On September 16, the fifth shield machine for the Qingdao Metro Line 8 Branch, "Jiaozhou Bay No. 5," was successfully launched. Over the course of 145 days, the Line 8 Branch achieved the launch of a total of five shield machines, setting a new record for shield launches in the third phase of Qingdao Metro construction.

The "Jiaozhou Bay No. 5" shield machine is a composite earth pressure balance shield machine that adopts a steel sleeve launching and receiving process. It has an excavation diameter of 6.5 meters, an overall length of approximately 90 meters, a total weight of about 500 tons, and a maximum thrust of 4,160 tons. "Jiaozhou Bay No. 5" was launched from Dagu River Museum Station on the Line 8 Branch, running along the right line of the Dagu River Museum Station–Shaohai North Station section, heading north from the right bank of the Dagu River dike, passing beneath the planned Shanghe Avenue road and the Baolong Historical and Cultural Street before turning onto Yangzhou Road, passing alongside the Canal Bridge, and finally being lifted out at Shaohai North Station. The tunneling length is 1,963 meters in total, with a maximum burial depth of nearly 30 meters. The strata traversed mainly consist of organic silty clay, medium and coarse sand, strongly to moderately weathered mudstone, and strongly to moderately weathered argillaceous siltstone, with poor geological conditions and high construction difficulty.

Because the shield machine travels a long distance through strongly to moderately weathered argillaceous siltstone, the project management team carried out a special design for the cutterhead to prevent mud cake formation, increasing the central opening ratio and adding central stirring rods and four radial high-pressure flushing ports, which can effectively prevent the formation of mud cakes and achieve long-distance tunneling without cutter replacement. In addition, to ensure the shield machine is launched and tunnels on schedule and safely, the China Communications Construction project management team scientifically allocated materials, equipment, and personnel, actively coordinated with all parties involved, resolved various difficulties, formulated special construction plans and organized expert reviews, conducted emergency drills before launch, and ultimately passed the launch condition acceptance.

Since the first shield machine, "Jiaozhou Bay No. 1," was launched on April 24, the Qingdao Metro Line 8 Branch has achieved the launch of five shield machines in 145 days, averaging one launch every 29 days.

The Qingdao Metro Line 8 Branch starts at Dajian Station and ends at Jiaozhou Railway Station, with a total length of approximately 20.4 kilometers. The entire line has 12 stations and 12 sections, with a designed maximum speed of 120 km/h. It is a rapid transit corridor serving the passenger flow between the Jiaozhou cluster and the Hongdao Economic Zone and Airport Economic Zone in the north bank urban area, as well as the east bank urban area. Once the line is completed, it will accelerate the integration of Jiaozhou with Qingdao's main urban area and help bring Jiaozhou into Qingdao's "one-hour living circle."