1974年,大连机车车辆工厂试制成功我国自行设计的第一台四千马力内燃机车——东风4型内燃机车,并从同年7月开始成批投入生产。这台东风四千马力内燃机车设计精良,主要技术指标达到了当时的世界先进水平。在炎热的夏季,机车牵引货物列车,顺利通过60多个山洞的丰沙线,而国外进口的四千三百马力的内燃机车却不能顺利通过。机车还 In 1974, Dalian locomotive and rolling stock factory successfully trial-produced China’s first 4,000 horsepower diesel locomotive - Dongfeng 4 diesel locomotive, and began mass production in July of the same year. This Dongfeng four thousand horsepower diesel locomotive well-designed, the main technical indicators reached the world’s advanced level. In the hot summer months, the locomotive trains cargo trains and smoothly passes the Fengsha line of more than 60 caves. However, the 4,300-bhp diesel engine imported from abroad can not pass smoothly. Locomotive also