Please ask me to be the emperor

As soon as Zhang Shun finished speaking, Governor Zhang showed off like he was offering a treasure: "This ten-thousand-jin Hongyi cannon is one foot, seven inches and two cents long, with an outer diameter of one foot and six inches, an inner diameter of five inches and six cents, and a tail diameter of two feet, one inch and nine cents." It can be loaded with 240 taels of powder and shoot 480 taels of iron bullets."

"After the cannon is completed, the sound is like a thunderbolt, the bullet is like thunder, and the cannon is corroded for dozens of miles..."

"Wait, wait!" Zhang Shun stretched out his hand to stop Governor Zhang from boasting and did some quick mental calculations.

One catty is sixteen taels, isn't four hundred and eighty taels just thirty catties?

Zhang Shun remembered that the density of iron was 7.8 grams per cubic centimeter. He used the method of measuring density to estimate that one pound in the Ming Dynasty was about 600 grams, and one inch in the Ming Dynasty was about 3.2 centimeters.

By successive calculations, we can see that the shell weighs 18 kilograms and the caliber of the artillery is about 180 millimeters.

It’s totally not enough!

Zhang Shun remembers the era of giant ship artillery in later generations. Without main guns above 200mm, he was embarrassed to go out and meet people. Even some battleships had a terrifying caliber of over 400mm.

Zhang Shun squatted down and held out a straw stick. He wrote calculations on the ground for a long time. He threw the straw stick away and said with a big mouth: "The original design was too conservative. If the caliber is expanded to six inches and a half, the shells must be at least heavier." Fifty pounds!”

Governor Zhang almost cried when he heard this. My design is a heavy Hongyi cannon that fires 30 kilograms of shells.

Your boss opened his mouth and almost doubled the ammunition for me. Isn't this a joke?

Is Zhang Shun kidding? Of course not.

He was currently in the process of casting the cannon, and after many experiments, he discovered a problem.

Most of the guns that exploded exploded from the rear part of the gun, or from the gun chamber to be precise.

According to Zhang Shunli's original analysis of the stress on various parts of the artillery measured using red copper, the pressure in the medicine chamber was far greater than that of other parts of the gun barrel.

In other words, the modular system transmitted from the West actually has big flaws in the data.

According to the modulus theory passed down from the West today, if the inner diameter of the gun is a, then the muzzle wall thickness is 0.5a, the muzzle outer diameter is 2a, the wall thickness at the lug is 0.75a, and the bottom diameter thickness is 3a, and the gun The length should be more than 20 times the artillery caliber.

The 10,000-pound Hongyi cannon designed by Captain Zhang based on Western models exploded as soon as it was fired, and the cannon wall had to be thickened.

The actual designed outer diameter of the gun has reached three times the inner diameter; the bottom diameter is close to four times the inner diameter, which is one of the reasons why the gun is too heavy.

However, judging from the results of Zhang Shun's experiment, this 10,000-pound Hongyi cannon actually used insufficient materials in the key part of the medicine room, and used more materials in unimportant parts such as the barrel, resulting in excessive dead weight. .

Therefore, Zhang Shun's idea is very simple. After increasing the caliber of the Wanjin Hongyi cannon, he only needs to strengthen the cannon's medicine chamber, which should be able to meet the requirements.

Thinking of this, Zhang asked by the way: "These few times the artillery exploded, where were the cracks probably?"

Governor Zhang was unhappy, but there was nothing he could do against his lord.

He had no choice but to frown and respond while thinking: "There are six doors... no, seven doors exploded from the rear; three doors exploded from the front, and one door exploded from the middle!"

Oh? Although it is somewhat different from what I thought, it does not seem to affect the conclusion very much.

Zhang Shun thought for a moment and realized that other parts exploded, probably due to the quality of casting.

He then smiled and said, "Mr. Zhang, don't be troubled. Let's try my method to cast two doors first. If it really works, wouldn't it be great?"

"If it doesn't work, it's never too late to try again!"

"Okay!" Governor Zhang cheered up after hearing this, and asked Zhang Shun for advice on the dimensions of the new cannon.

"First cast a cylinder from pig iron, nine feet seven inches long and six inches five inches in diameter, as a standard."

"Then wrap it with a half-inch-thick wrought iron bar that is red-hot. Hammer it until it reaches three-thirds, and make sure the joints are forged into one piece. When the first layer is completed, wrap the second layer staggeredly, just like hammer forging!"

"Both layers are completed, and the wrought iron wall is hammered until it is about six minutes thick. Then two more layers are wrapped around the back end, about a foot long, to strengthen the medicine chamber."

"Then take it out and put it into a mold to use as a cannon core. Inject it with pig iron. After the molten iron cools, take it out for use!"

"The muzzle is about one foot four inches thick, the wall thickness at the ears is about one foot seven inches, and the tail is two feet two inches thick. The overall weight is about 10,000 kilograms. What do you think, Mr. Zhang?"

"Isn't the muzzle and ear of the gun a bit too thin?" Although Governor Zhang was a little disgusted with Zhang Shun's "blind command", he still expressed his concerns in a responsible manner and based on his own experience. .

"It should be no problem!" Zhang Shun patted his chest and assured, "I was making cannons in Shanxi before and didn't know how to do it, so I asked the craftsmen to try it out in many ways. After verification, I found out: the power of gunpowder is all in the medicine chamber, the barrel, the cannon and the cannon. It’s just that I can’t bear the rest of the force.”

"If it is cast correctly, not only will the cannon body be lighter, but its firepower will be much greater than that of the original cannon!"

Although Governor Zhang still had some disbelief in his heart, he was so upset by the "Optimus Prime" artillery in Shanxi that he had no choice but to obey orders honestly.

Since the pig iron had been repeatedly smelted before, some of it had been decarburized and turned into "wrought iron", so Governor Zhang divided the craftsmen into three parts.

Some are responsible for picking iron ore and opening furnaces to smelt pig iron; some are responsible for making sand molds and preparing for casting; and some are using the hydraulic forging hammer "invented" by Zhang Shun to hammer wrought iron, and then wait for the pig iron core to be made to forge artillery. Bore.

There are difficulties in this:

For example, casting a 10,000-kilogram Hongyi cannon requires more than 10,000 kilograms of molten iron, and the crucible iron smelting method commonly used in Shanxi can only produce more than a hundred kilograms of crude iron at a time, which is not enough.

Governor Zhang had no choice but to choose the blast furnace iron-making method with slightly inferior iron quality, which could produce six to seven hundred kilograms of molten iron at a time.

Only seven or eight furnaces can be refining at the same time to make a mold.

Making a sand mold seems to be the simplest, but how to fully mix the sand and clay is also a big problem.

If there were no mixers in this era, it would be impossible to produce so many qualified clay and sand mixtures at once.

Governor Zhang ordered the craftsmen to mix it with small buckets and inspect them one by one. Only those qualified can be used on the mold.

The mold was made, but it was difficult to use when wet, so we had to put wheat straw into the mold, light it and slowly dry it over a low fire.

On the contrary, forging the wrought iron cannon breech, which is the most labor-intensive, is the simplest. Not only does it have a hydraulic forging hammer as a boost, but Zhang Shun's method of rolling the wrought iron around a pig iron pillar is also simple and easy.

But when the cannon barrel was forged, the pig iron pillar was caught in it, and eight oxen could not pull it out.

what to do? Zhang Shun had no choice but to use the principle of thermal expansion and contraction to immerse the iron pillar wrapped inside in cold water and heat the wrought iron barrel outside to separate the two.

Zhang Shun, Governor Zhang and others worked together and spent half a month to finally cast the cannon.

"King Shun, please open the mold!" Governor Zhang respectfully asked for instructions.

"Okay!" Zhang Shun looked at the two big guys half buried in the ground in front of him and nodded.

He was quite in the mood of playing games in his previous life, saving enough for a ten-game series, and preparing to draw cards.

Right or wrong, success or failure, all in one fell swoop!

The version of the artillery written about in this chapter, designed by Governor Zhang, is based on the late Qing Dynasty's 10,000-pound Hongyi cannon "General Yaowu", while the protagonist's design is based on the British 68-pound naval gun.

According to later cannon casting theories, the weight of the cannon body should be about one hundred and fifty times that of the cannonball. The artillery shell designed by the protagonist weighs fifty kilograms. One hundred and fifty times it should be seven thousand five hundred kilograms. In view of technical limitations and the fact that the charge in the late Ming Dynasty was higher than that of later ones, it was enlarged to ten thousand kilograms. As the protagonist's siege weapon!