrated in Port Alegre to be responsible for the construction of fortifications in the port area.

After receiving 3,000 Brazilian prisoners of war from the herald officer, He Yanliang asked, "I have 10,000 retired soldiers and 3,000 prisoners of war here, and the construction and production of the military factory can be completed within the specified time of the prince, but after the plan of the military factory is completed, how will these prisoners of war be arranged?" Is it going to be solved on the spot? ”

"Brigadier He misunderstood, these prisoners of war are not only used to build military factories, but the prince has other jobs entrusted to them."

The herald officer took out a drawing from his bosom as he spoke, handed it to He Yanliang and said, "This is a small fortification designed by the General Staff according to the proposal of the prince, and when the construction of the military factory is completed, the three thousand prisoners of war and some retired soldiers will be transferred to the work of building a small fortress, Brigade Commander He, this is the task assigned by the prince himself, you must complete it conscientiously." ”

He Yanliang studied military theory knowledge in the wounded corps for half a year, and he could understand the drawings of ordinary fortifications, but the drawings handed to him by the herald officer made him confused, the structure of the fortifications is very simple, but the construction area of a fortification is less than three or four meters long, what role can such a small construction fortification play?

"Staff Officer Wu, what's the use of the fortress on the drawings, why can't I understand it at all?"

"It's normal that Brigadier He can't understand it, some of the fortresses on the drawings are different from the fortresses built by foreigners in ordinary times."

The staff officer put the drawings on a table, pointed to the annotations at the bottom of the drawings, and said, "Ordinary fortresses are often built next to the city to form a defensive fulcrum for defending the city, but the small fortresses you are going to build this time are different, they will be arranged in various areas of the field according to the specific locations selected by the staff after measurement, forming a fortress group covering the entire Santa Maria area." ”

"St. Mary's area is not small, and the small fortresses built in the field are not well defended, and they are scattered throughout the area, so that the enemy can break them individually?" He Yanliang asked.

"No, each small fortress will choose to be in a hidden area such as high slopes and mountains and forests, the main structure of the fortress is deep underground, and the surface of the fortress retains the original appearance of the construction site to ensure that the enemy cannot find it, and each small fortress is connected by a dug tunnel, even if a fortress is exposed, the defenders in the fortress can also retreat through the tunnel to block the tunnel leading to the fortress to prevent the enemy from finding other fortress entrances."

"By connecting the small fortresses with tunnels, even if the enemy occupies the area on the ground of Santa Maria, our army can use the tunnels dug in advance to concentrate near the enemy, break into the enemy camp at night, and annihilate the enemy forces entering Santa Maria."

After listening to the introduction of the staff officer, He Yanliang thought for a while and understood.

"When the Brazilian army counterattacks again, the number of troops must be larger, and when the prince of Paraguay fights, he led our army to take advantage of the enemy's unpreparedness to defeat the Brazilian army, and after suffering a big loss, the Brazilian army will naturally be very vigilant, and it is basically impossible to annihilate the enemy as quickly as last time,

Therefore, the General Staff, at the suggestion of the prince, reformulated the plan to deal with the counteroffensive of the Brazilian army, in which Porto Alegre would be used as the main defensive position of our army to drag the offensive force of the Brazilian sea, and Santa Maria and other occupied areas would implement the strategy of clearing the walls and clearing the wilderness, and the whole people would be soldiers, and the enemy would be put into Rio Gro Sul, and then use the bunker fortresses connected in various places to carry out the concentration of troops, and annihilate the scattered Brazilian troops with local superior forces. ”

"The Brazilian army's counterattack on Rio Grolan do South is to regain lost territory, in the early stage of the enemy's attack, our army transferred to bunker fortresses and some important areas for defense, leaving the evacuated cities and small towns to the Brazilian army, they will not let these areas go unattended, and will definitely divide their forces to occupy various places, so that our army can avoid direct confrontation with the main forces of Brazil, but can use the sparrow warfare and surprise warfare taught by the prince to kill a small group of enemies, constantly weaken the enemy's vital forces, and create opportunities for the main force to annihilate the invading enemy."

The purpose of building the underground fortress was to divide the Brazilian army, and in order to recover the country, even in the face of empty cities and towns, the Brazilian army had to send troops to garrison, implement the superficial phenomenon of recovering the country, and fall into the trap set for them by the Chinese Independent Army.

"Brigadier He, St. Mary is the set rear base, the military factory and all kinds of factory facilities will be relocated and placed here, the prince placed the first batch of retired soldiers in St. Mary earlier and transferred 3,000 soldiers to you, all in order to better build and protect the safety of the base, the burden on Brigadier He is not light, if you have difficulties, you can raise them, and I will convey them to the General Staff and the prince in the future."

The Brazilian army's counteroffensive, Porto Alegre and Santa Maria Arsenal will become the two key points of defense, and it is impossible to give up easily, so He Yanliang will have to take on the responsibility of guarding the base after completing the construction of the base and the construction of the bunker fortress, and the burden is not heavy.

The staff officer asked him if he had any difficulties, He Yanliang thought about it seriously and said, "If the Brazilian army invades, will Division Commander Luo, who is stationed in Santa Maria, be transferred back to Porto Alegre?" ”

"The task of the mopping force is to expel the Brazilian population, and after the mission is completed, the 1st Division and the Cavalry Brigade will be transferred back to Porto Alegre for repairs."

The transfer of the sweeping force back to Porto Alegre meant that the garrison of Santa Maria was only 4,000 soldiers of the 1st Garrison Brigade and 10,000 retired soldiers, and 4,000 soldiers of the 1st Garrison Brigade were the main force of the operation, and the 10,000 soldiers who were not even selected by the garrison brigade were about 4,000 of the remaining 9,000 who could be selected to assist in the battle, and a total of 8,000 men was the entire force for the defense of Santa Maria.

In order to prevent the base from falling, He Yanliang proposed to transfer a regiment of field troops to garrison the St. Mary's base, and the staff officer nodded in agreement, promising to give a truthful response to the general staff.

After giving instructions to the General Staff, leaving behind to survey and screen the soldiers who built the bunker fortress, the Staff Officer left Santa Maria and returned to Porto Alegre.

Santa Maria, the retired soldiers who had just finished harvesting the corn under the command of He Yanliang, and the Brazilian prisoners of war began the construction work at the same time, of which 3,000 prisoners of war were arranged to dig the soil, carry stones and other most tiring work, and the retired soldiers were responsible for thickening and raising the city walls on the original basis of the Santa Maria Castle, and the musket production equipment disassembled into scattered parts was pulled into the castle by the retired soldiers, and a door cannon was also placed above the castle under the pull of the sling, and the busy construction works were all over the castle and field areas of Santa Maria.

Retired soldiers and prisoners of war of Santa Maria are constantly busy, and Porto Alegre is also a scene of construction.

After several battles, the Chinese Independence Army captured a total of 27,000 Brazilian troops, plus the 5,000 Brazilian prisoners transferred from Paraguay, the number of prisoners in the hands of the Chinese Independence Army reached 32,000, and more than 30,000 prisoners were all good free labor, and 3,000 prisoners were sent to He Yanliang, and 5,000 prisoners were sent to Erecin and South Cassias, two places close to the Brazilian forces, plus prisoners transferred from some other places, Fifteen thousand Brazilian prisoners of war remained in Porto Alegre, all of whom were fortified and fortified in the port of Lake Patus, which connected to the sea.

The naval units of the Chinese Independent Army have not been formally formed, and the naval units with insufficient combat effectiveness at sea need to be protected by batteries and fortifications at the port, so on the basis of the batteries built by the Brazilians, six newly planned batteries are under construction, and the newly planned six guns are distributed on the east and west sides of the port, with three new guns added on each side, and the artillery left by the Brazilians together form the core force to defend the port.

On the outside of the fort, all the gunboats that were destroyed and the sailboats that had lost their combat effectiveness captured in the Paraguayan war were dismantled, and the guns on the gunboats and warships were dismantled and installed on the outside of the batteries to form a perimeter protective firepower.

Between the outer batteries and the harbor batteries, a guerrilla fleet of 25 gunboats will be formed to take advantage of the small size and flexible activities of the gunboats to attack the attack of the Brazilian army, and at the same time, the 25 gunboats will also serve as an early warning effect, when the naval units patrolling the open sea issue a warning of the enemy's attack, the 25 gunboats will scatter the captured mines on the lake outside the port in the shortest possible time, acting as the first line of defense to block the Brazilian warships.

Modern mines first appeared during the Russo-Turkish War in 1769, when Russian sappers first tried to use drift mines to blow up the Turkish pontoon bridge to Dunay. Since then, various types of mines have been continuously developed and improved, and widely used. C. Yatulbi invented the electrolyte-triggered anchor mine. During the Crimean War of 1854-1856, Tsarist Russia used this trigger mine in the defense of harbors.

Then in the American Civil War, mines also played an important role in naval operations.

Li Mingyuan was very happy when he first heard that the mines had been captured, and he thought that he could lay a large number of mines to block the sea attack of the Brazilian warships, but after seeing the captured mines, this idea was immediately dispelled, and the number of captured mines was not large, at best, it was only enough to be laid for one use, and there was no factory for producing mines in Port Alegre.

After instructing the Chinese navy in training to keep the mines and take them out for use when the battle was in battle, Li Mingyuan felt that it was time to spend money again on weapons and weapons production equipment.