Case Study

Hyundai Rotem EMU fleet

Hyundai Rotem EMU fleet
Published: 01 March 2022 Client name: Hyundai Rotem Service provided: Independent Safety Assessment

In 2017, when Hyundai Rotem was awarded a contract to supply 50 new electrical multiple units (EMU) for Seoul’s Metropolitan Line 4, the manufacturer chose to appoint Ricardo as Independent Safety Assessor (ISA) for the project. 

This was the first time a South Korean rolling stock manufacturer had sought conformity against international safety standards for an entire vehicle platform, rather than undertaking such assessments at a generic application level for safety-critical subsystems, such as onboard signalling, brakes or passenger door systems.

As the ISA, it was our duty to monitor the vehicle's design and manufacture stages, and ensure that recognised industry, legal and regulatory safety standards were being met.



Also known as the Blue Line, Line 4 is a complex route that extends more than 70 miles from Seoul's north-eastern districts through to its south-western commuter areas. As a result, the line is managed jointly by Seoul Metro, which oversees the 30 mile section through the city centre, and by national operator, KORAIL, in the suburban sections to the south and west - the sections known locally as the Ansan and Gwaechn lines.

This meant our assessors had to work closely with both KORAIL and Seoul Metro to ensure the new fleet would integrate seamlessly with the procedures and rules of both operators.

Our experience from these assessments will provide valuable groundwork for future rolling stock certifications Myoung-Sang Kong, System Engineering Team Leader, Hyundai Rotem
Our experience from these assessments will provide valuable groundwork for future rolling stock certifications

Rigorous safety appraisal

Between January 2018 and November 2021, our assessors compiled more than 40 Assessment Records, undertook five separate audits, and witnessed two test events in the course of their auditing work.

When any technical issues or conflicts emerged, our findings were passed directly to Hyundai Rotem either for direct resolution or to request further evidence to show compliance with the standards. Where necessary, the manufacturer would also be required to pursue the additional documentation from its supply chain.

The eventual certification from Ricardo confirmed that the new EMUs had been assessed against the international standards IEC 62278 (reliability, availability, maintainability and safety (RAMS)), IEC 62279 (railway control and protection software) and IEC 62425 (safety related electronic systems).

The formal issue of our certificates meant that, from a safety point of view, the new fleet is ready for service on Line 4.

This work was delivered by Ricardo Certification, a set of companies within the Ricardo group that perform independent assurance and testing services in rail and other sectors. For more information, see Ricardo Certification accredited assurance services

What is an Independent Safety Assessment?

An Independent Safety Assessment (ISA) is a service undertaken by a third party to confirm that a product, system or entire railway meets recognised industry, legal and regulatory standards related to safety.

By proving that all safety aspects of your products or systems have been subjected to rigorous oversight by a -third party - one with no financial interest or connection to the project - you are sending a message of transparency to passengers, regulators, investors and employees, and demonstrating that your business prioritises safety above all else. 

For more information about or international portfolio of safety assessment work, see our Independent Safety Assessment service pages.

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