Cut-and-Cover Tunneling
With the Sima family’s collaboration secured, expansion into the Central Plains was certain to surge forward. Hwiyeom therefore threw every resource into driving the tunnel projects across Sichuan and Yunnan Province.
Thus, in April of the year he turned sixteen—just as the frozen earth of winter began to thaw—the soil of Sichuan shuddered under a shock it had never felt since the world was made.
“Fire in the hole~!”
“Fire!”
BOOOOM!!
Crude dynamite packed with black powder detonated, shattering bedrock. Mountains groaned; birds exploded into the sky in a single panicked cloud.
The method Hwiyeom had devised for the tunnel works can be summarized simply:
1. Scout routes that required the least mountain to be pierced. Even if they intended to bore tunnels, large-scale ones were still beyond them, so the goals were kept ruthlessly realistic.
“All right, couple up the drills!”
Just as oxen turned a millstone at a grain mill, four oxen were harnessed to an animal-powered boring machine. As the beasts snorted and trudged in circles, the linked steel rods spun the drill bit.
“Moo~.”
Like a corkscrew, the bit chewed into the earth. Once a vertical shaft was opened, long steel rebar was driven in; Tang family martial artists who could wield internal energy hammered the rods home with wooden mallets until they stood solid.
When the rebar had been planted in a twin parallel line—like the character 11—along both sides of the future tunnel path, the ground between those lines was excavated.
“Hey—rock!”
“Call a martial artist!”
When solid bedrock appeared and no rock-drill yet existed, direct-line martial artists of the Tang family used sword qi or whatever technique they possessed to punch holes large enough for a stalk of bamboo.
Dang Su-jeong tipped her head back and stared at the sky with the expression of someone suffering a profound existential crisis.
“I trained my whole life to become a Peak master… for this? I feel so degraded.”
Instead of throwing hidden weapons, she gripped a long, stake-like pile and flooded it with internal energy. The pile, drunk on her power, flared with a blade of sword qi. She drove it into the rock with all her strength.
Thuk—!
It sank in with the soft give of chopsticks piercing a boiled radish. When she wrenched the pile free, a clean hole remained—wide enough for a bamboo stalk. She repeated the process dozens of times on a single outcrop until the stone looked like a drained mudflat riddled with clam vents. Straightening with a sigh, she accepted the cold water the foreman scurried over to offer.
“You’ve worked hard, my lady!”
“Huu… this isn’t the last of it, is it?”
“No, ma’am! Over here—please bore this section too!”
“Aigoo, seriously…”
Dang Su-jeong slung the crude pile over her shoulder and trudged to the next site, sighing all the way. Every direct-line martial artist capable of loading internal energy into a projectile—first-rate and above—had been drafted the same way. The deeper their identity crisis as warriors became, the faster the work advanced.
“All right! ‘That stuff’ is going in!”
Still unwilling to let word of black powder leak outside the family, Hwiyeom had forbidden anyone from speaking of gunpowder beyond the estate walls. Laborers lifted bamboo-tube dynamite—hollow stalks stuffed with black powder and fitted with fuses, referred to only as “that stuff”—from wooden crates and slid them into the holes Dang Su-jeong had punched.
Fuses were trailed out long; the crew fell back.
“Blasting prep—check!”
“No people—clear!”
“No tools—clear!”
“Collapse prevention—clear!”
“Blasting prep complete!”
“Fire!”
BOOM!!
Dozens of bamboo charges erupted. A brief tremor ran through the ground and the bedrock crumbled like brittle biscuit. Black powder lacked the raw power of nitroglycerin-and-diatomaceous-earth dynamite, yet it delivered more than enough force for the job at hand.
Workers swarmed in with windlasses, hoists, and carts to clear the rubble; martial artists with shovels took their places. Once the path through the mountain had been carved out, wooden formwork was raised against the planted rebar, cement was poured and allowed to set, arched reinforced-concrete roof blocks were laid, and a final cement skin sealed everything. Earth was heaped back over the top and trees planted to hold the soil against landslides.
Thus was completed the first tunnel in the Central Plains—no, the first tunnel in the world.
Rather than boring in from the side, they excavated the road from above and then capped it. The technique was called the top-down cut-and-cover method. Simple to execute, though limited in depth, it was the same method first used to build Seoul Subway Line 1.
Hwiyeom of course knew of TBM and CAM methods as well, but the machinery those required was still beyond even him. Martial arts could not easily substitute either. So cut-and-cover it was.
To keep the secret of the powder, every worker on the project—down to the last man—was drawn exclusively from the direct and collateral branches of the Sichuan Tang family. And because speed was essential, Hwiyeom committed the outright outrage of converting the Dokwadae, an elite combat unit, into a combat-engineer battalion…
The world is a strange place.
When the Young Master first summoned us and ordered us to dig, the Dokwadae warriors rose in open revolt.
“We are honorable martial artists! We are not farmers—to hand us pickaxes and tell us to eat dirt is an insult to every warrior!”
Then the Young Master made his counter-offer:
“Special-duty bonus of one silver tael per day. Highest-performing platoon receives an extra month’s pay as performance bonus. Every man who works the site receives a black-iron dagger.”
Instantly the same men declared:
“Everyone knows earth should be moved with a shovel, not a pickaxe. So—where exactly do you need me to dig?”
Perhaps the Young Master’s frequent joke is true: when someone shouts “You dare try to buy me with money? You insult me!”, the correct response is simply to offer so much money that the insult becomes irresistible.
Warriors who stake their lives on weapon quality found the lure of black-iron daggers impossible to ignore. The Young Master, knowing he had merely added one more carrot people already craved to the bargaining table, smiled with pure mischief.
Though I notice he never actually consulted the blacksmiths who will have to forge those daggers… The forge will probably drop dead trying to produce enough black-iron blades for every Dokwadae member, but that is the forge’s problem, not mine. They’ll manage somehow.
As for my own work, good news has arrived. The Sima family sent twenty scholars with the message that the Young Master may use them as he likes. Instead of assigning them to the inner or outer administrative halls, he divided them among me, Ye-eun, and Elder Bak Chang-eon of the Elders’ Council and told us to work them freely!
Fresh slaves! Slaves!
Ye-eun, ever the head of Minjeongwon, voiced the natural worry: “Might they try to steal our secrets?”
The Young Master answered, “You think they’ll have free time to steal secrets? Looks like they need more work.”
Ye-eun fired back in a single breathless rush: “Of course not—I won’t let them near even the first letter of the word ‘secret.’ On their days off I’ll make them faint just from looking at written characters. So please, spare me!”
The Young Master is terrifying.
Anyway—yes. Keep them so crushed by workload they never have leisure to poke around. So that is exactly what we did. It was wonderful.
At first the scholars looked resentful at taking orders from someone their own age. But with every fresh assignment their attitude shifted:
“Please… no more… have mercy!”
“I-I never intended to steal secrets! Truly! Aren’t the Tang and Sima families one house? So please give that report to another section chief, not me!”
“S-sorry for looking at you with these eyes! My eyes have always been flat like a flounder’s—I’ll correct it!”
They are rapidly becoming proper Tang people.
Still—did any of them actually try to steal secrets? Ye-eun says none even made the attempt. Frankly, when you are this busy, anyone with energy left for espionage would have to be a monster, not a human being. The Sima apprentices under me (we call them the Sima lads) have already spent a full week sleeping on rush mats on the office floor, never once going home.
Heh heh heh. Perfect. This is how it should be.
While Lee Jinmyeong and Ye-eun, newly equipped with their own direct subordinates, squeezed those subordinates like juicers and reveled in their junior-Hwiyeom authority, Hwiyeom dangled the fresh carrot of black-iron weapons under every nose. The once-feared battle machines of the Dokwadae—renowned throughout Sichuan—mutated overnight into trench-digging maniacs who would have looked at home in the Second World War.
“Give me one shovel and I will move that mountain!”
“Every cun I dig brings me one step closer to a black-iron blade!”
“The earth knows the answer!”
“If anyone asks what the greatest invention in the history of the martial world is, point them to a Tang construction site.”
All hail the black-iron sword.
Each time a shovel blade charged with internal energy bit into the soil, earth rocketed skyward as though heavy machinery had been brought in. Watching the future tunnel race forward, Hwiyeom hummed under his breath, “Wingardium mountain-be-gone~♪.” The Young Master’s magic wand proved every bit as reliable as a division commander’s baton.
And then—even though absolute secrecy had been ordered—word somehow leaked. A few days later:
“Lord of the Hwamangdae, what brings you here?”
“Young Master… is there room for the Hwamangdae as well?”
“…Pardon?”
“Well… honestly, wouldn’t we guerrilla specialists be better suited to construction work than the Dokwadae, whose specialty is spraying poison?”
“?”
Where, exactly, had warrior pride gone? The Hwamangdae lord read the unspoken question perfectly and cleared his throat.
“Ahem… they say hoe work builds the shoulders and shoveling strengthens the waist… The young ones these days rely too much on internal energy and have grown soft. A little digging with shovel and hoe would toughen the body and make real men of them, don’t you think? When you get down to it, aren’t we all sons of farmers?”
So spoke a man born of a powerful clan. Hwiyeom pieced the truth together at once. Word that the Dokwadae were about to receive black-iron blades had reached the Hwamangdae warriors, who promptly boiled over demanding the same weapons for themselves.
Naturally Hwiyeom told the Hwamangdae lord who had barged in asking, “You’ll give us black-iron weapons too, right?” a flat “Equal work, equal pay.” The moment that answer was relayed, the Hwamangdae men began spouting nonsense:
“The earth is calling me.”
“Shoveling is spear art that stabs the land and sword art that cleaves mountains.”
“Send us to the front—no, to the worksite!”
“High mountains, deep valleys! Desolate landscape! To the digging ground! We go! Comrades, do you hear it? This furious rumble of earth! Comrades, do you see it? This grudge-laden shovel shaft!”
They performed a full career change from martial artists to construction laborers at a speed that would make even the actor who once uttered the “Talulah” line slap his forehead and leave Udyr himself in awe. The Hwamangdae lord abruptly became director of the “Hwamang Labor Agency,” nearly came to blows with the director of the “Dokwa Labor Agency,” and a minor scuffle ensued.
Of course Hwiyeom, who regarded inter-department competition as a virtue, was never going to let such a delicious opportunity pass.
Top-evaluated unit — every member:
Three days’ leave, plus seven additional black-iron bone-piercing nails!
The extra prize finally dragged Manager Han out of the forge; he stormed in bellowing that he would smash Hwiyeom’s skull with a steel hammer. Yet the moment he stood face-to-face with the Young Master and heard a few quiet words, he returned to the blacksmiths’ hall with his tail trembling like a scolded puppy. Exactly what passed between them remains known only to the two men.
And so, with the construction period slashed far shorter than anyone had expected, tunnels linking Seongdo to every corner of Sichuan opened one after another. Next would come the roads that would run through those tunnels and bind the cities together.