XiamenGuanxun Station of Metro Line 4 (under construction)

Xiamen Metro Line 4 is Xiamen's first fully automated metro express line, running from Ruansandong Station to Xiang'an Airport Station, with a total length of 45 kilometers and 12 stations. It was recently learned that Xiamen Metro Line 4 will organize a full-line trial operation in 2026. At present, all stations along Xiamen Metro Line 4 have been topped out, the section from Ruansandong to Caicuo has achieved tunnel breakthrough and track laying completion, more than half of the electromechanical works along the entire line have been completed, and track has been laid for about 41 kilometers of the line, with the full-line civil works "tunnel breakthrough" planned to be achieved by the end of this year. In 2025, Xiamen Metro Line 4 will successively achieve "track completion" and "power supply completion" along the entire line.

At the end of July this year, the first electric multiple unit (EMU) for Xiamen Metro Line 4 rolled off the production line at CRRC Changchun Railway Vehicles Co., Ltd., and officially arrived at the Jimei Houxi Depot in early August. At present, comprehensive, multi-disciplinary static commissioning of the train is being carried out.

By the end of this year, the trains for Xiamen Metro Line 4 will run on the main line for "commissioning tests." Xiamen Metro Line 4 will adopt phased commissioning, with the "north section first," to accumulate relevant commissioning experience for fully automated lines in advance for the subsequent airport section. The north section, namely the section from Ruansandong to Caicuo, is 33 kilometers long and has 10 stations.

Before trains enter service, the most important prerequisite is "power supply completion," which is divided into "ring network power supply completion" and "catenary power supply completion." In simple terms, after ring network power supply completion, the station equipment will have power and commissioning work can begin; the catenary is the main power artery for metro vehicles, and after catenary power supply completion, "hot sliding" tests and train commissioning can be carried out.

At present, 8 of the 10 stations in the north section of Line 4 have been powered, and Guanxun Station is scheduled to enter "individual system commissioning" in November, making full preparations for the "integrated joint commissioning" work after trains enter the line in the next step.

Xiamen Metro Line 4 has a maximum speed of 120 kilometers per hour, a high speed rating, and in addition to fully automated operation, this brings greater difficulty to the commissioning work. Dong Jun said that some work originally performed manually will be replaced by fully automated equipment, so a considerable amount of additional testing content is required. After the Line 4 trains run on the main line for "commissioning tests," commissioning will be carried out by "speed level," that is, initially testing at 10 kilometers per hour, collecting relevant data and configurations, and then gradually increasing the speed—20 kilometers per hour, 30 kilometers per hour, up to the maximum of 120 kilometers per hour.