The recruits who rushed to Po Song Province from Guannai were not only to replenish the soldiers, but also to accompany a large number of unicorn horses to transport supplies, and therefore also to act as people's husbands, at least the rations of these 400,000 people must be solved, and at the same time, as an armed escort, it is impossible for all these 400,000 people to be put into the front-line battle.

Crossing the river usually comes first, followed by the front army, the middle army, and then the rear army crosses the river under the cover of grain and grass.

In this way, the coalition forces can not resist and take military action, causing misjudgment to the Jinxuedi people, so that they can cross the river in the near vicinity of the coalition army, or cross the river within the reach of the coalition army, directly release their front army and middle army, and cut off their rear guards, horses, and grain and grass baggage, then the hundreds of thousands of people who cross the river will have no food to use, and can only eat the rations of other Jinxuedi people east of the West River.

Whether it is the Jinxuedi people outside the West Mountain, or the enemy soldiers stationed in the outer lake, their grain and grass transportation must be crossed through the West River, especially the barbarian army outside the West Mountain, most of their grain and grass are on the warship, after being intercepted by the coalition forces, the barbarian army outside the West Mountain has not much grain and grass, which will undoubtedly aggravate their grain and grass tension.

As long as the coalition forces blockade the West River, their grain and grass can only detour upstream in the short term, or further downstream to cross the river for supplies, although it cannot be reflected in the battle situation for a short time within 20 days, but after a long time, when the West River and even all the water networks are cut off by the coalition forces, the hundreds of thousands of troops of the Jin Xuedi people will be useless, and will eventually be trapped alive by the water network of the coalition army.

At this time, Bai Liyan seemed to have seen the capital to turn over, and Su Fangyi's strategy could not be described as far-sighted:

"Good plan, really good plan!" Bailiyan praised endlessly.

"The plan is good, but it's dangerous. At present, there is still a shortage of weapons in the valley, and secondly, this recruit after crossing the river is very likely to pounce on the West Mountain. Therefore, it was necessary to transport grain and grass into the valley after the heavy damage to the barbarian army outside the West Mountain, and before the barbarian recruits rushed to the aid of Zhixi Mountain. If there is a slight difference in time, this plan will be wasted, which is the most dangerous part of this plan. ”

"So, Mr. Su already has a plan to deal with the enemy of the outer lake?"

"Hmm......" Su Fangyi nodded, his face was quite confident, he twisted his short beard, and he leaned in and whispered:

"The people of Jin Xuedi thought that their plan had succeeded, but they didn't know that they would flood their army with the method of draining water in two stages."

Bai Liyan couldn't hear what the technique of the second stage of water discharge and pouring to the bottom was, so she frowned and hurriedly asked:

"Dare to ask sir, what is the two-stage drainage method?"

"In the next decision, he will first test me with soldiers and horses, lure me to drain water, and then take advantage of my lack of water to attack my cofferdam. Therefore, our army first drained the water, and when it came to a big attack, it drained the water again and drowned it. ”

"Oh, how can you store and drain water twice in a short period of time?"

Bai Liyan was puzzled when he heard the news, he knew very well that once the dam burst, it would immediately break all the breaches, and there would be no ability to release water a second time in a short period of time, let alone store water. With the flow rate of the inner lake in the valley, there is not enough water in a few days.

At this time, Su Fangyi said mysteriously:

"It's actually quite simple. Before the water is impounded, a large number of wooden piles have been rammed into the breach, and the wooden piles are tied with ropes, and the wooden piles are tamped with earthwork. Then ram the earth on the wooden pile, so that when the water storage expires, destroy the upper layer of the wooden pile, and the lower wooden pile will still strictly guard the gap, and wait until the upper layer of water is empty, and then use a rope to pull down the wooden pile, so that the water can be discharged twice. ”

Su Fangyi first rammed a large number of sharpened tall logs at the bottom of the cofferdam breach, and filled the logs with soil to seal them, so that the rammed earth could continue to block the breach.

In this way, when the upper layer of the breach is discharged, the logs of the lower layer will still firmly hold the breach and will not burst immediately. After the first discharge, the Jinxuedi people thought that everything was fine, and when they crossed the outer lake and entered the valley, they discharged the water for the second time, flooding their army, so that they were discharged for the second time.

Moreover, after the first discharge, the breach will be replenished immediately, and the water storage capacity will be increased, and when the second discharge is completed, the volume of water will be larger than the first.

"Hehaha, Mr. Su's plan is really wonderful, in this way, it will be effortless to hit the people of Jinxuedi in the outer lake."

"That's right, and in this way, the soldiers and horses in the valley can fully besiege the enemy who has introduced the West Mountain, as long as they can transport grain and grass into the valley before the barbarian army rushes to the aid of the upper reaches of the West River, our army can solve this danger."

"That being the case, I will lead the navy to respond to Mr. in the West River. I also asked Mr. to select people from the allied forces in the valley as soon as possible, and to intercept more enemy ships so that he could reorganize the navy as soon as possible. ”

Bai Liyan found that the skills of water warfare now depend on meteorological and hydrological conditions, as well as the training of sailors and the performance of warships.

The requirements for navigation, astronomy, logistics and other skills are low, and even the application of stargazing in the vassal states is very rare, the reason for this is that the combat on the inland rivers is completely different from the combat at sea.

The technical problems encountered by the Blue Water Navy and the technical support of the Yellow Water Inland Water Navy are qualitatively different, with a difference of several orders of magnitude.

In addition to requiring the personnel to have the quality of water, the direction of the wind and basic hydrology, the means and essence of the inland water army operations in the Bronze Farming Age were almost indistinguishable from those of the army in hand-to-hand combat.

After talking to Su Fangyi about getting dark and resting in the middle of the night, Bai Liyan returned to the river again with a team of 100 people in the second half of the night.

At the same time, the new regiment of Mooney, still troubled by the crossing of the river, received an urgent message from the Temir courier:

"Your Excellency, Legion Commander, this is an urgent letter from the Legion Commander of Temir that I have asked me to present to you."

Mooney took the letter, confirmed that the fire paint was intact, and first asked:

"Does Temir have a message?"

"The commander of the regiment said that the current situation is very bad, the northerners have robbed a large number of untouchables on the periphery of Posong Province, and also plundered dozens of warships of our army, and the losses are extremely heavy."

"What, I took the ship!" Mooney was taken aback by the news, and he quickly realized that this would be a huge hidden danger.

The letter was quickly opened, and the contents were all invective and accusations against officials at all levels in Po Song Province, denouncing the incompetence and inaction of local officials, and the letter focused on the latest black powder of the coalition forces.

When Mooney returned from Mt. Chitake, he seized a number of black powders from the Allied forces, and the results of the tests showed that it was a powerful black powder, which was originally called "black fire powder", which was packed into a copper or iron tubular container, filled with black fire powder and metal, and produced great power. Mooney gave the Black Fire Powder to the Academy Craftsmen in an attempt to figure out how to make it, but nothing came of it.

The Carezer massacre mentioned at the end of the letter shocked Mooney, who knew very well that the black powder used by the coalition forces was changing the course of the war.

Pressing the letter on the table, Mooney took up the pen to revise it, and then said to the messenger:

"Give the letter to Temir and tell him that he needs to wait for the rain to deal with the black fire powder, and only when it rains, the black fire powder will not work."

"Please rest assured, your subordinates will definitely bring the words."

As a rudimentary and primitive explosive, black powder is extremely sensitive to humidity in the absence of relevant sealing and processing technology, and moisture and water can weaken its reliability and lose its effectiveness.

The climate of Mt. Sengaku is dry, and even in spring and summer, it rarely rains heavily, and the dry snow in winter has little effect on black powder, but in the tropical water network area of the North Sea, it is extremely susceptible to moisture.

Through a military operation, the Jin Xuedi people learned the secret by capturing the soldiers of the Changsun Kingdom. In fact, even if you don't need to "teach by word and deed", Jin Xuedi people will quickly find out these characteristics of black powder.

A few days later, Bailiyan quietly returned to the warship and continued to travel between Khubigon and Derangi. Mooney led his army across Yasai Falls, and the vanguard light cavalry arrived at Dranky in one day.

After more than ten days of excavation, the width of the pass has been narrowed from 14 or 5 li to 7 or 8 li, and a large number of obstacles have been erected at the entrance to prevent horses and logs, and the Mooney recruit corps was forced to stop advancing and prepare for the crossing of the river in the upper reaches of the West River.

On this day, Bailiyan took a boat to the lower reaches to prevent the 60,000 men of Yabuk's department from crossing the river. The reason for the 60,000 men was that Yabuk was supposed to be from the north of the Dranky and south to encircle the Drangi coalition army, but unexpectedly encountered a swamp and was forced to leave 40,000 people to continue to press the marsh north of the Drangi to guard and find the entrance, Yabuk led 60,000 men to rush back to the camp outside the West Mountain, trying to join up with Cartenson's auxiliary legions.

However, Yabuk's troops and horses were only preparing for the riverbank, and there was no sign of forcing the crossing of the West River.

"My lord, it should be the water army of the Jin Xuedi people who is about to arrive!"

Jiang Jie guessed, Bailiyan put away the binoculars and said affirmatively:

"If it weren't for the arrival of the enemy's navy, they would never have been so calm, most likely waiting for their navy to defeat us and others, and then cross the river. Moreover, the barbarian army must be violent, and the number of warships is probably not a few. ”

Sikong Nan said at this time:

"If we take our Xianguo naval army as the target, and the national strength of the Jin Xuedi people is calculated, they must have at least two or three thousand large and small warships."

"It is true to calculate in terms of national capital, but the Jinxuedi people have long monopolized the southern water network and have never had large-scale water wars, so there are definitely not too many naval warships, but there are many merchant ships used for transportation. I wondered if there must be merchant ships among the ships here. If it is a merchant ship, it must have a large number of passengers, and we must not carry it. ”

"But they are all on land, and before the battle, they must load the infantry on the warship, why don't our troops take advantage of the fact that they are loaded on the ship."

Sikong Nan proposed, Bai Liyan agreed from the bottom of his heart, but the matter was obviously not that simple, he said:

"The Jinxuedi people stationed in the outer lake of the Chubigon Valley, among which all the auxiliary legions belong to the province of Posong, and among the soldiers and horses on both sides of the West River, most of the auxiliary legions are from the province of Sundia, and there are sailors in the infantry of the two provinces.

Even if our army blocks the West River, this naval army will definitely enter the West River from the downstream and go north to bypass the east of Cupigon, and the enemy army outside the lake outside Cupigong will also divide the army and go to the northeast river to find a place to board the boat, so that it will only take five or six days to come and go.

If our troops go north, this section of the river cannot be blocked. If they didn't pursue, the Jinxuedi people would inevitably load the sailors on the warships and fight again, so they were in a dilemma at the moment. ”

The water system of the West River leading to the lower reaches of Yasi Ai is one hundred and fifty or sixty miles north of the West River section outside the West Mountain, once it leaves for too long, the Yabuke Department on the west bank will rush to repair the pontoon bridge to cross the river, if it is not intercepted, the warships of the Jinxuedi people will go further downstream to load sailors, even if they are not used to water warfare, but after all, the strength will be several times that of Bailiyan, plus the number of ships, the situation will be extremely dangerous.

For the coalition forces walking on thin ice, the destruction of their own naval army is undoubtedly a huge blow, and the bond that holds Derangi and Cupigon will be gone.