Late Yuan Dynasty: I am the true emperor

Chapter 142 The Marshal's ideas are really wild
This time when he went to inspect the Feixi Iron Works, Lu Jin also brought a group of craftsmen from Luzhou City. He planned to build a large arsenal in Feixi, a one-stop production base from metallurgy to casting to machining.

Before the group arrived at the destination, they saw two blast furnaces standing in the open air from afar, constantly emitting hot steam, which distorted the air above the blast furnaces.

If you get closer, you can see hundreds of bricklayers laying bricks in the water canal, which is drawn from the Fei River and is used to power the ironworks' hydraulic machinery.

"Marshal, the horizontal water wheel in front is built using the method you mentioned. This type of vortex water wheel is very powerful and much easier to use than an ordinary vertical water wheel." Xu Jichuan, who was following the team, hurriedly introduced it to Lu Jin.

Lu Jin nodded. Although he was not a researcher of hydrodynamics, he still understood some basic concepts of water turbines. The traditional downstroke water wheel was the least efficient. Hydraulic plants before the Industrial Revolution in Europe generally used upstroke water wheels. However, the construction of this type of water wheel had extremely high requirements on the terrain and required a large water flow drop.

Hefei is surrounded by vast plains, so it is obviously impossible to build an upward-thrust water wheel. Even if it could be built, it would require large-scale landform transformation, which would be a huge undertaking. So Lu Jin borrowed the horizontal water wheel of the hydroelectric generator, which is equivalent to placing the water wheel flat on the ground, and then building an arc-shaped water diversion channel to impact the water wheel from a tangential angle, and the task was accomplished.

The advantage is that it does not require a large water flow drop, and efficiency can be guaranteed as long as there is sufficient water. The disadvantage is that a set of gear transmission is required to convert horizontal rotation into vertical rotation, but building a set of wooden gears is obviously much easier than changing the terrain.

The group came to the canal. Lu Jin picked up some plaster from the craftsmen and saw that it was white in color, so he asked.

"What kind of ash is this? If I use this to lay bricks, it shouldn't be water-resistant, right?"

Xu Jichuan immediately said, "Marshal, this is plaster made of lime and clay. It is very strong and not afraid of water washing. Besides, even if there is water washing, it can be repaired regularly."

Lu Jin nodded again. China also has the original version of cement. Common brick buildings use a lot of this traditional cement. However, it is somewhat different from the original cement in Europe. In Europe, lime and clay are mixed, sintered, and then ground into powder. In China, lime is directly burned, and then lime is mixed with clay and mud, which skips the mixing and sintering step.

But the cement in China has one more ingredient than in Europe.

"General, in fact, if you want to make the canal stronger, you can also add glutinous rice to the plaster, but now we are short of money and food, so I decided to save this step."

After Xu Jichuan finished speaking, he looked at Lu Jin carefully, thinking that Lu Jin would blame him, but Lu Jin praised him instead.

"Food is for people to eat, not for bricklaying. This is not rice bricklaying, it's human blood and bones. You did a good job. When you build other buildings in the future, you are not allowed to add rice to the ash."

Xu Jichuan was stunned for a moment after hearing this, and felt mixed emotions for a moment. After a while, he clasped his fists respectfully and said, "Yes, I will remember this."

When they arrived at the ironworks, Lu Jin discovered that one of the two blast furnaces was still in the process of baking the furnace, which was dry-burning firewood to dry the refractory clay inside and heat the furnace at the same time. The other blast furnace had already started to produce iron. When they arrived here, Fu Shicai brothers were directing the iron production and the feeding of materials.

A slope was built next to the six-meter-high vertical furnace. Craftsmen worked together to push a small cart and put coke, ore and lime from the top of the furnace. Next to it was a huge wooden bellows, which was pushed and pulled by manpower. Several groups of people took turns. However, behind the bellows, a mechanical interface had been reserved, and once the waterwheel was repaired, it could be converted to water-powered drive.

There was enough coke, ore and lime stored in the yard not far away, and a shed was built on top to protect it from rain and snow.

After all, coke production was started first. Before the furnace was built, Chao County had already been refining coke for a month. Even if three or four blast furnaces were started at the same time, there would be enough coke for use here.

Lu Jincai called them over only after Fu Shicai gave the order to load the materials for this furnace.

"I pay my respects to the commander-in-chief."

"Hahaha, Master Fu is not a commoner. You can command so many craftsmen and manage this iron factory in an orderly manner. How can you be called a commoner? I think you can do the job if I give you an official position." Lu Jin praised immediately.

Fu Shicai was overjoyed when he heard this. He came here from Jiangdong just to make a fortune. With Lu Jin's words, all his efforts these days were worthwhile.

"Thank you for your appreciation, Marshal. I will do my best to make more iron for you and make better iron!"

"Then I would like to thank you on behalf of the soldiers and civilians of Luzhou. Now the soldiers are in urgent need of weapons and armor, and the people are in urgent need of farm tools and iron pots. I am counting on you." Lu Jin pointed to the stove that was still smoking and asked again.

"How many days has this furnace been in operation? How much iron can it produce every day?"

Fu Shicai immediately replied, "General, after the furnace is built, the refractory clay inside is wet. We must first burn firewood to bake the furnace for seven days to completely dry out the moisture, and then add coke ore to smelt iron.

"This furnace has been in operation for three days, producing six batches of molten iron a day. The one just produced is the sixteenth batch. In total, it produces 2,400 kilograms of pig iron a day. The furnace next to it has been in operation for four days. It will be able to produce iron in three days, and by then it will be able to produce more than 4,000 kilograms of iron a day."

Lu Jin raised his eyebrows in surprise. Such a blast furnace could actually produce one ton of pig iron every day? It really can't be underestimated!
In fact, this is just because Lu Jin is ignorant. According to the Han Dynasty blast furnace unearthed in Henan, the blast furnace in the Western Han Dynasty could achieve a daily output of one ton per furnace. Now, more than a thousand years have passed, and at the end of the Yuan Dynasty, the output is still the same. It can only be said that there has been no progress.

And this is just iron smelting, not steel production. It is still quite difficult to produce qualified steel.

When Lu Jin heard that each furnace produced one ton of iron per day, he couldn't help but ask worriedly, "More than 2,000 kilograms of iron are produced every day. Can the ore mined in Lujiang supply it?"

This time it was Fu Shicai's turn to be surprised. After thinking about it, he thought that maybe the commander really didn't understand, so he explained.

"Reporting to the commander, the iron ore can be supplied. I have already marked out the mining area in Lujiang. Let them focus on mining the high-yield magnetite first. Every hundred kilograms of this ore can produce at least 40 to 50 kilograms of iron. Two thousand kilograms of iron a day is four thousand kilograms of ore. Only twenty people are needed every day to supply the furnace.

"The Lujiang County Magistrate has arranged a hundred people to mine. Even if we build a few more furnaces here, we can still supply them."

Well, this time it was Lu Jin's ignorance again. He learned a lot of theory, but had never done much work, especially metallurgical work. He had no idea how much iron ore was in a ton. In fact, there was only ten sacks of ore. The density of coke was relatively low, and one ton of coke could fill twenty sacks.

The iron ore needed here can be transported here by a small fishing boat every day.

If labor is counted, each person only needs to mine two sacks of ore a day. If they can't even do that, they are just slacking off. According to the manpower arranged by Fu Shicai, it is more than enough.

After all, iron ore is not as solid as granite or basalt, and it doesn’t need to be carved into a certain size. You can just smash it and put it in the basket.

Moreover, the Lujiang Iron Mine is an open-pit mine, which is simpler than mining bluestone. The crushed stone is mined from the mining area and transported to the river with a wheelbarrow. It can be loaded onto a ship within two miles and then directly transported to Feixi via Chaohu Lake. It is convenient to have a waterway connection!

For the time being, he really couldn't find any problems with the iron smelting. The output of each furnace was more than one ton per day, which was not a small amount. Lu Jin could only find ways to improve efficiency in machining.

Looking at the empty space with two blast furnaces and an iron factory with only a few sheds, Lu Jin said again.

"We need to build several workshops here. They must be able to shelter us from the wind and rain. We can't stop working when the weather is bad. There must also be accommodation for the craftsmen. Moreover, the workshop must be large, at least six feet wide, and there cannot be a pillar in the middle, because we need to install a gantry crane inside, otherwise it will be difficult to move the heavy artillery."

Everyone was shocked when they heard this. A house that is six meters wide cannot have pillars inside. Even the main hall of the imperial palace does not have such a large span.

This is child's play for modern steel structure factories. In the field of steel structure, spans below 30 meters are considered small spans, spans between 30 and 60 meters are considered medium spans, and spans above 60 meters are considered large spans. A factory building of only 20 meters in width is nothing, but it is a problem for this era.

But it would not work if it was too narrow, because it would have to accommodate machinery and a gantry crane. A large-caliber heavy gun weighed at least 3,000 pounds, and it could not be lifted without a gantry crane. "Su Qing, how about you build this factory?" Seeing that no one was talking, Lu Jin directly mentioned Su Qing, a carpenter. In this day and age, building a house was also the responsibility of the carpenter.

"Great, great commander, a house six feet wide without pillars, how big a piece of wood would be needed for the beams? This may be difficult. Even if we use the method of reducing pillars, it would be difficult to build such a large house."

The method of reducing columns was developed in the Yuan Dynasty. The Mongols might have been accustomed to living in tents and were not satisfied with the houses in the Central Plains. They hated those pillars. Therefore, the official architecture of the Yuan Dynasty highly advocated the method of reducing columns. The more open the room, the better, and the fewer pillars, the better. Through structural mechanics, the middle pillars were moved to the periphery of the house.

Although the Yuan Dynasty already had this technology, the span of twenty meters was still too exaggerated.

However, Lu Jin already had a countermeasure. These ancient craftsmen were too strictly bound by rules. Who told you that when building a house, you must follow the rules of beams, pillars, and brackets? He said immediately.

"Who says you have to use a whole huge tree as the beam? I heard that the stone bridge in Zhaozhou, Hebei, had a main span of more than ten feet, and the wooden bridge in the early Song Dynasty also had a main span of more than ten feet. You can just build a wooden arch bridge on the roof and cover it with tiles."

Su Qing was stunned. Build an arch bridge on the roof? This commander's idea is really wild, but if you think about it carefully, it seems to be feasible. If you calculate it according to the method of building a bridge, the span of six feet is really nothing. China has already had this technology.

He thought for a moment and said, "Marshal, you can give this idea a try, but an arch bridge needs piers. If the piers are not strong enough, it will not hold up. It will probably be difficult to support it with only two walls."

Lu Jin continued to give advice, "Then you can build two rows of brick buildings on both sides and use them as bridge piers. The weight of the brick buildings will definitely not be pushed down by the roofs. The middle is the factory building, and the brick buildings on both sides can also be used as warehouses, or for offices, or for craftsmen to rest."

Su Qing slapped his thigh and said, "This is a good idea, Marshal, this idea is amazing, I know how to build it."

"Once you know, we'll start designing as soon as possible. It just so happens that you're in charge of the hydraulic machinery here, so take a good look at the location and figure out how to build the factory and how to get the water channel in there."

"Yes."

After finishing the design of the factory building, it was almost noon, and Lu Jin had another meal with the craftsmen here. Currently, the iron factory's meals are specially allocated by the Construction Bureau. However, there are many craftsmen gathered here, and it still attracted many small vendors. Some people even spontaneously set up a sesame cake stall here.

After seeing this, Lu Jin immediately paid for everyone to have a meal of sesame cakes. Looking at the sesame cake vendor rolling the dough, Lu Jin asked Xue Gang and Sui Gu.

"You two are both blacksmiths. Let me ask you, what is the difference between kneading dough and forging iron?"

The two of them were stunned while chewing the sesame cakes, and then Xue Gang tried to answer.

"The iron needs to be struck while it is hot, but the noodles are cold, so it takes more strength to strike the iron."

"Anything else?" Lu Jin asked again.

The two looked at each other, unable to explain what was going on.

Seeing that they couldn't come up with an answer, Lu Jin immediately said, "In other words, apart from these two points, there is no difference between forging iron and kneading dough, right?"

The two still couldn't explain it, but they would not admit that forging iron was as easy as kneading dough.

Lu Jin pointed at the rolling pin in the vendor's hand and said, "Look, if you want to press the dough into thin sheets, you just need to roll it back and forth with the rolling pin. If you replace the dough with a red-hot iron block and roll it back and forth with an iron roller, can you make a thin iron plate?"

"This..." Xue Gang didn't know whether to laugh or cry. This general had so many amazing ideas that he didn't know how to complain for a moment.

"General, there is no blacksmith in the world who has ever used this method to forge iron."

Lu Jin said, "Just because it didn't exist before, does that mean it's wrong? Since red-hot iron can be used to draw wire, why can't it be rolled into iron sheets? Think about it, if there is such a 'rolling mill', can't we quickly produce thin iron sheets?

"If we can produce a large number of iron sheets and plates, then cut them into small pieces, punch holes in them, and then dip them in fire, can't we make a lot of armor plates? Isn't this much faster than hammering them one by one?"

"This..." Sui Gu fell silent after hearing this, but Lu Jin's idea was indeed very tempting. If there really was such a machine, it would definitely greatly improve production efficiency.

Seeing Xue Gang didn't say anything, Lu Jin continued, "If you can grind out an iron plate, and then use the iron plate to roll a gun barrel, wouldn't it be faster?"

Xue Gang's eyes suddenly lit up when he heard this and he nodded quickly. If this thing really existed, how much less work would he have to do?

"But if you want to grind the iron into iron sheets, how big a millstone do you need? If it's too small, I'm afraid it won't be able to grind it."

Lu Jin said this only because he was sure of it. Since they could build a hydraulic boring machine, there would be no problem in building a hydraulic rolling mill as well. At least there was no technical barrier.

The maximum weight of a single roller of a modern commonly used small four-roller rolling mill is six tons, which is 12,000 kilograms. The Qing Dynasty cast coastal defense guns weighing tens of thousands of kilograms, and the Tang Dynasty also cast a single 30-ton iron ox for the Yellow River. Therefore, it is technically feasible to cast an iron roller weighing more than 10,000 kilograms.

Lu Jin then said, "We can forge two five-inch thick iron rollers, make a frame, stack the two iron rollers up and down, and use a waterwheel to drive them to rotate. Each roller should weigh several thousand pounds.

"If it's still not heavy enough, we can also cast two heavy rollers weighing tens of thousands of pounds, press them on the light roller to provide gravity, put the red-hot discus in between, and roll it repeatedly. It will definitely be thinner. The specific thickness can be determined by the number of rolls. Do you think it's feasible?"

The two thought about the structure that Lu Jin mentioned and it seemed to be feasible. "Marshal, I'm just afraid that we can't build such a large mill."

At this time, Lu Jin glanced at the ironworker Shen An next to him. This guy used to cast bells. When he saw Lu Jin looking at him, he hurriedly said.

"The iron roller the Marshal is talking about is similar to a stone mill. It doesn't need to be cast with characters or carved with patterns. It's relatively easy to make as long as there's enough iron. More than 10,000 pounds is nothing. It's just a solid lump of iron. But I thought about it. The thing the Marshal wants needs to be rounded on the outside. I'm afraid it's difficult to polish."

A cast iron part weighing more than 10,000 kilograms is really nothing. In the Tang Dynasty, there was the Yellow River Iron Ox which weighed 30 tons each, in the Ming Dynasty there was the Yongle Iron Bell which weighed 3 tons each, and in the Qing Dynasty there was the Cangzhou Iron Lion which weighed dozens of tons. Don't underestimate the ancient cast iron technology.

Shen An can cast iron pieces weighing tens of thousands of pounds, but he cannot guarantee smooth precision. However, Lu Jin has a way to do this.

He immediately proposed the method of centrifugal casting, which opened the eyes of the people who heard it.

According to Lu Jin's method, one can first use centrifugal casting to cast several iron pipes, and then pour molten iron into the iron pipes to make solid iron rollers.

Such rolling mill rollers certainly cannot be compared with modern rolling mill rollers that are forged first and then turned, but in the late Yuan Dynasty, it was already considered black technology. As long as he could roll large pieces of thin iron plates, he could quickly produce armor.

This is Lu Jin's ultimate goal.

(End of this chapter)