The Aqueduct Construction Plan
It was the day after Hwiyeom finished his late-night private audience with Ma Jeonggu.
After surveying the Provincial Administration Commissioner's yamen and residence, along with the terrain of the upper Yangtze valley from which the water would be drawn, Hwiyeom reached his conclusion.
"This is a large-scale construction project. Even if we throw martial artists at it as human cranes, there are limits."
The aqueduct would run roughly ten li—about four kilometers by modern measure—from the source valley in the upper Yangtze, through Seongdo's city walls, and into the heart of the city. Because the water was being pulled down from a valley, they would also have to build a bridge spanning a gorge more than thirty meters deep.
In terms of difficulty, it's about the same as the aqueduct the people of Segovia built two thousand years ago. They managed it, so there's no reason I can't… The real problem is security.
If the aqueduct crossed over the top of the walls, an enemy force could use it as a highway straight into the city. Ordinary soldiers might struggle, but martial artists would simply race along the channel and vault over the battlements.
If Hwiyeom were the Regional Military Commander, he would have a fit. He would never approve a design like that.
How did the ancient Romans solve this? I don't actually know that part…
After long deliberation he settled on a combination of aqueduct and fountain. From the last hill before the city the pipes would be buried underground, pass beneath the walls, and then shoot upward again inside the city as fountains—using water pressure and the siphon effect.
By pure coincidence, it was the same solution the Romans had used. That was precisely why ancient Rome had been filled with so many fountain plazas.
Hwiyeom intended to build proper fountain basins and, right beside them, install taps so people could draw water directly. Watching laundry flapping next to a grand fountain would look terrible… Better to channel the raised water a short distance away and make a proper wash-house.
Even that much would spare the people the long trek to the river outside the walls or the back-breaking work of hauling well water. And the fountains themselves would be handsome enough to feed the vanity of every power-holder in the city.
All right. Let's do it.
With the broad outline finished, Hwiyeom summoned the carpenters and stonemasons who now belonged to the Innovation Hall and delivered a presentation.
When he announced he meant to build an aqueduct ten li long and ten zhang high—thirty meters—their faces went blank with despair.
"It's not impossible, Young Master. If you think about building a city wall…"
"But it's too hard. It'll take forever."
"This is the kind of massive public works only the state should attempt. Even if our Dang Family is formidable, we can't do it with just our own people…"
Faced with the craftsmen's gloom, Hwiyeom snapped.
"Silence! You start inventing excuses before you've even tried. And you call yourselves the finest artisans in Sichuan—no, in the entire Central Plains?"
"But…"
Their pride was stung, yet their faces still said this is a bit much. Hwiyeom clicked his tongue.
"Tsk, tsk, tsk… I always come with the answer, but if every meeting starts like this we're in trouble. Craftsmen need a spirit of challenge."
Coming from the man who normally treated them with such respect, the rebuke cut deep. The artisans bit their lips.
Fine. Let's see just how brilliant this design of yours really is.
What Hwiyeom laid before their eyes was the blueprint for a Roman-style multi-tier arched aqueduct: arches supporting a water channel, more arches stacked atop that channel, four full stories of them—one bridge carrying the greatest possible volume of water.
For a moment the craftsmen stared as if the drawing were absurd. Then understanding dawned, followed by low whistles of admiration.
"Ah… so that's how."
"Semicircular arches really do handle load better."
They already knew how strong an arch was under weight. China itself had been building arched bridges for centuries. What had stopped them from imagining an aqueduct of this scale was simply that Hwiyeom's structure was not an ordinary bridge; it was as massive as a city wall.
"Will the structure still hold under that much load?"
"It will. Think of a city gate. It supports the full weight of the wall above it, doesn't it?"
"Right—gates are arched too."
Once the connection between walls and bridges clicked into place, the master builders grasped the principle at once.
"Here—look at the load calculations for each pier and intermediate span."
They studied the figures Hwiyeom had written on the plans and nodded.
"…With these numbers it works."
"We're not building a solid wall, so it doesn't need to be thicker than necessary."
"Only the channel itself and the piers are solid; the sides are open arches. That alone will save a fortune in stone."
"And instead of dressing granite blocks the traditional way, we cast the members in concrete and stack them. Much faster."
"Reinforced concrete is stronger under load than solid granite anyway."
While they debated, Hwiyeom cut in.
"Casting bricks of concrete and hauling them is fine, but if we build wooden formwork on site and pour the mix, we can make larger, stronger pieces with no transport worries. Drive rebar into the foundation at regular intervals like planting rice seedlings, raise the wooden forms to the required height, and fill them with concrete…"
"Ohh! Same method we used for the long water pipes!"
"Exactly."
"I was fretting about moving heavy concrete blocks all the way to the site. This way it's far easier."
"Water we can get locally. Sand and gravel too—just shovel them through a screen."
"All we have to haul in is cement powder and rebar!"
"This will work!"
Watching the craftsmen grow excited and animated, Hwiyeom smiled and quietly produced one more sheet of drawings.
"Add these, and the work will race ahead."
"What are these, Young Master?"
"A geojunggi heavy-lifter, a nokro pulley crane, and a yuhyeonggeo balanced cart."
"Ropes and… some sort of round counterweight I've never seen?"
"Looks like you hang a load on it and hoist…"
"And this is a cart of some kind?"
They were looking at the ancestors of the modern crane and the wheeled lever cart. The nokro used simple pulley principles to raise heavy stone. The geojunggi was an upgraded version of the same idea—known in another world as the machine Jeong Yak-yong built for the walls of Hwaseong Fortress in 1792. The yuhyeonggeo resembled an ordinary cart but shifted its center of gravity with levers so far less force was needed.
Similar devices had appeared in late-Ming China in a treatise called the Illustrated Explanations of Wonderful Machines, which meant Hwiyeom was introducing the geojunggi several centuries early. Of course, equating the Qing and Ming as the same country was a meaningless exercise, but the point remained.
"Are these numbers correct? You're saying this little effort can lift that much weight?"
Hwiyeom grinned at their disbelief.
"I already built small models and tested them. You can't simply scale the numbers up, of course, but the principle is sound."
"If that's true… we really could raise large buildings in no time."
Once the aqueduct problem was solved, everything else flowed smoothly. The same artisans had already learned about siphon effect while installing water systems inside the family compound, so the idea of running pipes under the walls and raising them again as fountains made immediate sense. They even pointed out a few practical difficulties Hwiyeom himself had overlooked. The meeting ended on a thoroughly successful note.
Hwiyeom took the revised plans to his client, the Provincial Administration Commissioner. The commissioner brought along an official dispatched from the Regional Military Commander's office to review them. The military man, who had been fretting that the aqueduct would cross the walls, looked thoroughly relieved when he saw the pipes diving underground.
"The water enters through narrow pipes no man can crawl through. The wall's defenses remain intact. Excellent."
Even a master of the Bone-Shrinking Technique would find no army that could slither through lightless pipes. A peerless martial artist might hold his breath the whole way, only to emerge into an underground cistern connected to the fountains by slender copper tubes. No human body could pass; drowning would be the only outcome.
With the expert charged with the city's defense in agreement, nothing stood in the way of construction.
Hwiyeom immediately mobilized every craftsman of the Sacheondang Family and broke ground.
One problem remained: the family's own manpower was nowhere near enough. Concrete pours and wooden formwork had to stay secret, and critical design points could not be left to outsiders, yet countless other tasks still required unskilled labor. Hiring outside workers became unavoidable.
Instead of quietly subcontracting the work to the workshops run by the family's collateral branches, Hwiyeom threw the contracts open to public tender—awarding the job to whoever offered the best price and terms. Amusingly enough, the very concept of open bidding did not exist in the Central Plains. Everything was decided by personal connections—guanxi—and that was precisely the rot Hwiyeom had come to detest during his earlier life doing business with China. Even a worthless, price-gouging firm could win every contract if it had the right relationships, and progress died.
Besides, nothing will stick it to the Elder Council quite like this.
What was the strongest guanxi of all? Blood. Until now, whenever the Dang Family undertook a project that the main line did not handle from start to finish, the work had automatically fallen to the collateral branches. Hwiyeom refused.
Giving the job to the collaterals simply meant money flowing out of the main line's coffers and into theirs.
Why would I deliberately enrich expensive, incompetent enemies?
The Elder Council, expecting to sit back and skim a fortune from the huge project, was thrown into panic. The elders protested fiercely; Hwiyeom ignored them with complete calm.
"If you don't like it, put in a cheaper, better bid."
The collateral workshops, long accustomed to winning main-line contracts without effort, simply lacked the capacity for a project of this scale. They howled that the family was letting money leak outside, but their own prices were higher, so the complaints were empty noise.
And so the work pressed forward at full pace—until, one ordinary day in the middle of construction, Hwiyeom fell seriously ill.