Late March, 15th year of King Sejong’s reign (1433, Year of the Gui-chuk)
King Sejong was set to depart for a retreat to Onsu County (present-day Onyang).
On the day the retreat was decided:
“I heard you tried your best?”
“I did. In my own way…”
As Hyang questioned him with a sulky face, King Sejong answered with an embarrassed expression, looking into the distance.
***
Although Hyang had been at the center of intensively managing King Sejong’s health, unfavorable symptoms began to appear little by little.
The biggest cause of this was King Sejong’s overwork.
Of course, King Sejong’s eating habits of loving meat very, very much were also a problem, but that could be seen as trivial in a way.“In the 21st century, even people who did zero-carb diets were living just fine. The important thing is that he’s not burning off as much as he’s taking in.”
Looking at King Sejong’s belly that was gradually protruding forward, Hyang grumbled and continued to pressure King Sejong to exercise.
However, as mentioned above, overwork was the problem.
The regular Royal Lectures[1], though not held every morning and evening like before.
Following that, he had to deal with various issues that popped up while carrying out the reforms, and even had to pass judgments on various major crimes.
Finally, after finishing all that work, he had to use the remaining time to the fullest to create Hunminjeongeum.
As a result, King Sejong’s body, unable to withstand the overexertion, began to make small cracking sounds.
The first thing to start showing problems was his skin. Sitting for most of the day to handle work caused circulation problems, and various inflammations began to appear on his skin.
In response, all the clothes King Sejong wore were kept meticulously clean, and various boils on his skin were treated. As a bonus, the ointment created jointly by Hyang and the physicians of the Royal Clinic played a great role in this process.
However, skin disease became King Sejong’s chronic illness.
The next thing to cause problems was King Sejong’s eyes. Working late into the night, King Sejong’s eyesight gradually worsened. Not only was his vision a problem, but eye diseases also developed.
Eventually, Hyang and the Royal Clinic physicians reached an agreement.
“Rest is the best, Your Majesty!”
“I agree.”
This is how King Sejong’s retreat was decided.
***
King Sejong’s retreat was on an enormous scale.
It was a massive movement that included not only King Sejong, but also Queen Soheon and the royal concubines, the Crown Princess and the two consorts Yangwon and Yangje, as well as the grand princes, princes, princesses, royal princesses, and even the royal clan members.
It wasn’t just the royal family members who were moving. The ministers and vice ministers of each department also moved.
It was as if the entire Joseon government was moving to Onsu County, and because of this, elite soldiers selected from the Inner Palace Guard and the Ten Offices escorted the procession.
Behind the soldiers at the front, the palanquin carrying King Sejong moved. Behind the moving King Sejong, Hyang rode on horseback, and the ministers, vice ministers, grand princes, princes, and royal sons-in-law followed on horseback. And behind them, eunuchs and soldiers followed on horseback.
If King Sejong and the Crown Prince’s group was the first unit, the second unit behind them was centered around Queen Soheon and the personnel of the Queen’s Palace.
Behind the palanquin carrying Queen Soheon, the center of the Inner and Outer Court Ladies, followed the sedan chairs carrying the concubines. And behind them, the junior concubines, princesses, royal princesses, and court ladies followed on horseback. (Note 1)
This massive procession moved towards Heunginjimun Gate.
Outside Heunginjimun Gate, the officials and palace personnel who were to remain in Hanseong, as well as the people of Hanseong, had gathered to send off King Sejong.
Finally, as the palanquin carrying King Sejong appeared, all those gathered raised their voices to shout “Long live the King!”
“Long live His Majesty the King!”
“Long live!”
“May you enjoy longevity and good health!”
King Sejong lightly raised his hand in response to the people’s cheers. Looking at the people with a pleased expression, King Sejong turned to Hyang.
As Hyang rode his horse closer upon seeing King Sejong’s gaze, King Sejong opened his mouth.
“Isn’t it truly good to see the people like this?”
“Yes. It’s all thanks to your efforts, Father.”
“How could it be just my achievement? It’s thanks to the efforts of many, including you.”
After praising Hyang, King Sejong continued speaking while looking at the people shouting “Long live the King!”
“We must do our best to ensure they can continue to smile like this.”
At King Sejong’s pledge, Hyang quietly bowed his head.
***
The procession that left Heunginjimun Gate headed towards Dumulmeori. At Dumulmeori, where the Jungnangcheon Stream and the Han River meet, there was a port called Dumopo[2].
And now, at Dumopo, a pontoon bridge had been laid under Hyang’s direction.
“A pontoon bridge… You must have worked quite hard.”
At King Sejong’s words, Hyang answered with a small smile.
“The engineers worked hard.”
At Hyang’s answer, King Sejong’s eyes sparkled.
“The engineers? I see… It would be difficult to lay such a bridge without the engineers.”
“That’s right.”
***
The engineer corps, which was established while carrying out the reconstruction project after the great fire of Hanseong, was increasingly recognized for its usefulness and grew larger and more specialized.
And in this process, what received concentrated attention from the military was the pontoon bridge.
When projecting power to deal with the Jurchen tribes in the north, the biggest obstacles were the rivers spread across the Liaodong region, starting with the Yalu and Tumen Rivers.
Previously, they had crossed at shallow points, but as the size of the artillery grew, such primitive methods began to cause difficulties.
Therefore, Hyang introduced the construction of pontoon bridges using engineers.
The boats composing the pontoon bridge were also supplied by making dedicated vessels. Although not exactly the same as those used in the 20th and 21st centuries, it was an innovative item in the 15th century that shattered the thinking up to that point.
Of course, there were drawbacks. Since there were no small, high-powered motor boats like those used by the engineer units of the 21st century Korean military, the engineers had to use oars and poles. As a result, the soldiers, especially those in units operating pontoon bridges, boasted physiques of a different dimension compared to other soldiers.
As a side note, thanks to this size and strength, the soldiers of the engineer units were the number one choice for brides in the neighborhood.
***
King Sejong, who had dismounted from his palanquin and was crossing the pontoon bridge on foot for safety reasons, turned his head to look at one place.
“The bridge still doesn’t show its form, does it?”
“The cofferdam work has just finished, and they’re now digging out the riverbed. Once the foundation is properly laid, the speed will increase.”
The subject of the conversation between Hyang and King Sejong was the construction site of the Han River Steel Bridge, located a bit downstream from the pontoon bridge.
***
According to the plan devised by Hyang and approved by King Sejong, two bridges each were to be built at two locations across the Han River, for a total of four bridges.
One crossed the Han River passing west of Neobeol Island and Bam Island, while the other connected Jamsil and Oksu.
The former connected the railways and roads coming from Jemulpo, Honam, and Uiju, while the latter connected the railway and road starting from Dongnae to Wonsan and Gilju.
The reason for this division was, amusingly, because of Area 51 and the research institute.
Due to Area 51 and the research institute located in Yongsan and nearby areas, the Han River Steel Bridge connecting Noryangjin and Yongsan, as in the history before Hyang’s intervention, could not be built.
“Well, that Han River Steel Bridge was also placed there due to the Japanese military calculations…”
There were stories that both the pontoon bridge laid by Jeong Yak-yong during King Jeongjo’s era and the Han River Steel Bridge were placed there because the flow of the Han River slowed down near Noryangjin, but there were also stories that the bridge was placed at that point to quickly support the Japanese army stationed in Yongsan.
However, thanks to Area 51 and the research institute born due to Hyang’s intervention, a bridge connecting Noryangjin to Yongsan could absolutely not be built.
Anyway, with these two bridges being built, there was also an advantage: there would be no straight line running all the way to Gyeongbokgung Palace.
***
After King Sejong crossed the pontoon bridge, Hyang addressed him.
“We’ve prepared a new mode of transportation.”
“A new mode of transportation?”
King Sejong’s eyes sparkled at Hyang’s words.
“Is that so? I’m curious about what kind it is. Where is it?”
“This way.”
“Let’s see…”
King Sejong, guided by Hyang, moved his steps and seemed slightly disappointed when he saw what was before his eyes.
“Isn’t it an iron horse and passenger car?”
“It’s a traction engine and a road passenger car.”
“Traction engine? The one I’ve only seen in reports?”
“Yes.”
At Hyang’s answer, expectation replaced disappointment on King Sejong’s face.
What Hyang showcased was a steam tractor.
***
The reason Hyang created the steam tractor was that the size of the cannons operated by the land and naval forces was gradually increasing.
True to being the “original artillery unit,” the Joseon military wanted cannons with increasingly powerful firepower. And this also satisfied Hyang’s desire for benevolence.
The problem was that “greater power = increasing size.”
Because of this, in the case of the artillery currently being prepared for field deployment, its size was considerable.
Even the giant horses brought in from the West and mass-bred were struggling to move it with just one horse.
It was a natural progression for the military, which was agonizing over solving this problem, to think of the iron horse.
‘Please develop an iron horse that can move even where there are no rails.’
Receiving this order from the military, Hyang had to concentrate hard to keep the corners of his mouth from rising.
‘Come on! Finally, it’s steampunk Joseon!’
***
The process of creating the iron horse named ‘traction engine’ was smooth.
This was because the mobility required by the military could be sufficiently demonstrated even with the already-made iron horse. Thanks to this, the part that the people from the research institute and Area 51 focused on was ‘making it as small as possible while reducing power loss.’
“If this succeeds, we can reduce the size of high-powered iron horses!”
Thanks to their dedication, they were able to reduce the size while minimizing power loss.
However, they soon got stuck in the next process.
“The wheels are the problem…”
Wheels with iron flesh and wooden rims couldn’t move properly on even slightly soft ground.
“Why?”
After various trial and error to solve the problem, the conclusion was that ‘the wheels are too small and thin.’
The weight applied was too heavy compared to the area in contact with the ground.
“This didn’t happen with the iron horse and rails, right?”
“The rails distribute the load. And the ground where the rails are laid is extremely compacted…”
“But there’s a limit to just making the wheels bigger and thicker…”
While the researchers from the institute and the craftsmen from Area 51 were pondering, Hyang quietly intervened.
“I have an idea…”
As Hyang quietly opened his mouth, people looked at him with brightened expressions.
‘That’s right! We have the Crown Prince!’
‘If it’s His Highness, he’s sure to have a good idea!’
What Hyang proposed, receiving everyone’s attention, was ‘caterpillar tracks.’
“That’s an excellent idea, Your Highness!”
The first to cheer upon hearing Hyang’s suggestion was Jang Yeong-sil. As he had been constantly agonizing over creating a self-moving palanquin, or self-propelled palanquin, Jang Yeong-sil immediately understood.
“This has its own path to travel on, so if we adjust the width well, there’s no road it can’t travel! It’s truly, truly an ingenious idea!”
Thanks to the approval of Jang Yeong-sil, who was called ‘incomprehensible,’ the caterpillar tracks were adopted, and the traction engine was able to take shape.
It was the birth of another monster that would later make historians tear their hair out.
***
Note 1) Annals of King Sejong and Royal Medicine (14). Market Economy. 2018.03.15.
http://www.meconomynews.com/news/articleView.html?idxno=12085