Home / Standards / GB/T 39657-2020 GB/T 39657-2020 Active Backhoe dredger supervisory control system 反铲挖泥船疏浚监控系统 Standard Type GBT ICS 47.020.70 CCS U62 Status 现行 Issue Date 2020-12-14 Implementation 2021-07-01 Responsible Dept 交通运输部 Drafting Unit N/A