This machine is called Bridge Gantry Crane. 这种机器叫路桥门式起重机。
Successful development of the crane solves the problems of high-speed railways' unballasted track laying and brings obvious economic and social benefits. 博格板大悬臂门式起重机的研制成功解决了高速铁路无碴轨道板的铺设难题，创造了明显的经济和社会效益。
