Black Corporation: Joseon [EN]: Chapter 59

Jjangeura

Hello, Bomb

59. New Weapons (7)

“Making the Bigeokjincheonleoi [a type of Korean bomb] in the original way is too inefficient.”

The original Bigeokjincheonleoi used a sphere made of cast iron. From Hyang’s 21st-century perspective, this was a problematic method. Of course, creating a hollow, spherical shape was technically excellent, but it wasn’t a recommended method in terms of production efficiency.

“Considering the performance, ‘shut up and mass-produce’ would be better. We need to be clever.”

The first measure Hyang took was to split the Bigeokjincheonleoi’s sphere into two.

Hyang changed the design so that one hemisphere had internal threads, and the other had external threads. When the two hemispheres were screwed together, they would form a complete sphere.

Hyang also applied threads to the part where the time fuse was inserted and the hole for adding gunpowder. He made the lid covering the time fuse and the cap sealing the gunpowder hole more secure by adding threads to them as well.

Hyang then conducted a firing test with the prototypes.

“First, let’s exclude the process of launching from the Wan’gu [a type of Korean cannon].”

“Yes, Your Highness.”

The test results showed that the improved Bigeokjincheonleoi exploded perfectly as Hyang had expected.

“Amazing!”

“Should we send it to the North right away?”

Lee Cheon and Choi Hae-san, who witnessed the test site turned into a mess, couldn’t stop admiring it. However, Hyang shook his head with a smile.

“There are still many things to test. We need to start with the firing test.”

“Firing… That’s right. We forgot the ‘Bi-Gyeok’ [flying strike/attack, referring to the launch].”

In the subsequent firing test, the Bigeokjincheonleoi was successfully launched. After confirming the results, Hyang moved on to the next task.

“Now, let’s report to His Majesty and deploy it…”

“Now! Let’s reduce the thickness of the shell. Let’s start by reducing it by 5 ri (麗, a traditional Korean unit of measurement, approximately 1.5mm) at a time.”

Following Hyang’s orders, the artisans created prototypes with the shell thickness reduced in 5 ri increments, starting from 5 ri and going up to 4 hal (分, 40% of 1 chi [Korean unit of measurement, approx. 3cm], about 1.2cm). It was a process of trial and error, literally embedding it into their bodies.

“When fired from the Wan’gu with twice the gunpowder, as Your Highness mentioned, the thinnest shell that endured from launch to impact was the one with 3 hal (分, about 9mm) shaved off.”

“Then, shall we soak the gunpowder and test it?”

“Yes, Your Highness.”

In the following test, the Bigeokjincheonleoi with 3 hal shaved off endured the impact of launch and landing and exploded properly. Seeing the results, Choi Hae-san and Lee Cheon became greedy again.

“The results are good, so let’s report it…”

“The blast radius is too wide. There is a risk of harming our own troops. Let’s research ways to increase the lethality while reducing the blast radius.”

“Your Highness’s command is correct. I will consider it.”

Upon hearing Hyang’s command, Choi Hae-san, Lee Cheon, the military officers, and the artisans began to search for the best solution. However, it was difficult to find a way to simultaneously satisfy the contradictory conditions of ‘enhancing lethality’ and ‘reducing the danger radius.’

In the end, Hyang had to step in again.

“Bring clay, paper, and Palal-sized Joran Hwan [small iron pellets]. The Joran Hwan must be made of cast iron.”

“…Yes, Your Highness.”

When the artisans brought the materials, Hyang gave them instructions.

“Apply a thick layer of clay, about half a chi [Korean unit of measurement, approx. 3cm], to the inside of the Bigeokjincheonleoi shell, and embed the Joran Hwan densely. And when the clay dries, apply paper to firmly fix it so that it doesn’t fall off.”

Upon hearing Hyang’s instructions, the military officers and artisans immediately exclaimed in admiration.

“Ah! Such a solution!”

In the following test, the improved Bigeokjincheonleoi had a smaller danger radius than the first one, but its lethality was further enhanced. Hyang, examining the results, turned to Choi Hae-san and Lee Cheon.

“Let’s improve it a little more. Just a little more…”

“Yes, Your Highness.”

In the subsequent second improvement, Hyang and the artisans engraved lines like a Go [a Korean board game] board on the inside of the Bigeokjincheonleoi shell. And they laid another layer of Joran Hwan.

After finishing the second improvement and seeing the results in the following test, Hyang ordered Choi Hae-san and Lee Cheon.

“I think this is enough. If we proceed further, future generations will think of us as bloodthirsty and immoral people.”

“That’s right!”

Choi Hae-san and Lee Cheon nodded vigorously at Hyang’s words. The scene created by the Bigeokjincheonleoi that had undergone this improvement was bleak, in and of itself.

“Then, let’s report it…”

“Now, let’s improve the Hwapo [Korean cannon] that will launch this Hwatan [cannonball].”

“Pardon?”

Choi Hae-san and Lee Cheon wore gloomy expressions at Hyang’s words.

Hyang observed the Dae Wan’gu (大碗口, large bowl-shaped cannon) that would launch the Bigeokjincheonleoi.

“The amount of gunpowder entering the chamber is 35 nyang (兩, a Korean unit of weight, about 1.3 kg)… The problem is that it’s not an efficient shape.”

What Hyang pointed out was the overall design of the Wan’gu.

“Let’s change the structure!”

Hyang designed the Hwapo that would launch the Bigeokjincheonleoi in a traditional straight line shape. He also created a Poga [cannon carriage] similar to the ones on which Western-style cannons of the 18th and 19th centuries were mounted.

“Is it too Western? I don’t think so.”

Hyang tilted his head, looking at what he had drawn. To be precise, the design Hyang created was close to the infantry heavy cannons that Joseon made during the Daewongun [a Korean regent] era.

Hanging the Gwaedo [blueprint] depicting the Hwapo and Poga he had envisioned, Hyang shared his opinions with Choi Hae-san, Lee Cheon, and the artisans.

“It’s mounted on a cart with large wheels. Mobility will improve.”

“When dealing with the Jurchen [a nomadic people who later founded the Qing dynasty] in the North, wouldn’t it be much easier if the mobility of the Hwapo improved?”

Choi Hae-san and Lee Cheon nodded at Hyang’s words. Thanks to the fact that they were people with sufficient practical experience in the South and North, the two were able to immediately understand the advantages Hyang mentioned.

Lee Cheon, looking at the Gwaedo, concluded.

“A cart with a cannon mounted on it and a cart containing Hwatan and gunpowder… Even if only two Bigeokjincheonleoi accompany them, the Jurchen won’t dare to do anything reckless.”

When Choi Hae-san and Lee Cheon, who could be said to be the best experts in the Joseon army regarding Hwapo, agreed, the development of the Hwapo and Poga proceeded quickly.

The difference between the newly developed Hwapo and the existing Hwapo was that the back of the internal chamber, as well as the outside of the Hwapo, was rounded.

“General Choi, do you remember when we first tested the Pogeun [a type of Korean cannon]?”

“Yes.”

“At that time, if you look at the soot created on the copper plate, it spread out radially. I think this means that when gunpowder explodes, its energy spreads out that way.”

Choi Hae-san, who was thinking carefully about Hyang’s words, nodded.

“That seems likely.”

“Then, if we dig the back of the chamber round like this, wouldn’t the Hwapo become stronger? It will be the same thickness from any angle.”

Choi Hae-san, examining the drawing in detail, nodded.

“It seems worth trying.”

After the first Hwapo was made, Hyang and Choi Hae-san immediately started testing it.

They put twice the amount of gunpowder into the chambers of the existing Dae Wan’gu and the new Hwapo, tightly blocked it with Gyeokmok [wooden plug], and then put in a heavy Danseok [stone ball].

In about four consecutive firings, the new Hwapo did not cause any problems, but cracks occurred in the lower corner of the chamber of the Dae Wan’gu.

Choi Hae-san, confirming the results, opened the Seopan [official record book] and wrote.

“As a result of the test, it was confirmed that making the Hwapo and the rear of the chamber curved strengthens the internal structure. It seems right to improve other Hwapo or design new Hwapo of similar shape.”

* * *

“…Therefore, everything about this Bigeokjincheonleoi, including the Hwatan and the design of the Hwapo, has passed through the hands of the Crown Prince.”

At Choi Hae-san’s explanation, Sejong [the King] and the ministers looked at Hyang once again.

“You… You’re making me tired of even saying ‘amazing’ now.”

All the ministers nodded at Sejong’s words. The ministers were exhausted from seeing the continuous stream of amazing devices. No, the Prime Ministers and the Minister of Taxation were calculating the budget that would go into mass-producing these, and they were seeing stars.

“I want to see that newly made Hwapo.”

“I obey your command.”

After a while, two carriages entered the demonstration ground. The carriages were each pulled by two horses.

“The first cart is pulling the Poga with the Hwapo, and the second cart is carrying the Bigeokjincheonleoi and gunpowder to be used for the Hwapo.”

“Hmm…”

Sejong looked at the carts while listening to Choi Hae-san’s explanation. There were two wooden boxes on the cart connected to the Poga.

“Those boxes contain the Hwatan and explosives that will be used immediately after the Hwapo is set up.”

The soldiers opened the lids of the boxes on the cart. Small pouches came into Sejong’s eyes as he examined the boxes.

“What are these pouches?”

At Sejong’s question, Choi Hae-san opened a pouch and took out the contents.

“It is a Hwaseung [time fuse] that determines the time to explosion, a Mokgok [cotton wrapping] to wrap the Hwaseung, 1 nyang (兩, a Korean unit of weight) of Gapsik gunpowder [fast-burning gunpowder] to ignite the Eulsik gunpowder [slower-burning gunpowder], and a Jitong (紙筒, paper tube) to put everything in and plant it in the Bigeokjincheonleoi.”

Sejong nodded at Choi Hae-san’s explanation.

“I see. Eulsik gunpowder does not ignite with a wick, so Gapsik gunpowder is used to light the fire. But Jitong?”

“At first, we used bamboo, but there was a problem with uniformity, so we made the tube out of paper.”

“I see. Good idea.”

“It was the Crown Prince’s wise opinion.”

When Choi Hae-san gave credit to Hyang, Sejong turned to Hyang.

“Your hard work is visible.”

“It is the merit of the military officers and artisans, including General Choi and General Lee.”

Hyang was giving credit to the soldiers and artisans.

Sejong’s eyes, who was looking at the Hwapo, stopped at the back of the Hwapo. The part that caught Sejong’s attention was the part connected to the Hwapo’s stand. There was a pillar with screws engraved on it, and next to the gears connected here and there, there was a handle similar to a reel. And next to it, there was a semi-circular plate with the Chinese characters ‘Won (遠, far), Geun (近, near), Chogeun (超近, very near)’ written on it.

“Sejaya [Crown Prince], what is this used for?”

“Yes, it is used to adjust the angle of the Hwapo to control the range.”

“Adjust the range?”

“Yes. It’s like this.”

When Hyang turned the handle similar to a reel, the muzzle moved up and down. Sejong, who was watching the scene, turned his head.

“You adjust the angle of the muzzle like this to adjust the distance?”

Choi Hae-san, who was next to him, immediately answered Sejong’s question.

“That’s right, Your Majesty.”

“How?”

“It is the same principle as shooting a bow. When you shoot a bow at a distant target, don’t you lift the bow upwards and shoot it in a curved line?”

“Aha!”

Sejong exclaimed in admiration at Choi Hae-san’s explanation. Choi Hae-san pointed to the semi-circular rangefinder and explained.

“If you adjust the angle of the muzzle according to this scale, you can adjust the distance from 300 steps to 500 steps.”

Sejong, who was examining the scale in detail at Choi Hae-san’s explanation, turned to Choi Hae-san and Lee Cheon.

“You must have put in a lot of effort to find out this scale.”

“That’s right.”

Choi Hae-san and Lee Cheon nodded at Sejong’s words.

In order to accurately measure the fact that they had accidentally discovered – an accident mixed with Hyang’s intentions – Choi Hae-san, Lee Cheon, and the artisans fired hundreds of Bigeokjincheonleoi.

In order to reduce unnecessary gunpowder consumption, Bigeokjincheonleoi filled with soil and gravel flew through the air without rest, and in the end, nearly 100 Bigeokjincheonleoi that could not withstand metal fatigue had to be newly made. That wasn’t all.

Many of the cows raised on farms near Area 51 died because they could not overcome the stress caused by the explosions, and a considerable amount of wealth had to be spent on the price of these cows. And the meat from the slaughtered cows was served on the tables of the artisans and soldiers.

“If you can adjust the distance like this, it will show a better effect in battle. Can it be applied to other Hwapo?”

Hyang answered Sejong’s question.

“The officials at the research center are currently researching it.”

“However?”

Sejong, hearing the answer, looked for Jeong Cho among the officials.

“Deputy Director Jeong, I trust you.”

Jeong Cho bowed his head and answered Sejong’s words.

“I obey your command.”

Jeong Cho’s voice, answering, was full of moisture.

‘I still can’t go home….’

Thanks to Hyang already giving the same order, the officials at the research center were holding books recording the results of the shelling and fighting a ‘war with numbers.’

Hyang’s order was to investigate the varying distances in all sorts of diverse and bizarre situations, create tables, and formulate them to create distance control devices for each Hwapo.

Thanks to that, the officials at the research center could only go home on scheduled holidays – 9 days of work, 1 day off. That was because Hyang kept this rule like clockwork.

However, there were also periods when the officials volunteered to work overtime. That period was the period of ‘Meju’ [fermented soybean brick] fermentation.

* * *

Joseon consumed a lot of soybean paste and soy sauce, so much so that it was called the ‘country of Jang [fermented sauces].’ As much as there was consumption, every house was full of Jangdok [crocks for storing sauces], and the residential areas of Hanseong [old name for Seoul] were full of the smell of soybean paste. As such, the smell of Jang was familiar to Joseon people. However, even those Joseon people found the smell coming from fermenting Meju to be a chore.

In particular, the more family members there were, the more Meju had to be fermented, so the houses of high-ranking officials with many servants and guests had a more pungent smell of Meju.

The palace also fermented a large amount of Meju, but the palace had absolutely large spaces, so the smell of Meju was not very strong. For this reason, the officials would postpone leaving the office as much as possible during the Meju fermentation season.

* * *

Anyway, due to the orders of Sejong and Hyang, Joseon became the first country in the world to create and apply a firing table (射表) for Hwapo.

Sejong, who had examined everything from the Hwapo that fired the Bigeokjincheonleoi to the support equipment, straightened his back.

“Hmm, I think I’ve seen everything I need to see, but before I check the ledger, there’s one last thing I need to confirm. The armor worn by the military officers and soldiers here is different from what I’ve seen before, so explain it.”

“We have prepared it. I will guide you.”