Courtyard House: Initial Donation of 50 Million

Wang Huanbo completely entered "inventor" mode. His study in the west courtyard became a temporary design center, the walls covered with structural sketches, transmission system diagrams, hydraulic schematics, and preliminary 81-bar improvement designs for the "Red Star Little Cannon" tractor. His desk was piled high with various technical manuals, domestic and international agricultural machinery catalogs (some obtained through special channels), and books on materials mechanics and mechanical design. The air was thick with the scent of drawing ink and paper, and a unique atmosphere of focused contemplation.

When the holiday ended, he continued to handle the factory's technical affairs during the day, listening to progress reports on projects such as electronic computers, CNC machine tools, and the automobile branch, and making decisions. But whenever he had free time, or even late at night, he devoted all his energy to these two "optional activities".

First up is the "Red Star Little Cannon".

With the concept of hand-drawn sketches and the initial 3D model established by Pangu, Wang Huanbo began to refine the technology in depth. He knew that when designing a usable machine, especially one that could adapt to the complex and ever-changing environment of rural China where maintenance conditions might not be adequate, reliability had to be the top priority, followed by functionality and performance.

The powertrain is the core of the system. For the 40-horsepower diesel engine, he decided to make significant improvements based on domestically developed or trial-produced vertical, water-cooled, four-stroke single-cylinder or twin-cylinder diesel engines. He obtained technical data from several domestic diesel engine manufacturers (such as Shanghai Diesel Engine Factory and Wuxi Diesel Engine Factory) through Pangu, and combined this with his understanding of efficient combustion, low friction, and lightweight design. He redesigned the key dimensions and shapes of the cylinder head, pistons, connecting rods, and crankshaft, optimized the intake and exhaust ports, improved the fuel supply system (using a more precise Borsch pump and multi-hole injectors), and particularly enhanced the reliability of the lubrication and cooling systems. For the electric start system, he selected the latest 12V 100Ah high-capacity dry-charged battery from Hongxing Battery Factory, paired with a DC starter motor and silicon rectifier generator, ensuring smooth starting even in low-temperature environments and meeting basic lighting needs during nighttime operations (he included a pre-installed headlight interface).

The transmission system is far more complex than that of ordinary tractors. To achieve a wide speed range for both low-speed precision work in the fields and medium-speed transport on highways, he designed a 4×2 mechanical manual gearbox (four forward gears and two reverse gears), but through a secondary gearbox (for high and low gear switching), he achieved an actual total of eight forward gears and four reverse gears. The gear positions are clear, and the shifting force is moderate. Among them, gears 1 and 2 are ultra-low speed crawling gears, used for extreme heavy loads or precision work; gears 3 to 5 are standard working gears; gears 6 to 8 are road transport gears. The transmission ratio of the highest gear (8th gear) was carefully calculated and matched with the rear axle final drive ratio to ensure a theoretical speed of 45-48 km/h when a 1.5-ton trailer is attached at the engine's rated speed. Considering the road conditions at the time (mostly dirt roads or gravel roads) and the poor shock absorption of tractors, this speed ensured both a certain level of transport efficiency and safety and vehicle lifespan.

The rear axle uses a rigid drive axle, which is robust and has a high load-bearing capacity. The differential ensures agile cornering. The braking system is a mechanical shoe type, acting on the rear wheels, which is reliable but has limited braking force. Wang Huanbo specifically emphasized in the instruction manual that engine braking must be used and the vehicle speed controlled when going downhill on highways.

The hydraulic suspension system was key to its "multi-functionality." He designed a simple, separate hydraulic system consisting of a gear pump, distributor, and hydraulic cylinders. By manipulating the distributor handle, one could control the lifting, lowering, and floating of the suspended implements, as well as force adjustment (automatically adjusting tillage depth based on tillage resistance) and position adjustment (maintaining the relative position of the implements and the tractor). While not as complex as later systems, this system was quite advanced in the mid-1950s, greatly improving tillage quality and efficiency. The hydraulic output interface (quick-connect coupling) also allowed for the future attachment of more complex hydraulic implements (such as the hydraulic lifting of a dump trailer).

The cab? No, considering cost and intended use, Wang Huanbo only designed a safety frame made of curved steel plates, which could provide shade and rain protection, but was not enclosed. The seat was a mechanically adjustable seat with spring shock absorption, which was definitely a "luxury feature" at the time. The instrument panel integrated a water temperature gauge, oil pressure gauge, ammeter, fuel gauge, engine hour meter, and an air filter clogging alarm—this small device could remind the operator when the air filter was clogged, preventing engine wear due to insufficient air intake, which was very thoughtful.

His design for the standardized three-point suspension and power take-off shaft (PTO) referenced later mature standards but simplified them. The PTO was available in two speeds, 540 rpm and 1000 rpm (switched via an auxiliary gearbox), to suit the needs of different machines.

In all designs, Wang Huanbo strives to find the optimal balance between advancement, reliability, manufacturability, and economy. Materials are selected primarily from high-quality carbon structural steel, alloy structural steel, and cast iron that can be stably produced domestically. Machining processes also take into account the capabilities of existing machine tools (including CNC machine tools produced by Hongxing Factory itself), minimizing the use of special cutting tools and complex fixtures.

"Pangu conducted finite element analysis on the final digital model of the 'Red Star Little Steel Cannon,' focusing on verifying the stress distribution of the frame, rear axle housing, and suspension supports under maximum load and impact load. It also simulated the dynamic performance under typical working conditions such as field cultivation and road transportation. The weight distribution was optimized."

"Analysis in progress... The maximum stress point on the chassis is located at the rear axle connection. It is recommended to add local reinforcement ribs. Optimization suggestions have been generated."

While Wang Huanbo was engrossed in perfecting the tractor design, he did not forget his promise to Li Yunlong. Meanwhile, improvements to the Type 81 automatic rifle were being developed on another drawing board.

He didn't directly draw the complete blueprints for the 81-bar weapon—that would be too shocking. Instead, he conducted an "academic" discussion titled "Based on the technical analysis of existing Soviet automatic weapons (AK-47/SKS) and the assessment of future individual weapon development, I propose several improvement directions and key technology pre-research suggestions."

He first systematically analyzed the advantages of the AK-47 assault rifle (learned from internal documents): simple structure, reliable operation, good serviceability, and moderate power. However, he also pointed out its shortcomings: poor accuracy in continuous fire (significant muzzle rise), short sight radius affecting accuracy, ergonomics needing improvement (position of fire selector, magazine release button, etc.), and lack of bolt hold-open device.

In response to these problems, he proposed his own improvement ideas and explained them using rigorous engineering language:

1. Improve accuracy and controllability:

Optimize the gas guiding system: By adjusting the position of the gas guide orifice, piston stroke, and gas chamber volume, and by adding a gas pressure regulating device to the piston (preliminary concept), the energy of the propellant gas can be released more gently and evenly, thereby effectively reducing the recoil of the automatic mechanism and muzzle rise, and improving the accuracy of burst and short burst fire. He drew a comparison diagram of the gas guiding device before and after the improvement.

Improved bolt and buffer: Optimize the mass distribution of the bolt assembly and add a rubber buffer pad behind the bolt to further absorb recoil impact and make the weapon firing more smoothly.

Extend the aiming baseline: Move the rear sight forward and appropriately increase the distance between it and the front sight base to improve aiming accuracy, especially for shooting at distant targets.

2. Improve ergonomics and operational efficiency:

Adding a bolt hold-open feature: A bolt catch is designed at the bolt carrier or magazine well. After the last round is fired, the bolt recoils and locks in place, prompting the shooter to change the magazine. After changing to a new magazine, the bolt can be released by striking the bolt release button (located on the left side of the receiver) or by pulling back the bolt to chamber a new round. This feature significantly improves reloading speed and tactical awareness in combat. He drew a detailed diagram illustrating the working principle of the bolt hold-open mechanism.

Improved operating components: Move the fire selector from the right side of the receiver to the left side (for easier thumb operation when shooting with the right hand) and enlarge the paddle; optimize the shape and force of the magazine release button for quick magazine changes; consider adding anti-slip textures or using engineering plastics (materials development required) to the handguard and pistol grip to improve grip and heat insulation.

3. Application of new materials and processes:

Barrel steel: It is recommended to develop a new type of nickel-chromium-molybdenum alloy steel to improve the barrel's resistance to ablation and fatigue, and extend its service life.

Casing machining: Explore the use of precision forging or steel plate stamping and welding processes to replace traditional milling, reducing weight, lowering costs, and improving production efficiency while ensuring strength. This requires breakthroughs in related processes and equipment.

Surface treatment: Research more wear-resistant and corrosion-resistant phosphating, bluing or new ceramic coating technologies.

4. Extended and forward-looking appendix (this part is even more advanced):

He proposed designing a continuous, standardized mounting rail with a locking mechanism on the top of the receiver (which he called a prototype of a "universal tactical rail"), which could be used to mount optical sights (such as the simple holographic diffraction sight he was conceiving), night vision devices (in the future), tactical lights, laser designators, etc., to improve the weapon's adaptability in different environments and missions. He drew detailed cross-sectional diagrams and dimensioning for this "rail".

To verify his idea of ​​"improving accuracy with optical sights," he even hand-drew a very simplified schematic diagram of a reflective holographic sight. Of course, this was just a conceptual illustration; he knew that with the current level of optics, electronics, and precision manufacturing in Taiwan, producing a practical holographic sight was almost a pipe dream. But this didn't stop him from proposing this future direction and from starting preliminary research with relatively simple white-light sights or simple optical direct sights.

He compiled his thoughts on rifle improvements into a well-structured, rigorously argued, and visually appealing technical report. The report did not use the name "Type 81," but was instead titled "Exploration of Improvement Directions for a Certain Type of Automatic Rifle." He planned to present this report, along with the project proposal for the "Red Star Little Cannon," to his superiors at an appropriate time.

After several days of working at his desk, Wang Huanbo's eyes were bloodshot, but his spirits were exceptionally high. The sense of accomplishment from creation, especially creation that can tangibly improve people's lives and enhance national strength, is immense.

That afternoon, Li Huaide arrived uninvited and knocked on the door of the west courtyard. He was currently riding high; production at the automobile branch was gradually getting back on track, demand for Hongqi sedans and Hongxing Mengshi was booming, and the main factory's logistics were running smoothly under his management. But he knew all too well that the foundation of all this was Wang Huanbo's technical magic. Therefore, he kept a close eye on Wang Huanbo's activities.

"Engineer Wang, busy?" Li Huaide's eyes lit up when he saw the wall covered with blueprints. "Oh! What are you drawing? A new machine?"

Wang Huanbo didn't hide anything from him, pointing to the tractor assembly diagram on the wall and saying, "Director Li, you've come at the right time. I was just about to discuss this with you. This is something I've been thinking about recently, a multi-functional small wheeled tractor. I've named it 'Red Star Little Cannon'."

"A tractor? A small cannon?" Li Huaide curiously leaned closer to examine it. On the drawing, the tractor, with its strong lines and compact structure, was lifelike. Wang Huanbo briefly introduced its design concept, 40-horsepower diesel engine, electric start, multi-speed gearbox, hydraulic suspension, multi-functional interface, and especially its road transport capacity of 45 km/h and 1.5 tons when a trailer is attached.

Li Huaide, being an expert, listened intently, his eyes lighting up, his breathing becoming rapid. "Engineer Wang! You truly... truly understand our country's needs!" He slapped his thigh. "You don't know, in the rural areas, people are desperately waiting for tractors! The large 'Dongfanghong' tractors are nowhere to be seen, and besides, they're too big for many applications. Your 'Little Cannon' design is the perfect size, and so versatile! It can plow, transport, and even pump water and drill wells? If this were built, it would solve so many problems! It would definitely be in high demand!"

He rubbed his hands excitedly: "Engineer Wang, just tell me, what do you need the factory to do? We'll provide manpower and equipment! Some of the production capacity and processes in our automobile branch are interchangeable—engines, transmissions, axles, hydraulic components… many of these can be borrowed or even directly improved and used! I think this can be done! And it's a great thing, a great thing for the country, for the farmers, and for our factory!"

Wang Huanbo nodded; this was exactly the attitude and support he needed from Li Huaide. "I've prepared a detailed project proposal and technical plan, including preliminary drawings, calculations, and material and process requirements. We still need to do more in-depth engineering design, prototype manufacturing, and testing. This requires setting up a dedicated project team, drawing on skilled technical personnel and workers. We may also need to coordinate with other supporting manufacturers, such as those producing diesel engines, tires, hydraulic components, and electrical parts."

"No problem! Leave it to me!" Li Huaide patted his chest confidently. "I'll report to Secretary Yao and the ministry immediately! Such a great project will definitely get support from above! I'll lead the project team, and you'll be the chief designer and technical advisor! Our Hongxing Factory is going to launch a 'little powerhouse' satellite!"

With Li Huaide's strong support, Wang Huanbo felt more at ease. He knew that with the current technical strength, manufacturing capabilities, and influence at the top of the hierarchy of Hongxing Factory, the "Hongxing Little Cannon" had a solid foundation to move from blueprints to the field.

Just as Wang Huanbo and Li Huaide were discussing the details of the "Little Cannon" project, news that Engineer Wang was "tinkering with new gadgets" had already spread like wildfire throughout the courtyard. Although no one knew exactly what it was, the rumor that "Engineer Wang is building a new machine" was enough to make everyone in the courtyard speculate, especially Yan Bugui and Liu Haizhong.

Yan Bugui thought to himself: "The things that Engineer Wang makes must be good! Maybe there will be some benefits leaked out? I need to keep a closer eye on Jie Cheng."

Liu Haizhong grumbled sourly: "Another new invention? How come he always gets all the good things? I've worked in the factory my whole life and haven't accomplished anything..."

In his study in the west wing, Wang Huanbo had already bound the detailed project proposal and the 81-bar improvement report for the "Little Cannon." Next, he awaited the higher-ups' decision and the intensive research and development work. He could almost hear the "Little Cannon" roaring across the fields and see the improved automatic rifle firing precisely in the hands of soldiers. The torrent of technology was beginning to surge in the direction he had set. And all of this was just the beginning.