Central Railway successfully commissioned the long-awaited Karjat Yard Remodelling and new Route Relay Interlocking (RRI) system at Karjat Central Cabin on 12th October 2025 at 6:30 pm, marking a major milestone in its modernization drive. The Rs 74.53-crore project replaces one of the oldest operational RRIs on Central Railway with a safer, faster, and more reliable system.
The new RRI system includes 487 routes, 46 main signals, and 39 shunt signals. A dual detection system comprising Multi-Section Digital Axle Counters (MSDAC) and Audio Frequency Track Circuits (AFTC) has been implemented to enhance operational reliability. Automatic Block Signalling has been introduced between Karjat and Bhivpuri, enabling seamless train movement with minimal manual intervention. Real-time monitoring is facilitated through Efftronics Data Loggers, while fire alarms, fuse alarms, and advanced safety mechanisms further strengthen the system.
Extensive Engineering and Electrical Upgrades
Alongside signalling modernization, significant civil and electrical works were undertaken. Eight railway bridges and two foot overbridges (FOBs) were extended, and 4.9 km of new track was linked to improve connectivity.
Electrification works included 9 km of new Overhead Equipment (OHE) wiring, erection of 350 masts, and complete yard electrification. Track infrastructure improvements involved the insertion of 20 new turnouts, dismantling eight outdated ones, and widespread D-switch replacements. Civil works included earthwork, ballasting, and foundation reinforcement to ensure long-term stability and operational efficiency.
Key Operational Benefits
According to officials, the fourth line between Karjat and Palasdari separates Khopoli branch movements from the main ghat section, significantly improving throughput, punctuality, and safety. Up and down reception lines have been extended and standardized, allowing full-length goods trains to be received and dispatched on proper signals, saving up to 10 minutes per train.
With the addition of a bi-directional line and remodelling of multiple tracks, the yard’s capacity has increased by 25%, facilitating efficient train handling, including direct reception of freight trains from Panvel without crossing main lines.
Shadow Block Works Enhance Ghat Section
During the Karjat interlocking work, Central Railway utilized the shadow block period for infrastructure upgrades across the Karjat–Lonavala ghat section. Key works included: Launch of new FOB girders at Khandala, Replacement of old steel bridges with new PSC slab bridges near Tunnel No. 51, Track welding and tamping over 3.5 km, Rehabilitation of major tunnels with steel arch ribs and shotcreting, including the double-track portal construction of Tunnel No. 48, OHE maintenance and upgrades, including replacement of insulators, X-feeder adjustments, and span realignment
“These extensive works have improved track strength, safety, and train handling capacity, enhancing punctuality and reliability for suburban and long-distance passengers,” an official said.
