After Li Su arrived in Yangzhou, he quickly started his field survey and visits and was very diligent.

Of course, this is related to the fact that he had already been in Luoyang for enough rest in a while ago, so it was time to do it.

So when I arrived at the local area, I was on the surface and took a vacation to return to the fiefdom, but in fact, I was busier than when I was working in Luoyang.

For the rest of October, Li Su handed over the immigration work to Zhuge Liang and other subordinates for concern. At the same time, Qingzhou and Yanzhou also received explanations in advance and knew that they should cooperate. Li Su himself focused on selecting a location for the future river and sea transport hub.

In mid-October, he first visited Huating in Lou County and Haiyan County on site. This was the first time Li Su came to the estuary of the Yangtze River to observe the geographical situation of the Yangtze River during the Han Dynasty.

During the Han Dynasty, the shipping industry that entered the sea from the Yangtze River Estuary was indeed not very developed. The silt at the estuary was very severe, almost the same as the "New Orleans Mississippi River Delta" on later maps. The river water even had severe forking at the end of the river, and the shallow water flow was slow.

However, Li Su quickly understood: This is the normal state of slow flow of rivers into the sea under the lack of human economic activities and shipping.

On the contrary, the state of a river that is very tight and does not have the forking and muddy like leaf veins, requires repeated treatment, dredging, and building seawalls to be obtained.

From the Song Dynasty to the Ming Dynasty in history, sea transportation at the Yangtze River Estuary gradually became more and more important, but how expensive is the cost of repairing the coast of the Yangtze River Estuary every year?

During the Ming and Qing Dynasties, it even reached the point where "the seawall needs to be repaired every few years, and more than 80,000 columns of wood are required each time", and the earth and stone consumed are even more difficult to count (of course, Li Su did not know this data, this is from "History of Ming Dynasty")

Of course, given that the Yangtze River is the largest river in China after all, even if it is so shallow and slow, the main channel of the river estuary is still completely open to navigation. Not to mention ships from the Han Dynasty, even ships with a draft of 20 meters and a depth of hundreds of thousands of tons in later generations are fine.

And those ships with a few meters of water in the Han Dynasty had no problem with docking, and they didn’t need to be excavated, just build a pier. But new problems also followed-

It is no problem to dock, but it is not on the shore at the edge of the Yangtze River, but just the forked shore of the central main channel. Next to the fork of the main channel, there are silt beaches at least twenty or thirty miles wide, with three or five parallel tributaries mixed in the middle. You have to build all bridges to connect, or fill what should be filled, and dig what should be excavated to finally connect to a stable land settlement area.

This is completely meaningless.

"I always feel that it is shallow on paper. I have to practice it myself. I have long thought that I might face problems, and in the end I have to visit and survey it myself to confirm that this place is not good."

On the last day after leaving Haiyan County, Li Su personally came back from the alluvial mud at the estuary of the river. His legs were covered with mud, one deep and one shallow, which really made the people around him feel that the prime minister was very diligent and that he had to come to inspect the harsh environment in person.

After all, it is winter in late October of the lunar calendar, and Li Su is very experienced and stepping on the wet mud without wearing shoes, which is still very cold. He knows that it is useless to wear shoes, because shoes will definitely sink into the mud, so it is better not to wear shoes when you get off the beach at the beginning.

Zhuge Liang and Zhou Yu also accompanied his inspection. Zhou Yu was quite familiar with the neighborhood. After all, he had been in Wujun for many years and couldn't help but humbly ask Li Su how he planned to deploy.

After officially eliminating all the wrong options, Li Su said cautiously: "At present, I guess I can only choose the plan that I didn't dare to choose at the beginning. Build the shipyard and the new transshipment port on an island dozens of miles away from the river mouth."

Zhou Yu was shocked when he heard this. This option was something he had never considered. After all, no one in the Han Dynasty developed an island. Even if it was built, it would have to be transported more every year in the future. It would have to be transported from the island to the land. How troublesome?

If there are too many people living on the island, shipbuilding and port services are provided, and food and daily life supplies must be transported from the mainland by ship. This is another cost. After the shipyard is larger, the trees on the island will definitely not be enough. It is a waste of money to cut down the shared trees from other places to transport them to the island for processing.

This does not mean that "it saves some trouble during construction, but the subsequent maintenance and use will increase every year." This is not like Prime Minister Li's style of service.

The prime minister has always liked to solve problems fundamentally, and it is better to have short pain than long pain.

However, Li Su was very confident in his heart because he had experience in later generations, so as long as the wrong option was ruled out, he believed that the correct option was implemented with conditions.

Later, when the Shanghai Stock Exchange opened a port, it was also built directly at the estuary along the river and the sea. The maintenance cost was huge and it also blocked the further natural land formation of the Yangtze River silt alluvial alluvial.

Finally, when we found that the required deep-water ports were getting deeper and the cost of dredging was getting higher and higher, wouldn’t we choose to build Yangshan Port in the Zhoushan Islands in one step?

Islands a hundred miles away from the river estuary will not be silted by the river estuary, so that dredging and maintenance are almost never required. This advantage is incomparable to any harbor directly in the river estuary.

Of course, this "almost never" also requires a limited condition. For example, according to the geographical history known to Li Su, if the dredging of the Yangtze River estuary is not interfered with the dredging of the Yangtze River estuary in the next thousand years, the land will naturally grow, which is equivalent to the fact that most parts of the Shanghai Stock Exchange will grow from the sea in the future.

As for the Ming Dynasty in history, the area growth of the Shanghai Stock Exchange slowed down in later generations, mainly because human activities began to dredge and repair seawalls, and the soil that rushed over was dug up, and the land growth was suppressed. However, Chongming Island was still growing bigger and bigger.

Without the suppression of human activities, Li Su has calculated that the mud and sand brought by the Yangtze River estuary can slowly accumulate and grow in another three thousand years to turn the islands at the northwest end of the Zhoushan Islands into shallow sea beaches. At that time, even if you build a deep-water port in the Zhoushan Islands, you must consider digging the sand and dredging the waterway.

However, that was all happened more than 3,000 AD. The historical development of human activities is simply not worth mentioning compared to the deduction of geographical geology. So at least in the next three thousand years, Li Su's choice will be correct from a geographical point of view.

As for the higher cost of living on the island, Li Su felt that as long as the sea transportation continues to develop in the future, large ships will generally be built. After the scale increases, the freight per unit weight will definitely decrease. The living cost of islanders can definitely be covered. The cost of this area is definitely much lower than dredging ports and repairing seawalls every year.

Moreover, after the ship grows bigger, if the ship reaches the estuary of the Yangtze River, it will not be very risky. As long as you avoid typhoon days, those inland boats with a length of more than four or five meters, whether it is a sand boat bottom or a blessed boat bottom, will it still be easy to drive to the Zhoushan Islands? They will never go to the ship to the ship.

In the future, small sand boats below four meters will be completely eliminated and not built. Or fishermen are only allowed to make fishing, but not for shipping.

Li Su has this resource and authority to uniformly improve the ship standards in the Dahan shipping industry in the future.

Among the ships in the shipping industry, the smallest one is also planned according to the traffic capacity of the canal, and the width is built to less than half of the width of the narrowest part of each major canal to ensure that the incoming and passing ships can meet in the canal, so there is no problem.

A ship of this size can definitely sail safely from the coastline a hundred miles away from the coastline in the offshore area.

Moreover, Li Su also vaguely understood why the Tang and Song dynasties in history had set up the Maritime Bureau in Mingzhou (Ningbo) in the initial stage of East China Sea trade.

Isn’t it just that this place is not far from the Yangtze River Estuary and can serve the river-sea transportation at the Yangtze River Estuary, and there is no alluvialization and siltation of large rivers, so there is no need to dredge and dig deep waterways all year round?

After Li Su, Zhuge Liang and Zhou Yu discussed these details, they had no objection to the design of Zhoushan Port.

At first, some staff members speculated with selfishness, thinking that the Prime Minister was in order to better build his fiefdom and to allow his descendants to receive more taxes in the fiefdom of Kuaiji County in the future, so they had to look far and move the harbor and shipyard from Wujun to Kuaiji County.

After all, Lou County and Haiyan belong to Wu County, while Zhoushan Islands now have almost no administrative system, but theoretically belong to Juzhang County (Ningbo).

Now, everyone is convinced and knows that the Prime Minister has far-reaching considerations and has taken into account astronomy and geography to make the best choice.

However, building the harbor on an island more than 100 miles outside the Yangtze River estuary also brings a problem, that is, it will cause certain difficulties in the navigation of boatmen and sailors-

For those who have been running the sea all year round, it is still very easy to find an island port with a known location in the vast ocean with a general direction and positioning.

But the problem is that the sailors this port will receive in the future are not just sailors. This is the hub for river and sea transportation. In the future, there will be tens of thousands of boatmen and sailors who have never traveled across the sea in their lives and are only focusing on inland shipping to come here to transfer.

For inland river sailors, their navigation ability is almost zero, and there are tens of thousands of such people. In an era when literacy rates are not yet popular, it is very exaggerated to let tens of thousands of fishermen sailors improve their quality and learn to navigate near-shore navigation.

And even if you learn it well, it is not worth investing so much. After all, you have a specialty in your profession, so you don’t need to know how to run on the sea. Li Su estimated that at most 20% of the sailors in Yangzhou and Jingzhou would be enough to know how to sail on the sea in the future. At least 80% of the people will deal with inland rivers all their lives.

This problem once made the overall planning personnel helpless, but fortunately it was solved soon-

Didn’t Li Su, inspired by Zhou Yu, learn the Polynesian bonfire navigation technique and prepare to absorb and digest it, and change it to “build a lighthouse outside the port to navigation, roughly guiding the course of going out to the sea to the Sanhan Yematai Liuqiuyizhou”?

Now, these planned lighthouses can obviously solve a new problem - to guide the direction of the port for future inland boaters who do not understand maritime navigation in the Yangtze River estuary.

Each island in the Zhoushan Islands is only a few dozen miles apart, which can completely form the relay of the bonfire lighthouse.

When an inland river boat exits the Yangtze River estuary from Huating, as long as you can see the first lighthouse, you can drive directly towards the lighthouse without considering the problem of navigation and direction search. The sailor's skills do not require universal training and improvement, and can be solved by fool-like operations.

Li Su, Zhuge Liang and Zhou Yu planned the chart and found that the largest lighthouse had to be built on Sangu Mountain (Yangshan Island), more than 120 miles away from the estuary of the Yangtze River. After all, these 120 miles were the farthest distance of the entire distance.

The subsequent journey from Yangshan to Daishan and Zhoushan is no more than fifty miles, and you can see it without a too high lighthouse.

Zhuge Liang could calculate the radius and curvature of the earth. After some estimation, he found that at least the lighthouse had to be built at least 70 meters high. In addition, with the natural altitude of the islands of Sangu Mountain, the final altitude could be close to 90 meters high. This would ensure that the bonfire platform could be clearly seen 120 miles away, and the bonfire was set off during the day and burned at night.

It is best to use a giant metal reflector facing the estuary of the Yangtze River. If necessary, most of the lighthouse's firelight will gather there, and the brightness will be more obvious.

Of course, considering that there must be fog in the near sea or being blocked by clouds, bonfires and wolf smoke may not be enough.

After Zhuge Liang thought about it, he carefully designed it and thought that he could open another layer under the bonfire layer of the lighthouse to make a bell tower, and cast a large copper bell of millions of kilograms (the four kilograms are less than one kilogram, so it is only a bell of more than 200 tons). He could at least tens of miles of the slogans, and he could barely navigate nearby ships with the sound of the bell, and at least the distance of one island was relayed.

As for the specific detailed design and construction, of course, the Ministry of Works will send top-level craftsmen to the supervisor, plus the famous Roman trade union recruited by Li Su in recent years.

Anyway, this project is not in a hurry to launch now. We can wait for five years and ten years. After the national strength is restored, the transportation of rivers and seas at the estuary of the Yangtze River will become more and more prosperous. We have to consider shipping safety and navigation issues before starting construction.

After all, as mentioned earlier, there were 80% of inland river sailors in the Han Dynasty who could not navigate at sea, but aren’t 20% used to traveling by sea?

When these 20% of the shipping talents are fully overtime, they are not enough, and it is not too late to get these supporting facilities when they have to be brought up by the inland sailors.

After discussing with the supervisory officials, Li Su, he felt that Zhuge Liang's idea was too whimsical and could not be realized by the great man's craftsman skills.

However, Titus, a famous Roman craftsman, knew Western stone architecture, and he had also seen more navigation civilizations.

When Titus followed the Roman nobles to escape the Commod Rebellion, he took the Mediterranean route eastward. Of course, he went to Alexandria, the largest port in the Eastern Mediterranean, and also saw the Alexandria Lighthouse left by the Ptolemy II period.

The big lighthouse in Alexandria is one of the seven wonders of ancient humans. Even if it has been four or five hundred years since the time when Li Su lived.

This lighthouse could have existed for more than 1,500 years in history, but it was not destroyed by frequent earthquakes in Egypt in 13XX. Therefore, in more than 200 AD, the Alexander Lighthouse was still in its peak service period.

Titus had seen its construction pattern, and of course he felt that as long as there was sufficient investment and stone, the great man could build a larger lighthouse.

After all, technology has improved for 500 years, and the engineering technology of the Han Dynasty is now inclusive, combining Chinese and Western styles, and its own tradition has been preserved. Li Su also organized people to learn Roman technology. So what if you create a spectacle that will increase your height by 20 feet?

Moreover, Li Su and Zhuge Liang themselves invented many construction machinery, such as treadmill cranes and pulley squirrel cage cranes, etc. The mechanization level of wood processing and stone processing has also improved a lot in recent years. Many links can make full use of water energy. No matter how you look at it, the situation is very good.
Chapter completed!