干线机车 meaning in English

main-line locomotive

Railway applications - rolling stock - characteristics and tests of pantographs for main line vehicles
铁路应用机车车辆.干线机车车辆受电弓特性和试验
A linearization method is suggested for optimizing vehicle suspension parameters under the same track condition , which is obtained by huge of online testing and simulation for main line vehicles in this paper
探讨利用线性化技术对地铁车辆悬挂参数进行快速优化的方法，并在大量干线机车车辆试验与仿真基础上，建议以一种线路不平顺条件作为这种方法的评价基础。