Recently，It is designed and manufactured by China Railway Construction Heavy Industries.，5 used by Sinohydro Bureau 4 for construction.5 meters open typeTBM（DZ301）Formally arrive at the equipment tunneling task section。It is reported that，The total tunneling mileage of the equipment is 26 kilometers.，Creates an open typeTBMWorld Record of Longest Single Machine Tunneling。This is the open type after the railway construction heavy industry.TBMAfter the breakthrough of 21 kilometers in the project，Set a new world record again！

Initial stage of initiation，Go through ups and downs

September 25, 2017，The 18th Bureau of China Railway used the equipment for formal excavation.。The project served by the equipment is located in the desert.，The geological conditions are complex，The natural environment is harsh。This section requires more than 18 kilometers of excavation under high rock strength.，High requirements for equipment support performance and reliability，Still withstanding many tests.，Efficient origination，In the first three months, the average footage exceeded 1000 meters.，It only took more than two months to complete the task of protecting 2 kilometers of trial excavation.。

Tunneling begins，Uncommon skill

During tunnel construction，The equipment has encountered surrounding rock fragmentation.、Landslide、Various complex construction problems such as rapid geological changes，There is seepage water in some strata.、Flowing water phenomenon。

Difficulties lie ahead，Railway Construction Heavy IndustryTBMStill go forward，CreatedTBMMaximum daily footage of excavation 56.61 meters、The maximum monthly footage is 1280m.、The average monthly footage of the whole section is 720 meters, which is a high yield record.，TBMThe average utilization rate is 39.62%，Average intact rate of equipment 94.6%，Monthly footage breaks kilometers for many times，Create the same type of tunnelTBMThe highest construction record，Highly recognized and praised by the owner，Set a benchmark for other projects under construction。

Rock breaking through，Heavy industry speed

This equipment is used for the construction task of the 18th Bureau of China Railway.（Total Task 20.551 kilometers）It was successfully completed on July 2, 2020.，Advance the construction period by at least 9 months，It is 18 sets along the project.TBMThe first through bid section，It is also made in ChinaTBMBreakthrough in continuous tunneling for the first time 20.54 kilometers，The average monthly footage of the whole section is more than 700 meters.，It shows“Heavy industry speed”。

Green construction，Keep fighting

November 18, 2021，The equipment has been overhauled by China Railway Construction Heavy Industry.，Transferred to Sinohydro Bureau 4 for construction。During which a long step is experienced、Mud burst and water gushing、Fracture, breakage, belt card machine and other tests.，The design mileage 5 is still completed on schedule..45 kilometers，A total of 26 kilometers of excavation，It also creates an open type.TBMWorld Record of Longest Single Machine Tunneling。