Chapter 145: Casting Cannons (Part 2)

"There's no rush to become arms merchants," Zhang Bailin said. "We can equip the smoothbores ourselves—we have far too many firepower gaps at the moment. The three blockhouses along the Bopu road don't have a single cannon between them. Bairren Fortress has none either. And eventually, we'll need to build native armies. Those forces can use smoothbores for their artillery units, and when the time comes to convert to Armstrong guns, we'll already have trained, qualified gunners."

As an artillery fanatic, Zhang Bailin cared most about realizing his dream of a proper artillery corps. To his mind, any cannon was better than no cannon at all.

Everyone found this suggestion reasonable. Setting aside manufacturing costs and the needs of future native armies, smoothbores also had far lower operating costs. Without rifling, projectiles could theoretically be anything that fit the bore—no precision shells required. The simplest option was solid iron balls. Even well into the nineteenth century, such balls remained perfectly acceptable for inflicting casualties on both land and sea. In fact, solid shot had remained the most commonly fired ammunition right up until smoothbores disappeared from warfare, proving more reliable than the questionable high-explosive shells of the era.

"We could also develop specialized spherical shells," someone added. "High-explosive rounds, incendiaries, and the like."

"There's another advantage you might not have considered," Wang Luobin said. "Director Wen's generation gap theory."

"Generation gap theory?"

"In this timespace, at least within our lifetimes, we'll always be outsiders. To conquer and rule effectively, we need local assistance. That means building native armies eventually."

Once such armies existed, their sheer numbers would inevitably make them the main armed forces of the transmigrator state. No matter how thorough the brainwashing, how diligent the political work, or how tight the controls—armies were violence machines at their core. Once their soldiers realized the power they wielded, greed would follow. They would demand more power, more benefits. The transmigrators' own strength was limited; they could never match those numbers. The only solution was maintaining technological gaps.

If native troops received twenty-millimeter flintlocks, then transmigrators needed bolt-action rifles as a counter. This ensured that a tiny minority could always suppress a much larger force. By the same logic, if the transmigrators could produce Type-92 infantry guns, then the best cannons available to native armies should never exceed thirty-seven-millimeter carriage recoil guns.

Wen Desi hadn't yet perfected this theory—he spent many sleepless nights contemplating future military institutions and political organizations. His ultimate goal was nothing less than a "transmigrators' eternal dynasty."

After several days of preparation, cannon casting finally began. As a technical reserve and for practice purposes, the Artillery Group would start by casting traditional smoothbores. Generally speaking, smoothbores made from copper were preferred, offering approximately one thousand rounds of service life compared to cast iron's six hundred. But copper was far more expensive, a precious industrial material the transmigrators could ill afford to waste. Fortunately, the Guangdong pig iron from the Deng Yingzhou was of excellent quality with low sulfur content—ideal for cannon casting.

Historically, pig iron from Fujian and Guangdong during the Ming era had been renowned for its quality. Regional ironworks used charcoal as fuel, which kept sulfur content far lower than the coal-smelted pig iron of the north. Sulfur was the primary element that made pig iron brittle and prone to degradation. Though the Ming people didn't understand the underlying chemistry, a consensus had emerged: "Southern-cast cannons are sturdier than northern ones." Consequently, all large-scale cannon casting during the late Ming dynasty took place in Guangdong. In 1619, during the forty-seventh year of the Wanli Emperor's reign, Xu Guangqi had been commanded to train troops for the capital's defense and suggested recruiting Fujian and Guangdong craftsmen to cast cannons in Beijing. By the third year of the Chongzhen Emperor's reign, he volunteered to travel to Guangzhou for cannon casting because, as he wrote, "Craftsmen are numerous there, the iron materials are especially fine, and prices can be saved by one-third." During the early Chongzhen period, Governor-General Wang Zunde had cast two hundred cannons in a single batch.

Wang Luobin suggested recruiting Guangzhou cannon smiths to demonstrate traditional Chinese casting techniques, giving the transmigrators an intuitive foundation before implementing improvements. But Lin Shenhe dismissed the idea as unnecessary. The Chinese cannon smiths of 1628 weren't particularly skilled—even their European instructors' casting technology wasn't much more advanced. There was nothing the transmigrators needed to learn from them.

Matteo Ricci had written extensively about the problems plaguing contemporary Chinese cannons: insufficient powder charges, short range, no sights, and no meaningful aiming capability. The bores were wide at the mouth but narrow inside, which prevented effective concentration of propellant gases. Bore interiors weren't properly circular, nor were they polished. Shell sizes and even shapes varied arbitrarily, and the gaps between shells and bores were excessive. Cannons lacked trunnions and were dangerously top-heavy. Dense-packed powder often caused the weapons to explode upon firing.

The imported "Red Barbarian Cannons" of the period were fundamentally identical to traditional Ming cannons—both were smoothbore muzzle-loaders using black powder and solid shot. But European designs benefited from scientific understanding and possessed several key advantages: thicker barrel walls, higher caliber-to-length ratios, and barrels that tapered from rear to front. These features translated to superior range, killing power, and safety. European barrels commonly featured front sights and rear apertures, and the inclusion of trunnions made them convenient to mount on carriages, adjust for elevation, and transport.

The smoothbores the transmigrators planned to build could also be considered "Red Barbarian Cannons," but with slightly more advanced blueprints. They were copying early nineteenth-century French six-pounder cannons—effective range of five hundred meters, maximum range of fifteen hundred meters, with barrel weight of approximately two hundred fifty kilograms.

Lin Shenhe and Wang Luobin decided to start with seventeenth and eighteenth-century Western casting methods, which also required clay molds.

They commissioned the Lumber Factory to machine specialized wooden patterns: conical wood for the support bodies and turned patterns for the cannon breech. After completion, the first step was creating the positive mold blanks. Starting with the conical wood supports, hemp rope was densely wound into the shape of a cannon barrel. At this stage, the positive mold blanks were approximately twenty-five centimeters oversized compared to final dimensions. Then a clay-water mixture was evenly layered onto the blanks, with each layer completely dried before adding the next.

During application, overall dimensions were kept slightly larger than the actual cannon to account for casting shrinkage. After the final layer dried and the shape was corrected, the positive mold blank was coated with wax—lacking paraffin, they substituted beeswax. The wax created a smooth surface that wouldn't stick to the negative mold during the next step. The breech pattern, turned from wood, was screw-fixed to the positive mold blank.

Once the positive mold was complete, work began on the negative mold. This used a mixture of clay, pottery clay, fine sand, and water, blended into a semi-liquid consistency and layered onto the positive mold. Again, each layer had to fully dry before the next was applied. After complete drying, iron bar reinforcement ribs were added externally.

When the molds had dried completely, the positive mold was removed. The method was straightforward: cut the negative mold open at both ends, extract the conical wood core from the positive mold, then pull out the wound hemp rope. The wax layer between molds allowed easy separation—if difficulties arose, gentle heating would melt the wax and create gaps. The breech mold was made separately.

The third component was the core—a clay-encased iron rod, generally cylindrical, though the powder chamber might have a special shape. The core was inserted into the main mold; iron core supports at the mold's rear and a pottery ring at the cannon mouth held it fixed in position.

The separately made breech negative mold was then reassembled with the barrel negative mold. With all three molds firmly assembled, the entire unit was fired to harden completely. Finally, the molds were buried cannon-mouth-up in a compacted earth pit beside the cupola. Jiang Ye designed and installed a wooden hoist to lift the heavy molds—a necessity since cannon casting hadn't been considered during the original cupola construction, and the steelmaking workshop floor had already been hardened. They built a separate cupola in the casting workshop, but since the process only required melting rather than iron smelting, no regenerator was used. The runner system was one-to-four. Ji Wusheng personally supervised the operation while Zhan Wuya contributed his casting experience—and the first attempt succeeded.

After pouring, the cast required twenty-four hours of insulation before being excavated from the pit. After further cooling, the external reinforcement ribs were removed and the molds broken apart. The Artillery Group then used hammers and chisels to clear residual slag from inside the barrel.

At last, they had a cast-iron six-pounder cannon. But it still required further processing: bore polishing. The Mechanical Group constructed a simple boring mill—powered not by electricity or diesel, but by a donkey. The animal drove a capstan that rotated a boring bar fitted with a high-carbon-steel boring head.

The bore polishing significantly improved the smoothness of the interior surface, but measurements revealed a problem: polishing couldn't truly cut precise cylinders or correct the core deviation that occurred during casting. Throughout the process, hard residues severely damaged the boring bars. In other words, the process was prohibitively costly.

"No wonder the drilling method replaced this by 1713," Lin Shenhe said with some dejection. The drilling method involved first casting solid iron rods, then boring out the interior. It was first used by the Dutch but didn't become widespread until the late eighteenth century. British naval arsenals continued using the traditional casting method for naval guns until 1770.

(End of Chapter)