Chinese CBTC technology

The past decade has seen an unprecedented level of urban transit development across China.

In the period between 2009 and 2015, almost 90 transit lines have been constructed across 20 different cities – collectively totalling more than 3,000 km in length.

The networks serving Shanghai (which only opened its first line in 1993) and Beijing are now the two longest urban systems anywhere in the world.

Over the next four years, another 11 cities will open their inaugural transit lines.

Throughout this period, a number of technological advances have been introduced to improve the overall safety and performance of systems. And none more so than the roll-out of new domestically-developed Communication-Based Train Control (CBTC) technologies.

For many years, China’s metro networks installed imported CBTC systems to manage the flow of traffic through these systems. But in 2004, Beijing Traffic Control Technology Co., Limited (TCT), one of China’s leading manufacturers of signalling technologies for urban metros, began the development of a CBTC system of its own, backed by the support of a national government looking to encourage domestically developed signalling technologies.

The original LCF-300 system was certified for operation by Ricardo’s Product Certification team (then called CCS-LR) in 2010. During this assessment process our independent experts assessed that the system was developed against International and European standards, with safety functions that met Safety Integrity Level (SIL4).

It took two years to certify LCF-300 system(V1.0) for its first application on the Yizhuang Line in 2010, with the team applying risk and process-based audit methods throughout the product’s development.

A risk-based methodology identifies and evaluates the significant risks at each stage of the development cycle to determine whether they are reasonably controlled and reduced to an acceptable level. Using this approach, the focus is kept squarely on safety-related technical issues.

The accompanying process-based approach involves a through expert review of the output documents submitted by the client of each phase of the product development. This includes requirement files, risk analysis, outline and detailed design, testing documents, verification & validation, as well as quality management documents. The team also audited safety related product development activities.

Since its initial installation - the first domestically developed CBTC system - the LCF-300 system has been upgraded and applied on metro lines in cities such as Chengdu Shenzhen Chongqing and Tianjin.

The Ricardo Beijing office has worked with TCT’s product teams throughout his period to support each upgrade/variation and commissioning, each time in accordance with the specific requirements of the intended metro line.

We have accessed all the upgraded systems since LCF 300 V1.0, including LCF-300 V2.0, LCF-300 V3.0 LCF-300 V4.0, LCF-300 V5.0, LCF-300 V6.0, LCF-300 V7.0, LCF-300 V8.0, LCF-300 V9.0 and the latest LCF-300 V10.0.

To meet the challenging deadlines of assessing constantly evolving product our approach has been to assess how any variation would generate a new system risk and then seek clarification that it would not jeopardize the safety level of existing systems.

CBTC in China comes of age

In 2014 TCT asked us to work with them on the next major advance for their product: its installation on the Yanfang Line - the first driverless line on Beijing’s Metro.

Our teams were assigned to provide independent assessment service on LCF-300 ATP Generic Upgrade and Automatic Train Supervision System Upgrade to meet the specific Unmanned Train Operations (UTO) requirements of the new Yan Fang Line.

Such driverless systems require considerable changes to the base technology, such as its ability to deliver automated operational functions as well as support automatic responses to emergency situations in accordance with operational rules.

To gain confidence for the first UTO operation in China, the operator, Beijing Metro, also requested our experts provided similar services looking beyond the technology itself, with the scope of our safety assessment extending across rolling stock, track, telecommunications, depot equipment and station facilities such as platform screen doors, elevators and access controls. All of which was to be independently assessed to ensure the designs and operational processes are sufficient for unattended operation from its scheduled opening date in 2017.

Following the extensive experience gained from supporting the introduction of an entirely new CBTC technology to the market, the team have begun to support other signalling technologies under development in Asia, bringing a truly objective and independent assessment of the safety and efficiency of the final designs and eventual products.