A retired Chinese farmer, without specialized studies, has achieved what many would have considered impossible: he built a fully functional submarine alone.
The 60 -year -old Zhang Shengwu grew up in Anhui province near the Yangtze River, a place where water, ships and river trade were part of everyday life, since then interested in how commercial vessels were among the powerful currents of the river.
Throughout his life, he has worked in various fields: he built landing, transported goods on the water and earned his existence from trades such as carpentry and welding.
The idea of building a submersible came in 2014, when, watching a report on the television, he saw a submarine for the first time.
“I had seen wood and iron boats, but never one that could go underwater,” He told about the moment when he began to take shape the idea of making such a ship, according to Chinadailyhk.
The first step: a rudimentary submarine
Shortly after that time, Zhang Shengwu decided to try to join her in practice and, with a budget of only 5,000 yuans (about $ 700), started with old iron, a small engine and a battery. At night, after finishing his daily tasks, he worked for hours, welding and assembling the pieces.
Thus appeared the first prototype, a ship 6 meters long, 1.2 meters high and 2 tonnes, which could only dive up to a meter, but had big problems with water infiltration. However, the project brought a national patent for a utility model in 2016, which, says the 0 -year -old man, confirmed that he was on the right track and determined to continue.
“It was far from perfection, but it was the beginning. Without that first submarine, I would not have arrived here”, said Zhang Shengwu.
“Big Black Fish” brought him the celebrity
After almost a decade of trials and plans, in July 2025, Zhang Shengwu completed his second submarine, which he called “Big Black Fish” (“Great Black Fish”). This time, the investment was much higher, 40,000 yui, ie about $ 5,600, but the satisfaction was tailor -made.
The result is a ship 7 meters long, 1.8 meters high and 5 tonnes, capable of transporting two passengers and navigating at a speed of 4 knots. It can reach a depth of 8 meters, using two ballast tanks for floatability control, and a concrete slowness of two tons, placed in the corner, gives it stability. With the experience with the previous Sumbbarin, who took water, this time it ensured the sealing through reinforced welds and sealed with silicone and adhesive.
The pilot cabin is equipped with an instrument panel and a joystick, and a five -meter pillar with a waterproof camera allows the inventor to inspect the river before diving.
The first official test took place on the Fengle river, where “Big Black Fish” slowly slipped under cloudy water before returning to the surface. The moment was filmed and loaded on the Douyin platform, the Chinese equivalent of Tiktok, and the images became rapidly viral.
Thousands of internets praised the courage and inventiveness of the pensioner, but online discussions have also revealed safety, experts pointing out that handmade technical problems may arise, especially in maintaining internal pressure and the ability to return to the surface in case of emergency.
The Chinese pensioner already dreams of an even better submarine
In the beginning, Zhang Shengwu's family looked at the project with fear, worried both the high costs and the risks involved, but, with the success of the first dive, the doubts have been scattered.
“Only when you try and succeed you realize why you are truly capable”, said Zhang Shengwu, specifying that he is already making plans to build a larger submarine, capable of deeper diving and longer travel.
