At 4 a.m. on October 11, with the last train smoothly returning to the depot, the signaling system cutover for the project of splitting Suzhou Metro Line 4 Branch (Hongzhuang Station-Muli Station) and incorporating it with Line 7, implemented by CASCO, was officially completed. This initiative not only laid a solid foundation for the opening of Line 7, but also injected new vitality into the optimization and reorganization of Suzhou Metro network.

This splitting and connection project is a significant innovation in the history of Suzhou Metro construction, achieving the interconnection between two lines after splitting an existing line and merging it into a newly built line for the first time with the goal of connection and operation. The entire project involves both the renovation of existing line and the construction of new line, posing numerous construction difficulties and technical challenges. The CASCO team carefully formulated a scientific and rigorous plan for the splitting and operation, after detailed on-site surveys and professional technical discussions.

CASCO team ensures smooth signaling system cutover

Both Suzhou Metro Line 4 and Line 7 utilize CASCO’s CBTC signaling system, with the two lines' signaling systems mutually compatible. The Line 4 branch was opened in 2017, while Line 7 is a newly built line. Given the rapid iteration of CBTC technology, Line 4 required signaling system upgrade, including software and equipment upgrades, before connecting to Line 7. Additionally, intelligent maintenance function was added, and turnout auxiliary direction indicators were installed to help drivers confirm the direction of the turnout ahead.

The signaling system cutover involved Line 7 from Changlou Station to Hongzhuang Station, and three depots of the main line and branch line of Line 4, as well as two control centers. To minimize the impact on citizens' travel, the CASCO team fully utilized the "window period" after the subway was closed and completed the splitting and testing work efficiently over more than 40 night shifts, enabling the signaling system to meet the conditions for splitting and cutover ahead of schedule.

In the near future, Line 7 will further achieve connection and operation with the main line of Line 4, supporting cross-line operation of trains between the two lines at Hongzhuang Station, greatly facilitating the daily travel of Suzhou citizens. The successful implementation of this innovative project has set an example for the subsequent reconstruction and connection of metro lines, injecting strong momentum and laying a solid foundation for the high-quality development of Suzhou Metro.