The son, named Hanghang, was diagnosed with autism at 3. After completing primary school, he was forced to drop out because he couldn't catch up in classes and also had difficulty communicating with other children his age.As his parents have day jobs, Hanghang spent most of his time at home staring at the TV screen with his grandmother. During that time, he developed a fascination for miniature trains in animated programs. He even drew trains on the walls of his family's yard and slept with toy trains close at hand.Seeing his son's obsession, Li Jiawei, an electrician, had an idea: to build a real miniature train for his son.So whenever he had free time, Li would closely observe the exterior structure and internal components of steam trains and asked professionals at railway stations about the machinery.Later, Li was given a book from 1984 called "Steam Locomotives". It was a gift from a retired steam train driver. He spent three months teaching himself how to draw blueprints using software, and standardize and size the required parts for a locomotive.At times he thought about giving up, but he chose to persist for the sake of his son. "I must give my son something through which he can feel his father truly loves him," Li said.But Li did not stop there. To make the train more powerful, he continued to improve it, and thus came locomotives two, three and beyond.As he continued work to improve the train, Li noticed Hanghang also changed."My son was being healed little by little. He was no longer afraid of strangers and becoming more cheerful and lively," Li recalled.Now, Li has made a total of eight miniature steam locomotives, and Hanghang has become a skilled "conductor." The 15-year-old often confidently introduces his beloved miniature trains to others.The son, named Hanghang, was diagnosed with autism at 3. After completing primary school, he was forced to drop out because he couldn't catch up in classes and also had difficulty communicating with other children his age.As his parents have day jobs, Hanghang spent most of his time at home staring at the TV screen with his grandmother. During that time, he developed a fascination for miniature trains in animated programs. He even drew trains on the walls of his family's yard and slept with toy trains close at hand.Seeing his son's obsession, Li Jiawei, an electrician, had an idea: to build a real miniature train for his son.So whenever he had free time, Li would closely observe the exterior structure and internal components of steam trains and asked professionals at railway stations about the machinery.Later, Li was given a book from 1984 called "Steam Locomotives". It was a gift from a retired steam train driver. He spent three months teaching himself how to draw blueprints using software, and standardize and size the required parts for a locomotive.At times he thought about giving up, but he chose to persist for the sake of his son. "I must give my son something through which he can feel his father truly loves him," Li said.But Li did not stop there. To make the train more powerful, he continued to improve it, and thus came locomotives two, three and beyond.As he continued work to improve the train, Li noticed Hanghang also changed."My son was being healed little by little. He was no longer afraid of strangers and becoming more cheerful and lively," Li recalled.Now, Li has made a total of eight miniature steam locomotives, and Hanghang has become a skilled "conductor." The 15-year-old often confidently introduces his beloved miniature trains to others.