Twenty-six years ago today, on September 8, 1999 (July 29, 1999 lunar calendar), China's first AC drive diesel locomotive was successfully developed. On September 8, 1999, China's first AC drive diesel locomotive was successfully developed at Qingdao Sifang Locomotive and Locomotive Factory, the birthplace of the first locomotive in New China. AC drive diesel locomotives replace traditional DC drive technology with advanced AC drive technology, which is a major breakthrough in the transmission mode of railway locomotives.