Jigsaw Construction and Cellular Honeycomb
What is most needed to build a massive valley dam—an arch dam, no less?
A structure sturdy enough to withstand the water pressure generated by an enormous reservoir and the crushing weight of that water.
It demanded precise calculations and vast quantities of iron and concrete.
Michelangelo was unquestionably a genius of architecture, and precisely because of that, he understood the importance of mathematics better than anyone. Unlike his counterpart in original history—so eccentric he hated criticism or interference with his work more than death itself—in this world, though he still disliked it, he had grown relatively accustomed to others meddling in his affairs.
Ironically, what made that possible was none other than the murderous work environment.
A craftsman's pride?
What broke Michelangelo's nose—pride that recognized no one but Leonardo da Vinci—was neither noble pressure nor papal authority.
It was the murderous work schedule of roughly one hundred thirty hours a week.
He was so busy he could die, ready to borrow even a dog's paw if it would help, so how was he supposed to handle every last detail from start to finish himself?
Secret techniques? My own proprietary methods? Eat shit.
The Dang family's working conditions endlessly forced the craftsmen onto the same tightrope: clutch your secrets and work yourselves to death, or freely open your foundations to others and live a little more like human beings.
In the end Michelangelo too surrendered, and he too began driving numerous apprentices and disciples like cogs in a machine.
He did not particularly resent it.
He could have been sensitive about having his knowledge and experience taken from him, but in the Dang family there was Hwi-yeom—who, as if mocking their meager pride, casually tossed out designs, plans, and ideas that were always several steps ahead.
Frankly, when I'm the one sucking dry Hwi-yeom's ideas and techniques, wouldn't it be shameless of me to curse my disciples for stealing a bit of mine?
With that thought, Michelangelo brazenly marched into Hwi-yeom's office.
"You Dang bastard!! Hand it over!"
"Huh?"
When Hwi-yeom tilted his head, Michelangelo spoke with an air of swagger.
"There's bound to be one, right? The dam design you've already calculated. Let's not waste each other's time—pull it out so I can cut down on trial and error."
"…"
Hwi-yeom stared at Michelangelo as if looking at a madman, then let out a soft sigh.
"I can't decide whether to celebrate your progressive attitude or warn you against treating your employer like an all-purpose general store. If only you'd fix that one point, you'd truly be the greatest craftsman without question, Chief Buonarroti."
"You already know the answer and still leave your underlings to thrash around and suffer every hardship imaginable—you need to fix that nasty personality of yours!"
"Am I some kind of god? I calculated it through my own trial and error, and I could be wrong. Someone of your caliber ought to know that the moment you treat it like an answer key and stop thinking, progress stagnates…"
"That's true enough, but you little shit, hearing it from you pisses me off! Then give us plenty of time for research and contemplation! You work people so hard that even the imps of hell would flee barefoot…"
"In exchange, I take excellent care of employee welfare."
"The best welfare is sleep!"
"Then go sleep to your heart's content. I'll have someone else build the architectural masterpiece of the century that will leave its name in history."
"I never said I wouldn't do it! Damn bastard!"
As they traded banter, Hwi-yeom rummaged through a drawer and handed Michelangelo a bundle of papers.
Michelangelo was about to unfold the papers when he happened to notice the number written on the index section and stopped dead.
"…What date is this?"
"The date I drew that blueprint."
"…It has a date from three years ago?"
"Because that's when I drew it."
"Crazy bastard."
Looking thoroughly disgusted, Michelangelo tucked the blueprint into his clothes.
"I don't know whether old man Leonardo was lucky or unlucky not to have met you before he died."
"One thing is certain: thanks to meeting me, posterity will remember the greatest genius architect and artist of humanity not as Leonardo of Vinci, but as Michelangelo of Florence."
"Of Sichuan, more like."
Michelangelo smiled bitterly.
"I'll look forward to whatever novel construction method you've got that'll turn my lungs inside out again."
"It shouldn't be anything particularly impressive…"
But of course,
in Michelangelo's eyes it was anything but unimpressive.
After returning with the blueprint Hwi-yeom had given him and laying it side by side with the one he had drawn himself, Michelangelo sighed.
"What the hell is this. You've dragged in some weird concept from somewhere again…"
The method Michelangelo had designed was a block-lifting technique—stacking reinforced concrete blocks the way one builds a brick house. Applying cement and waterproof mortar between the blocks and bonding them as they rose was a simple approach used even in ancient Rome, yet sturdy enough that portions of those structures still stood thousands of years later. With rebar inside the concrete blocks, it would be far stronger still.
Yet in the blueprint Hwi-yeom had drawn, the concrete blocks were not neat rectangular bricks; they were shaped with interlocking irregularities like pieces of a jigsaw puzzle. The blocks could be fitted and locked together like toy puzzles without any special adhesive.
Instead of smearing cement into the gaps and joining them that way, Hwi-yeom had introduced a contraction-joint method: interlocking incompletely hardened concrete puzzle pieces and using the shrinkage that occurs during curing to bind them together.
Typically, the contraction-joint method is simpler to construct than ordinary block work while being more than twice as strong.
Michelangelo blankly read the calculation formulas Hwi-yeom had written beside the drawings—the water pressure and weight per unit area the wall could withstand under this method, and the proofs verifying them—then contorted his face and flung his own blueprint aside.
"Ah, shit, this is so fucking annoying!!"
He had lost again.
How on earth did this young man who had not even lived half his years casually conceive of such tremendous things every single time?
He might have felt a deep sense of defeat, but instead Michelangelo burned with fighting spirit.
"Hmph, what's so great about a puzzle method. I'll develop something even more awesome!"
He immediately wrapped his head and dove into research.
He too was one of the greatest geniuses humanity had produced—a proven genius Hwi-yeom might never have dared approach if he had not brought future knowledge with him.
After days and nights of agony, he finally produced an improvement that even Hwi-yeom would admire, marched in, and thrust it forward with a shout.
"Here, how about this!"
Hwi-yeom's eyes went round as he looked at the blueprint.
"Cellular honeycomb…? Wait—crazy—how did you—"
"Cellu… what?"
When Hwi-yeom opened his eyes wide and muttered unconsciously, Michelangelo, who had been waiting quietly for the reaction, asked.
Hwi-yeom shook his head.
"It's nothing. At any rate, a genius is a genius. I never expected you'd come back with a structure that raises strength while being lighter and more resistant to external force."
A honeycomb structure—or cellular honeycomb—is used when constructing massive dams or buildings that must support enormous weight, or when fabricating extremely sturdy yet light structures such as spacecraft. Overlapping octagonal cells like a beehive produce a form that is lighter than solid construction yet stronger. Rather than forging a thick solid titanium wall, fabricating two thin titanium plates and filling the space between them with a titanium honeycomb uses far less material, weighs less, and is sturdier. Modern spacecraft outer hulls almost all incorporate the design.
The reason Hwi-yeom had known of the structure yet left it out of the dam blueprints was a kind of fixed idea: that this form belonged to "spaceship outer walls."
But Michelangelo used the structure not for the wall faces of the dam, but for the pillars and the areas around the floodgates—reducing the overall load while increasing strength.
The absolute strength of the structure itself would still be greater with the jigsaw-style construction using Hwi-yeom's contraction-joint method. Yet by building the pressure-facing walls that way while forming the joint pillars between wall sections and the surroundings of the floodgates in honeycomb, the dam's total load dropped. Reduced load meant the structure bore less of its own weight, which in turn produced greater overall strength.
Hwi-yeom gave a short laugh.
"Chief Buonarroti, this time you win. I'll have the method recorded in the Dang Family Heroes Register and the Patent Register. What will you name it?"
"Hmm. Then I'll call it the Beehive Foundation Construction Method. Since it was inspired by a beehive. And…"
Michelangelo glanced sideways at Hwi-yeom, then tossed the next words out gruffly, as if throwing them.
"The patent proposers can be joint with you, you Dang bastard."
"Huh?"
"Your share went into it quite a bit, so I'm saying we go with joint proposal!"
"Oh…"
Looking with a strange expression at Michelangelo—who was spitting out hmphs and tchs with a reddened face—Hwi-yeom smiled gently.
"Thank you."
"Hmph!"
Michelangelo whipped his head around.
He really was an easy man to understand.
Thanks to the new construction methods Hwi-yeom and Michelangelo had developed, work on the Second State-run Ironworks gained real speed. It accelerated so dramatically that when labor ran short and progress threatened to stall, Shaolin Temple specially dispatched warrior monks to support the site.
The Sa River was, as its name suggested, a river thick with sand. Fine sedimentary soil lay piled along its banks in abundance—an environment perfectly suited for mixing cement paste.
And the moment the Shaolin monks entered the work, they once again proved with their entire bodies why scientific and technological progress had been so slow in this world.
"Hmph!"
A muscular warrior monk drove an enormous shovel—so massive it looked more like a small boat with a pole attached—deep into the riverside sand, then heaved it upward with full force. The muscles of a Shaolin monk who boasted the finest internal and external arts under heaven rippled; white breath burst from his mouth, and as if a bomb had detonated, a hole punched open in the sandbank while a great heap of sand sailed into the air and poured into a wire sieve.
A waiting Shaolin monk released palm force; the sand caught in the sieve crumbled and sifted through. Another monk casually shouldered the wooden barrel now full of fine sand and carried it to the mixing station, where he poured it out.
Hup—!!
As if the steam-powered mixer were insufficient, a Shaolin monk seized an extra basin and whirled a massive iron rod through the stiff cement paste. The staff work that freely wound the heavy mixture faithfully followed the Lan and Na forms of the Xingzhe Staff Method.
And that was not all.
"Monk, hey—drive some rebar in over here~."
"Yes, mister."
A young Shaolin monk who had already grown familiar with the crew ran over with a bright face, rebar in hand, at the foreman's request. The kind young monk in his early twenties held the rebar like a Shaolin staff, gazed quietly down at the bedrock, then drew up his internal energy and twisted as he drove it home.
"Nianshe Staff!"
Kagagak!!
Bedrock that would normally require a pile driver parted as easily as chopsticks sinking into a well-cooked potato; the rebar sank cleanly in. Seeing it, the foreman gave the monk a thumbs-up.
"Aigo~! As expected, our Shaolin Temple monk brothers are completely different~ Heroes—real heroes!"
As the workers cheered, the Shaolin monk withdrew with a shy smile.
"Haha… Then keep up the good work!"
"Yeah! See you at mealtime later~!"
The atmosphere on site was excellent, and support was more than sufficient.
And so,
after a full construction period of one year and four months, the world's first valley dam stood complete.
On the day of the completion ceremony,
"Floodgate! Open the gate!"
Someone who saw the river water come pouring through muttered blankly,
"…Am I dreaming?"