Chapter 459: The Compound Steam Engine

“How did you modify it?”

The changes in Dengzhou lifted Xiao Ming’s spirits throughout the journey. Now that progress had been made with the compound steam engine, he was overjoyed. The industrial revolution was right before him. How could he not be excited? He was already thinking about applying the steam engine to various industries.

As they walked toward Bowen Academy, Lin Wentao explained, “Your Highness, it’s actually simple. I connected two ports on the cylinder: one for intake at the front, and one for exhaust. When the piston moves to the top, the intake closes and the exhaust opens. Outside the exhaust is a condenser waiting for the hot steam. The steam instantly condenses, is sucked out of the cylinder, creating near vacuum inside, which pulls the piston down.”

He paused, then continued, “Repeating this cycle makes the piston move up and down continuously. Once connected with the crank and connecting rod, it becomes rotary motion. I tested it — the compound steam engine is five times as efficient as the Newcomen steam engine.”

“Good, Lin Wentao. Your physics academy has done a great service. Qingzhou will undergo huge changes thanks to you. I must admit, this time chemistry academy really lost to you, hahaha,” Xiao Ming laughed.

Lin Wentao then said, “But Your Highness, the cylinder boring is really slow. Producing compound steam engines is very slow. Could the first steam engine be used for boring on the lathe? This would greatly increase the lathe’s efficiency. The hydraulic workshop’s lathe depends heavily on water flow and is inefficient.”

“Of course. Now your physics academy doesn’t need to do anything else. Work closely with the machinery department to build a steam engine production line. Whether it’s money or manpower, I’d even sell my manor to provide it,” Xiao Ming declared boldly.

What his fief lacked most was population. The steam engine’s development would greatly ease that problem.

“Thank you, Your Highness.” Lin Wentao was so happy he could barely contain himself.

The two arrived at Bowen Academy. Inside the physics lab were two steam engines: a Newcomen steam engine and a compound steam engine. Craftsmen like Zhang Liu were observing their movements. One engine moved pistons up and down; the other had crankshaft motion.

“Your Highness, Lin Wentao is quite capable. We just helped him produce the Newcomen steam engine, and now they want us to assemble another one,” Zhang Liu smiled. “We’re currently researching how to combine the boring lathe with the steam engine.”

Seeing the real steam engines in the lab, Xiao Ming felt as if he had come to industrial revolution-era England.

Lin Wentao said, “Your Highness, this compound steam engine is not just my credit but the collective effort of all physics academy students. We researched, discussed, and solved problems together to create it.”

“Looks like everyone is improving. This is exactly what I want to see,” Xiao Ming said as he looked around the physics academy members. “I think I should award you all a group honor medal.”

“Thank you, Your Highness,” the students said excitedly.

While everyone laughed, Xiao Ming suddenly noticed a glass model of a steam engine on the lab’s central podium. Below it was an alcohol lamp.

He walked over and asked Lin Wentao, “Did you have the glass workshop make this glass steam engine?”

“Yes, Your Highness. Glass is easier to shape, so we made this model after the compound steam engine,” Lin Wentao said. “Then the machinery department reproduced the steam engine based on this model.”

“Good idea. In the future, all devices can start with a glass model,” Xiao Ming said as he turned toward the real compound steam engine—a machine made purely of steel and copper, radiating a full-metallic feel characteristic of the steel age.

This single steam engine already gave him the basis to catch up with European civilization.

Now the Great Yu Empire’s first steam engine was officially born in Qingzhou. The next challenge was mass production and application across industries.

At this era, steam engine motion had only two types: one using connecting rods for linear motion, the other using a flywheel for rotary motion.

To speed up applying the steam engine to machine tools, Xiao Ming decided to hold an on-site lesson. He gathered all students and craftsmen from the machinery department to explain connecting rod motion, crankshaft motion, and flywheel use.

“The connecting rod consists of three parts. The part connected to the piston pin is called the small end; the part connected to the crankshaft is the big end. The rod connecting the two is the rod body. The small end is usually a thin-walled circular ring. To reduce wear between it and the piston pin, a thin-walled bronze bushing is pressed inside the small end hole. Holes or grooves are drilled in the small end and bushing so splashed oil can reach the lubricated surfaces.”

Pausing, Xiao Ming continued, “The rod body is a long member that bears a large force during work. To prevent bending, you should make the rod with an I-shaped cross section, because I-sections have enough strength. Next is the flywheel, a disk structure that allows the steam engine to produce rotary motion…”

While Xiao Ming lectured, the students and craftsmen visualized the connecting rod, crankshaft, flywheel, and the steam engine driving these components moving clearly in their minds.

Given Qingzhou’s current industrial base, steel supply for the steam engine was no problem. The quality of connecting rods, crankshafts, and flywheels was naturally no issue either. So Xiao Ming only needed to instruct Lin Wentao and Zhang Liu on how to use these components. How to manufacture them? They would figure it out.

After the explanation, everyone gained a basic understanding of the steam engine’s use. Many had known the steam engine must be developed, but few understood its purpose until now.

“Your Highness, we understand. When we return, we will start producing flywheels,” Zhang Liu said. Xiao Ming had explained clearly—applying a certain torque to the flywheel via the connecting rod and crankshaft would make it rotate.