MRT Jakarta Completes Indonesia's Deepest Underground Tunnel

PT MRT Jakarta (Perseroda) has completed the construction of the approximately 5.8-kilometre northbound tunnel connecting Bundaran HI Bank Jakarta Station to Kota Station, linking Phase 1 and Phase 2A of the north-south line. The completion was marked by a breakthrough moment when Tunnel Boring Machine 1 reached the final excavation point and penetrated the southern side of Mangga Besar Station. “With this achievement, the northbound tunnel spanning approximately 5.8 kilometres now connects Phase 1 and Phase 2A of the MRT Jakarta north-south line,” said MRT Jakarta Director of Construction, Weni Maulina, in Jakarta on Thursday (9/7). Weni stated that the successful completion of the northbound tunnel excavation is an important milestone in the construction of MRT Jakarta Phase 2A, achieved on target. During the construction process, MRT Jakarta and the contractor team used three tunnel boring machines to build the northbound tunnel on the Phase 2A north-south line. Each machine worked according to its contract package: CP201 from Bundaran HI Bank Jakarta Station to Harmoni, CP202 from Harmoni to Mangga Besar, and CP203 from Mangga Besar to Kota. At the breakthrough point on the southern side of Mangga Besar Station, the northbound tunnel reaches a depth of up to 28 metres below ground level. “This achievement makes it the deepest underground railway tunnel in Indonesia, together with the tunnel at Sawah Besar Station. A milestone in civil construction in Indonesia,” said Weni. Tunnel Boring Machine 1 in CP202 worked to build the tunnel between Harmoni and Sawah Besar stations spanning approximately 395 metres, as well as the connecting tunnel between Sawah Besar Station and Mangga Besar Station spanning 800 metres. To connect the two stations, Tunnel Boring Machine 1 crossed beneath the canal located between Jalan Gajah Mada and Jalan Hayam Wuruk. Weni added that this achievement is the result of careful planning, good coordination, and the hard work of all parties involved in the construction of MRT Jakarta Phase 2A. Thanks to this synergy, the northbound tunnel excavation process was completed according to the established target. “This success is an important step towards completing the next construction stages, so the project can continue on schedule,” she said. Currently, the MRT Jakarta construction team and contractors are completing the southbound tunnel from Kota to Bundaran HI. All Phase 2A north-south line tunnels are targeted for completion by the fourth quarter of 2026, while as of 25 June 2026, Phase 2A construction progress has reached 61.8 per cent. PT MRT Jakarta (Perseroda) is targeting the completion and operation of Phase 2A of the north-south line by the end of 2027 for segment one, Bundaran HI-Monas, and segment two through to Kota by the end of 2029.