Recently, Shanghai Metro Line 16 completed the pre-operational verification of online coupling and uncoupling in the automatic train operation (ATO) mode at Longyang Road Station, achieving another breakthrough in online flexible train formation in the domestic metro.

With the support of CASCO's signaling technology, the metro trains were given the same superpower as Transformers to spilt and merge on the main line according to passenger flow. Moreover, the transformation "level" has upgraded constantly.

3+3, The First Online Flexible Train Formation in China

The online coupling and uncoupling of trains is not only the physical splitting and merging of trains. Changes in the number of train formation, length and other parameters can have a significant impact on signal safety and protection. In addition, various factors such as safe stopping distance, coupled impact speed, and remote dispatch coordination all contribute to ultra-high standards on the signaling system that controls train operations.

Thanks to continuous optimization of the train dispatch control system, TDCS and a series of software development, CASCO overcame the technical difficulties of online coupling and uncoupling, and successfully completed the first on-site test and commissioning at Huinan Station of Shanghai Metro Line 16 on July 15, 2020.

“3+3” mode testing site

After further commissioning verification, operation rehearsal, and expert evaluation, Shanghai Metro Line 16 started the "3+3" pilot operation of online flexible train formation on November 12, 2021, which is the first in the domestic urban rail transit.

3+3+3, Unlock the Online Flexible Train Formation of Multiple Trains

In addition to the basic function of "3+3", CASCO then made a technological breakthrough under the new model of "3+3+3". 

On October 2, 2021, Shanghai Metro Line 16 successfully completed the online coupling and uncoupling test for multiple-unit trains. During the test, three trains with three units could operate automatically under ATO mode after completing online coupling and uncoupling.

“3+3+3” mode testing site

Upgrade Automation Again with ATO All the Way

Under the "3+3" and "3+3+3" modes, due to the small interval between the two trains and the need for energy protection of automatic train protection (ATP), the two trains can only come close to a certain distance during the coupling process, and then the driver is required to drive the train in restricted manual (RM) mode to complete the coupling. In order to further improve the efficiency and automation of the whole process of coupling and reduce the risk of manual operation, the full ATO coupling mode was born.

On June 14, 2022, Shanghai Metro Line 16 completed the pre-operational verification of online train coupling and uncoupling in full ATO mode at Longyang Road Station. During the period, the driver can switch the operation mode with only one button and no more other manual operations, which reduced time from startup to coupling by more than half, and greatly improved grade of automation and operational efficiency of coupling and uncoupling.

From "3+3" to "3+3+3" and then to full ATO mode, with the continuous upgrading of CASCO's signaling technology, the online flexible train formation has become one of the leading technological achievements in the domestic metro industry, and will play a great role in creating huge economic and social benefits in response to tidal passenger flow, accurate operation capacity, dead mileage reduction, energy conservation and carbon reduction. 

Currently, CASCO has already started working on coupling and uncoupling in the driverless project. In the future, what other new ways for the online flexible train formation will be available, and perhaps more surprises are on their way.