“I thought, if others can do it, I can do it too.”
Despite his wife’s opposition to the “expensive, risky, useless” idea, Zhang began pursuing his submarine dream, first by spending 5000 yuan ($1180) on steel plates, engines and other materials.
The inventor launched his “first-generation” sub in 2016, but it leaked.
“It was like a dream. I was both afraid of it leaking and hoped to go deeper,” Zhang said.
Years later, after he had spent another 40,000 yuan on a new hulking steel structure, pouring two tonnes of concrete into the bottom of the submarine and adding two ballast tanks, Zhang’s Big Black Fish was ready for sea trials.
Unlike the Chinese Navy’s advanced nuclear-powered submarines, which can spend months submerged, Zhang’s sub uses a small battery and electric motor, can travel at just four knots per hour and needs to surface after half an hour.
He plans to build an even bigger submarine in the future.
Zhang is not the first Chinese inventor to take a deep dive into submarine construction.
In 2015, a villager in China’s northern Shaanxi province accumulated a debt of 200,000 yuan to fund the construction of his 9.2m-long submarine.
In 2009, karaoke bar worker Tao Xiangli cruised around a local reservoir in Beijing in a homemade submarine.
– Agence France-Presse