22 April,2026 05:12 PM IST | Mumbai | mid-day online correspondent
Pic/Special Arrangement
Work on installing high-speed rail tracks for India's first bullet train corridor has commenced, marking a key milestone in the Mumbai-Ahmedabad project. The line will use a ballastless "J-Slab" track system derived from Japan's Shinkansen technology, being deployed in India for the first time.
The ballastless track system being adopted is designed to deliver stability, durability and precision required for trains operating at speeds of up to 320 kmph. It comprises four primary components: a reinforced concrete (RC) track bed, cement asphalt mortar (CAM), pre-cast track slabs, and rails fitted with specialised fasteners.
Officials associated with the project indicated that the system has been adapted to suit local climatic and operational conditions while retaining the engineering standards of Japan's high-speed rail network. A considerable portion of the machinery and components used in construction has been manufactured domestically, reflecting efforts to localise technology and production.
To support the track installation process, two dedicated Track Slab Manufacturing Facilities have been established in Gujarat - one in Surat (Kim) and another in Anand. These facilities produce high-precision concrete slabs required for the ballastless track system.
Once produced, the slabs are stored at the manufacturing sites before being transported to Track Construction Bases (TCBs). These bases function as logistical hubs for handling slabs, machinery and equipment both at ground level and along elevated viaduct sections. At present, ten such bases are operational across key stretches in Gujarat, including between Surat, Bilimora and Vapi, as well as Vadodara, Anand and Ahmedabad.
Project data indicates that the construction of the track system is advancing in phases. Around 185 route kilometres of RC track bed have been laid so far, while track slabs covering approximately 188 route kilometres have been manufactured. Of this, about 70 route kilometres have seen the completion of slab laying along with cement asphalt mortar injection.
This phased approach reflects the technical complexity of the ballastless system, which requires precise positioning and calibration at each stage before subsequent work can proceed.
The track installation process is being carried out using a fully mechanised approach with specialised equipment designed in accordance with Japanese construction practices. Among the key machines in use is the Flash Butt Welding Machine, which welds 25-metre-long rails into 200-metre panels. These panels undergo stringent quality checks before being cleared for use in high-speed operations.
Training and certification for welding, inspection and testing have been conducted by Japan Railway Technical Service, which is involved in ensuring adherence to safety and quality standards.
Other machinery deployed includes the Track Slab Laying Car, which lifts and positions pre-cast slabs onto the viaduct, and the Rail Feeder Car, which places long rail panels onto the track bed. A Cement Asphalt Mortar Injection Car is subsequently used to inject a specially prepared mixture beneath the slabs, ensuring the required alignment and stability of the track.
The start of track installation marks a significant shift in the Mumbai-Ahmedabad high-speed rail project from large-scale civil construction to system-level execution. As installation progresses, the focus is expected to gradually move towards testing, certification and operational readiness of the corridor.
