Bullet train project: 1,405-tonne steel bridge moved 1,300 km, installed in Thane

Maharashtra's stretch of the Mumbai-Ahmedabad bullet train project has completed a major and difficult task, with the state's first steel bridge for the high-speed rail corridor successfully erected. The bridge has been built over the Nashik highway, NH-3, at Dive-Anjur village in Bhiwandi, Thane district. The 100-metre-long steel bridge weighs a total of 1,405 metric tonnes.

The bridge's biggest feature is that it was fabricated at a workshop in Trichy, Tamil Nadu, around 1,300 kilometres from the site. It was brought to Maharashtra in stages on special trailers. All the parts were then assembled into the complete structure and installed at the actual location. The work is an example of India's technical capability to build, transport and erect such large and complex steel structures.

Cutting, drilling, welding and painting during construction were carried out precisely as per the set design, drawings and technical standards. Every batch of steel used underwent ultrasonic testing, or UT. All welders and supervisors involved in the work were certified by international welding experts. The project showcases India's own technical and construction capability and is an important example in the direction of Make in India.

At the site, the 100-metre bridge was assembled on a temporary trestle at a height of about 17.5 metres from the ground. The work involved 22 skid arrangements and a total of 54,076 torshear-type high-strength bolts (TTHSB). A C5 protective painting system was used for the bridge's strength and durability, while elastomeric bearings have been installed to control vibration.

An automatic system was used to move the bridge to its final position, using two hollow jacks of 150 metric tonnes capacity each and pre-tension Macalloy bars. To cause minimum inconvenience to people and vehicles passing on National Highway NH-3, the difficult work was carried out by taking traffic blocks on the highway at night.

Steel bridges are typically used where long spans are needed, such as over highways, expressways, major rivers and railway lines. This bridge is 100 metres long, 14 metres high and 14 metres wide, while the main bridge weighs 1,405 metric tonnes.

A total of 28 steel bridges are to be built on the Mumbai-Ahmedabad bullet train corridor. Of these, 16 bridges have been completed so far, and the one installed in Maharashtra is the first steel bridge in the state.