In a detailed blog titled 'How India is building its first bullet train', Vaishnaw outlined the construction methods, engineering challenges and technology transfers behind the 508-km project, which is designed for speeds of up to 350 kmph.
The minister said the project was not simply about laying railway tracks but about developing an entire industrial ecosystem capable of building high-speed rail networks in India.
"The first project is not just a line on the map. It is the absorption of an entire technology by an entire industry," he wrote.
"Must Read: ₹1.08 lakh crore to ₹2 lakh crore: Why India’s bullet train costs have surged
How India is building viaducts 10 times faster
One of the biggest innovations, according to Vaishnaw, is the Full Span Launching Method, which allows engineers to construct elevated sections much faster than conventional methods.
Instead of assembling bridge spans in smaller segments, workers manufacture an entire 40-metre concrete girder weighing 970 tonnes in a casting yard.
The completed girder is then transported to the construction site and lifted onto supporting pillars in a single operation.
Vaishnaw said this method was ten times faster than the conventional segmented girder approach.
The technology has also undergone significant localisation.
"The first few launching machines were imported. Then our engineers worked on the designs. Today, the giant cranes that lift more than 1,000 tonnes in a single movement are designed and manufactured in India," he said.
According to the minister, Japanese experts visiting the corridor have expressed interest in construction technologies developed by Indian engineers.
He quoted Masafumi Shukuri, Chairman of the International High-Speed Rail Association, as saying, "Japan could not have done it at this speed."
In Case You Missed It: Mumbai-Ahmedabad bullet train project hits milestone as first steel bridge launched in Maharashtra
Why more than 90% of the bullet train route is elevated
Another important design decision is to build most of the Mumbai-Ahmedabad corridor above ground level.
Of the total 508 km, approximately 465 km will run on elevated viaducts.
Vaishnaw explained that high-speed trains require straight alignments and dedicated tracks without interference from road traffic, animals or pedestrians.
An elevated corridor eliminates level crossings and reduces the risk of trespassing, while allowing agricultural land and roads to remain operational beneath the railway.
The corridor has been designed for a maximum speed of 350 kmph, with trains expected to operate at 320 kmph.
At such speeds, even relatively small changes in track alignment, vibration and aerodynamic forces become critical engineering considerations.
"Kinetic energy grows with the square of speed. Double the speed, and the energy becomes four times," Vaishnaw explained.
How 3,000-tonne machines are digging India's first undersea rail tunnel
The project also involves constructing a 21-km tunnel in Maharashtra, including a 7-km stretch beneath Thane Creek.
Two tunnel boring machines were launched in July 2026 from Vikhroli and Sawli.
Each machine weighs more than 3,000 tonnes, has a cutterhead measuring 13.6 metres in diameter and stretches 96 metres in length.
The machines are designed to excavate through challenging geological conditions while creating the tunnel required for high-speed rail operations.
Vaishnaw said 5 km of the Maharashtra tunnel had already been excavated using the mountain tunnelling method as of September 2026.
Building a railway station 100 feet beneath Mumbai
At Mumbai's Bandra Kurla Complex, engineers are constructing the corridor's only underground station at a depth of approximately 32 metres.
The station is being built in one of Mumbai's busiest commercial districts, surrounded by existing buildings, roads and metro infrastructure.
The excavation will accommodate three levels comprising platforms, passenger concourses and services.
Six platforms, each more than 400 metres long, will accommodate full-length bullet trains.
The remaining 11 stations along the corridor will be elevated.
Why electrification becomes more complex at 350 kmph
The bullet train will use an advanced 2×25 kV compound catenary electrification system, which Vaishnaw described as being deployed in India for the first time.
Unlike conventional railway electrification, the overhead wires must maintain precise mechanical tension to ensure uninterrupted contact with the train's pantograph at very high speeds.
Nearly 22,000 steel masts will support the electrification network. More than 9,300 masts had been installed as of September 2026.
Vaishnaw said major transformers, cross arms, ground wires, protection wires and feeder wires for the system were being manufactured domestically.
How India is absorbing Japanese bullet train technology
The minister said India was progressively developing the ability to manufacture both high-speed railway infrastructure and rolling stock.
The corridor will use Japanese J-slab ballastless track technology, but the slabs are being manufactured in Indian casting yards by Indian engineers.
Meanwhile, the Integral Coach Factory and BEML are developing the indigenous B28 trainset, designed for 280 kmph. "The first body frame is complete and is undergoing structural testing. Track trials are expected by mid-2027. A faster B35, designed for 350 kmph, is the next step," the railway minister stated.
A faster B35 trainset, designed for 350 kmph, is planned subsequently. "This is what technology absorption means. We are learning to build every part of the system, and manufacture it at home," Vaishnaw wrote.
How the first corridor will help build seven more
Vaishnaw said the Mumbai-Ahmedabad project was establishing common engineering standards that could be replicated across India's proposed high-speed rail network.
The approach involves designing foundations according to local soil conditions while standardising the structures, tracks, stations, electrification and signalling systems above them.
This would allow components to be manufactured in factories and assembled at construction sites, potentially reducing costs and construction time.
Standardised designs would also make maintenance, spare parts procurement and workforce training easier across future corridors.
The Union Budget 2026–27 announced seven additional high-speed rail corridors covering nearly 4,000 km, with estimated investment of approximately ₹16 lakh crore.
"Every one of them will be built on the standards, the suppliers and the skills created by the first corridor. That is why the first one matters so much," Vaishnaw said.
When will India's first bullet train start?
According to the minister, 371 km of viaduct construction and 456 km of pier work had been completed as of September 2026. Civil work had also been completed at eight stations.
The first high-speed rail service is scheduled to begin in the final quarter of 2027, initially connecting Surat and Vapi. The remaining Mumbai-Ahmedabad corridor will become operational in phases.
Once completed, the railway is expected to reduce the Ahmedabad-Mumbai journey to approximately 1 hour and 58 minutes.