The Rise of the European Emperor

The difficulty of building a concrete road is much lower than the difficulty of opening a road in the jungle before. After all, it doesn't require cutting down trees. In fact, the amount of labor for cutting down trees is not very large. The really large amount of labor is digging the roots and transporting the trunk and roots away.

In the tropical rain forest, there are many thousand-year-old trees, each with a height of tens of meters, and the root area is also extremely large. The older the tree, the thicker the roots, and the more intertwined, the distribution area is quite large. The roots of the roots of these thousand-year-old trees are widely distributed, and they are all deep in the soil, making it extremely laborious to dig.

Therefore, the Panama colonial team led by Gollard took so long to open up this road. In addition to cutting down trees, it is also necessary to consider drainage issues and choose a place with higher terrain. Also, try to avoid rivers as much as possible. After all, to cross one more river, you need to build a bridge.

In this era, without construction machinery, it was very troublesome to build bridges. For example, a small stone bridge takes many masons months to build. And this time Gollard's report mentioned that this road has to pass through 24 small rivers and 3 large rivers... These 27 bridges are as troublesome to build as the entire cement road...

Constructing a cement road is actually very simple. Without a road roller, Marin could have the masons build a few more stone poles, and let a few black people use fiber ropes to pull and flatten the roadbed together. Gollard's subordinates now have more than 6,000 strong black slaves. As long as there are enough stone drums, it is relatively simple to build roadbeds.

After laying the roadbed, the line is laid out with lime. This needs to be measured to ensure that the distance between the two lime lines is 3.5 meters or 4 meters. This is not difficult, just take a ruler to measure it.

After that, bricks were erected on both sides of the road...

The purpose of the vertical brick is very simple, it is to set the limit of the cement poured on the cement pavement. At the same time, the height of the bricks standing sideways is the thickness of the cement pavement. Therefore, the purpose of standing bricks on the side, in addition to serving as a boundary, also serves as a reference for pouring cement. At the same time, there are bricks to protect both sides, and the cement will not leak to the outside. Of course, after the bricks are erected, you need to mix a part of the cement and apply it between the bricks to fix it.

After that, the biggest problem is the cement mixing. Cement mixing is a pure physical activity, but also requires technology. Because, in addition to mastering the ratio of cement and sand, it is also necessary to pay attention to the amount of water added. Therefore, this link requires the participation of professionals. At the very least, have a professional instructing labor on how to stir.

After mixing the cement, the rest is simple. Just let the young and middle-aged people pack the mixed cement in a bucket and pour it between the bricks standing on both sides. Then, pat and flatten it with a wooden board. Seeing that the pressure is almost there, I will use a long wooden board or a long stick to stick to the upper edge of the bricks on both sides and scrape it hard. By this, use a large wooden board to press on the road surface to make the road surface firm enough.

The last step is to square and line.

Square cutting means that every other section of the cement road will be cut with a knife, so that the road surface is divided into pieces. In fact, this is to prevent cracks in the pavement due to thermal expansion and contraction of the exposed surface of the cement. And the line is to use a knife-shaped wooden board to press shallow lines on the exposed surface of the cement. These shallow lines are to prevent the cement road from being too slippery on rainy days...

The pouring and post-processing of cement pavement is not difficult. On average, it can be done by hundreds of people paving one kilometer a day. Gaullard had more than 6,000 strong black slaves. Even if the blacks were not proficient in labor, they could still lay a few kilometers a day. The premise is that Marin needs to send a group of craftsmen to guide them.

Finally, there is the problem of drying of the cement pavement. This stage takes a long time. Generally, it takes one month (standard 28 days) before the cement road can be put into use. Until then, the cement surface needs to be maintained. Don't be afraid of drying and air-drying, but most afraid of rain in the middle.

Therefore, during the drying period of the cement surface, it is necessary to prepare a cover. For example, straw mats, straw curtains, etc. Once it rains, cover the exposed surface of cement that has not yet dried to avoid continued moisture and prolong the drying time.

It is precisely because the drying period is too long that the construction time of a general cement road, even a small rural cement road of several kilometers, takes several months. It's not that it takes so long to build a concrete road, but it takes a month to dry a kilometer of concrete road...

Therefore, as long as the materials are available and the guidance of skilled craftsmen is provided, the concrete road can be built very quickly. But Marin doesn't expect them to fix it any faster. why? Because the time of laying the roadbed is uncertain... In modern times, there are road rollers to help, and the time required for laying the roadbed is very short. And using Uncle Hei to pull Shi Yan down the road, God knows how long it will take...

...

In fact, it is not very difficult to build a village-level concrete road, even in ancient times, as long as it is out of the way. However, the 24 small bridges and 3 bridges gave Marin a lot of trouble.

This era is not the later generation, with a large number of construction machinery. Marin remembered that in later generations, bridges could be built in as fast as 5 minutes. Of course, that kind of bridge. As long as the cranes are hoisting concrete slabs (or simply iron slabs) made of reinforced concrete across the banks of the creek, a proposed bridge is a success.

However, there are two prerequisites for this, that is, the strength of the cement board or iron board is high enough. Because, this is to travel, and the carrying capacity must be strong. In addition, this bridge is only suitable for narrow streams. For a slightly larger river, it is not so easy. When it comes to building piers, it's not easy. If an arch bridge without piers like Zhaozhou Bridge is built, the engineering difficulty will be even higher.

However, Marin does not have a high-strength cement board in his hand now, and he will not be willing to make such a big iron board as a small bridge. Now that iron is so expensive, the big iron plate might be stolen... Moreover, before the stainless steel came out, ordinary steel bridges were exposed to the wind and rain, and it was easy to rust and then collapse... Besides, even if there is stainless steel, You can't have the luxury of building a small bridge. At least, in this era, no idiot would use a treasure like stainless steel to build a bridge...

However, if a bridge is built using traditional methods, such as a small stone bridge, it will take a large group of masons and several months of labor to complete. 24 stone bridges require a lot of craftsmen, and the working hours are also very long. It is estimated that it will take more than two or three years to complete the construction of 24 small stone bridges.

This is still a small bridge, and the bridge is even more finished. In this era, there is no ability to build bridges. In the absence of stay-cable technology, bridge piers must be used to build bridges. However, building piers is a technical job. The piers of the small bridge are easy to handle, but the piers of the bridge are difficult to get. Because, to repair the piers, you have to drain the water first. Then, piling can be done. Before piling, it is necessary to do calculations and site selection... It is very troublesome to complete the whole set... With the current technology, whether it is to drain the water in part of the river or to build large bridge piers, it is difficult to do .

Of course, it is also a pity to follow the example of the Luding Bridge on the Dadu River, where iron cables cross the river and then are covered with wooden boards... However, most people leave such a bridge, and horses and carts cannot be used. But Marin built the concrete road on the Isthmus of Panama to transport goods. In the future, the carriages must be heavy to transport gold and silver from the Potosi silver mines. This kind of cable-stayed bridge must not be used to walk a carriage full of gold and silver...

If it were to fill up the river and build bridges... the bridges on the small rivers were just enough, it would be unrealistic to fill three big rivers to build bridges...

"Could it be that we can only use the ferry method to cross the big river?" Marin thought while scratching his head in the captain's room.

However, it is very troublesome to let a carriage full of gold and silver on the ferry, and it is easy to delay time. If there are bandits who take the opportunity to intercept them in the middle, it will be very bad.

Annoyed, Marin went to rest on the deck and looked out at the sea...

walk on deck...

"Deck!" Marin's heart was shocked...

"It seems that a pontoon bridge can be built!"

When the army marches, pontoon bridges are often built. Generally, pontoon bridges are built with boats, rafts, etc., and can temporarily march large troops.

However, the pontoon has a troublesome place, that is, it affects the navigation of the river. If it is a temporary pontoon bridge, it is fine. If a long-term pontoon bridge is built, then this pontoon bridge is equivalent to cutting off the navigation channel of the river. If the pontoon bridge is not withdrawn, no other ships will think about it... Then, the inland shipping of this river will be abolished...

So, generally speaking, no one wants to build a permanent pontoon bridge over a river. The pontoon bridge was temporarily built only when the army was marching.

Marin didn't bring any civil servants, and Schwartz wasn't there, so he didn't know who to talk to. So, he had no choice but to play the piano to the ox, and talked to Kahn, the rambunctious guy.

As a result, Kahn, who was fighting a roast duck, asked strangely:

"Master, what is inland shipping? Why are you doing inland shipping in Panama?"

Seeing Kahn, a scumbag with a curious look on the baby's face, Malin was so depressed that he almost vomited blood. But suddenly, he reacted——

"Yeah, why should I think about kernel shipping in Panama?"

Panama is already a colony, and Marin doesn't want to develop large-scale development there. Why should he care about the impact of inland shipping there? To put it badly, there is no inland shipping there at all. Maybe, but it's just a canoe for the Native Americans. Even if you encounter a pontoon that blocks the river, carrying a canoe around it is...

I was also stunned, and considered the Panama region as the land. In fact, the only useful thing in the Panama region for Marin is the transit function here. Others, Marin can ignore it...

After suddenly realizing it, Marin found that these 24 small bridges and 3 bridges can all be replaced by pontoon bridges...

Marin first planned to send boat builders to Panama to use locally cut wood to make more inland river boats, and then line them across the river to make pontoon bridges.

However, it takes a long time to build a ship, and it is still a waste of materials... Marin needs to realize the opening of the cement road on the Isthmus of Panama as soon as possible, so he does not want to wait...

After thinking about it, Marin suddenly found out that the logs cut down from the tropical rain forest can be tied into a super-large raft directly across the river...

Logs are inherently floating, and the larger the log, the stronger the floating ability. A pile of logs with a length of tens of meters that have been felled is gathered and tied together, and it is easy to form a pontoon bridge across the river. Moreover, the load-bearing capacity is very strong. At least, crossing the carriage is not a problem.

Even big rivers (in fact, the big rivers in Panama are not very big), as long as you get enough logs and tie or nail them into a group, you can cross the big river.

The pontoon bridge made of so many tens of meters long and thick logs lined up together is not a problem...

Moreover, Gollard and several thousand blacks had just cut down an 80-kilometer-long road from the tropical rainforest by cutting down trees. On the way, there were huge logs that were cut down. As long as a lot of manpower is used, these logs along the road are pushed down the river and tied into a super-large raft, which can be made into a large pontoon bridge that can be used for horse racing.

Because the source of logs is extremely rich, it basically does not take too much time to build a pontoon bridge. Even with 27 bridges, it's not too much trouble...

Of course, the pontoon made of this oversized raft will not last too long. But what Marin needs is to put it into application quickly, and speed is the most important thing. As for the long-term point, Marin will build a serious concrete bridge beside the pontoon bridge, which will replace the pontoon bridge made of logs in the future. However, because there are pontoon bridges made of log rafts, the construction of cement bridges or stone bridges will not be so stressful. Just use log raft pontoon bridges... Later, if you have the energy and financial resources, then build a formal bridge. , to replace this temporary pontoon...

It's just that the pontoon bridges on the 24 small rivers are relatively easy to replace by cement or stone bridges, but the bridges on the three big rivers are difficult to replace. After all, the river is too wide and the water volume is too large. With the current technology, it is difficult to build a bridge across the river.

However, fortunately, the log resources in Panama are very rich and can be cut anywhere. The big deal, if it is broken, I will cut down a few more trees to repair the three log pontoon bridges...

Thinking of this, Marin immediately wrote an order document and sent someone to Panama:

"You can use the felled giant logs to make or nail into giant rafts, cross the river banks, make bridges, and ensure the unimpeded passage of carriages..."

Anyway, Marin's meaning is very clear - first use the pontoon bridge made of giant rafts to connect this road first. As long as this road is open, whether it is to transport the precious goods from Daming on the Pacific route, or the silver of Peru and the saltpeter of Chile, it can be started. Once the profit has been recorded, it will be simple to use the funds to repair the bridge in earnest. Anyway, after the pontoon bridge, there is no need to rush to repair the regular bridge...

Even a broken pontoon bridge can last for several years. There is no sea maggots in the Danshui River, and the pontoon bridge can be maintained for several years or more. Before the life of the pontoon bridge expires, it is estimated that it is still possible to replace all the 24 small bridges along the line with regular bridges. As for the bridges over the three great rivers, I can only say more. With the level of engineering technology in this era, God knows when a formal bridge across the river can be built...

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