By contrast with long time blockaded and high mechanization of abroad track sky window, the time of sky window is short and the workload is large as traffic flow high in China railway.

• 与国外铁路线路维修中长时间天窗封锁，机械化程度高的特点相比，我国铁路由于行车密度高，天窗封锁时间短、工作量大，这就要求对于施工天窗开行方式有合理的选择。