全国铁路第 5次大提速准备工作从 1 0月展开 ,明年 4月完成提速。全长 669km的宝成线是此次提速的重头戏 ,目前宝成线的平均时速还不到60km。提速的准备工作包括线路的测试和养护 ,以及加固桥梁 ,缓和弯道长度 ,换道岔等。但提速并非一步到位 ,而是针对不同的路段逐步进行。完 The nation’s fifth largest railway speed-raising preparatory work started from January to January and completed speeding up in April next year. The full-length 669km Baocheng line is the highlight of this speed increase, the current average speed of Po-line less than 60km. Speed-up preparations include line testing and maintenance, as well as strengthening the bridge, to ease the length of the bend, turnout and so on. However, speed is not one step, but for different sections gradually. Finish