Qingque and Datou walked over with a basket of charcoal, put it on the ground, and waited for Fang Jing's next operation.

"Brother Jing, we got the charcoal, do you want to fetch water?" Qingque's face was full of excitement, more because of the desire to learn, maybe because he could participate in the idea, or maybe because his father came to show it in front of his father.

"Well, let's go fetch a bucket of water." Fang Jing didn't pay attention to Qingque's performance, you can do whatever you want, Qingque's parents are here, and she feels a little weird in her heart when she orders her like this.

Fang Jing wanted to unscrew the lid of the water pipe, but was scalded by the iron pipe, thinking that the water in the boiler was still steaming.

"Daying, go get a piece of cloth for your cousin." Fang Jing had to call Daying to get a piece of cloth out, and waited for Qingque and Datou to come back with water, so that they could wet the cloth so that they could unscrew the cover.

After Qingque and Datou came over with two buckets of water, Fang Jing took the cloth and got wet, unscrewed the lid, and was almost scalded by the steam, Fang Jing was a little helpless, there was a problem with this method he designed, if he had to add water every time, and he would be scalded by the steam, it would be a big trouble, and he would have to change it after he came.

The pipe for adding water is connected to the boiler, although it is only the water inlet, but only when water is added to the boiler, the shrapnel inside will automatically pop up, and when the steam rises, the steam pressure will resist the shrapnel, but there will still be steam coming out.

Fang Jing secretly said in his heart, if he really wants to build this train in the future, he has to build two water chambers, otherwise this steam leaks, then it is possible to leak all the steam, then he can only stop on the middle of the road, waiting for the next fire to boil the water.

Fang Jing was also helpless in his heart, after all, he was not an industrial designer, let alone a mechanical designer, and he even had a lot of pipes outside in a mess, not to mention designing this small locomotive, this is a grand project, Fang Jing took a month to build a simple locomotive, which is already very rare.

Fang Jing had no choice but to open the vent pipe and slowly discharge all the steam out of the boiler, otherwise if he added water directly, if he didn't burn himself, it would be a miracle.

"Zi ......" When Fang Jingyi opened the vent pipe, steam mist sprayed out, fortunately, there was no one in front of the vent pipe, otherwise, this person would have become a steam pig.

Half an hour later, the steam in the boiler was finally exhausted, Fang Jing carried the bucket and poured water into the water inlet pipe, after pouring a bucket of water, Fang Jing closed the vent, screwed the water inlet pipe, opened the combustion chamber, and stuffed charcoal into it, the charcoal in the combustion chamber has not been extinguished until now, and Fang Jing is saved to burn charcoal again.

The combustion chamber has an air inlet, and an exhaust port, in order to provide air to the combustion chamber, easy to combustion, if it is a confined space, it is estimated that it is impossible to burn, Fang Jing squatted in front of the locomotive, staring at the instrument to check, as the temperature water pipe instrument rises, the pressure value of the pressure gauge rises to a certain scale, Fang Jing can determine whether the steam in the boiler has reached the time that can be started.

Li Shimin and his wife, who were standing on the side, were also curious in their hearts, they only needed to add some charcoal and water to drive this small iron train? Just now, Li Shimin walked to the front of the locomotive, and carried it with his hand, and found that he could only move a little, this is a locomotive weighing nearly 100 kilograms, but it is not made of wood.

"Holy Lord, Queen, stay away, when this steam is discharged, it will hurt people, and the little babies are also far away." Two quarters of an hour later, Fang Jing saw that the value of the meter could reach the starting scale, and then he shouted to everyone.

"Yes, sir, you can do it." Li Shimin and his wife took the little baby away a little, but the distance was only three or five meters, and they didn't get any farther.

Fang Jing didn't care anymore, and directly pulled down the door valve lever and pulled it to the intake gear, 'Zi...... Click...... Clang...... 'Various sounds indicate that the train is ready to start.

The large wheels of the locomotive are propelled by the steam propulsion, and the connecting rod drives the other small wheels to start moving forward.

'...... Syllable...... When the ......' train dragged the two small carriages behind it and began to move forward slowly, Li Shimin and his wife were staring at the progress of the small train like a monster at this time.

Fang Jing followed the small train, and when the speed could reach the speed of his own walking, he pulled down the door valve lever and went directly to the acceleration gear, and then left to stand beside Li Shimin and his wife, staring at the small train in the field and began to accelerate around the hardwood track.

"Sir, this ...... This ......" Li Shimin was shocked and opened his mouth wide, and he couldn't make any sound in his mouth, and the scene he saw in front of him had subverted his cognition.

"Sir, is this train really just charcoal and water to move forward?" The queen recovered quickly from the shock and asked Fang Jing.

"Queen, you also saw just now, this little train only has charcoal and water, charcoal fire boils water, produces steam, and then through some principles, pushes the wheels to turn, so that it can run forward quickly, but it is only limited to traveling on the track, it can travel on the ordinary ground, but the speed is as slow as an ox." Fang Jing had no choice but to explain to the queen,

"Brother Jing, what is the principle of that? I've drawn a lot of pictures, but they don't feel right, Brother Jing, you won't tell me about it. After listening to Fang Jing's words, Qingque hurriedly opened his mouth and asked Fang Jing, can you not lose this opportunity.

"This principle, I used to talk about in class, steam in a confined space, will produce pressure, and when the pressure value reaches a zero point, if there is no vent, then it may explode, then if a pipeline is designed to become the steam vent, then the steam will be continuously generated, and the steam discharged from the vent is also a kind of pressure, when the pressure value reaches a certain level, connect a certain device, you can drive the wheels, so that the train can move forward."

After Fang Jing listened to Qingque's question, he opened his mouth to explain to Qingque, it was simple and easy to understand, even if he didn't understand the principle, but what Fang Jing said was already the most understandable to normal people, if he really didn't understand, then Fang Jing probably couldn't do anything, not to mention, Fang Jing sometimes transmitted this concept to the students when he was in class, as well as some knowledge.

"Brother Jing, I understand, as long as there is steam, it can push the wheels and drive the train, but how much pressure does it take to drive the train forward?" Qingque is like a good student, as long as you don't understand, you want to ask clearly.

"This pressure value, in fact, we are not experimenting, this needs to be tested step by step, in order to determine the final appropriate pressure value, but also to check the leakage points of the pipeline, otherwise the next experiment, these leakage points increase, then it can be directly sprayed with water or steam." Fang Jing is not a technician who knows a lot about steam trains, but she has also read a lot of books.

As for what kind of train was built in the Tang Dynasty, Fang Jing can say with certainty that it is basically impossible to achieve, at least the current iron-making technology cannot reach the level of making trains, let alone these bending techniques, the elbows are easy to do, but the difficult ones are sealed, and the material of the elbows.

Even if the current Tang Dynasty can smelt ordinary steel, it still can't make alloy materials, each type of steel has a different carbon-sulfur ratio, and the alloy is even more different, so if you want to build a train in ancient times, it can be said that it is just a dream, and it is a big dream.

"Sir, dare to ask how long this train can run? How far can you run? Li Shimin recovered from the shock and asked Fang Jing with a confused expression.

"Holy Lord, how long can this train run, or how far it can go, depends on how long the track is built? It also depends on the amount of charcoal and the amount of water, and there are not many other basic requirements, of course, if the locomotive burns out, then it is another matter, along the track can reach all the places that can be reached, where you want to stop, as long as you close the intake valve, the train will also slowly stop, if you want to start, as long as you pull down the door valve, you can naturally start it, of course, you have to add some charcoal and water. After Fang Jing listened to Li Shimin's question, she also replied casually.

"How about shipping goods? What about the loaders? Li Shimin asked again, his heart full of questions, just like the original Qingque.

"If it is a train of normal size, the carriage can reach four or five zhang long and about one zhang wide, but it can drive about ten carriages to transport goods or people, and the saint can calculate it." Fang Jing didn't know what Li Shimin wanted to transport, but if he transported people, it would be no problem to transport three or five hundred people in one carriage, and if he transported a thousand people in one carriage, it could also be done, anyway, this is the Tang Dynasty, there is no location limit, so what's the harm in squeezing it.

If you really want to transport grain, a carriage can transport more than 100,000 catties, and other heavier things can only be calculated according to this power.

"This ...... So how much does this track cost? How much does this train cost? Li Shimin said in his heart that he naturally knew how large the volume of these ten carriages was, and if he transported people, ten trains, he would be able to transport tens of thousands of people.

"Shengshang, the cost of this track is not cheap, normal size trains, need to use rails, but also need sleepers, small stones, it is estimated that the cost of a mile is not small, sleepers are good, as long as there is the corresponding wood can be cut to make sleepers, but this rail, need different processes to build, the cost of personnel, food and drink, this price should be counted in the saint, it is estimated that the cost of this will also cost a lot of money."

"The cost of this locomotive, it's not that I said cool words, with the current ironmaking technology, it can't be done at all, unless it can be made of better steel, it can be built, not to mention some other small things, it is even more difficult than steel, even if the saint spends a lot of money to make it with 100 steel, how high the cost can imagine, so at present, we can only invest in the research of ironmaking technology, maybe ten or twenty years later, it is possible to build this locomotive."

It's really not Fang Jing's information to attack Li Shimin, the steelmaking technology of iron and steel can be said to rely entirely on manpower, but there is no degree of industrialization, and if you really want to build this locomotive, it is more difficult than climbing to the sky.

"This ...... Could it be that so many people in Datang can't build this train? When I return to Chang'an, I will inevitably summon people to discuss, such a great good thing cannot be completed, twenty years, too long, I can't wait. Li Shimin understood what Fang Jing said in his heart, and he also knew the current situation of Datang, although the whole Datang territory has been pacified, but at present, there are many disasters in many places, and the personnel of the whole Datang are tightened to eat and clothing, but they can't afford to spend this huge expense.

"Holy Lord, Queen, it's better to let this matter go first, first solve the current problem of eating for the whole Tang Dynasty, and then consider the others, at present, there are still many people in the Tang Dynasty who can't eat enough, and they are all living in dire straits, I ask for the Holy God for those poor people." Fang Jing didn't want Li Shimin to miss this train, and hoped that Li Shimin would still focus on the common people in the world.

PS: In the collection of villain names in this book, if you are interested in the book, please submit it in the comment area, thank you.

()