In the early morning of August 29, Beijing Subway Line 1 and Ba Tong Line, equipped with CASCO’s CBTC signaling system, successfully realized cross-line operation, marking a new era of "Two-way direct access without transfer" for the central urban area and urban sub-centers. The travel efficiency and experience of passengers have been greatly improved.

After cross-line operation, Si Hui station is changed from transfer stations to ordinary station

The cross-line operation project of Beijing Subway Line 1 and Ba Tong Line is the largest transformation project implemented by the Beijing Subway so far, aiming to improve the traffic efficiency between Beijing's central urban area and urban sub-centers through seamless connection of the two lines.

As the first subway line in the PRC and the main line of Beijing urban area, Beijing Subway Line 1 runs through the east and west directions of the entire central urban area in a straight line along the underground of Chang An Avenue, connecting many prosperous areas in the downtown, with an average daily passenger flow exceeding 1 million. The Ba Tong Line extends from Si Hui Dong (E.) Station, the terminus of Line 1, to Universal Resort Station, with an average daily passenger flow exceeding 300,000 passengers and an very obvious tidal characteristics of the passenger flow.

Schematic diagram of the stations of Beijing Subway Line 1 and Ba Tong Line

Source: Beijing Subway

Although these two lines look like one on the map, the actual operation is separate as passengers must disembark at Si Hui Station or Si Hui Dong (E.) Station, change platforms and then board a subway vehicle to transfer from one line to the other. The extremely high passenger flow for transferring between the two lines during morning and evening peaks present the two stations with great transfer pressure. To this end, Beijing Subway launched the two-line cross-line operation transformation project in 2020.

Previously, CASCO completed the transformation of Beijing Subway Line 1 in 2015 and completed the signal transformation of the existing line of the Ba Tong Line and put into full operation the southern extension section in 2019 by equipping them with a new generation of CBTC signaling system with greater safety, stability, automation and operational efficiency, which creates the basic conditions for cross-line operations.

Nevertheless, it is a formidable challenge to achieve the cross-line operation transformation of this high-density long line without interrupting daily operations of the two lines. After the cross-line is put into operation, there are 38 stations along the whole line, the whole journey takes about 85 minutes, and the minimum headway is 1 minute and 45 seconds. In order to avoid interrupting daily operations and minimize the impact on passenger travel, after design and research, the transformation plan was finally determined as a three-step plan:

In the first step, 8 sets of switches were added to Si Hui Dong (E.) Station and the signaling system was partially upgraded to achieve the physical connection of the two lines and tracks. At this phase, the two lines are still operated independently.

The second step is cross-line operation, in which the stations are completely organized as if they are one subway line.

In the third step, the Si Hui Station and the Si Hui Dong (E.) Station are combined with interlocking equipment to support a more flexible operation organization.

In order to ensure the high-quality delivery of the project, CASCO built a FIVP simulation platform combining software and hardware, and conducted simulation tests in laboratories for several months based on real-life software data of the project; at the same time, CASCO make full use of more than 3 hours after night outage for on-site verification; under the unified organization of BeiJing Subway Operation Corporation, the high-density (2 minute interval) stress test of 93 sets of vehicles was completed twice in May this year.

Today, with the cross-line operation of Beijing Subway Line 1 and Ba Tong Line, Beijing residents finally ushered in an era of more efficient traveling, and the traffic efficiency of the central urban area and urban sub-centers will be greatly improved. CASCO, with a commitment to a people-oriented approach, takes the building of a smart city as the blueprint to actively support the layout and construction of smart subways to maximize the rail transit travel experience of urban residents.