Chennai Metro completes Intermediate Overhauling of Phase 1 Rolling Stock Trains

Chennai, India (Metro Rail Today): Chennai Metro Rail Limited (CMRL) has successfully completed Intermediate Overhauling (IOH) Phase-1 of its entire metro train fleet, marking a major operational milestone and reaffirming its commitment to safety, reliability, and service excellence.

The completion of this planned overhaul programme ensures that Chennai’s metro system continues to deliver world-class urban mobility with high standards of passenger comfort and operational efficiency.

CMRL has been operating metro services since 2015 with a fleet of 52 four-car trainsets, which form the backbone of Chennai’s urban transit network. From the beginning, the organisation has prioritised punctuality, passenger safety, and ride quality through a robust and disciplined maintenance regime.

Each train undergoes periodic inspections at monthly, quarterly, half-yearly, and annual intervals, along with mandatory fitness certifications. Beyond routine maintenance, trains are subjected to Intermediate Overhauling before major overhauls, ensuring consistent performance throughout their service life.

Comprehensive Scope of Intermediate Overhauling

The IOH process is a technically intensive activity involving partial dismantling of trains to facilitate in-depth inspection and servicing of safety-critical components.

Key activities undertaken during IOH include:

• Removal, inspection, repair, and repainting of under-frame equipment such as wheelsets and suspension systems

• Replacement of worn or ageing components

• Wheel reprofiling to restore original geometry for smoother and more stable rides

• Advanced non-destructive testing (NDT) of axles to detect hidden flaws

• Complete servicing of braking systems, electrical equipment, and air-conditioning units

Passenger areas also received equal attention, with deep cleaning of interiors and exteriors, including air-conditioning ducts, using environment-friendly materials to maintain hygiene and comfort standards.

Rigorous Testing and Certification

After reassembly, each train underwent a stringent testing regime, including stationary functional tests and dynamic trial runs at different speeds. Only after meeting all prescribed safety and performance benchmarks were the trains certified fit for passenger service by the competent authority.

With the overhaul of the 52nd and final train, CMRL has successfully completed the scheduled IOH Phase-1 cycle for its entire fleet, demonstrating strong asset management and long-term operational planning.

The 52nd train, marking the completion of the IOH programme, was flagged off for revenue service by Shri Manoj Goyal, Director (Systems & Operations). The occasion was attended by Shri A.R. Rajendran, Chief General Manager (Rolling Stock), Shri Gopinath Mallya, Chief Advisor, Shri Ramasubbu, Advisor (O&RS), along with senior officials and rolling stock personnel.

A Milestone in Preventive Maintenance

The successful completion of Intermediate Overhauling Phase-1 across the fleet underscores CMRL’s safety-first approach, emphasis on preventive maintenance, and dedication to high-quality metro services. This milestone ensures sustained reliability and further strengthens Chennai Metro’s position as a dependable and modern urban transport system.