Since 2021, Honrock has directly and indirectly supplied 1,085 high-performance safety latches to the depots of Delhi Metro (North India) and Chennai Metro (South India). These latches are installed in the interior door systems of their new-generation metro trains, supporting the modernization of core urban rail transit in India.

I. Project Background

• Line Significance:

• Delhi Metro and Chennai Metro are India's busiest and most extensive core urban rail transit networks, with a combined daily ridership exceeding 4 million passengers, serving as the absolute backbone of urban transportation.

• Both metro systems are undergoing significant network expansion and rolling stock upgrades, demanding extremely high equipment reliability.

• Vehicle Upgrade Requirements:

• The project involved multiple batches of new metro train cars (including standard cars, female-only compartments, driver cabins, equipment rooms, etc.), requiring components to withstand India's tropical monsoon climate – high temperatures, extreme humidity, monsoon rains, and urban high-dust pollution.

• The safety latches must ensure absolute reliability and passenger safety under all operating conditions.

• Stringent Standards:

• Design and manufacturing adhered simultaneously to Indian Railway Standards (IRS) and International Standards (ISO).

• Latches were required to maintain ultra-long service life and zero failure rates under conditions of constant vibration, high humidity/heat, dust, and frequent operation, meeting the demands of high-intensity metro operations.

II. Pain Point Analysis & Solutions

1. Reliability Challenges in Extreme Climate & High-FrequencyUse

• ✅ Pain Points:

§  High temperature and humidity accelerate metal corrosion and lubricant degradation, potentially causing sluggish or stuck latch bolt action.

§  Monsoon moisture combined with urban pollutant dust can infiltrate the lock body, causing mechanism wear or functional failure.

§  Daily high-frequency door cycling (far exceeding typical applications) poses a major challenge to the latch's mechanical lifespan.

• ✅ Solutions:

§  Triple Reinforcement Protection Design:
▶ Core lock body components made from high-strength stainless steel base material with multi-layer composite anti-corrosion coating (Salt Spray Test > 1000 hours).
▶ Precision transmission mechanisms filled with wide-temperature-range long-lasting grease (-20°C to +80°C).
▶ Multi-stage labyrinth sealing structure effectively blocks dust and moisture from penetrating the core lock mechanism.

2. Maintenance Efficiency & Zero-Failure Requirement underHigh-Intensity Operations

• ✅ Pain Points:

§  Large metro networks and high vehicle turnover rates result in extremely short maintenance windows, demanding near "maintenance-free" equipment.

§  Traditional latches wear quickly under high-frequency use, requiring periodic adjustment or replacement, impacting vehicle availability and increasing operational costs.

§  Any door latching failure could trigger safety hazards or cause train delays, demanding a "zero-tolerance" policy towards failure.

• ✅ Solutions:

§  Ultra-Long Life & Maintenance-Free Design:
▶ Reinforced alloy latch bolt and precision bearing structure significantly reduce friction loss, enhancing impact and fatigue resistance.
▶ Lifetime sealed lubrication system ensures maintenance-free operation for over 500,000 operating cycles.
▶ Optimized, simplified structure features self-compensating wear functionality to maintain consistent locking force and operation feel long-term.

III. Product Delivery Summary

This project delivered a total of 1,085 industrial-grade safety latches, primarily used in:

• HK9325T / HK9316T Safety Latches: Installedin critical locations within metro cars, including internal partitiondoors (e.g., driver cabin doors, equipment room doors, gangway doors) andpassenger compartment interior doors (e.g., equipment cabinet doors, crewroom doors), providing reliable latching and unlatching functions.

• All products passed rigorous depot testing and line trial runs,fully complying with the project's required technical specifications,safety standards, and performance metrics.

IV. Project Highlights & Collaboration Value

• Precise Product Selection: Providedtailored HK9325T / HK9316T safety latch solutions specifically matched tothe unique Indian metro operating environment (climate, frequency,vibration) and safety requirements.

• Efficient Collaborative Response: Rapidlycompleted technical solution alignment, drawing approval, sampleprototyping, and mass production, seamlessly aligning with customerproject milestones.

• Agile and Reliable Delivery: Completedthe production, testing, and delivery of 1,085 sets of customized latcheswithin 60 days, ensuring vehicle assembly schedules were met.

• Localized Support: Providedcomprehensive technical documentation, installation guidance, andafter-sales response mechanisms to support local Indian teams.

V. Conclusion

By supplying 1,085 safety latches, Honrock has deeply participated in the metro modernization projects of India's core cities, Delhi and Chennai. The products have successfully withstood the rigorous tests of the tropical monsoon climate and ultra-high-intensity operations. This project fully demonstrates Honrock's comprehensive core capabilities in extreme environment adaptability design, ultra-high reliability assurance, large-scale customized delivery, and international project services. Moving forward, Honrock will continue to deepen its presence in India and the global rail transit market, providing robust technical support for the "zero-defect, full-lifecycle" safe and reliable operation of metro systems, trains, and other mobile assets.